J. Bamboo and Rattan, Vol. 3, No. 1, p. 1 (2004) Ó VSP 2004. Also available online - www.vsppub.com Foreword Dear Reader, This issue being the rst one of Volume 3, I like to congratulate all of us with the completion of the second volume. We published four issues with a total number of 462 pages. For the second volume of a new and young scienti c journal this is reason for a feeling of satisfaction. We owe many thanks to INBAR and VSP which made the publication possible, to our authors who sent their articles, to the members of the Editorial Board who gave good advise and guidance, and to our external reviewers. They spent many hours reviewing articles, without any remuneration. I like to express our gratitude to all of them: Ed van Berkum, Bert Bras, Craig Cogger, Victor Cusack, Huib Hengsdijk, Inagaki, Wil de Jong, Hans-Jurgen Klüppel, Colby Loucks, Don Koo Lee, Richard Murphy, Trek Sean and Pita Verweij. All these people did contribute to this journal. Peer review is the guarantee for a high quality level of any scienti c publication. The last issue of the previous volume contains the proceedings of the bamboo workshop at the World Forestry Congress in September 2003 in Quebec, Canada. This was an issue with a different character, containing papers presented at the said workshop. I am pretty sure this information will be appreciated by our readers in the same way as they do the regular issues. Honestly only one item still is missing in our journal: letters to the editor, raising points of discussion. In other journals this is quite common; readers express critical feelings about what they have read, and authors answer them. This makes any journal even more interesting. Discussion is an essential part of scienti c activities. I do hope we will see in this year a start with such discussions. I wish all of you a very fruitful year! JULES JANSSEN Eindhoven, January 13, 2004
Transcript
J Bamboo and Rattan Vol 3 No 1 p 1 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Foreword
Dear Reader
This issue being the rst one of Volume 3 I like to congratulate all of us with thecompletion of the second volume We published four issues with a total numberof 462 pages For the second volume of a new and young scienti c journal this isreason for a feeling of satisfaction We owe many thanks to INBAR and VSP whichmade the publication possible to our authors who sent their articles to the membersof the Editorial Board who gave good advise and guidance and to our externalreviewers They spent many hours reviewing articles without any remuneration Ilike to express our gratitude to all of them Ed van Berkum Bert Bras Craig CoggerVictor Cusack Huib Hengsdijk Inagaki Wil de Jong Hans-Jurgen Kluumlppel ColbyLoucks Don Koo Lee Richard Murphy Trek Sean and Pita Verweij All thesepeople did contribute to this journal Peer review is the guarantee for a high qualitylevel of any scienti c publication
The last issue of the previous volume contains the proceedings of the bambooworkshop at the World Forestry Congress in September 2003 in Quebec CanadaThis was an issue with a different character containing papers presented at the saidworkshop I am pretty sure this information will be appreciated by our readers inthe same way as they do the regular issues
Honestly only one item still is missing in our journal letters to the editor raisingpoints of discussion In other journals this is quite common readers express criticalfeelings about what they have read and authors answer them This makes anyjournal even more interesting Discussion is an essential part of scienti c activitiesI do hope we will see in this year a start with such discussions I wish all of you avery fruitful year
JULES JANSSENEindhoven January 13 2004
J Bamboo and Rattan Vol 3 No 1 pp 3ndash11 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Root development in rattans 2 Soil requirements andef ciency of the root systems of Calamus thwaitesii Beccand Hook f and Calamus rotang L in the seedling stage
V K JAYASREE 1 C RENUKA 2curren and P RUGMINI 2
1 Sree Krishna College Guruvayur Thrissur Kerala India2 Kerala Forest Research Institute Peechi 680 653 Thrissur Kerala India
AbstractmdashThe function and activity of a root system is closely linked to its normal environmentthe soil The soil volume exploited by the two species was calculated and a comparison showed thatCalamus rotang exploited more soil volume than C thwaitesii The effective soil volume was alsofound to show an increase in C rotang when compared to C thwaitesii Knowing the effective soilvolume the size of the polybag to be used in the nursery can be adjusted The root spread of the twospecies shows that a 30pound30pound30 cm pit size will be suf cient for seedlings up to 2 years old Rootingdensity is found to be more in the upper 30 cm layer of soil in both species Root density total rootintensity and ne root intensity are higher in C thwaitesii when compared to C rotang Root surfacearea also is more in C thwaitesii Hence this species will be more ef cient in water and nutrientuptake in the seedling stage Both species are good soil binders
Key words Rattans effective soil volume rooting density root intensity root surface area soilbinding capacity
INTRODUCTION
The function and activity of a root system is closely linked to its normal environ-ment the soil A plant is dependent on a volume of soil for supply of water and min-eral resources and for physical support Ef ciency in nutrient uptake is in uencedby the rooting density The number of roots and root surface area also are indicatorsof root system ef ciency Soil binding capacity which is a measure of the bindingeffect on the soil particles is of direct value in soil conservation A knowledge ofthese aspects of a root system will aid in management decisions when a species is tobe raised on a large scale In this paper soil requirements and ef ciency of the root
currenTo whom correspondence should be addressed E-mail renukakfriorg
4 V K Jayasree et al
system of selected species of commercially important rattans Calamus thwaitesiiand C rotang in their seedling stages are discussed The growth characteristicsand root spread were discussed in the rst part of this paper [1]
MATERIALS AND METHODS
The experimental design has been published in the rst paper of this series [1] Inaddition at the third year soil samples were collected using a 4-cm diameter corefrom four different depths (0ndash15 cm 15ndash30 cm 30ndash45 cm and 40ndash60 cm) at 010and 30 cm from the base of the plant There were three randomly selected samplingpoints around a single plant in order to get fragments of the roots from all directionsThere were a total of 28 samples from a single plant Root fragments were separatedfrom each sample and used for determining the different root parameters like rootlength total root weight ne root weight rooting density etc
The soil volume exploited by the root system for the two species of Calamus wascalculated on a yearly basis using the formula frac14h=22ordm where lsquohrsquo is the meanhorizontal spread of the root system in each year obtained from the data collected attwo-month intervals and lsquoordmrsquo is the mean vertical depth of the roots The two specieswere compared based on the soil exploited by their root system
The effective soil volume for the two species in each year was calculated fromthe graph drawn by plotting exploited soil volume against rooting density foreach period and soil volume at which rooting density shows a sharp decline wasnoted [2]
The rooting density of each species was calculated on a yearly basis applyingthe formula Rmax=s where lsquoRmaxrsquo is the total length of the main roots laterals andsublaterals and lsquosrsquo is the soil volume exploited by the entire root system Rootingdensity was also calculated making use of the data with respect to core samples ofsoil taken at the end of the third year
The root intensity of each species was calculated from the total number of rootspresent in unit area of the soil Percentage root intensity contributed by ne rootsless than 2 mm in diameter was also calculated by considering the number of neroots alone
The root surface area a measure of the total absorptive area of the roots wascalculated separately for roots less than 2 mm diameter and greater than or equal to2 mm diameter using the formula 2frac14rl where lsquorrsquo is the radius of the root and lsquolrsquothe length
The soil binding capacity for lateral and sublateral roots was found by using theformula v=r2 where lsquovrsquo is the average root volume obtained and lsquorrsquo the mean radiusof the roots of the plants The root volume was found using the formula frac14r2l wherelsquorrsquo stands for mean radius of the lateralssublaterals of the plants considered for thestudy and lsquolrsquo their mean length
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 5
RESULTS AND DISCUSSION
Root spread
The root spread has been discussed in Ref [1] The data are repeated here for easyreference In a 3 year old C thwaitesii the average horizontal spread was 616 cmand in C rotang 918 cm They grow vertically downward up to a distance of298 cm in C rotang and 391 cm in C thwaitesii (Table 1)
Soil exploitation
The volume of soil available for rooting is an important factor governing the growthof seedlings In fact the soil is only partly utilised and a large proportion of the soilis not exploited by the roots In C rotang soil volume exploited in the second yearis about 30 times the volume exploited in the rst year There is an about 220-timesincrease in the exploited soil volume in the third year In C thwaitesii in the rsttwo years the soil volume exploited is more or less the same while a more than60-times increase is seen in the third year (Table 2) A comparison between speciesshows that C rotang is exploiting more soil volume than C thwaitesii
Effective soil volume
In the nursery the plant seldom has enough soil at its disposal to allow optimaldevelopment of its root system However such a restriction of soil volume hardly
n D 5 replicates Cr mdash C rotang Ct mdash C thwaitesii
Table 2Comparison of soil volume exploited
Period (year) Soil exploited (cm3)
Cr Ct
First 877 1843Second 25 769 1821Third 192 219 113 742
n D 5 replicates Cr mdash C rotang Ct mdash C thwaitesii
6 V K Jayasree et al
impairs the growth of the plant and plants absorb only a small part of the nutrientspresent
Stevenson [2] de ned the effective soil volume as the volume of soil that is ableto supply water to a root system and which does not restrict the growth of thoseroots By calculation effective soil volume or Ve is a maximal 785 (905 withtriangular spacing of roots) of a total volume that does not restrict growth Belowthis level root density will decline sharply as soil volume increases For maximumeffects from nutritional or water content treatments plants should be provided withsuf cient soil at least to approach the conditions laid down in the de nition ofeffective soil volume The smaller the plant the easier it is to meet this provision
In this study it is seen that rooting density declines year by year (Table 3) Thisshows that the effective soil volume has been attained in the two species Theeffective soil volume in the rst year for C rotang was 447 cm3 and 632 cm3
for C thwaitesii Hence the polybag or other container should hold this amount ofsoil to attain the maximum growth of roots In the second year the effective soilvolume was found to increase in C rotang compared to C thwaitesii In the thirdyear while the effective soil volume showed an enormous increase in C rotang itremained the same as that of the second year in C thwaitesii (Table 4)
Cultivation practices in the nursery can be based on this observation For anoptimal development of the root system the bag should contain the effective soilvolume For C rotang since the vertical spread is 133 cm the bag size should be
Table 3Rooting density
Period C rotang C thwaitesii(year)
Soil Rooting density (cm per cm3) Soil Rooting density (cm cmiexcl3)
volume Main Lateral Sublateral volume Main Lateral Sublateral(cm3) (cm3)
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 7
about 14 pound 10 cm of which 14 cm is the height of the bag and 10 cm is the widthWhen the bag is lled with soil it will attain a diameter of approximately 64 cmFor C thwaitesii it should be 16 pound 1115 cm (Table 1) If the seedlings need to bekept for the second year the bag size should be about 27 pound 21 cm for C rotang and18 pound 155 cm for C thwaitesii
Rattan seedlings can be out planted from the polybag generally after one year ofhardening in the nursery For one year seedlings a pit size of 30 pound 30 pound 30 cm willbe suf cient for the two species For two year old seedlings also the same pit sizewill suf ce since the vertical spread is below 30 cm in both species
Rooting density
The ef ciency in nutrient uptake is in uenced by the rooting density Rootingdensity can be expressed relative to either soil surface area (LA in cmcm2) orsoil volume (LV in cmcm3) Atkinson and Wilson [3 4] have described theconsequences of a low LA value When a plant transpires water will come initiallyfrom soil immediately adjacent to the root with this zone being replenished frombulk soil If the rate of withdrawal exceeds the rate of water movement through thesoil to the root (ie the rate of uptake exceeds soil hydraulic conductivity) then thesoil adjacent to the root will become drier than the soil bulk and the rate of water ow into the root will decrease and may result in water stress Localized dryingoccurs and thus the gradients of water potential at the root surface will reduce theuptake of minerals thought to be moved by mass ow If root density is high owrates will always tend to be low and gradients at the root surface will be rare Whereroot density is low as in fruit trees the contrary will be true
Root density varies with depth Hence reduced soil water potentials will not be thesame at all depths and this will affect the balance of nutrient uptake from differentparts of the soil pro le
In the present study while C rotang possesses a higher rooting density during the rst year of growth C thwaitesii does so later The rooting density in both speciesis found to be inversely related to the amount of soil exploited by the root systemThere is a major contribution of the laterals and sublaterals towards rooting densityof the plant occurs during the second year in both species (Table 3)
Measurements using the core method at different depths and radial distances inthe third year reveal that rooting density is greater in C thwaitesii compared to thatof C rotang With respect to depth rooting density is much higher in the upper30 cm of soil compared to the lower 30 cm in both species While 81 of the totalrooting density is the contribution of the upper 30 cm of soil in C rotang 89 ofthe total rooting density is contributed by the upper 30 cm in C thwaitesii At alldepths other than 30ndash45 cm rooting density is found to be more in C thwaitesiicompared to C rotang (Table 5)
As far as the different lateral distances from the base of the plant are concernedthe percentage contribution of the rooting density within a soil depth of 0ndash60 cmat the centre of the rooting zone and at 10 cm away from the base of the plant is
8 V K Jayasree et al
Table 5Root density at different radial distances and depths from the base of the plant
RD C rotang C thwaitesii(cm) Depth (cm) Depth (cm)
0ndash15 15ndash30 30ndash45 45ndash60 Average 0ndash15 15ndash30 30ndash45 45ndash60 Average
36 and 37 respectively in C rotang While C rotang shows almost the samerooting density at these regions C thwaitesii shows markedly more percentage rootdensity (46) at the centre of the rooting zone than at 10 cm away from the plant(29) (calculated from Table 5) Since a higher rooting density is observed inC thwaitesii this species will be more ef cient in nutrient uptake
Root intensity
When total root intensity is considered C thwaitesii is more ef cient in absorptioncompared to C rotang (Table 6) the percentage of total intensity being more inthe surface layer (0ndash15 cm depth) Published data are often dif cult to assess Forinstance according to Wright [5] the absorbing roots of oil palm are concentrated inthe upper 10 cm of soil whereas Grey [6] observed predominance of the absorbingroots in the upper 30 cm soil In the two rattan species studied the absorbing rootsare found to be more in the upper 15 cm of soil In C rotang 83 of the total rootintensity is contributed by ne roots while in C thwaitesii 87 of the total rootintensity is the contribution of ne roots Thus C thwaitesii is more ef cient inabsorption even when only the ne absorbing roots are taken into account
Table 7 shows the lateral distribution of roots In C rotang more absorbing rootsare found at a lateral distance of 10 cm whereas in C thwaitesii ne roots aremaximal at the centre of the rooting zone
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 9
Table 7Lateral distribution of total roots and contributionof ne roots
Radial Total roots () Fine roots ()distances (cm) Cr Ct Cr Ct
Root activity decreased with increasing soil depth In C rotang about 76 ofthe active roots are located at 0ndash30 cm depth while 86 of the active roots inC thwaitesii are located at 0ndash30 cm depth Wright [5] reported that 70ndash80 of theactive roots of oil palm are located at 0ndash20 cm depth
Root surface area
In the two species main roots alone are present in the initial stage and C thwaitesiihas more root surface area at this stage With the initiation of laterals in the rst yearthe total surface areaplant is also more in C thwaitesii However in the secondyear C rotang has more surface area due to the occurrence of more roots bothlt2 mm and gt2 mm At the end of the third year the trend was reversed (Table 8)
However the surface area of the ne roots even though few in number wasfound to be greater in C rotang due to their increased length and diameter Thisis supported by the statement that plants with greater lsquospeci c root surface arearsquo aremore ef cient and opportunistic absorbers of ions and water [7] Such plants alsoappear to be more competitive in single and mixed plant communities [8] The rootsystem of C thwaitesii is seen to be more ef cient as measured by more speci croot surface area
10 V K Jayasree et al
Table 9Comparison of soil binding factor
Period (year) C rotang C thwaitesii
First 175 150Second 303 401Third 334 285
Soil binding capacity
The binding of soil particles and the promotion of soil aggregation are of directvalue in soil conservation The length and thickness of roots play an importantrole in binding soil particles ne roots with their close and elaborate network havegreater binding capacity than thicker roots Soil binding capacity shows an increasewith age in C rotang while in C thwaitesii soil binding is highest in the secondyear (Table 9)
The soil binding capacity of grass roots was studied by Bhaskaran and Chakrabarty[9] and the binding capacity ranged from 219 to 876 in four species of grassesMathur et al [10] noted that in Populus ciliata a promising species for soil con-servation the soil binding factor after one year growth was 6129 and after twoyears 10665 Dhyani et al [11] have calculated soil binding capacity factor for ve tree genera and Ougeinea Leucaena and Grewia were shown to be useful forconservation in this respect
Compared with grasses and trees rattans appear to be good soil binders Banikand Ahamed [12] also pointed out that another rattan C viminalis is likely to checksoil erosion
Final inference
It can be inferred that C thwaitesii is more ef cient than C rotang in water andnutrient uptake because its root density total root intensity ne root intensity androot surface area are higher However one could also argue the case the otherway round C rotang is more ef cient because it is able to survive and growwith less dry matter investment in root structure than C thwaitesii C thwaitesiiis less ef cient because it needs more root surface area to survive Nonethelessboth species are good soil binders
Acknowledgements
We are grateful to Dr J K Sharma Director KFRI for providing the facilitiesfor the work The rst author gratefully acknowledges the University GrantsCommission for permitting the bene t of FIP under the IXth plan for the completionof her PhD work Thanks are due to Mr K K Unni Of cer-in-charge Fieldresearch station Palappilly for his unreserved help in the eld
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 11
REFERENCES
1 V K Jayasree C Renuka and P Rugmini Root morphology and development in rattans1 A quantitativestudy of the roots in two species of Calamus L Journal of Bamboo and Rattan2 (2) 135ndash152 (2003)
2 D S Stevenson Effective soil volume and its importance to root and top growth of plantsCanadian Journal of Soil Science 47 163ndash174 (1967)
3 D Atkinson and S A Wilson The root soil interface and its signi cance for fruit tree roots ofdifferent ages in The Soil Root Interface J L Harley and R S Russell (Eds) pp 259ndash271Academic press London (1979)
4 D Atkinson and S A Wilson The growth and distribution of fruit tree roots some conse-quences for nutrient uptake in Mineral Nutrition of Fruit Trees D Atkinson J E JacksonR O Sharples and W M Waller (Eds) pp 137ndash150 Butterworths London (1980)
5 J O Wright Unusual features of the root system of the oil palm in West Africa Nature 1687ndash48 (1951)
6 B S Grey A study of the in uence of genetic agronomic and environmental factors on thegrowth owering and bunch production of Oil palm on the West Coast of Malaysia PhD thesisUniversity of Aberdeen Aberdeen (1969)
7 S A Barber and M Silverbush Plant root morphology and nutrient uptake in Roots Nutrientand Water In ux and Plant Growth S A Barber and D R Boulden (Eds) pp 65ndash87 AmericanSociety of Agronomy Madison WI (1984)
8 D M Eissenstat and M M Caldwell Competitive ability is linked to water extraction A eldstudy of two arid land tussock grasses Oecologia 75 1ndash7 (1988)
9 A R Bhaskaran and D C Chakrabarty A preliminary study on the variations in the soil bindingcapacity of some grass roots Indian Journal of Agronomy 10 326ndash330 (1965)
10 H N Mathur R P Singh and K C Sharma Populus ciliata mdash A promising tree species for soilconservation in hilly areas The Indian Forest 108 (9) 599ndash604 (1982)
11 K Dhyani P Narain and R K Singh Studies on root distribution of ve multipurpose treespecies in Doon Valley India Agroforestry Systems 12 149ndash161 (1990)
12 R L Banik and F U Ahmed An investigation on the roots of Bara bet (Calamus viminalisWilld var fasciculatus Becc) Bano Biggyan Patrika 15 (1-2) 37ndash40 (1986)
J Bamboo and Rattan Vol 3 No 1 pp 13ndash22 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Manufacturing laminates from sympodial bamboos mdashan Indian experience
A K BANSAL curren and T R N PRASADIndian Plywood Industries Research and Training Institute Tumkur Road P O Box 2273Bangalore 560 022 India
AbstractmdashIn recent years bamboo has been rediscovered as an important renewable material withgreat potential Industrial bamboo products will also result in alleviating the pressure on forestsas well as creating employment opportunities for ruraltribal poor particularly women Consideringthis the Government of India has launched an important national initiative for promotion of bambooproducts in mission mode Laminated bamboo boards are closest to wood both in appearance andproperties and are generally manufactured from the monopodial bamboo namely Phyllostachyspubescens The material is highly suitable for ooring and furniture Working on a project fundedby the Ministry of Environment and Forests Government of India IPIRTI has evolved a process formaking bamboo wood (laminates) from a sympodial bamboo found in several states of India namelyBambusa bambos Strength properties of bamboo wood are comparable to those of Tectona grandis(teak) A at-pack table and a wall stand were also designed and fabricated indicating the suitabilityof the material for furniture
Key words Laminates bamboo-wood wood substitute sympodial bamboo
INTRODUCTION
The development of wood substitutes is one of the important interventions enunci-ated in the 1988 National Forest Policy of India aiming at the conservation of naturalforests [1] Such substitution has necessarily to be done by the use of renewable -bres due to the fact that wood alternates made from non-renewable resources willnot be sustainable More over alternates based on plastics metals and such othermaterials are highly energy consuming non-biodegradable and are not conduciveto our environment [2 3] Of the several renewable bre resources bamboo is beingrediscovered throughout the world as a futuristic material Bamboo is perhaps oneof the fastest growing plants on the earth and sequesters atmospheric carbon most
currenTo whom correspondence should be addressed E-mail bansalkavsnlcom
14 A K Bansal and T R N Prasad
ef ciently Several panel products have been developed or are under developmentusing bamboo in different form including stripslaths slivers and particles [4 5]India has rich resources of bamboo both in terms of extent and variety In fact sev-eral species of bamboos occur naturally in the country and have been part of Indianculture with more than thousand traditional uses IPIRTI has been associated withdevelopment of several useful products from woven bamboo mats that are not onlyenvironment-friendly but also people friendly [6 7]
A new generation product made from bamboo strips known as bamboo laminatehas gained importance in Europe and America particularly as ooring materialin place of hardwoods due to the fact that it resembles wood in appearance andhas similar workability [8] Bamboo laminate can replace timber in many otherapplications such as doors and windows frames partitions and furniture Theselaminates are manufactured from a temperate zone monopodial bamboo namelyPhyllostachys pubescens referred to in the international technical literature also asmoso bamboo (Ref [9] and data not shown)
Working under a project funded by the Ministry of Environment and ForestsGovernment of India IPIRTI screened a number of Indian sympodial or clumpforming bamboo species and developed the technology for the manufacturingbamboo laminates from Bambusa bambos one of the common bamboo species inseveral parts of the country covering around 15 of the total bamboo bearing forestareas The species is also raised as plantations outside forests
MATERIALS AND METHODS
A generalized process ow chart for manufacturing bamboo laminates is given inFig 1 In simple terms the process involves conversion of bamboo into stripshaving uniform rectangular cross-section drying them to reduce the moisture todesirable level application of adhesive and hot pressing using both vertical and sidepressure to achieve proper bonding Some of the bamboo processing machines wereimported as they are not available in the country One of the available hydraulic hotpresses was modi ed so as to provide both vertical and side pressure required formaking bamboo laminates
The bamboo strips are required to have a uniform rectangular cross-section Thestrips are put side by side in two different fashions and accordingly they are termedas vertical and horizontal laminates (Fig 2) The normal minimum size (the lesserdimension of the cross-section) for use in furniture is 18ndash20 mm Moreover suchstrips are made from bamboo splits having a cross-section as shown in Fig 3From such a cross-section strips of rectangular cross-sections are cut by removingthe extra material in two stages of planing This speci c processing requirementputs a constraint on minimum diameter and wall thickness of bamboos that can beeconomically used for making laminates
Since culm diameter and wall thickness are two very important parameters thatlimit the conversion of bamboo into strips of suitable sizes for making laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 15
Figure 1 Process ow chart for manufacturing bamboo laminates
Figure 2 Bamboo laminates
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
J Bamboo and Rattan Vol 3 No 1 pp 3ndash11 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Root development in rattans 2 Soil requirements andef ciency of the root systems of Calamus thwaitesii Beccand Hook f and Calamus rotang L in the seedling stage
V K JAYASREE 1 C RENUKA 2curren and P RUGMINI 2
1 Sree Krishna College Guruvayur Thrissur Kerala India2 Kerala Forest Research Institute Peechi 680 653 Thrissur Kerala India
AbstractmdashThe function and activity of a root system is closely linked to its normal environmentthe soil The soil volume exploited by the two species was calculated and a comparison showed thatCalamus rotang exploited more soil volume than C thwaitesii The effective soil volume was alsofound to show an increase in C rotang when compared to C thwaitesii Knowing the effective soilvolume the size of the polybag to be used in the nursery can be adjusted The root spread of the twospecies shows that a 30pound30pound30 cm pit size will be suf cient for seedlings up to 2 years old Rootingdensity is found to be more in the upper 30 cm layer of soil in both species Root density total rootintensity and ne root intensity are higher in C thwaitesii when compared to C rotang Root surfacearea also is more in C thwaitesii Hence this species will be more ef cient in water and nutrientuptake in the seedling stage Both species are good soil binders
Key words Rattans effective soil volume rooting density root intensity root surface area soilbinding capacity
INTRODUCTION
The function and activity of a root system is closely linked to its normal environ-ment the soil A plant is dependent on a volume of soil for supply of water and min-eral resources and for physical support Ef ciency in nutrient uptake is in uencedby the rooting density The number of roots and root surface area also are indicatorsof root system ef ciency Soil binding capacity which is a measure of the bindingeffect on the soil particles is of direct value in soil conservation A knowledge ofthese aspects of a root system will aid in management decisions when a species is tobe raised on a large scale In this paper soil requirements and ef ciency of the root
currenTo whom correspondence should be addressed E-mail renukakfriorg
4 V K Jayasree et al
system of selected species of commercially important rattans Calamus thwaitesiiand C rotang in their seedling stages are discussed The growth characteristicsand root spread were discussed in the rst part of this paper [1]
MATERIALS AND METHODS
The experimental design has been published in the rst paper of this series [1] Inaddition at the third year soil samples were collected using a 4-cm diameter corefrom four different depths (0ndash15 cm 15ndash30 cm 30ndash45 cm and 40ndash60 cm) at 010and 30 cm from the base of the plant There were three randomly selected samplingpoints around a single plant in order to get fragments of the roots from all directionsThere were a total of 28 samples from a single plant Root fragments were separatedfrom each sample and used for determining the different root parameters like rootlength total root weight ne root weight rooting density etc
The soil volume exploited by the root system for the two species of Calamus wascalculated on a yearly basis using the formula frac14h=22ordm where lsquohrsquo is the meanhorizontal spread of the root system in each year obtained from the data collected attwo-month intervals and lsquoordmrsquo is the mean vertical depth of the roots The two specieswere compared based on the soil exploited by their root system
The effective soil volume for the two species in each year was calculated fromthe graph drawn by plotting exploited soil volume against rooting density foreach period and soil volume at which rooting density shows a sharp decline wasnoted [2]
The rooting density of each species was calculated on a yearly basis applyingthe formula Rmax=s where lsquoRmaxrsquo is the total length of the main roots laterals andsublaterals and lsquosrsquo is the soil volume exploited by the entire root system Rootingdensity was also calculated making use of the data with respect to core samples ofsoil taken at the end of the third year
The root intensity of each species was calculated from the total number of rootspresent in unit area of the soil Percentage root intensity contributed by ne rootsless than 2 mm in diameter was also calculated by considering the number of neroots alone
The root surface area a measure of the total absorptive area of the roots wascalculated separately for roots less than 2 mm diameter and greater than or equal to2 mm diameter using the formula 2frac14rl where lsquorrsquo is the radius of the root and lsquolrsquothe length
The soil binding capacity for lateral and sublateral roots was found by using theformula v=r2 where lsquovrsquo is the average root volume obtained and lsquorrsquo the mean radiusof the roots of the plants The root volume was found using the formula frac14r2l wherelsquorrsquo stands for mean radius of the lateralssublaterals of the plants considered for thestudy and lsquolrsquo their mean length
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 5
RESULTS AND DISCUSSION
Root spread
The root spread has been discussed in Ref [1] The data are repeated here for easyreference In a 3 year old C thwaitesii the average horizontal spread was 616 cmand in C rotang 918 cm They grow vertically downward up to a distance of298 cm in C rotang and 391 cm in C thwaitesii (Table 1)
Soil exploitation
The volume of soil available for rooting is an important factor governing the growthof seedlings In fact the soil is only partly utilised and a large proportion of the soilis not exploited by the roots In C rotang soil volume exploited in the second yearis about 30 times the volume exploited in the rst year There is an about 220-timesincrease in the exploited soil volume in the third year In C thwaitesii in the rsttwo years the soil volume exploited is more or less the same while a more than60-times increase is seen in the third year (Table 2) A comparison between speciesshows that C rotang is exploiting more soil volume than C thwaitesii
Effective soil volume
In the nursery the plant seldom has enough soil at its disposal to allow optimaldevelopment of its root system However such a restriction of soil volume hardly
n D 5 replicates Cr mdash C rotang Ct mdash C thwaitesii
Table 2Comparison of soil volume exploited
Period (year) Soil exploited (cm3)
Cr Ct
First 877 1843Second 25 769 1821Third 192 219 113 742
n D 5 replicates Cr mdash C rotang Ct mdash C thwaitesii
6 V K Jayasree et al
impairs the growth of the plant and plants absorb only a small part of the nutrientspresent
Stevenson [2] de ned the effective soil volume as the volume of soil that is ableto supply water to a root system and which does not restrict the growth of thoseroots By calculation effective soil volume or Ve is a maximal 785 (905 withtriangular spacing of roots) of a total volume that does not restrict growth Belowthis level root density will decline sharply as soil volume increases For maximumeffects from nutritional or water content treatments plants should be provided withsuf cient soil at least to approach the conditions laid down in the de nition ofeffective soil volume The smaller the plant the easier it is to meet this provision
In this study it is seen that rooting density declines year by year (Table 3) Thisshows that the effective soil volume has been attained in the two species Theeffective soil volume in the rst year for C rotang was 447 cm3 and 632 cm3
for C thwaitesii Hence the polybag or other container should hold this amount ofsoil to attain the maximum growth of roots In the second year the effective soilvolume was found to increase in C rotang compared to C thwaitesii In the thirdyear while the effective soil volume showed an enormous increase in C rotang itremained the same as that of the second year in C thwaitesii (Table 4)
Cultivation practices in the nursery can be based on this observation For anoptimal development of the root system the bag should contain the effective soilvolume For C rotang since the vertical spread is 133 cm the bag size should be
Table 3Rooting density
Period C rotang C thwaitesii(year)
Soil Rooting density (cm per cm3) Soil Rooting density (cm cmiexcl3)
volume Main Lateral Sublateral volume Main Lateral Sublateral(cm3) (cm3)
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 7
about 14 pound 10 cm of which 14 cm is the height of the bag and 10 cm is the widthWhen the bag is lled with soil it will attain a diameter of approximately 64 cmFor C thwaitesii it should be 16 pound 1115 cm (Table 1) If the seedlings need to bekept for the second year the bag size should be about 27 pound 21 cm for C rotang and18 pound 155 cm for C thwaitesii
Rattan seedlings can be out planted from the polybag generally after one year ofhardening in the nursery For one year seedlings a pit size of 30 pound 30 pound 30 cm willbe suf cient for the two species For two year old seedlings also the same pit sizewill suf ce since the vertical spread is below 30 cm in both species
Rooting density
The ef ciency in nutrient uptake is in uenced by the rooting density Rootingdensity can be expressed relative to either soil surface area (LA in cmcm2) orsoil volume (LV in cmcm3) Atkinson and Wilson [3 4] have described theconsequences of a low LA value When a plant transpires water will come initiallyfrom soil immediately adjacent to the root with this zone being replenished frombulk soil If the rate of withdrawal exceeds the rate of water movement through thesoil to the root (ie the rate of uptake exceeds soil hydraulic conductivity) then thesoil adjacent to the root will become drier than the soil bulk and the rate of water ow into the root will decrease and may result in water stress Localized dryingoccurs and thus the gradients of water potential at the root surface will reduce theuptake of minerals thought to be moved by mass ow If root density is high owrates will always tend to be low and gradients at the root surface will be rare Whereroot density is low as in fruit trees the contrary will be true
Root density varies with depth Hence reduced soil water potentials will not be thesame at all depths and this will affect the balance of nutrient uptake from differentparts of the soil pro le
In the present study while C rotang possesses a higher rooting density during the rst year of growth C thwaitesii does so later The rooting density in both speciesis found to be inversely related to the amount of soil exploited by the root systemThere is a major contribution of the laterals and sublaterals towards rooting densityof the plant occurs during the second year in both species (Table 3)
Measurements using the core method at different depths and radial distances inthe third year reveal that rooting density is greater in C thwaitesii compared to thatof C rotang With respect to depth rooting density is much higher in the upper30 cm of soil compared to the lower 30 cm in both species While 81 of the totalrooting density is the contribution of the upper 30 cm of soil in C rotang 89 ofthe total rooting density is contributed by the upper 30 cm in C thwaitesii At alldepths other than 30ndash45 cm rooting density is found to be more in C thwaitesiicompared to C rotang (Table 5)
As far as the different lateral distances from the base of the plant are concernedthe percentage contribution of the rooting density within a soil depth of 0ndash60 cmat the centre of the rooting zone and at 10 cm away from the base of the plant is
8 V K Jayasree et al
Table 5Root density at different radial distances and depths from the base of the plant
RD C rotang C thwaitesii(cm) Depth (cm) Depth (cm)
0ndash15 15ndash30 30ndash45 45ndash60 Average 0ndash15 15ndash30 30ndash45 45ndash60 Average
36 and 37 respectively in C rotang While C rotang shows almost the samerooting density at these regions C thwaitesii shows markedly more percentage rootdensity (46) at the centre of the rooting zone than at 10 cm away from the plant(29) (calculated from Table 5) Since a higher rooting density is observed inC thwaitesii this species will be more ef cient in nutrient uptake
Root intensity
When total root intensity is considered C thwaitesii is more ef cient in absorptioncompared to C rotang (Table 6) the percentage of total intensity being more inthe surface layer (0ndash15 cm depth) Published data are often dif cult to assess Forinstance according to Wright [5] the absorbing roots of oil palm are concentrated inthe upper 10 cm of soil whereas Grey [6] observed predominance of the absorbingroots in the upper 30 cm soil In the two rattan species studied the absorbing rootsare found to be more in the upper 15 cm of soil In C rotang 83 of the total rootintensity is contributed by ne roots while in C thwaitesii 87 of the total rootintensity is the contribution of ne roots Thus C thwaitesii is more ef cient inabsorption even when only the ne absorbing roots are taken into account
Table 7 shows the lateral distribution of roots In C rotang more absorbing rootsare found at a lateral distance of 10 cm whereas in C thwaitesii ne roots aremaximal at the centre of the rooting zone
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 9
Table 7Lateral distribution of total roots and contributionof ne roots
Radial Total roots () Fine roots ()distances (cm) Cr Ct Cr Ct
Root activity decreased with increasing soil depth In C rotang about 76 ofthe active roots are located at 0ndash30 cm depth while 86 of the active roots inC thwaitesii are located at 0ndash30 cm depth Wright [5] reported that 70ndash80 of theactive roots of oil palm are located at 0ndash20 cm depth
Root surface area
In the two species main roots alone are present in the initial stage and C thwaitesiihas more root surface area at this stage With the initiation of laterals in the rst yearthe total surface areaplant is also more in C thwaitesii However in the secondyear C rotang has more surface area due to the occurrence of more roots bothlt2 mm and gt2 mm At the end of the third year the trend was reversed (Table 8)
However the surface area of the ne roots even though few in number wasfound to be greater in C rotang due to their increased length and diameter Thisis supported by the statement that plants with greater lsquospeci c root surface arearsquo aremore ef cient and opportunistic absorbers of ions and water [7] Such plants alsoappear to be more competitive in single and mixed plant communities [8] The rootsystem of C thwaitesii is seen to be more ef cient as measured by more speci croot surface area
10 V K Jayasree et al
Table 9Comparison of soil binding factor
Period (year) C rotang C thwaitesii
First 175 150Second 303 401Third 334 285
Soil binding capacity
The binding of soil particles and the promotion of soil aggregation are of directvalue in soil conservation The length and thickness of roots play an importantrole in binding soil particles ne roots with their close and elaborate network havegreater binding capacity than thicker roots Soil binding capacity shows an increasewith age in C rotang while in C thwaitesii soil binding is highest in the secondyear (Table 9)
The soil binding capacity of grass roots was studied by Bhaskaran and Chakrabarty[9] and the binding capacity ranged from 219 to 876 in four species of grassesMathur et al [10] noted that in Populus ciliata a promising species for soil con-servation the soil binding factor after one year growth was 6129 and after twoyears 10665 Dhyani et al [11] have calculated soil binding capacity factor for ve tree genera and Ougeinea Leucaena and Grewia were shown to be useful forconservation in this respect
Compared with grasses and trees rattans appear to be good soil binders Banikand Ahamed [12] also pointed out that another rattan C viminalis is likely to checksoil erosion
Final inference
It can be inferred that C thwaitesii is more ef cient than C rotang in water andnutrient uptake because its root density total root intensity ne root intensity androot surface area are higher However one could also argue the case the otherway round C rotang is more ef cient because it is able to survive and growwith less dry matter investment in root structure than C thwaitesii C thwaitesiiis less ef cient because it needs more root surface area to survive Nonethelessboth species are good soil binders
Acknowledgements
We are grateful to Dr J K Sharma Director KFRI for providing the facilitiesfor the work The rst author gratefully acknowledges the University GrantsCommission for permitting the bene t of FIP under the IXth plan for the completionof her PhD work Thanks are due to Mr K K Unni Of cer-in-charge Fieldresearch station Palappilly for his unreserved help in the eld
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 11
REFERENCES
1 V K Jayasree C Renuka and P Rugmini Root morphology and development in rattans1 A quantitativestudy of the roots in two species of Calamus L Journal of Bamboo and Rattan2 (2) 135ndash152 (2003)
2 D S Stevenson Effective soil volume and its importance to root and top growth of plantsCanadian Journal of Soil Science 47 163ndash174 (1967)
3 D Atkinson and S A Wilson The root soil interface and its signi cance for fruit tree roots ofdifferent ages in The Soil Root Interface J L Harley and R S Russell (Eds) pp 259ndash271Academic press London (1979)
4 D Atkinson and S A Wilson The growth and distribution of fruit tree roots some conse-quences for nutrient uptake in Mineral Nutrition of Fruit Trees D Atkinson J E JacksonR O Sharples and W M Waller (Eds) pp 137ndash150 Butterworths London (1980)
5 J O Wright Unusual features of the root system of the oil palm in West Africa Nature 1687ndash48 (1951)
6 B S Grey A study of the in uence of genetic agronomic and environmental factors on thegrowth owering and bunch production of Oil palm on the West Coast of Malaysia PhD thesisUniversity of Aberdeen Aberdeen (1969)
7 S A Barber and M Silverbush Plant root morphology and nutrient uptake in Roots Nutrientand Water In ux and Plant Growth S A Barber and D R Boulden (Eds) pp 65ndash87 AmericanSociety of Agronomy Madison WI (1984)
8 D M Eissenstat and M M Caldwell Competitive ability is linked to water extraction A eldstudy of two arid land tussock grasses Oecologia 75 1ndash7 (1988)
9 A R Bhaskaran and D C Chakrabarty A preliminary study on the variations in the soil bindingcapacity of some grass roots Indian Journal of Agronomy 10 326ndash330 (1965)
10 H N Mathur R P Singh and K C Sharma Populus ciliata mdash A promising tree species for soilconservation in hilly areas The Indian Forest 108 (9) 599ndash604 (1982)
11 K Dhyani P Narain and R K Singh Studies on root distribution of ve multipurpose treespecies in Doon Valley India Agroforestry Systems 12 149ndash161 (1990)
12 R L Banik and F U Ahmed An investigation on the roots of Bara bet (Calamus viminalisWilld var fasciculatus Becc) Bano Biggyan Patrika 15 (1-2) 37ndash40 (1986)
J Bamboo and Rattan Vol 3 No 1 pp 13ndash22 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Manufacturing laminates from sympodial bamboos mdashan Indian experience
A K BANSAL curren and T R N PRASADIndian Plywood Industries Research and Training Institute Tumkur Road P O Box 2273Bangalore 560 022 India
AbstractmdashIn recent years bamboo has been rediscovered as an important renewable material withgreat potential Industrial bamboo products will also result in alleviating the pressure on forestsas well as creating employment opportunities for ruraltribal poor particularly women Consideringthis the Government of India has launched an important national initiative for promotion of bambooproducts in mission mode Laminated bamboo boards are closest to wood both in appearance andproperties and are generally manufactured from the monopodial bamboo namely Phyllostachyspubescens The material is highly suitable for ooring and furniture Working on a project fundedby the Ministry of Environment and Forests Government of India IPIRTI has evolved a process formaking bamboo wood (laminates) from a sympodial bamboo found in several states of India namelyBambusa bambos Strength properties of bamboo wood are comparable to those of Tectona grandis(teak) A at-pack table and a wall stand were also designed and fabricated indicating the suitabilityof the material for furniture
Key words Laminates bamboo-wood wood substitute sympodial bamboo
INTRODUCTION
The development of wood substitutes is one of the important interventions enunci-ated in the 1988 National Forest Policy of India aiming at the conservation of naturalforests [1] Such substitution has necessarily to be done by the use of renewable -bres due to the fact that wood alternates made from non-renewable resources willnot be sustainable More over alternates based on plastics metals and such othermaterials are highly energy consuming non-biodegradable and are not conduciveto our environment [2 3] Of the several renewable bre resources bamboo is beingrediscovered throughout the world as a futuristic material Bamboo is perhaps oneof the fastest growing plants on the earth and sequesters atmospheric carbon most
currenTo whom correspondence should be addressed E-mail bansalkavsnlcom
14 A K Bansal and T R N Prasad
ef ciently Several panel products have been developed or are under developmentusing bamboo in different form including stripslaths slivers and particles [4 5]India has rich resources of bamboo both in terms of extent and variety In fact sev-eral species of bamboos occur naturally in the country and have been part of Indianculture with more than thousand traditional uses IPIRTI has been associated withdevelopment of several useful products from woven bamboo mats that are not onlyenvironment-friendly but also people friendly [6 7]
A new generation product made from bamboo strips known as bamboo laminatehas gained importance in Europe and America particularly as ooring materialin place of hardwoods due to the fact that it resembles wood in appearance andhas similar workability [8] Bamboo laminate can replace timber in many otherapplications such as doors and windows frames partitions and furniture Theselaminates are manufactured from a temperate zone monopodial bamboo namelyPhyllostachys pubescens referred to in the international technical literature also asmoso bamboo (Ref [9] and data not shown)
Working under a project funded by the Ministry of Environment and ForestsGovernment of India IPIRTI screened a number of Indian sympodial or clumpforming bamboo species and developed the technology for the manufacturingbamboo laminates from Bambusa bambos one of the common bamboo species inseveral parts of the country covering around 15 of the total bamboo bearing forestareas The species is also raised as plantations outside forests
MATERIALS AND METHODS
A generalized process ow chart for manufacturing bamboo laminates is given inFig 1 In simple terms the process involves conversion of bamboo into stripshaving uniform rectangular cross-section drying them to reduce the moisture todesirable level application of adhesive and hot pressing using both vertical and sidepressure to achieve proper bonding Some of the bamboo processing machines wereimported as they are not available in the country One of the available hydraulic hotpresses was modi ed so as to provide both vertical and side pressure required formaking bamboo laminates
The bamboo strips are required to have a uniform rectangular cross-section Thestrips are put side by side in two different fashions and accordingly they are termedas vertical and horizontal laminates (Fig 2) The normal minimum size (the lesserdimension of the cross-section) for use in furniture is 18ndash20 mm Moreover suchstrips are made from bamboo splits having a cross-section as shown in Fig 3From such a cross-section strips of rectangular cross-sections are cut by removingthe extra material in two stages of planing This speci c processing requirementputs a constraint on minimum diameter and wall thickness of bamboos that can beeconomically used for making laminates
Since culm diameter and wall thickness are two very important parameters thatlimit the conversion of bamboo into strips of suitable sizes for making laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 15
Figure 1 Process ow chart for manufacturing bamboo laminates
Figure 2 Bamboo laminates
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
4 V K Jayasree et al
system of selected species of commercially important rattans Calamus thwaitesiiand C rotang in their seedling stages are discussed The growth characteristicsand root spread were discussed in the rst part of this paper [1]
MATERIALS AND METHODS
The experimental design has been published in the rst paper of this series [1] Inaddition at the third year soil samples were collected using a 4-cm diameter corefrom four different depths (0ndash15 cm 15ndash30 cm 30ndash45 cm and 40ndash60 cm) at 010and 30 cm from the base of the plant There were three randomly selected samplingpoints around a single plant in order to get fragments of the roots from all directionsThere were a total of 28 samples from a single plant Root fragments were separatedfrom each sample and used for determining the different root parameters like rootlength total root weight ne root weight rooting density etc
The soil volume exploited by the root system for the two species of Calamus wascalculated on a yearly basis using the formula frac14h=22ordm where lsquohrsquo is the meanhorizontal spread of the root system in each year obtained from the data collected attwo-month intervals and lsquoordmrsquo is the mean vertical depth of the roots The two specieswere compared based on the soil exploited by their root system
The effective soil volume for the two species in each year was calculated fromthe graph drawn by plotting exploited soil volume against rooting density foreach period and soil volume at which rooting density shows a sharp decline wasnoted [2]
The rooting density of each species was calculated on a yearly basis applyingthe formula Rmax=s where lsquoRmaxrsquo is the total length of the main roots laterals andsublaterals and lsquosrsquo is the soil volume exploited by the entire root system Rootingdensity was also calculated making use of the data with respect to core samples ofsoil taken at the end of the third year
The root intensity of each species was calculated from the total number of rootspresent in unit area of the soil Percentage root intensity contributed by ne rootsless than 2 mm in diameter was also calculated by considering the number of neroots alone
The root surface area a measure of the total absorptive area of the roots wascalculated separately for roots less than 2 mm diameter and greater than or equal to2 mm diameter using the formula 2frac14rl where lsquorrsquo is the radius of the root and lsquolrsquothe length
The soil binding capacity for lateral and sublateral roots was found by using theformula v=r2 where lsquovrsquo is the average root volume obtained and lsquorrsquo the mean radiusof the roots of the plants The root volume was found using the formula frac14r2l wherelsquorrsquo stands for mean radius of the lateralssublaterals of the plants considered for thestudy and lsquolrsquo their mean length
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 5
RESULTS AND DISCUSSION
Root spread
The root spread has been discussed in Ref [1] The data are repeated here for easyreference In a 3 year old C thwaitesii the average horizontal spread was 616 cmand in C rotang 918 cm They grow vertically downward up to a distance of298 cm in C rotang and 391 cm in C thwaitesii (Table 1)
Soil exploitation
The volume of soil available for rooting is an important factor governing the growthof seedlings In fact the soil is only partly utilised and a large proportion of the soilis not exploited by the roots In C rotang soil volume exploited in the second yearis about 30 times the volume exploited in the rst year There is an about 220-timesincrease in the exploited soil volume in the third year In C thwaitesii in the rsttwo years the soil volume exploited is more or less the same while a more than60-times increase is seen in the third year (Table 2) A comparison between speciesshows that C rotang is exploiting more soil volume than C thwaitesii
Effective soil volume
In the nursery the plant seldom has enough soil at its disposal to allow optimaldevelopment of its root system However such a restriction of soil volume hardly
n D 5 replicates Cr mdash C rotang Ct mdash C thwaitesii
Table 2Comparison of soil volume exploited
Period (year) Soil exploited (cm3)
Cr Ct
First 877 1843Second 25 769 1821Third 192 219 113 742
n D 5 replicates Cr mdash C rotang Ct mdash C thwaitesii
6 V K Jayasree et al
impairs the growth of the plant and plants absorb only a small part of the nutrientspresent
Stevenson [2] de ned the effective soil volume as the volume of soil that is ableto supply water to a root system and which does not restrict the growth of thoseroots By calculation effective soil volume or Ve is a maximal 785 (905 withtriangular spacing of roots) of a total volume that does not restrict growth Belowthis level root density will decline sharply as soil volume increases For maximumeffects from nutritional or water content treatments plants should be provided withsuf cient soil at least to approach the conditions laid down in the de nition ofeffective soil volume The smaller the plant the easier it is to meet this provision
In this study it is seen that rooting density declines year by year (Table 3) Thisshows that the effective soil volume has been attained in the two species Theeffective soil volume in the rst year for C rotang was 447 cm3 and 632 cm3
for C thwaitesii Hence the polybag or other container should hold this amount ofsoil to attain the maximum growth of roots In the second year the effective soilvolume was found to increase in C rotang compared to C thwaitesii In the thirdyear while the effective soil volume showed an enormous increase in C rotang itremained the same as that of the second year in C thwaitesii (Table 4)
Cultivation practices in the nursery can be based on this observation For anoptimal development of the root system the bag should contain the effective soilvolume For C rotang since the vertical spread is 133 cm the bag size should be
Table 3Rooting density
Period C rotang C thwaitesii(year)
Soil Rooting density (cm per cm3) Soil Rooting density (cm cmiexcl3)
volume Main Lateral Sublateral volume Main Lateral Sublateral(cm3) (cm3)
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 7
about 14 pound 10 cm of which 14 cm is the height of the bag and 10 cm is the widthWhen the bag is lled with soil it will attain a diameter of approximately 64 cmFor C thwaitesii it should be 16 pound 1115 cm (Table 1) If the seedlings need to bekept for the second year the bag size should be about 27 pound 21 cm for C rotang and18 pound 155 cm for C thwaitesii
Rattan seedlings can be out planted from the polybag generally after one year ofhardening in the nursery For one year seedlings a pit size of 30 pound 30 pound 30 cm willbe suf cient for the two species For two year old seedlings also the same pit sizewill suf ce since the vertical spread is below 30 cm in both species
Rooting density
The ef ciency in nutrient uptake is in uenced by the rooting density Rootingdensity can be expressed relative to either soil surface area (LA in cmcm2) orsoil volume (LV in cmcm3) Atkinson and Wilson [3 4] have described theconsequences of a low LA value When a plant transpires water will come initiallyfrom soil immediately adjacent to the root with this zone being replenished frombulk soil If the rate of withdrawal exceeds the rate of water movement through thesoil to the root (ie the rate of uptake exceeds soil hydraulic conductivity) then thesoil adjacent to the root will become drier than the soil bulk and the rate of water ow into the root will decrease and may result in water stress Localized dryingoccurs and thus the gradients of water potential at the root surface will reduce theuptake of minerals thought to be moved by mass ow If root density is high owrates will always tend to be low and gradients at the root surface will be rare Whereroot density is low as in fruit trees the contrary will be true
Root density varies with depth Hence reduced soil water potentials will not be thesame at all depths and this will affect the balance of nutrient uptake from differentparts of the soil pro le
In the present study while C rotang possesses a higher rooting density during the rst year of growth C thwaitesii does so later The rooting density in both speciesis found to be inversely related to the amount of soil exploited by the root systemThere is a major contribution of the laterals and sublaterals towards rooting densityof the plant occurs during the second year in both species (Table 3)
Measurements using the core method at different depths and radial distances inthe third year reveal that rooting density is greater in C thwaitesii compared to thatof C rotang With respect to depth rooting density is much higher in the upper30 cm of soil compared to the lower 30 cm in both species While 81 of the totalrooting density is the contribution of the upper 30 cm of soil in C rotang 89 ofthe total rooting density is contributed by the upper 30 cm in C thwaitesii At alldepths other than 30ndash45 cm rooting density is found to be more in C thwaitesiicompared to C rotang (Table 5)
As far as the different lateral distances from the base of the plant are concernedthe percentage contribution of the rooting density within a soil depth of 0ndash60 cmat the centre of the rooting zone and at 10 cm away from the base of the plant is
8 V K Jayasree et al
Table 5Root density at different radial distances and depths from the base of the plant
RD C rotang C thwaitesii(cm) Depth (cm) Depth (cm)
0ndash15 15ndash30 30ndash45 45ndash60 Average 0ndash15 15ndash30 30ndash45 45ndash60 Average
36 and 37 respectively in C rotang While C rotang shows almost the samerooting density at these regions C thwaitesii shows markedly more percentage rootdensity (46) at the centre of the rooting zone than at 10 cm away from the plant(29) (calculated from Table 5) Since a higher rooting density is observed inC thwaitesii this species will be more ef cient in nutrient uptake
Root intensity
When total root intensity is considered C thwaitesii is more ef cient in absorptioncompared to C rotang (Table 6) the percentage of total intensity being more inthe surface layer (0ndash15 cm depth) Published data are often dif cult to assess Forinstance according to Wright [5] the absorbing roots of oil palm are concentrated inthe upper 10 cm of soil whereas Grey [6] observed predominance of the absorbingroots in the upper 30 cm soil In the two rattan species studied the absorbing rootsare found to be more in the upper 15 cm of soil In C rotang 83 of the total rootintensity is contributed by ne roots while in C thwaitesii 87 of the total rootintensity is the contribution of ne roots Thus C thwaitesii is more ef cient inabsorption even when only the ne absorbing roots are taken into account
Table 7 shows the lateral distribution of roots In C rotang more absorbing rootsare found at a lateral distance of 10 cm whereas in C thwaitesii ne roots aremaximal at the centre of the rooting zone
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 9
Table 7Lateral distribution of total roots and contributionof ne roots
Radial Total roots () Fine roots ()distances (cm) Cr Ct Cr Ct
Root activity decreased with increasing soil depth In C rotang about 76 ofthe active roots are located at 0ndash30 cm depth while 86 of the active roots inC thwaitesii are located at 0ndash30 cm depth Wright [5] reported that 70ndash80 of theactive roots of oil palm are located at 0ndash20 cm depth
Root surface area
In the two species main roots alone are present in the initial stage and C thwaitesiihas more root surface area at this stage With the initiation of laterals in the rst yearthe total surface areaplant is also more in C thwaitesii However in the secondyear C rotang has more surface area due to the occurrence of more roots bothlt2 mm and gt2 mm At the end of the third year the trend was reversed (Table 8)
However the surface area of the ne roots even though few in number wasfound to be greater in C rotang due to their increased length and diameter Thisis supported by the statement that plants with greater lsquospeci c root surface arearsquo aremore ef cient and opportunistic absorbers of ions and water [7] Such plants alsoappear to be more competitive in single and mixed plant communities [8] The rootsystem of C thwaitesii is seen to be more ef cient as measured by more speci croot surface area
10 V K Jayasree et al
Table 9Comparison of soil binding factor
Period (year) C rotang C thwaitesii
First 175 150Second 303 401Third 334 285
Soil binding capacity
The binding of soil particles and the promotion of soil aggregation are of directvalue in soil conservation The length and thickness of roots play an importantrole in binding soil particles ne roots with their close and elaborate network havegreater binding capacity than thicker roots Soil binding capacity shows an increasewith age in C rotang while in C thwaitesii soil binding is highest in the secondyear (Table 9)
The soil binding capacity of grass roots was studied by Bhaskaran and Chakrabarty[9] and the binding capacity ranged from 219 to 876 in four species of grassesMathur et al [10] noted that in Populus ciliata a promising species for soil con-servation the soil binding factor after one year growth was 6129 and after twoyears 10665 Dhyani et al [11] have calculated soil binding capacity factor for ve tree genera and Ougeinea Leucaena and Grewia were shown to be useful forconservation in this respect
Compared with grasses and trees rattans appear to be good soil binders Banikand Ahamed [12] also pointed out that another rattan C viminalis is likely to checksoil erosion
Final inference
It can be inferred that C thwaitesii is more ef cient than C rotang in water andnutrient uptake because its root density total root intensity ne root intensity androot surface area are higher However one could also argue the case the otherway round C rotang is more ef cient because it is able to survive and growwith less dry matter investment in root structure than C thwaitesii C thwaitesiiis less ef cient because it needs more root surface area to survive Nonethelessboth species are good soil binders
Acknowledgements
We are grateful to Dr J K Sharma Director KFRI for providing the facilitiesfor the work The rst author gratefully acknowledges the University GrantsCommission for permitting the bene t of FIP under the IXth plan for the completionof her PhD work Thanks are due to Mr K K Unni Of cer-in-charge Fieldresearch station Palappilly for his unreserved help in the eld
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 11
REFERENCES
1 V K Jayasree C Renuka and P Rugmini Root morphology and development in rattans1 A quantitativestudy of the roots in two species of Calamus L Journal of Bamboo and Rattan2 (2) 135ndash152 (2003)
2 D S Stevenson Effective soil volume and its importance to root and top growth of plantsCanadian Journal of Soil Science 47 163ndash174 (1967)
3 D Atkinson and S A Wilson The root soil interface and its signi cance for fruit tree roots ofdifferent ages in The Soil Root Interface J L Harley and R S Russell (Eds) pp 259ndash271Academic press London (1979)
4 D Atkinson and S A Wilson The growth and distribution of fruit tree roots some conse-quences for nutrient uptake in Mineral Nutrition of Fruit Trees D Atkinson J E JacksonR O Sharples and W M Waller (Eds) pp 137ndash150 Butterworths London (1980)
5 J O Wright Unusual features of the root system of the oil palm in West Africa Nature 1687ndash48 (1951)
6 B S Grey A study of the in uence of genetic agronomic and environmental factors on thegrowth owering and bunch production of Oil palm on the West Coast of Malaysia PhD thesisUniversity of Aberdeen Aberdeen (1969)
7 S A Barber and M Silverbush Plant root morphology and nutrient uptake in Roots Nutrientand Water In ux and Plant Growth S A Barber and D R Boulden (Eds) pp 65ndash87 AmericanSociety of Agronomy Madison WI (1984)
8 D M Eissenstat and M M Caldwell Competitive ability is linked to water extraction A eldstudy of two arid land tussock grasses Oecologia 75 1ndash7 (1988)
9 A R Bhaskaran and D C Chakrabarty A preliminary study on the variations in the soil bindingcapacity of some grass roots Indian Journal of Agronomy 10 326ndash330 (1965)
10 H N Mathur R P Singh and K C Sharma Populus ciliata mdash A promising tree species for soilconservation in hilly areas The Indian Forest 108 (9) 599ndash604 (1982)
11 K Dhyani P Narain and R K Singh Studies on root distribution of ve multipurpose treespecies in Doon Valley India Agroforestry Systems 12 149ndash161 (1990)
12 R L Banik and F U Ahmed An investigation on the roots of Bara bet (Calamus viminalisWilld var fasciculatus Becc) Bano Biggyan Patrika 15 (1-2) 37ndash40 (1986)
J Bamboo and Rattan Vol 3 No 1 pp 13ndash22 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Manufacturing laminates from sympodial bamboos mdashan Indian experience
A K BANSAL curren and T R N PRASADIndian Plywood Industries Research and Training Institute Tumkur Road P O Box 2273Bangalore 560 022 India
AbstractmdashIn recent years bamboo has been rediscovered as an important renewable material withgreat potential Industrial bamboo products will also result in alleviating the pressure on forestsas well as creating employment opportunities for ruraltribal poor particularly women Consideringthis the Government of India has launched an important national initiative for promotion of bambooproducts in mission mode Laminated bamboo boards are closest to wood both in appearance andproperties and are generally manufactured from the monopodial bamboo namely Phyllostachyspubescens The material is highly suitable for ooring and furniture Working on a project fundedby the Ministry of Environment and Forests Government of India IPIRTI has evolved a process formaking bamboo wood (laminates) from a sympodial bamboo found in several states of India namelyBambusa bambos Strength properties of bamboo wood are comparable to those of Tectona grandis(teak) A at-pack table and a wall stand were also designed and fabricated indicating the suitabilityof the material for furniture
Key words Laminates bamboo-wood wood substitute sympodial bamboo
INTRODUCTION
The development of wood substitutes is one of the important interventions enunci-ated in the 1988 National Forest Policy of India aiming at the conservation of naturalforests [1] Such substitution has necessarily to be done by the use of renewable -bres due to the fact that wood alternates made from non-renewable resources willnot be sustainable More over alternates based on plastics metals and such othermaterials are highly energy consuming non-biodegradable and are not conduciveto our environment [2 3] Of the several renewable bre resources bamboo is beingrediscovered throughout the world as a futuristic material Bamboo is perhaps oneof the fastest growing plants on the earth and sequesters atmospheric carbon most
currenTo whom correspondence should be addressed E-mail bansalkavsnlcom
14 A K Bansal and T R N Prasad
ef ciently Several panel products have been developed or are under developmentusing bamboo in different form including stripslaths slivers and particles [4 5]India has rich resources of bamboo both in terms of extent and variety In fact sev-eral species of bamboos occur naturally in the country and have been part of Indianculture with more than thousand traditional uses IPIRTI has been associated withdevelopment of several useful products from woven bamboo mats that are not onlyenvironment-friendly but also people friendly [6 7]
A new generation product made from bamboo strips known as bamboo laminatehas gained importance in Europe and America particularly as ooring materialin place of hardwoods due to the fact that it resembles wood in appearance andhas similar workability [8] Bamboo laminate can replace timber in many otherapplications such as doors and windows frames partitions and furniture Theselaminates are manufactured from a temperate zone monopodial bamboo namelyPhyllostachys pubescens referred to in the international technical literature also asmoso bamboo (Ref [9] and data not shown)
Working under a project funded by the Ministry of Environment and ForestsGovernment of India IPIRTI screened a number of Indian sympodial or clumpforming bamboo species and developed the technology for the manufacturingbamboo laminates from Bambusa bambos one of the common bamboo species inseveral parts of the country covering around 15 of the total bamboo bearing forestareas The species is also raised as plantations outside forests
MATERIALS AND METHODS
A generalized process ow chart for manufacturing bamboo laminates is given inFig 1 In simple terms the process involves conversion of bamboo into stripshaving uniform rectangular cross-section drying them to reduce the moisture todesirable level application of adhesive and hot pressing using both vertical and sidepressure to achieve proper bonding Some of the bamboo processing machines wereimported as they are not available in the country One of the available hydraulic hotpresses was modi ed so as to provide both vertical and side pressure required formaking bamboo laminates
The bamboo strips are required to have a uniform rectangular cross-section Thestrips are put side by side in two different fashions and accordingly they are termedas vertical and horizontal laminates (Fig 2) The normal minimum size (the lesserdimension of the cross-section) for use in furniture is 18ndash20 mm Moreover suchstrips are made from bamboo splits having a cross-section as shown in Fig 3From such a cross-section strips of rectangular cross-sections are cut by removingthe extra material in two stages of planing This speci c processing requirementputs a constraint on minimum diameter and wall thickness of bamboos that can beeconomically used for making laminates
Since culm diameter and wall thickness are two very important parameters thatlimit the conversion of bamboo into strips of suitable sizes for making laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 15
Figure 1 Process ow chart for manufacturing bamboo laminates
Figure 2 Bamboo laminates
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 5
RESULTS AND DISCUSSION
Root spread
The root spread has been discussed in Ref [1] The data are repeated here for easyreference In a 3 year old C thwaitesii the average horizontal spread was 616 cmand in C rotang 918 cm They grow vertically downward up to a distance of298 cm in C rotang and 391 cm in C thwaitesii (Table 1)
Soil exploitation
The volume of soil available for rooting is an important factor governing the growthof seedlings In fact the soil is only partly utilised and a large proportion of the soilis not exploited by the roots In C rotang soil volume exploited in the second yearis about 30 times the volume exploited in the rst year There is an about 220-timesincrease in the exploited soil volume in the third year In C thwaitesii in the rsttwo years the soil volume exploited is more or less the same while a more than60-times increase is seen in the third year (Table 2) A comparison between speciesshows that C rotang is exploiting more soil volume than C thwaitesii
Effective soil volume
In the nursery the plant seldom has enough soil at its disposal to allow optimaldevelopment of its root system However such a restriction of soil volume hardly
n D 5 replicates Cr mdash C rotang Ct mdash C thwaitesii
Table 2Comparison of soil volume exploited
Period (year) Soil exploited (cm3)
Cr Ct
First 877 1843Second 25 769 1821Third 192 219 113 742
n D 5 replicates Cr mdash C rotang Ct mdash C thwaitesii
6 V K Jayasree et al
impairs the growth of the plant and plants absorb only a small part of the nutrientspresent
Stevenson [2] de ned the effective soil volume as the volume of soil that is ableto supply water to a root system and which does not restrict the growth of thoseroots By calculation effective soil volume or Ve is a maximal 785 (905 withtriangular spacing of roots) of a total volume that does not restrict growth Belowthis level root density will decline sharply as soil volume increases For maximumeffects from nutritional or water content treatments plants should be provided withsuf cient soil at least to approach the conditions laid down in the de nition ofeffective soil volume The smaller the plant the easier it is to meet this provision
In this study it is seen that rooting density declines year by year (Table 3) Thisshows that the effective soil volume has been attained in the two species Theeffective soil volume in the rst year for C rotang was 447 cm3 and 632 cm3
for C thwaitesii Hence the polybag or other container should hold this amount ofsoil to attain the maximum growth of roots In the second year the effective soilvolume was found to increase in C rotang compared to C thwaitesii In the thirdyear while the effective soil volume showed an enormous increase in C rotang itremained the same as that of the second year in C thwaitesii (Table 4)
Cultivation practices in the nursery can be based on this observation For anoptimal development of the root system the bag should contain the effective soilvolume For C rotang since the vertical spread is 133 cm the bag size should be
Table 3Rooting density
Period C rotang C thwaitesii(year)
Soil Rooting density (cm per cm3) Soil Rooting density (cm cmiexcl3)
volume Main Lateral Sublateral volume Main Lateral Sublateral(cm3) (cm3)
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 7
about 14 pound 10 cm of which 14 cm is the height of the bag and 10 cm is the widthWhen the bag is lled with soil it will attain a diameter of approximately 64 cmFor C thwaitesii it should be 16 pound 1115 cm (Table 1) If the seedlings need to bekept for the second year the bag size should be about 27 pound 21 cm for C rotang and18 pound 155 cm for C thwaitesii
Rattan seedlings can be out planted from the polybag generally after one year ofhardening in the nursery For one year seedlings a pit size of 30 pound 30 pound 30 cm willbe suf cient for the two species For two year old seedlings also the same pit sizewill suf ce since the vertical spread is below 30 cm in both species
Rooting density
The ef ciency in nutrient uptake is in uenced by the rooting density Rootingdensity can be expressed relative to either soil surface area (LA in cmcm2) orsoil volume (LV in cmcm3) Atkinson and Wilson [3 4] have described theconsequences of a low LA value When a plant transpires water will come initiallyfrom soil immediately adjacent to the root with this zone being replenished frombulk soil If the rate of withdrawal exceeds the rate of water movement through thesoil to the root (ie the rate of uptake exceeds soil hydraulic conductivity) then thesoil adjacent to the root will become drier than the soil bulk and the rate of water ow into the root will decrease and may result in water stress Localized dryingoccurs and thus the gradients of water potential at the root surface will reduce theuptake of minerals thought to be moved by mass ow If root density is high owrates will always tend to be low and gradients at the root surface will be rare Whereroot density is low as in fruit trees the contrary will be true
Root density varies with depth Hence reduced soil water potentials will not be thesame at all depths and this will affect the balance of nutrient uptake from differentparts of the soil pro le
In the present study while C rotang possesses a higher rooting density during the rst year of growth C thwaitesii does so later The rooting density in both speciesis found to be inversely related to the amount of soil exploited by the root systemThere is a major contribution of the laterals and sublaterals towards rooting densityof the plant occurs during the second year in both species (Table 3)
Measurements using the core method at different depths and radial distances inthe third year reveal that rooting density is greater in C thwaitesii compared to thatof C rotang With respect to depth rooting density is much higher in the upper30 cm of soil compared to the lower 30 cm in both species While 81 of the totalrooting density is the contribution of the upper 30 cm of soil in C rotang 89 ofthe total rooting density is contributed by the upper 30 cm in C thwaitesii At alldepths other than 30ndash45 cm rooting density is found to be more in C thwaitesiicompared to C rotang (Table 5)
As far as the different lateral distances from the base of the plant are concernedthe percentage contribution of the rooting density within a soil depth of 0ndash60 cmat the centre of the rooting zone and at 10 cm away from the base of the plant is
8 V K Jayasree et al
Table 5Root density at different radial distances and depths from the base of the plant
RD C rotang C thwaitesii(cm) Depth (cm) Depth (cm)
0ndash15 15ndash30 30ndash45 45ndash60 Average 0ndash15 15ndash30 30ndash45 45ndash60 Average
36 and 37 respectively in C rotang While C rotang shows almost the samerooting density at these regions C thwaitesii shows markedly more percentage rootdensity (46) at the centre of the rooting zone than at 10 cm away from the plant(29) (calculated from Table 5) Since a higher rooting density is observed inC thwaitesii this species will be more ef cient in nutrient uptake
Root intensity
When total root intensity is considered C thwaitesii is more ef cient in absorptioncompared to C rotang (Table 6) the percentage of total intensity being more inthe surface layer (0ndash15 cm depth) Published data are often dif cult to assess Forinstance according to Wright [5] the absorbing roots of oil palm are concentrated inthe upper 10 cm of soil whereas Grey [6] observed predominance of the absorbingroots in the upper 30 cm soil In the two rattan species studied the absorbing rootsare found to be more in the upper 15 cm of soil In C rotang 83 of the total rootintensity is contributed by ne roots while in C thwaitesii 87 of the total rootintensity is the contribution of ne roots Thus C thwaitesii is more ef cient inabsorption even when only the ne absorbing roots are taken into account
Table 7 shows the lateral distribution of roots In C rotang more absorbing rootsare found at a lateral distance of 10 cm whereas in C thwaitesii ne roots aremaximal at the centre of the rooting zone
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 9
Table 7Lateral distribution of total roots and contributionof ne roots
Radial Total roots () Fine roots ()distances (cm) Cr Ct Cr Ct
Root activity decreased with increasing soil depth In C rotang about 76 ofthe active roots are located at 0ndash30 cm depth while 86 of the active roots inC thwaitesii are located at 0ndash30 cm depth Wright [5] reported that 70ndash80 of theactive roots of oil palm are located at 0ndash20 cm depth
Root surface area
In the two species main roots alone are present in the initial stage and C thwaitesiihas more root surface area at this stage With the initiation of laterals in the rst yearthe total surface areaplant is also more in C thwaitesii However in the secondyear C rotang has more surface area due to the occurrence of more roots bothlt2 mm and gt2 mm At the end of the third year the trend was reversed (Table 8)
However the surface area of the ne roots even though few in number wasfound to be greater in C rotang due to their increased length and diameter Thisis supported by the statement that plants with greater lsquospeci c root surface arearsquo aremore ef cient and opportunistic absorbers of ions and water [7] Such plants alsoappear to be more competitive in single and mixed plant communities [8] The rootsystem of C thwaitesii is seen to be more ef cient as measured by more speci croot surface area
10 V K Jayasree et al
Table 9Comparison of soil binding factor
Period (year) C rotang C thwaitesii
First 175 150Second 303 401Third 334 285
Soil binding capacity
The binding of soil particles and the promotion of soil aggregation are of directvalue in soil conservation The length and thickness of roots play an importantrole in binding soil particles ne roots with their close and elaborate network havegreater binding capacity than thicker roots Soil binding capacity shows an increasewith age in C rotang while in C thwaitesii soil binding is highest in the secondyear (Table 9)
The soil binding capacity of grass roots was studied by Bhaskaran and Chakrabarty[9] and the binding capacity ranged from 219 to 876 in four species of grassesMathur et al [10] noted that in Populus ciliata a promising species for soil con-servation the soil binding factor after one year growth was 6129 and after twoyears 10665 Dhyani et al [11] have calculated soil binding capacity factor for ve tree genera and Ougeinea Leucaena and Grewia were shown to be useful forconservation in this respect
Compared with grasses and trees rattans appear to be good soil binders Banikand Ahamed [12] also pointed out that another rattan C viminalis is likely to checksoil erosion
Final inference
It can be inferred that C thwaitesii is more ef cient than C rotang in water andnutrient uptake because its root density total root intensity ne root intensity androot surface area are higher However one could also argue the case the otherway round C rotang is more ef cient because it is able to survive and growwith less dry matter investment in root structure than C thwaitesii C thwaitesiiis less ef cient because it needs more root surface area to survive Nonethelessboth species are good soil binders
Acknowledgements
We are grateful to Dr J K Sharma Director KFRI for providing the facilitiesfor the work The rst author gratefully acknowledges the University GrantsCommission for permitting the bene t of FIP under the IXth plan for the completionof her PhD work Thanks are due to Mr K K Unni Of cer-in-charge Fieldresearch station Palappilly for his unreserved help in the eld
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 11
REFERENCES
1 V K Jayasree C Renuka and P Rugmini Root morphology and development in rattans1 A quantitativestudy of the roots in two species of Calamus L Journal of Bamboo and Rattan2 (2) 135ndash152 (2003)
2 D S Stevenson Effective soil volume and its importance to root and top growth of plantsCanadian Journal of Soil Science 47 163ndash174 (1967)
3 D Atkinson and S A Wilson The root soil interface and its signi cance for fruit tree roots ofdifferent ages in The Soil Root Interface J L Harley and R S Russell (Eds) pp 259ndash271Academic press London (1979)
4 D Atkinson and S A Wilson The growth and distribution of fruit tree roots some conse-quences for nutrient uptake in Mineral Nutrition of Fruit Trees D Atkinson J E JacksonR O Sharples and W M Waller (Eds) pp 137ndash150 Butterworths London (1980)
5 J O Wright Unusual features of the root system of the oil palm in West Africa Nature 1687ndash48 (1951)
6 B S Grey A study of the in uence of genetic agronomic and environmental factors on thegrowth owering and bunch production of Oil palm on the West Coast of Malaysia PhD thesisUniversity of Aberdeen Aberdeen (1969)
7 S A Barber and M Silverbush Plant root morphology and nutrient uptake in Roots Nutrientand Water In ux and Plant Growth S A Barber and D R Boulden (Eds) pp 65ndash87 AmericanSociety of Agronomy Madison WI (1984)
8 D M Eissenstat and M M Caldwell Competitive ability is linked to water extraction A eldstudy of two arid land tussock grasses Oecologia 75 1ndash7 (1988)
9 A R Bhaskaran and D C Chakrabarty A preliminary study on the variations in the soil bindingcapacity of some grass roots Indian Journal of Agronomy 10 326ndash330 (1965)
10 H N Mathur R P Singh and K C Sharma Populus ciliata mdash A promising tree species for soilconservation in hilly areas The Indian Forest 108 (9) 599ndash604 (1982)
11 K Dhyani P Narain and R K Singh Studies on root distribution of ve multipurpose treespecies in Doon Valley India Agroforestry Systems 12 149ndash161 (1990)
12 R L Banik and F U Ahmed An investigation on the roots of Bara bet (Calamus viminalisWilld var fasciculatus Becc) Bano Biggyan Patrika 15 (1-2) 37ndash40 (1986)
J Bamboo and Rattan Vol 3 No 1 pp 13ndash22 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Manufacturing laminates from sympodial bamboos mdashan Indian experience
A K BANSAL curren and T R N PRASADIndian Plywood Industries Research and Training Institute Tumkur Road P O Box 2273Bangalore 560 022 India
AbstractmdashIn recent years bamboo has been rediscovered as an important renewable material withgreat potential Industrial bamboo products will also result in alleviating the pressure on forestsas well as creating employment opportunities for ruraltribal poor particularly women Consideringthis the Government of India has launched an important national initiative for promotion of bambooproducts in mission mode Laminated bamboo boards are closest to wood both in appearance andproperties and are generally manufactured from the monopodial bamboo namely Phyllostachyspubescens The material is highly suitable for ooring and furniture Working on a project fundedby the Ministry of Environment and Forests Government of India IPIRTI has evolved a process formaking bamboo wood (laminates) from a sympodial bamboo found in several states of India namelyBambusa bambos Strength properties of bamboo wood are comparable to those of Tectona grandis(teak) A at-pack table and a wall stand were also designed and fabricated indicating the suitabilityof the material for furniture
Key words Laminates bamboo-wood wood substitute sympodial bamboo
INTRODUCTION
The development of wood substitutes is one of the important interventions enunci-ated in the 1988 National Forest Policy of India aiming at the conservation of naturalforests [1] Such substitution has necessarily to be done by the use of renewable -bres due to the fact that wood alternates made from non-renewable resources willnot be sustainable More over alternates based on plastics metals and such othermaterials are highly energy consuming non-biodegradable and are not conduciveto our environment [2 3] Of the several renewable bre resources bamboo is beingrediscovered throughout the world as a futuristic material Bamboo is perhaps oneof the fastest growing plants on the earth and sequesters atmospheric carbon most
currenTo whom correspondence should be addressed E-mail bansalkavsnlcom
14 A K Bansal and T R N Prasad
ef ciently Several panel products have been developed or are under developmentusing bamboo in different form including stripslaths slivers and particles [4 5]India has rich resources of bamboo both in terms of extent and variety In fact sev-eral species of bamboos occur naturally in the country and have been part of Indianculture with more than thousand traditional uses IPIRTI has been associated withdevelopment of several useful products from woven bamboo mats that are not onlyenvironment-friendly but also people friendly [6 7]
A new generation product made from bamboo strips known as bamboo laminatehas gained importance in Europe and America particularly as ooring materialin place of hardwoods due to the fact that it resembles wood in appearance andhas similar workability [8] Bamboo laminate can replace timber in many otherapplications such as doors and windows frames partitions and furniture Theselaminates are manufactured from a temperate zone monopodial bamboo namelyPhyllostachys pubescens referred to in the international technical literature also asmoso bamboo (Ref [9] and data not shown)
Working under a project funded by the Ministry of Environment and ForestsGovernment of India IPIRTI screened a number of Indian sympodial or clumpforming bamboo species and developed the technology for the manufacturingbamboo laminates from Bambusa bambos one of the common bamboo species inseveral parts of the country covering around 15 of the total bamboo bearing forestareas The species is also raised as plantations outside forests
MATERIALS AND METHODS
A generalized process ow chart for manufacturing bamboo laminates is given inFig 1 In simple terms the process involves conversion of bamboo into stripshaving uniform rectangular cross-section drying them to reduce the moisture todesirable level application of adhesive and hot pressing using both vertical and sidepressure to achieve proper bonding Some of the bamboo processing machines wereimported as they are not available in the country One of the available hydraulic hotpresses was modi ed so as to provide both vertical and side pressure required formaking bamboo laminates
The bamboo strips are required to have a uniform rectangular cross-section Thestrips are put side by side in two different fashions and accordingly they are termedas vertical and horizontal laminates (Fig 2) The normal minimum size (the lesserdimension of the cross-section) for use in furniture is 18ndash20 mm Moreover suchstrips are made from bamboo splits having a cross-section as shown in Fig 3From such a cross-section strips of rectangular cross-sections are cut by removingthe extra material in two stages of planing This speci c processing requirementputs a constraint on minimum diameter and wall thickness of bamboos that can beeconomically used for making laminates
Since culm diameter and wall thickness are two very important parameters thatlimit the conversion of bamboo into strips of suitable sizes for making laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 15
Figure 1 Process ow chart for manufacturing bamboo laminates
Figure 2 Bamboo laminates
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
6 V K Jayasree et al
impairs the growth of the plant and plants absorb only a small part of the nutrientspresent
Stevenson [2] de ned the effective soil volume as the volume of soil that is ableto supply water to a root system and which does not restrict the growth of thoseroots By calculation effective soil volume or Ve is a maximal 785 (905 withtriangular spacing of roots) of a total volume that does not restrict growth Belowthis level root density will decline sharply as soil volume increases For maximumeffects from nutritional or water content treatments plants should be provided withsuf cient soil at least to approach the conditions laid down in the de nition ofeffective soil volume The smaller the plant the easier it is to meet this provision
In this study it is seen that rooting density declines year by year (Table 3) Thisshows that the effective soil volume has been attained in the two species Theeffective soil volume in the rst year for C rotang was 447 cm3 and 632 cm3
for C thwaitesii Hence the polybag or other container should hold this amount ofsoil to attain the maximum growth of roots In the second year the effective soilvolume was found to increase in C rotang compared to C thwaitesii In the thirdyear while the effective soil volume showed an enormous increase in C rotang itremained the same as that of the second year in C thwaitesii (Table 4)
Cultivation practices in the nursery can be based on this observation For anoptimal development of the root system the bag should contain the effective soilvolume For C rotang since the vertical spread is 133 cm the bag size should be
Table 3Rooting density
Period C rotang C thwaitesii(year)
Soil Rooting density (cm per cm3) Soil Rooting density (cm cmiexcl3)
volume Main Lateral Sublateral volume Main Lateral Sublateral(cm3) (cm3)
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 7
about 14 pound 10 cm of which 14 cm is the height of the bag and 10 cm is the widthWhen the bag is lled with soil it will attain a diameter of approximately 64 cmFor C thwaitesii it should be 16 pound 1115 cm (Table 1) If the seedlings need to bekept for the second year the bag size should be about 27 pound 21 cm for C rotang and18 pound 155 cm for C thwaitesii
Rattan seedlings can be out planted from the polybag generally after one year ofhardening in the nursery For one year seedlings a pit size of 30 pound 30 pound 30 cm willbe suf cient for the two species For two year old seedlings also the same pit sizewill suf ce since the vertical spread is below 30 cm in both species
Rooting density
The ef ciency in nutrient uptake is in uenced by the rooting density Rootingdensity can be expressed relative to either soil surface area (LA in cmcm2) orsoil volume (LV in cmcm3) Atkinson and Wilson [3 4] have described theconsequences of a low LA value When a plant transpires water will come initiallyfrom soil immediately adjacent to the root with this zone being replenished frombulk soil If the rate of withdrawal exceeds the rate of water movement through thesoil to the root (ie the rate of uptake exceeds soil hydraulic conductivity) then thesoil adjacent to the root will become drier than the soil bulk and the rate of water ow into the root will decrease and may result in water stress Localized dryingoccurs and thus the gradients of water potential at the root surface will reduce theuptake of minerals thought to be moved by mass ow If root density is high owrates will always tend to be low and gradients at the root surface will be rare Whereroot density is low as in fruit trees the contrary will be true
Root density varies with depth Hence reduced soil water potentials will not be thesame at all depths and this will affect the balance of nutrient uptake from differentparts of the soil pro le
In the present study while C rotang possesses a higher rooting density during the rst year of growth C thwaitesii does so later The rooting density in both speciesis found to be inversely related to the amount of soil exploited by the root systemThere is a major contribution of the laterals and sublaterals towards rooting densityof the plant occurs during the second year in both species (Table 3)
Measurements using the core method at different depths and radial distances inthe third year reveal that rooting density is greater in C thwaitesii compared to thatof C rotang With respect to depth rooting density is much higher in the upper30 cm of soil compared to the lower 30 cm in both species While 81 of the totalrooting density is the contribution of the upper 30 cm of soil in C rotang 89 ofthe total rooting density is contributed by the upper 30 cm in C thwaitesii At alldepths other than 30ndash45 cm rooting density is found to be more in C thwaitesiicompared to C rotang (Table 5)
As far as the different lateral distances from the base of the plant are concernedthe percentage contribution of the rooting density within a soil depth of 0ndash60 cmat the centre of the rooting zone and at 10 cm away from the base of the plant is
8 V K Jayasree et al
Table 5Root density at different radial distances and depths from the base of the plant
RD C rotang C thwaitesii(cm) Depth (cm) Depth (cm)
0ndash15 15ndash30 30ndash45 45ndash60 Average 0ndash15 15ndash30 30ndash45 45ndash60 Average
36 and 37 respectively in C rotang While C rotang shows almost the samerooting density at these regions C thwaitesii shows markedly more percentage rootdensity (46) at the centre of the rooting zone than at 10 cm away from the plant(29) (calculated from Table 5) Since a higher rooting density is observed inC thwaitesii this species will be more ef cient in nutrient uptake
Root intensity
When total root intensity is considered C thwaitesii is more ef cient in absorptioncompared to C rotang (Table 6) the percentage of total intensity being more inthe surface layer (0ndash15 cm depth) Published data are often dif cult to assess Forinstance according to Wright [5] the absorbing roots of oil palm are concentrated inthe upper 10 cm of soil whereas Grey [6] observed predominance of the absorbingroots in the upper 30 cm soil In the two rattan species studied the absorbing rootsare found to be more in the upper 15 cm of soil In C rotang 83 of the total rootintensity is contributed by ne roots while in C thwaitesii 87 of the total rootintensity is the contribution of ne roots Thus C thwaitesii is more ef cient inabsorption even when only the ne absorbing roots are taken into account
Table 7 shows the lateral distribution of roots In C rotang more absorbing rootsare found at a lateral distance of 10 cm whereas in C thwaitesii ne roots aremaximal at the centre of the rooting zone
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 9
Table 7Lateral distribution of total roots and contributionof ne roots
Radial Total roots () Fine roots ()distances (cm) Cr Ct Cr Ct
Root activity decreased with increasing soil depth In C rotang about 76 ofthe active roots are located at 0ndash30 cm depth while 86 of the active roots inC thwaitesii are located at 0ndash30 cm depth Wright [5] reported that 70ndash80 of theactive roots of oil palm are located at 0ndash20 cm depth
Root surface area
In the two species main roots alone are present in the initial stage and C thwaitesiihas more root surface area at this stage With the initiation of laterals in the rst yearthe total surface areaplant is also more in C thwaitesii However in the secondyear C rotang has more surface area due to the occurrence of more roots bothlt2 mm and gt2 mm At the end of the third year the trend was reversed (Table 8)
However the surface area of the ne roots even though few in number wasfound to be greater in C rotang due to their increased length and diameter Thisis supported by the statement that plants with greater lsquospeci c root surface arearsquo aremore ef cient and opportunistic absorbers of ions and water [7] Such plants alsoappear to be more competitive in single and mixed plant communities [8] The rootsystem of C thwaitesii is seen to be more ef cient as measured by more speci croot surface area
10 V K Jayasree et al
Table 9Comparison of soil binding factor
Period (year) C rotang C thwaitesii
First 175 150Second 303 401Third 334 285
Soil binding capacity
The binding of soil particles and the promotion of soil aggregation are of directvalue in soil conservation The length and thickness of roots play an importantrole in binding soil particles ne roots with their close and elaborate network havegreater binding capacity than thicker roots Soil binding capacity shows an increasewith age in C rotang while in C thwaitesii soil binding is highest in the secondyear (Table 9)
The soil binding capacity of grass roots was studied by Bhaskaran and Chakrabarty[9] and the binding capacity ranged from 219 to 876 in four species of grassesMathur et al [10] noted that in Populus ciliata a promising species for soil con-servation the soil binding factor after one year growth was 6129 and after twoyears 10665 Dhyani et al [11] have calculated soil binding capacity factor for ve tree genera and Ougeinea Leucaena and Grewia were shown to be useful forconservation in this respect
Compared with grasses and trees rattans appear to be good soil binders Banikand Ahamed [12] also pointed out that another rattan C viminalis is likely to checksoil erosion
Final inference
It can be inferred that C thwaitesii is more ef cient than C rotang in water andnutrient uptake because its root density total root intensity ne root intensity androot surface area are higher However one could also argue the case the otherway round C rotang is more ef cient because it is able to survive and growwith less dry matter investment in root structure than C thwaitesii C thwaitesiiis less ef cient because it needs more root surface area to survive Nonethelessboth species are good soil binders
Acknowledgements
We are grateful to Dr J K Sharma Director KFRI for providing the facilitiesfor the work The rst author gratefully acknowledges the University GrantsCommission for permitting the bene t of FIP under the IXth plan for the completionof her PhD work Thanks are due to Mr K K Unni Of cer-in-charge Fieldresearch station Palappilly for his unreserved help in the eld
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 11
REFERENCES
1 V K Jayasree C Renuka and P Rugmini Root morphology and development in rattans1 A quantitativestudy of the roots in two species of Calamus L Journal of Bamboo and Rattan2 (2) 135ndash152 (2003)
2 D S Stevenson Effective soil volume and its importance to root and top growth of plantsCanadian Journal of Soil Science 47 163ndash174 (1967)
3 D Atkinson and S A Wilson The root soil interface and its signi cance for fruit tree roots ofdifferent ages in The Soil Root Interface J L Harley and R S Russell (Eds) pp 259ndash271Academic press London (1979)
4 D Atkinson and S A Wilson The growth and distribution of fruit tree roots some conse-quences for nutrient uptake in Mineral Nutrition of Fruit Trees D Atkinson J E JacksonR O Sharples and W M Waller (Eds) pp 137ndash150 Butterworths London (1980)
5 J O Wright Unusual features of the root system of the oil palm in West Africa Nature 1687ndash48 (1951)
6 B S Grey A study of the in uence of genetic agronomic and environmental factors on thegrowth owering and bunch production of Oil palm on the West Coast of Malaysia PhD thesisUniversity of Aberdeen Aberdeen (1969)
7 S A Barber and M Silverbush Plant root morphology and nutrient uptake in Roots Nutrientand Water In ux and Plant Growth S A Barber and D R Boulden (Eds) pp 65ndash87 AmericanSociety of Agronomy Madison WI (1984)
8 D M Eissenstat and M M Caldwell Competitive ability is linked to water extraction A eldstudy of two arid land tussock grasses Oecologia 75 1ndash7 (1988)
9 A R Bhaskaran and D C Chakrabarty A preliminary study on the variations in the soil bindingcapacity of some grass roots Indian Journal of Agronomy 10 326ndash330 (1965)
10 H N Mathur R P Singh and K C Sharma Populus ciliata mdash A promising tree species for soilconservation in hilly areas The Indian Forest 108 (9) 599ndash604 (1982)
11 K Dhyani P Narain and R K Singh Studies on root distribution of ve multipurpose treespecies in Doon Valley India Agroforestry Systems 12 149ndash161 (1990)
12 R L Banik and F U Ahmed An investigation on the roots of Bara bet (Calamus viminalisWilld var fasciculatus Becc) Bano Biggyan Patrika 15 (1-2) 37ndash40 (1986)
J Bamboo and Rattan Vol 3 No 1 pp 13ndash22 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Manufacturing laminates from sympodial bamboos mdashan Indian experience
A K BANSAL curren and T R N PRASADIndian Plywood Industries Research and Training Institute Tumkur Road P O Box 2273Bangalore 560 022 India
AbstractmdashIn recent years bamboo has been rediscovered as an important renewable material withgreat potential Industrial bamboo products will also result in alleviating the pressure on forestsas well as creating employment opportunities for ruraltribal poor particularly women Consideringthis the Government of India has launched an important national initiative for promotion of bambooproducts in mission mode Laminated bamboo boards are closest to wood both in appearance andproperties and are generally manufactured from the monopodial bamboo namely Phyllostachyspubescens The material is highly suitable for ooring and furniture Working on a project fundedby the Ministry of Environment and Forests Government of India IPIRTI has evolved a process formaking bamboo wood (laminates) from a sympodial bamboo found in several states of India namelyBambusa bambos Strength properties of bamboo wood are comparable to those of Tectona grandis(teak) A at-pack table and a wall stand were also designed and fabricated indicating the suitabilityof the material for furniture
Key words Laminates bamboo-wood wood substitute sympodial bamboo
INTRODUCTION
The development of wood substitutes is one of the important interventions enunci-ated in the 1988 National Forest Policy of India aiming at the conservation of naturalforests [1] Such substitution has necessarily to be done by the use of renewable -bres due to the fact that wood alternates made from non-renewable resources willnot be sustainable More over alternates based on plastics metals and such othermaterials are highly energy consuming non-biodegradable and are not conduciveto our environment [2 3] Of the several renewable bre resources bamboo is beingrediscovered throughout the world as a futuristic material Bamboo is perhaps oneof the fastest growing plants on the earth and sequesters atmospheric carbon most
currenTo whom correspondence should be addressed E-mail bansalkavsnlcom
14 A K Bansal and T R N Prasad
ef ciently Several panel products have been developed or are under developmentusing bamboo in different form including stripslaths slivers and particles [4 5]India has rich resources of bamboo both in terms of extent and variety In fact sev-eral species of bamboos occur naturally in the country and have been part of Indianculture with more than thousand traditional uses IPIRTI has been associated withdevelopment of several useful products from woven bamboo mats that are not onlyenvironment-friendly but also people friendly [6 7]
A new generation product made from bamboo strips known as bamboo laminatehas gained importance in Europe and America particularly as ooring materialin place of hardwoods due to the fact that it resembles wood in appearance andhas similar workability [8] Bamboo laminate can replace timber in many otherapplications such as doors and windows frames partitions and furniture Theselaminates are manufactured from a temperate zone monopodial bamboo namelyPhyllostachys pubescens referred to in the international technical literature also asmoso bamboo (Ref [9] and data not shown)
Working under a project funded by the Ministry of Environment and ForestsGovernment of India IPIRTI screened a number of Indian sympodial or clumpforming bamboo species and developed the technology for the manufacturingbamboo laminates from Bambusa bambos one of the common bamboo species inseveral parts of the country covering around 15 of the total bamboo bearing forestareas The species is also raised as plantations outside forests
MATERIALS AND METHODS
A generalized process ow chart for manufacturing bamboo laminates is given inFig 1 In simple terms the process involves conversion of bamboo into stripshaving uniform rectangular cross-section drying them to reduce the moisture todesirable level application of adhesive and hot pressing using both vertical and sidepressure to achieve proper bonding Some of the bamboo processing machines wereimported as they are not available in the country One of the available hydraulic hotpresses was modi ed so as to provide both vertical and side pressure required formaking bamboo laminates
The bamboo strips are required to have a uniform rectangular cross-section Thestrips are put side by side in two different fashions and accordingly they are termedas vertical and horizontal laminates (Fig 2) The normal minimum size (the lesserdimension of the cross-section) for use in furniture is 18ndash20 mm Moreover suchstrips are made from bamboo splits having a cross-section as shown in Fig 3From such a cross-section strips of rectangular cross-sections are cut by removingthe extra material in two stages of planing This speci c processing requirementputs a constraint on minimum diameter and wall thickness of bamboos that can beeconomically used for making laminates
Since culm diameter and wall thickness are two very important parameters thatlimit the conversion of bamboo into strips of suitable sizes for making laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 15
Figure 1 Process ow chart for manufacturing bamboo laminates
Figure 2 Bamboo laminates
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 7
about 14 pound 10 cm of which 14 cm is the height of the bag and 10 cm is the widthWhen the bag is lled with soil it will attain a diameter of approximately 64 cmFor C thwaitesii it should be 16 pound 1115 cm (Table 1) If the seedlings need to bekept for the second year the bag size should be about 27 pound 21 cm for C rotang and18 pound 155 cm for C thwaitesii
Rattan seedlings can be out planted from the polybag generally after one year ofhardening in the nursery For one year seedlings a pit size of 30 pound 30 pound 30 cm willbe suf cient for the two species For two year old seedlings also the same pit sizewill suf ce since the vertical spread is below 30 cm in both species
Rooting density
The ef ciency in nutrient uptake is in uenced by the rooting density Rootingdensity can be expressed relative to either soil surface area (LA in cmcm2) orsoil volume (LV in cmcm3) Atkinson and Wilson [3 4] have described theconsequences of a low LA value When a plant transpires water will come initiallyfrom soil immediately adjacent to the root with this zone being replenished frombulk soil If the rate of withdrawal exceeds the rate of water movement through thesoil to the root (ie the rate of uptake exceeds soil hydraulic conductivity) then thesoil adjacent to the root will become drier than the soil bulk and the rate of water ow into the root will decrease and may result in water stress Localized dryingoccurs and thus the gradients of water potential at the root surface will reduce theuptake of minerals thought to be moved by mass ow If root density is high owrates will always tend to be low and gradients at the root surface will be rare Whereroot density is low as in fruit trees the contrary will be true
Root density varies with depth Hence reduced soil water potentials will not be thesame at all depths and this will affect the balance of nutrient uptake from differentparts of the soil pro le
In the present study while C rotang possesses a higher rooting density during the rst year of growth C thwaitesii does so later The rooting density in both speciesis found to be inversely related to the amount of soil exploited by the root systemThere is a major contribution of the laterals and sublaterals towards rooting densityof the plant occurs during the second year in both species (Table 3)
Measurements using the core method at different depths and radial distances inthe third year reveal that rooting density is greater in C thwaitesii compared to thatof C rotang With respect to depth rooting density is much higher in the upper30 cm of soil compared to the lower 30 cm in both species While 81 of the totalrooting density is the contribution of the upper 30 cm of soil in C rotang 89 ofthe total rooting density is contributed by the upper 30 cm in C thwaitesii At alldepths other than 30ndash45 cm rooting density is found to be more in C thwaitesiicompared to C rotang (Table 5)
As far as the different lateral distances from the base of the plant are concernedthe percentage contribution of the rooting density within a soil depth of 0ndash60 cmat the centre of the rooting zone and at 10 cm away from the base of the plant is
8 V K Jayasree et al
Table 5Root density at different radial distances and depths from the base of the plant
RD C rotang C thwaitesii(cm) Depth (cm) Depth (cm)
0ndash15 15ndash30 30ndash45 45ndash60 Average 0ndash15 15ndash30 30ndash45 45ndash60 Average
36 and 37 respectively in C rotang While C rotang shows almost the samerooting density at these regions C thwaitesii shows markedly more percentage rootdensity (46) at the centre of the rooting zone than at 10 cm away from the plant(29) (calculated from Table 5) Since a higher rooting density is observed inC thwaitesii this species will be more ef cient in nutrient uptake
Root intensity
When total root intensity is considered C thwaitesii is more ef cient in absorptioncompared to C rotang (Table 6) the percentage of total intensity being more inthe surface layer (0ndash15 cm depth) Published data are often dif cult to assess Forinstance according to Wright [5] the absorbing roots of oil palm are concentrated inthe upper 10 cm of soil whereas Grey [6] observed predominance of the absorbingroots in the upper 30 cm soil In the two rattan species studied the absorbing rootsare found to be more in the upper 15 cm of soil In C rotang 83 of the total rootintensity is contributed by ne roots while in C thwaitesii 87 of the total rootintensity is the contribution of ne roots Thus C thwaitesii is more ef cient inabsorption even when only the ne absorbing roots are taken into account
Table 7 shows the lateral distribution of roots In C rotang more absorbing rootsare found at a lateral distance of 10 cm whereas in C thwaitesii ne roots aremaximal at the centre of the rooting zone
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 9
Table 7Lateral distribution of total roots and contributionof ne roots
Radial Total roots () Fine roots ()distances (cm) Cr Ct Cr Ct
Root activity decreased with increasing soil depth In C rotang about 76 ofthe active roots are located at 0ndash30 cm depth while 86 of the active roots inC thwaitesii are located at 0ndash30 cm depth Wright [5] reported that 70ndash80 of theactive roots of oil palm are located at 0ndash20 cm depth
Root surface area
In the two species main roots alone are present in the initial stage and C thwaitesiihas more root surface area at this stage With the initiation of laterals in the rst yearthe total surface areaplant is also more in C thwaitesii However in the secondyear C rotang has more surface area due to the occurrence of more roots bothlt2 mm and gt2 mm At the end of the third year the trend was reversed (Table 8)
However the surface area of the ne roots even though few in number wasfound to be greater in C rotang due to their increased length and diameter Thisis supported by the statement that plants with greater lsquospeci c root surface arearsquo aremore ef cient and opportunistic absorbers of ions and water [7] Such plants alsoappear to be more competitive in single and mixed plant communities [8] The rootsystem of C thwaitesii is seen to be more ef cient as measured by more speci croot surface area
10 V K Jayasree et al
Table 9Comparison of soil binding factor
Period (year) C rotang C thwaitesii
First 175 150Second 303 401Third 334 285
Soil binding capacity
The binding of soil particles and the promotion of soil aggregation are of directvalue in soil conservation The length and thickness of roots play an importantrole in binding soil particles ne roots with their close and elaborate network havegreater binding capacity than thicker roots Soil binding capacity shows an increasewith age in C rotang while in C thwaitesii soil binding is highest in the secondyear (Table 9)
The soil binding capacity of grass roots was studied by Bhaskaran and Chakrabarty[9] and the binding capacity ranged from 219 to 876 in four species of grassesMathur et al [10] noted that in Populus ciliata a promising species for soil con-servation the soil binding factor after one year growth was 6129 and after twoyears 10665 Dhyani et al [11] have calculated soil binding capacity factor for ve tree genera and Ougeinea Leucaena and Grewia were shown to be useful forconservation in this respect
Compared with grasses and trees rattans appear to be good soil binders Banikand Ahamed [12] also pointed out that another rattan C viminalis is likely to checksoil erosion
Final inference
It can be inferred that C thwaitesii is more ef cient than C rotang in water andnutrient uptake because its root density total root intensity ne root intensity androot surface area are higher However one could also argue the case the otherway round C rotang is more ef cient because it is able to survive and growwith less dry matter investment in root structure than C thwaitesii C thwaitesiiis less ef cient because it needs more root surface area to survive Nonethelessboth species are good soil binders
Acknowledgements
We are grateful to Dr J K Sharma Director KFRI for providing the facilitiesfor the work The rst author gratefully acknowledges the University GrantsCommission for permitting the bene t of FIP under the IXth plan for the completionof her PhD work Thanks are due to Mr K K Unni Of cer-in-charge Fieldresearch station Palappilly for his unreserved help in the eld
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 11
REFERENCES
1 V K Jayasree C Renuka and P Rugmini Root morphology and development in rattans1 A quantitativestudy of the roots in two species of Calamus L Journal of Bamboo and Rattan2 (2) 135ndash152 (2003)
2 D S Stevenson Effective soil volume and its importance to root and top growth of plantsCanadian Journal of Soil Science 47 163ndash174 (1967)
3 D Atkinson and S A Wilson The root soil interface and its signi cance for fruit tree roots ofdifferent ages in The Soil Root Interface J L Harley and R S Russell (Eds) pp 259ndash271Academic press London (1979)
4 D Atkinson and S A Wilson The growth and distribution of fruit tree roots some conse-quences for nutrient uptake in Mineral Nutrition of Fruit Trees D Atkinson J E JacksonR O Sharples and W M Waller (Eds) pp 137ndash150 Butterworths London (1980)
5 J O Wright Unusual features of the root system of the oil palm in West Africa Nature 1687ndash48 (1951)
6 B S Grey A study of the in uence of genetic agronomic and environmental factors on thegrowth owering and bunch production of Oil palm on the West Coast of Malaysia PhD thesisUniversity of Aberdeen Aberdeen (1969)
7 S A Barber and M Silverbush Plant root morphology and nutrient uptake in Roots Nutrientand Water In ux and Plant Growth S A Barber and D R Boulden (Eds) pp 65ndash87 AmericanSociety of Agronomy Madison WI (1984)
8 D M Eissenstat and M M Caldwell Competitive ability is linked to water extraction A eldstudy of two arid land tussock grasses Oecologia 75 1ndash7 (1988)
9 A R Bhaskaran and D C Chakrabarty A preliminary study on the variations in the soil bindingcapacity of some grass roots Indian Journal of Agronomy 10 326ndash330 (1965)
10 H N Mathur R P Singh and K C Sharma Populus ciliata mdash A promising tree species for soilconservation in hilly areas The Indian Forest 108 (9) 599ndash604 (1982)
11 K Dhyani P Narain and R K Singh Studies on root distribution of ve multipurpose treespecies in Doon Valley India Agroforestry Systems 12 149ndash161 (1990)
12 R L Banik and F U Ahmed An investigation on the roots of Bara bet (Calamus viminalisWilld var fasciculatus Becc) Bano Biggyan Patrika 15 (1-2) 37ndash40 (1986)
J Bamboo and Rattan Vol 3 No 1 pp 13ndash22 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Manufacturing laminates from sympodial bamboos mdashan Indian experience
A K BANSAL curren and T R N PRASADIndian Plywood Industries Research and Training Institute Tumkur Road P O Box 2273Bangalore 560 022 India
AbstractmdashIn recent years bamboo has been rediscovered as an important renewable material withgreat potential Industrial bamboo products will also result in alleviating the pressure on forestsas well as creating employment opportunities for ruraltribal poor particularly women Consideringthis the Government of India has launched an important national initiative for promotion of bambooproducts in mission mode Laminated bamboo boards are closest to wood both in appearance andproperties and are generally manufactured from the monopodial bamboo namely Phyllostachyspubescens The material is highly suitable for ooring and furniture Working on a project fundedby the Ministry of Environment and Forests Government of India IPIRTI has evolved a process formaking bamboo wood (laminates) from a sympodial bamboo found in several states of India namelyBambusa bambos Strength properties of bamboo wood are comparable to those of Tectona grandis(teak) A at-pack table and a wall stand were also designed and fabricated indicating the suitabilityof the material for furniture
Key words Laminates bamboo-wood wood substitute sympodial bamboo
INTRODUCTION
The development of wood substitutes is one of the important interventions enunci-ated in the 1988 National Forest Policy of India aiming at the conservation of naturalforests [1] Such substitution has necessarily to be done by the use of renewable -bres due to the fact that wood alternates made from non-renewable resources willnot be sustainable More over alternates based on plastics metals and such othermaterials are highly energy consuming non-biodegradable and are not conduciveto our environment [2 3] Of the several renewable bre resources bamboo is beingrediscovered throughout the world as a futuristic material Bamboo is perhaps oneof the fastest growing plants on the earth and sequesters atmospheric carbon most
currenTo whom correspondence should be addressed E-mail bansalkavsnlcom
14 A K Bansal and T R N Prasad
ef ciently Several panel products have been developed or are under developmentusing bamboo in different form including stripslaths slivers and particles [4 5]India has rich resources of bamboo both in terms of extent and variety In fact sev-eral species of bamboos occur naturally in the country and have been part of Indianculture with more than thousand traditional uses IPIRTI has been associated withdevelopment of several useful products from woven bamboo mats that are not onlyenvironment-friendly but also people friendly [6 7]
A new generation product made from bamboo strips known as bamboo laminatehas gained importance in Europe and America particularly as ooring materialin place of hardwoods due to the fact that it resembles wood in appearance andhas similar workability [8] Bamboo laminate can replace timber in many otherapplications such as doors and windows frames partitions and furniture Theselaminates are manufactured from a temperate zone monopodial bamboo namelyPhyllostachys pubescens referred to in the international technical literature also asmoso bamboo (Ref [9] and data not shown)
Working under a project funded by the Ministry of Environment and ForestsGovernment of India IPIRTI screened a number of Indian sympodial or clumpforming bamboo species and developed the technology for the manufacturingbamboo laminates from Bambusa bambos one of the common bamboo species inseveral parts of the country covering around 15 of the total bamboo bearing forestareas The species is also raised as plantations outside forests
MATERIALS AND METHODS
A generalized process ow chart for manufacturing bamboo laminates is given inFig 1 In simple terms the process involves conversion of bamboo into stripshaving uniform rectangular cross-section drying them to reduce the moisture todesirable level application of adhesive and hot pressing using both vertical and sidepressure to achieve proper bonding Some of the bamboo processing machines wereimported as they are not available in the country One of the available hydraulic hotpresses was modi ed so as to provide both vertical and side pressure required formaking bamboo laminates
The bamboo strips are required to have a uniform rectangular cross-section Thestrips are put side by side in two different fashions and accordingly they are termedas vertical and horizontal laminates (Fig 2) The normal minimum size (the lesserdimension of the cross-section) for use in furniture is 18ndash20 mm Moreover suchstrips are made from bamboo splits having a cross-section as shown in Fig 3From such a cross-section strips of rectangular cross-sections are cut by removingthe extra material in two stages of planing This speci c processing requirementputs a constraint on minimum diameter and wall thickness of bamboos that can beeconomically used for making laminates
Since culm diameter and wall thickness are two very important parameters thatlimit the conversion of bamboo into strips of suitable sizes for making laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 15
Figure 1 Process ow chart for manufacturing bamboo laminates
Figure 2 Bamboo laminates
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
8 V K Jayasree et al
Table 5Root density at different radial distances and depths from the base of the plant
RD C rotang C thwaitesii(cm) Depth (cm) Depth (cm)
0ndash15 15ndash30 30ndash45 45ndash60 Average 0ndash15 15ndash30 30ndash45 45ndash60 Average
36 and 37 respectively in C rotang While C rotang shows almost the samerooting density at these regions C thwaitesii shows markedly more percentage rootdensity (46) at the centre of the rooting zone than at 10 cm away from the plant(29) (calculated from Table 5) Since a higher rooting density is observed inC thwaitesii this species will be more ef cient in nutrient uptake
Root intensity
When total root intensity is considered C thwaitesii is more ef cient in absorptioncompared to C rotang (Table 6) the percentage of total intensity being more inthe surface layer (0ndash15 cm depth) Published data are often dif cult to assess Forinstance according to Wright [5] the absorbing roots of oil palm are concentrated inthe upper 10 cm of soil whereas Grey [6] observed predominance of the absorbingroots in the upper 30 cm soil In the two rattan species studied the absorbing rootsare found to be more in the upper 15 cm of soil In C rotang 83 of the total rootintensity is contributed by ne roots while in C thwaitesii 87 of the total rootintensity is the contribution of ne roots Thus C thwaitesii is more ef cient inabsorption even when only the ne absorbing roots are taken into account
Table 7 shows the lateral distribution of roots In C rotang more absorbing rootsare found at a lateral distance of 10 cm whereas in C thwaitesii ne roots aremaximal at the centre of the rooting zone
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 9
Table 7Lateral distribution of total roots and contributionof ne roots
Radial Total roots () Fine roots ()distances (cm) Cr Ct Cr Ct
Root activity decreased with increasing soil depth In C rotang about 76 ofthe active roots are located at 0ndash30 cm depth while 86 of the active roots inC thwaitesii are located at 0ndash30 cm depth Wright [5] reported that 70ndash80 of theactive roots of oil palm are located at 0ndash20 cm depth
Root surface area
In the two species main roots alone are present in the initial stage and C thwaitesiihas more root surface area at this stage With the initiation of laterals in the rst yearthe total surface areaplant is also more in C thwaitesii However in the secondyear C rotang has more surface area due to the occurrence of more roots bothlt2 mm and gt2 mm At the end of the third year the trend was reversed (Table 8)
However the surface area of the ne roots even though few in number wasfound to be greater in C rotang due to their increased length and diameter Thisis supported by the statement that plants with greater lsquospeci c root surface arearsquo aremore ef cient and opportunistic absorbers of ions and water [7] Such plants alsoappear to be more competitive in single and mixed plant communities [8] The rootsystem of C thwaitesii is seen to be more ef cient as measured by more speci croot surface area
10 V K Jayasree et al
Table 9Comparison of soil binding factor
Period (year) C rotang C thwaitesii
First 175 150Second 303 401Third 334 285
Soil binding capacity
The binding of soil particles and the promotion of soil aggregation are of directvalue in soil conservation The length and thickness of roots play an importantrole in binding soil particles ne roots with their close and elaborate network havegreater binding capacity than thicker roots Soil binding capacity shows an increasewith age in C rotang while in C thwaitesii soil binding is highest in the secondyear (Table 9)
The soil binding capacity of grass roots was studied by Bhaskaran and Chakrabarty[9] and the binding capacity ranged from 219 to 876 in four species of grassesMathur et al [10] noted that in Populus ciliata a promising species for soil con-servation the soil binding factor after one year growth was 6129 and after twoyears 10665 Dhyani et al [11] have calculated soil binding capacity factor for ve tree genera and Ougeinea Leucaena and Grewia were shown to be useful forconservation in this respect
Compared with grasses and trees rattans appear to be good soil binders Banikand Ahamed [12] also pointed out that another rattan C viminalis is likely to checksoil erosion
Final inference
It can be inferred that C thwaitesii is more ef cient than C rotang in water andnutrient uptake because its root density total root intensity ne root intensity androot surface area are higher However one could also argue the case the otherway round C rotang is more ef cient because it is able to survive and growwith less dry matter investment in root structure than C thwaitesii C thwaitesiiis less ef cient because it needs more root surface area to survive Nonethelessboth species are good soil binders
Acknowledgements
We are grateful to Dr J K Sharma Director KFRI for providing the facilitiesfor the work The rst author gratefully acknowledges the University GrantsCommission for permitting the bene t of FIP under the IXth plan for the completionof her PhD work Thanks are due to Mr K K Unni Of cer-in-charge Fieldresearch station Palappilly for his unreserved help in the eld
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 11
REFERENCES
1 V K Jayasree C Renuka and P Rugmini Root morphology and development in rattans1 A quantitativestudy of the roots in two species of Calamus L Journal of Bamboo and Rattan2 (2) 135ndash152 (2003)
2 D S Stevenson Effective soil volume and its importance to root and top growth of plantsCanadian Journal of Soil Science 47 163ndash174 (1967)
3 D Atkinson and S A Wilson The root soil interface and its signi cance for fruit tree roots ofdifferent ages in The Soil Root Interface J L Harley and R S Russell (Eds) pp 259ndash271Academic press London (1979)
4 D Atkinson and S A Wilson The growth and distribution of fruit tree roots some conse-quences for nutrient uptake in Mineral Nutrition of Fruit Trees D Atkinson J E JacksonR O Sharples and W M Waller (Eds) pp 137ndash150 Butterworths London (1980)
5 J O Wright Unusual features of the root system of the oil palm in West Africa Nature 1687ndash48 (1951)
6 B S Grey A study of the in uence of genetic agronomic and environmental factors on thegrowth owering and bunch production of Oil palm on the West Coast of Malaysia PhD thesisUniversity of Aberdeen Aberdeen (1969)
7 S A Barber and M Silverbush Plant root morphology and nutrient uptake in Roots Nutrientand Water In ux and Plant Growth S A Barber and D R Boulden (Eds) pp 65ndash87 AmericanSociety of Agronomy Madison WI (1984)
8 D M Eissenstat and M M Caldwell Competitive ability is linked to water extraction A eldstudy of two arid land tussock grasses Oecologia 75 1ndash7 (1988)
9 A R Bhaskaran and D C Chakrabarty A preliminary study on the variations in the soil bindingcapacity of some grass roots Indian Journal of Agronomy 10 326ndash330 (1965)
10 H N Mathur R P Singh and K C Sharma Populus ciliata mdash A promising tree species for soilconservation in hilly areas The Indian Forest 108 (9) 599ndash604 (1982)
11 K Dhyani P Narain and R K Singh Studies on root distribution of ve multipurpose treespecies in Doon Valley India Agroforestry Systems 12 149ndash161 (1990)
12 R L Banik and F U Ahmed An investigation on the roots of Bara bet (Calamus viminalisWilld var fasciculatus Becc) Bano Biggyan Patrika 15 (1-2) 37ndash40 (1986)
J Bamboo and Rattan Vol 3 No 1 pp 13ndash22 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Manufacturing laminates from sympodial bamboos mdashan Indian experience
A K BANSAL curren and T R N PRASADIndian Plywood Industries Research and Training Institute Tumkur Road P O Box 2273Bangalore 560 022 India
AbstractmdashIn recent years bamboo has been rediscovered as an important renewable material withgreat potential Industrial bamboo products will also result in alleviating the pressure on forestsas well as creating employment opportunities for ruraltribal poor particularly women Consideringthis the Government of India has launched an important national initiative for promotion of bambooproducts in mission mode Laminated bamboo boards are closest to wood both in appearance andproperties and are generally manufactured from the monopodial bamboo namely Phyllostachyspubescens The material is highly suitable for ooring and furniture Working on a project fundedby the Ministry of Environment and Forests Government of India IPIRTI has evolved a process formaking bamboo wood (laminates) from a sympodial bamboo found in several states of India namelyBambusa bambos Strength properties of bamboo wood are comparable to those of Tectona grandis(teak) A at-pack table and a wall stand were also designed and fabricated indicating the suitabilityof the material for furniture
Key words Laminates bamboo-wood wood substitute sympodial bamboo
INTRODUCTION
The development of wood substitutes is one of the important interventions enunci-ated in the 1988 National Forest Policy of India aiming at the conservation of naturalforests [1] Such substitution has necessarily to be done by the use of renewable -bres due to the fact that wood alternates made from non-renewable resources willnot be sustainable More over alternates based on plastics metals and such othermaterials are highly energy consuming non-biodegradable and are not conduciveto our environment [2 3] Of the several renewable bre resources bamboo is beingrediscovered throughout the world as a futuristic material Bamboo is perhaps oneof the fastest growing plants on the earth and sequesters atmospheric carbon most
currenTo whom correspondence should be addressed E-mail bansalkavsnlcom
14 A K Bansal and T R N Prasad
ef ciently Several panel products have been developed or are under developmentusing bamboo in different form including stripslaths slivers and particles [4 5]India has rich resources of bamboo both in terms of extent and variety In fact sev-eral species of bamboos occur naturally in the country and have been part of Indianculture with more than thousand traditional uses IPIRTI has been associated withdevelopment of several useful products from woven bamboo mats that are not onlyenvironment-friendly but also people friendly [6 7]
A new generation product made from bamboo strips known as bamboo laminatehas gained importance in Europe and America particularly as ooring materialin place of hardwoods due to the fact that it resembles wood in appearance andhas similar workability [8] Bamboo laminate can replace timber in many otherapplications such as doors and windows frames partitions and furniture Theselaminates are manufactured from a temperate zone monopodial bamboo namelyPhyllostachys pubescens referred to in the international technical literature also asmoso bamboo (Ref [9] and data not shown)
Working under a project funded by the Ministry of Environment and ForestsGovernment of India IPIRTI screened a number of Indian sympodial or clumpforming bamboo species and developed the technology for the manufacturingbamboo laminates from Bambusa bambos one of the common bamboo species inseveral parts of the country covering around 15 of the total bamboo bearing forestareas The species is also raised as plantations outside forests
MATERIALS AND METHODS
A generalized process ow chart for manufacturing bamboo laminates is given inFig 1 In simple terms the process involves conversion of bamboo into stripshaving uniform rectangular cross-section drying them to reduce the moisture todesirable level application of adhesive and hot pressing using both vertical and sidepressure to achieve proper bonding Some of the bamboo processing machines wereimported as they are not available in the country One of the available hydraulic hotpresses was modi ed so as to provide both vertical and side pressure required formaking bamboo laminates
The bamboo strips are required to have a uniform rectangular cross-section Thestrips are put side by side in two different fashions and accordingly they are termedas vertical and horizontal laminates (Fig 2) The normal minimum size (the lesserdimension of the cross-section) for use in furniture is 18ndash20 mm Moreover suchstrips are made from bamboo splits having a cross-section as shown in Fig 3From such a cross-section strips of rectangular cross-sections are cut by removingthe extra material in two stages of planing This speci c processing requirementputs a constraint on minimum diameter and wall thickness of bamboos that can beeconomically used for making laminates
Since culm diameter and wall thickness are two very important parameters thatlimit the conversion of bamboo into strips of suitable sizes for making laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 15
Figure 1 Process ow chart for manufacturing bamboo laminates
Figure 2 Bamboo laminates
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 9
Table 7Lateral distribution of total roots and contributionof ne roots
Radial Total roots () Fine roots ()distances (cm) Cr Ct Cr Ct
Root activity decreased with increasing soil depth In C rotang about 76 ofthe active roots are located at 0ndash30 cm depth while 86 of the active roots inC thwaitesii are located at 0ndash30 cm depth Wright [5] reported that 70ndash80 of theactive roots of oil palm are located at 0ndash20 cm depth
Root surface area
In the two species main roots alone are present in the initial stage and C thwaitesiihas more root surface area at this stage With the initiation of laterals in the rst yearthe total surface areaplant is also more in C thwaitesii However in the secondyear C rotang has more surface area due to the occurrence of more roots bothlt2 mm and gt2 mm At the end of the third year the trend was reversed (Table 8)
However the surface area of the ne roots even though few in number wasfound to be greater in C rotang due to their increased length and diameter Thisis supported by the statement that plants with greater lsquospeci c root surface arearsquo aremore ef cient and opportunistic absorbers of ions and water [7] Such plants alsoappear to be more competitive in single and mixed plant communities [8] The rootsystem of C thwaitesii is seen to be more ef cient as measured by more speci croot surface area
10 V K Jayasree et al
Table 9Comparison of soil binding factor
Period (year) C rotang C thwaitesii
First 175 150Second 303 401Third 334 285
Soil binding capacity
The binding of soil particles and the promotion of soil aggregation are of directvalue in soil conservation The length and thickness of roots play an importantrole in binding soil particles ne roots with their close and elaborate network havegreater binding capacity than thicker roots Soil binding capacity shows an increasewith age in C rotang while in C thwaitesii soil binding is highest in the secondyear (Table 9)
The soil binding capacity of grass roots was studied by Bhaskaran and Chakrabarty[9] and the binding capacity ranged from 219 to 876 in four species of grassesMathur et al [10] noted that in Populus ciliata a promising species for soil con-servation the soil binding factor after one year growth was 6129 and after twoyears 10665 Dhyani et al [11] have calculated soil binding capacity factor for ve tree genera and Ougeinea Leucaena and Grewia were shown to be useful forconservation in this respect
Compared with grasses and trees rattans appear to be good soil binders Banikand Ahamed [12] also pointed out that another rattan C viminalis is likely to checksoil erosion
Final inference
It can be inferred that C thwaitesii is more ef cient than C rotang in water andnutrient uptake because its root density total root intensity ne root intensity androot surface area are higher However one could also argue the case the otherway round C rotang is more ef cient because it is able to survive and growwith less dry matter investment in root structure than C thwaitesii C thwaitesiiis less ef cient because it needs more root surface area to survive Nonethelessboth species are good soil binders
Acknowledgements
We are grateful to Dr J K Sharma Director KFRI for providing the facilitiesfor the work The rst author gratefully acknowledges the University GrantsCommission for permitting the bene t of FIP under the IXth plan for the completionof her PhD work Thanks are due to Mr K K Unni Of cer-in-charge Fieldresearch station Palappilly for his unreserved help in the eld
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 11
REFERENCES
1 V K Jayasree C Renuka and P Rugmini Root morphology and development in rattans1 A quantitativestudy of the roots in two species of Calamus L Journal of Bamboo and Rattan2 (2) 135ndash152 (2003)
2 D S Stevenson Effective soil volume and its importance to root and top growth of plantsCanadian Journal of Soil Science 47 163ndash174 (1967)
3 D Atkinson and S A Wilson The root soil interface and its signi cance for fruit tree roots ofdifferent ages in The Soil Root Interface J L Harley and R S Russell (Eds) pp 259ndash271Academic press London (1979)
4 D Atkinson and S A Wilson The growth and distribution of fruit tree roots some conse-quences for nutrient uptake in Mineral Nutrition of Fruit Trees D Atkinson J E JacksonR O Sharples and W M Waller (Eds) pp 137ndash150 Butterworths London (1980)
5 J O Wright Unusual features of the root system of the oil palm in West Africa Nature 1687ndash48 (1951)
6 B S Grey A study of the in uence of genetic agronomic and environmental factors on thegrowth owering and bunch production of Oil palm on the West Coast of Malaysia PhD thesisUniversity of Aberdeen Aberdeen (1969)
7 S A Barber and M Silverbush Plant root morphology and nutrient uptake in Roots Nutrientand Water In ux and Plant Growth S A Barber and D R Boulden (Eds) pp 65ndash87 AmericanSociety of Agronomy Madison WI (1984)
8 D M Eissenstat and M M Caldwell Competitive ability is linked to water extraction A eldstudy of two arid land tussock grasses Oecologia 75 1ndash7 (1988)
9 A R Bhaskaran and D C Chakrabarty A preliminary study on the variations in the soil bindingcapacity of some grass roots Indian Journal of Agronomy 10 326ndash330 (1965)
10 H N Mathur R P Singh and K C Sharma Populus ciliata mdash A promising tree species for soilconservation in hilly areas The Indian Forest 108 (9) 599ndash604 (1982)
11 K Dhyani P Narain and R K Singh Studies on root distribution of ve multipurpose treespecies in Doon Valley India Agroforestry Systems 12 149ndash161 (1990)
12 R L Banik and F U Ahmed An investigation on the roots of Bara bet (Calamus viminalisWilld var fasciculatus Becc) Bano Biggyan Patrika 15 (1-2) 37ndash40 (1986)
J Bamboo and Rattan Vol 3 No 1 pp 13ndash22 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Manufacturing laminates from sympodial bamboos mdashan Indian experience
A K BANSAL curren and T R N PRASADIndian Plywood Industries Research and Training Institute Tumkur Road P O Box 2273Bangalore 560 022 India
AbstractmdashIn recent years bamboo has been rediscovered as an important renewable material withgreat potential Industrial bamboo products will also result in alleviating the pressure on forestsas well as creating employment opportunities for ruraltribal poor particularly women Consideringthis the Government of India has launched an important national initiative for promotion of bambooproducts in mission mode Laminated bamboo boards are closest to wood both in appearance andproperties and are generally manufactured from the monopodial bamboo namely Phyllostachyspubescens The material is highly suitable for ooring and furniture Working on a project fundedby the Ministry of Environment and Forests Government of India IPIRTI has evolved a process formaking bamboo wood (laminates) from a sympodial bamboo found in several states of India namelyBambusa bambos Strength properties of bamboo wood are comparable to those of Tectona grandis(teak) A at-pack table and a wall stand were also designed and fabricated indicating the suitabilityof the material for furniture
Key words Laminates bamboo-wood wood substitute sympodial bamboo
INTRODUCTION
The development of wood substitutes is one of the important interventions enunci-ated in the 1988 National Forest Policy of India aiming at the conservation of naturalforests [1] Such substitution has necessarily to be done by the use of renewable -bres due to the fact that wood alternates made from non-renewable resources willnot be sustainable More over alternates based on plastics metals and such othermaterials are highly energy consuming non-biodegradable and are not conduciveto our environment [2 3] Of the several renewable bre resources bamboo is beingrediscovered throughout the world as a futuristic material Bamboo is perhaps oneof the fastest growing plants on the earth and sequesters atmospheric carbon most
currenTo whom correspondence should be addressed E-mail bansalkavsnlcom
14 A K Bansal and T R N Prasad
ef ciently Several panel products have been developed or are under developmentusing bamboo in different form including stripslaths slivers and particles [4 5]India has rich resources of bamboo both in terms of extent and variety In fact sev-eral species of bamboos occur naturally in the country and have been part of Indianculture with more than thousand traditional uses IPIRTI has been associated withdevelopment of several useful products from woven bamboo mats that are not onlyenvironment-friendly but also people friendly [6 7]
A new generation product made from bamboo strips known as bamboo laminatehas gained importance in Europe and America particularly as ooring materialin place of hardwoods due to the fact that it resembles wood in appearance andhas similar workability [8] Bamboo laminate can replace timber in many otherapplications such as doors and windows frames partitions and furniture Theselaminates are manufactured from a temperate zone monopodial bamboo namelyPhyllostachys pubescens referred to in the international technical literature also asmoso bamboo (Ref [9] and data not shown)
Working under a project funded by the Ministry of Environment and ForestsGovernment of India IPIRTI screened a number of Indian sympodial or clumpforming bamboo species and developed the technology for the manufacturingbamboo laminates from Bambusa bambos one of the common bamboo species inseveral parts of the country covering around 15 of the total bamboo bearing forestareas The species is also raised as plantations outside forests
MATERIALS AND METHODS
A generalized process ow chart for manufacturing bamboo laminates is given inFig 1 In simple terms the process involves conversion of bamboo into stripshaving uniform rectangular cross-section drying them to reduce the moisture todesirable level application of adhesive and hot pressing using both vertical and sidepressure to achieve proper bonding Some of the bamboo processing machines wereimported as they are not available in the country One of the available hydraulic hotpresses was modi ed so as to provide both vertical and side pressure required formaking bamboo laminates
The bamboo strips are required to have a uniform rectangular cross-section Thestrips are put side by side in two different fashions and accordingly they are termedas vertical and horizontal laminates (Fig 2) The normal minimum size (the lesserdimension of the cross-section) for use in furniture is 18ndash20 mm Moreover suchstrips are made from bamboo splits having a cross-section as shown in Fig 3From such a cross-section strips of rectangular cross-sections are cut by removingthe extra material in two stages of planing This speci c processing requirementputs a constraint on minimum diameter and wall thickness of bamboos that can beeconomically used for making laminates
Since culm diameter and wall thickness are two very important parameters thatlimit the conversion of bamboo into strips of suitable sizes for making laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 15
Figure 1 Process ow chart for manufacturing bamboo laminates
Figure 2 Bamboo laminates
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
10 V K Jayasree et al
Table 9Comparison of soil binding factor
Period (year) C rotang C thwaitesii
First 175 150Second 303 401Third 334 285
Soil binding capacity
The binding of soil particles and the promotion of soil aggregation are of directvalue in soil conservation The length and thickness of roots play an importantrole in binding soil particles ne roots with their close and elaborate network havegreater binding capacity than thicker roots Soil binding capacity shows an increasewith age in C rotang while in C thwaitesii soil binding is highest in the secondyear (Table 9)
The soil binding capacity of grass roots was studied by Bhaskaran and Chakrabarty[9] and the binding capacity ranged from 219 to 876 in four species of grassesMathur et al [10] noted that in Populus ciliata a promising species for soil con-servation the soil binding factor after one year growth was 6129 and after twoyears 10665 Dhyani et al [11] have calculated soil binding capacity factor for ve tree genera and Ougeinea Leucaena and Grewia were shown to be useful forconservation in this respect
Compared with grasses and trees rattans appear to be good soil binders Banikand Ahamed [12] also pointed out that another rattan C viminalis is likely to checksoil erosion
Final inference
It can be inferred that C thwaitesii is more ef cient than C rotang in water andnutrient uptake because its root density total root intensity ne root intensity androot surface area are higher However one could also argue the case the otherway round C rotang is more ef cient because it is able to survive and growwith less dry matter investment in root structure than C thwaitesii C thwaitesiiis less ef cient because it needs more root surface area to survive Nonethelessboth species are good soil binders
Acknowledgements
We are grateful to Dr J K Sharma Director KFRI for providing the facilitiesfor the work The rst author gratefully acknowledges the University GrantsCommission for permitting the bene t of FIP under the IXth plan for the completionof her PhD work Thanks are due to Mr K K Unni Of cer-in-charge Fieldresearch station Palappilly for his unreserved help in the eld
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 11
REFERENCES
1 V K Jayasree C Renuka and P Rugmini Root morphology and development in rattans1 A quantitativestudy of the roots in two species of Calamus L Journal of Bamboo and Rattan2 (2) 135ndash152 (2003)
2 D S Stevenson Effective soil volume and its importance to root and top growth of plantsCanadian Journal of Soil Science 47 163ndash174 (1967)
3 D Atkinson and S A Wilson The root soil interface and its signi cance for fruit tree roots ofdifferent ages in The Soil Root Interface J L Harley and R S Russell (Eds) pp 259ndash271Academic press London (1979)
4 D Atkinson and S A Wilson The growth and distribution of fruit tree roots some conse-quences for nutrient uptake in Mineral Nutrition of Fruit Trees D Atkinson J E JacksonR O Sharples and W M Waller (Eds) pp 137ndash150 Butterworths London (1980)
5 J O Wright Unusual features of the root system of the oil palm in West Africa Nature 1687ndash48 (1951)
6 B S Grey A study of the in uence of genetic agronomic and environmental factors on thegrowth owering and bunch production of Oil palm on the West Coast of Malaysia PhD thesisUniversity of Aberdeen Aberdeen (1969)
7 S A Barber and M Silverbush Plant root morphology and nutrient uptake in Roots Nutrientand Water In ux and Plant Growth S A Barber and D R Boulden (Eds) pp 65ndash87 AmericanSociety of Agronomy Madison WI (1984)
8 D M Eissenstat and M M Caldwell Competitive ability is linked to water extraction A eldstudy of two arid land tussock grasses Oecologia 75 1ndash7 (1988)
9 A R Bhaskaran and D C Chakrabarty A preliminary study on the variations in the soil bindingcapacity of some grass roots Indian Journal of Agronomy 10 326ndash330 (1965)
10 H N Mathur R P Singh and K C Sharma Populus ciliata mdash A promising tree species for soilconservation in hilly areas The Indian Forest 108 (9) 599ndash604 (1982)
11 K Dhyani P Narain and R K Singh Studies on root distribution of ve multipurpose treespecies in Doon Valley India Agroforestry Systems 12 149ndash161 (1990)
12 R L Banik and F U Ahmed An investigation on the roots of Bara bet (Calamus viminalisWilld var fasciculatus Becc) Bano Biggyan Patrika 15 (1-2) 37ndash40 (1986)
J Bamboo and Rattan Vol 3 No 1 pp 13ndash22 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Manufacturing laminates from sympodial bamboos mdashan Indian experience
A K BANSAL curren and T R N PRASADIndian Plywood Industries Research and Training Institute Tumkur Road P O Box 2273Bangalore 560 022 India
AbstractmdashIn recent years bamboo has been rediscovered as an important renewable material withgreat potential Industrial bamboo products will also result in alleviating the pressure on forestsas well as creating employment opportunities for ruraltribal poor particularly women Consideringthis the Government of India has launched an important national initiative for promotion of bambooproducts in mission mode Laminated bamboo boards are closest to wood both in appearance andproperties and are generally manufactured from the monopodial bamboo namely Phyllostachyspubescens The material is highly suitable for ooring and furniture Working on a project fundedby the Ministry of Environment and Forests Government of India IPIRTI has evolved a process formaking bamboo wood (laminates) from a sympodial bamboo found in several states of India namelyBambusa bambos Strength properties of bamboo wood are comparable to those of Tectona grandis(teak) A at-pack table and a wall stand were also designed and fabricated indicating the suitabilityof the material for furniture
Key words Laminates bamboo-wood wood substitute sympodial bamboo
INTRODUCTION
The development of wood substitutes is one of the important interventions enunci-ated in the 1988 National Forest Policy of India aiming at the conservation of naturalforests [1] Such substitution has necessarily to be done by the use of renewable -bres due to the fact that wood alternates made from non-renewable resources willnot be sustainable More over alternates based on plastics metals and such othermaterials are highly energy consuming non-biodegradable and are not conduciveto our environment [2 3] Of the several renewable bre resources bamboo is beingrediscovered throughout the world as a futuristic material Bamboo is perhaps oneof the fastest growing plants on the earth and sequesters atmospheric carbon most
currenTo whom correspondence should be addressed E-mail bansalkavsnlcom
14 A K Bansal and T R N Prasad
ef ciently Several panel products have been developed or are under developmentusing bamboo in different form including stripslaths slivers and particles [4 5]India has rich resources of bamboo both in terms of extent and variety In fact sev-eral species of bamboos occur naturally in the country and have been part of Indianculture with more than thousand traditional uses IPIRTI has been associated withdevelopment of several useful products from woven bamboo mats that are not onlyenvironment-friendly but also people friendly [6 7]
A new generation product made from bamboo strips known as bamboo laminatehas gained importance in Europe and America particularly as ooring materialin place of hardwoods due to the fact that it resembles wood in appearance andhas similar workability [8] Bamboo laminate can replace timber in many otherapplications such as doors and windows frames partitions and furniture Theselaminates are manufactured from a temperate zone monopodial bamboo namelyPhyllostachys pubescens referred to in the international technical literature also asmoso bamboo (Ref [9] and data not shown)
Working under a project funded by the Ministry of Environment and ForestsGovernment of India IPIRTI screened a number of Indian sympodial or clumpforming bamboo species and developed the technology for the manufacturingbamboo laminates from Bambusa bambos one of the common bamboo species inseveral parts of the country covering around 15 of the total bamboo bearing forestareas The species is also raised as plantations outside forests
MATERIALS AND METHODS
A generalized process ow chart for manufacturing bamboo laminates is given inFig 1 In simple terms the process involves conversion of bamboo into stripshaving uniform rectangular cross-section drying them to reduce the moisture todesirable level application of adhesive and hot pressing using both vertical and sidepressure to achieve proper bonding Some of the bamboo processing machines wereimported as they are not available in the country One of the available hydraulic hotpresses was modi ed so as to provide both vertical and side pressure required formaking bamboo laminates
The bamboo strips are required to have a uniform rectangular cross-section Thestrips are put side by side in two different fashions and accordingly they are termedas vertical and horizontal laminates (Fig 2) The normal minimum size (the lesserdimension of the cross-section) for use in furniture is 18ndash20 mm Moreover suchstrips are made from bamboo splits having a cross-section as shown in Fig 3From such a cross-section strips of rectangular cross-sections are cut by removingthe extra material in two stages of planing This speci c processing requirementputs a constraint on minimum diameter and wall thickness of bamboos that can beeconomically used for making laminates
Since culm diameter and wall thickness are two very important parameters thatlimit the conversion of bamboo into strips of suitable sizes for making laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 15
Figure 1 Process ow chart for manufacturing bamboo laminates
Figure 2 Bamboo laminates
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Soil requirements and ef ciency of the root systems in rattans in the seedling stage 11
REFERENCES
1 V K Jayasree C Renuka and P Rugmini Root morphology and development in rattans1 A quantitativestudy of the roots in two species of Calamus L Journal of Bamboo and Rattan2 (2) 135ndash152 (2003)
2 D S Stevenson Effective soil volume and its importance to root and top growth of plantsCanadian Journal of Soil Science 47 163ndash174 (1967)
3 D Atkinson and S A Wilson The root soil interface and its signi cance for fruit tree roots ofdifferent ages in The Soil Root Interface J L Harley and R S Russell (Eds) pp 259ndash271Academic press London (1979)
4 D Atkinson and S A Wilson The growth and distribution of fruit tree roots some conse-quences for nutrient uptake in Mineral Nutrition of Fruit Trees D Atkinson J E JacksonR O Sharples and W M Waller (Eds) pp 137ndash150 Butterworths London (1980)
5 J O Wright Unusual features of the root system of the oil palm in West Africa Nature 1687ndash48 (1951)
6 B S Grey A study of the in uence of genetic agronomic and environmental factors on thegrowth owering and bunch production of Oil palm on the West Coast of Malaysia PhD thesisUniversity of Aberdeen Aberdeen (1969)
7 S A Barber and M Silverbush Plant root morphology and nutrient uptake in Roots Nutrientand Water In ux and Plant Growth S A Barber and D R Boulden (Eds) pp 65ndash87 AmericanSociety of Agronomy Madison WI (1984)
8 D M Eissenstat and M M Caldwell Competitive ability is linked to water extraction A eldstudy of two arid land tussock grasses Oecologia 75 1ndash7 (1988)
9 A R Bhaskaran and D C Chakrabarty A preliminary study on the variations in the soil bindingcapacity of some grass roots Indian Journal of Agronomy 10 326ndash330 (1965)
10 H N Mathur R P Singh and K C Sharma Populus ciliata mdash A promising tree species for soilconservation in hilly areas The Indian Forest 108 (9) 599ndash604 (1982)
11 K Dhyani P Narain and R K Singh Studies on root distribution of ve multipurpose treespecies in Doon Valley India Agroforestry Systems 12 149ndash161 (1990)
12 R L Banik and F U Ahmed An investigation on the roots of Bara bet (Calamus viminalisWilld var fasciculatus Becc) Bano Biggyan Patrika 15 (1-2) 37ndash40 (1986)
J Bamboo and Rattan Vol 3 No 1 pp 13ndash22 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Manufacturing laminates from sympodial bamboos mdashan Indian experience
A K BANSAL curren and T R N PRASADIndian Plywood Industries Research and Training Institute Tumkur Road P O Box 2273Bangalore 560 022 India
AbstractmdashIn recent years bamboo has been rediscovered as an important renewable material withgreat potential Industrial bamboo products will also result in alleviating the pressure on forestsas well as creating employment opportunities for ruraltribal poor particularly women Consideringthis the Government of India has launched an important national initiative for promotion of bambooproducts in mission mode Laminated bamboo boards are closest to wood both in appearance andproperties and are generally manufactured from the monopodial bamboo namely Phyllostachyspubescens The material is highly suitable for ooring and furniture Working on a project fundedby the Ministry of Environment and Forests Government of India IPIRTI has evolved a process formaking bamboo wood (laminates) from a sympodial bamboo found in several states of India namelyBambusa bambos Strength properties of bamboo wood are comparable to those of Tectona grandis(teak) A at-pack table and a wall stand were also designed and fabricated indicating the suitabilityof the material for furniture
Key words Laminates bamboo-wood wood substitute sympodial bamboo
INTRODUCTION
The development of wood substitutes is one of the important interventions enunci-ated in the 1988 National Forest Policy of India aiming at the conservation of naturalforests [1] Such substitution has necessarily to be done by the use of renewable -bres due to the fact that wood alternates made from non-renewable resources willnot be sustainable More over alternates based on plastics metals and such othermaterials are highly energy consuming non-biodegradable and are not conduciveto our environment [2 3] Of the several renewable bre resources bamboo is beingrediscovered throughout the world as a futuristic material Bamboo is perhaps oneof the fastest growing plants on the earth and sequesters atmospheric carbon most
currenTo whom correspondence should be addressed E-mail bansalkavsnlcom
14 A K Bansal and T R N Prasad
ef ciently Several panel products have been developed or are under developmentusing bamboo in different form including stripslaths slivers and particles [4 5]India has rich resources of bamboo both in terms of extent and variety In fact sev-eral species of bamboos occur naturally in the country and have been part of Indianculture with more than thousand traditional uses IPIRTI has been associated withdevelopment of several useful products from woven bamboo mats that are not onlyenvironment-friendly but also people friendly [6 7]
A new generation product made from bamboo strips known as bamboo laminatehas gained importance in Europe and America particularly as ooring materialin place of hardwoods due to the fact that it resembles wood in appearance andhas similar workability [8] Bamboo laminate can replace timber in many otherapplications such as doors and windows frames partitions and furniture Theselaminates are manufactured from a temperate zone monopodial bamboo namelyPhyllostachys pubescens referred to in the international technical literature also asmoso bamboo (Ref [9] and data not shown)
Working under a project funded by the Ministry of Environment and ForestsGovernment of India IPIRTI screened a number of Indian sympodial or clumpforming bamboo species and developed the technology for the manufacturingbamboo laminates from Bambusa bambos one of the common bamboo species inseveral parts of the country covering around 15 of the total bamboo bearing forestareas The species is also raised as plantations outside forests
MATERIALS AND METHODS
A generalized process ow chart for manufacturing bamboo laminates is given inFig 1 In simple terms the process involves conversion of bamboo into stripshaving uniform rectangular cross-section drying them to reduce the moisture todesirable level application of adhesive and hot pressing using both vertical and sidepressure to achieve proper bonding Some of the bamboo processing machines wereimported as they are not available in the country One of the available hydraulic hotpresses was modi ed so as to provide both vertical and side pressure required formaking bamboo laminates
The bamboo strips are required to have a uniform rectangular cross-section Thestrips are put side by side in two different fashions and accordingly they are termedas vertical and horizontal laminates (Fig 2) The normal minimum size (the lesserdimension of the cross-section) for use in furniture is 18ndash20 mm Moreover suchstrips are made from bamboo splits having a cross-section as shown in Fig 3From such a cross-section strips of rectangular cross-sections are cut by removingthe extra material in two stages of planing This speci c processing requirementputs a constraint on minimum diameter and wall thickness of bamboos that can beeconomically used for making laminates
Since culm diameter and wall thickness are two very important parameters thatlimit the conversion of bamboo into strips of suitable sizes for making laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 15
Figure 1 Process ow chart for manufacturing bamboo laminates
Figure 2 Bamboo laminates
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
J Bamboo and Rattan Vol 3 No 1 pp 13ndash22 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Manufacturing laminates from sympodial bamboos mdashan Indian experience
A K BANSAL curren and T R N PRASADIndian Plywood Industries Research and Training Institute Tumkur Road P O Box 2273Bangalore 560 022 India
AbstractmdashIn recent years bamboo has been rediscovered as an important renewable material withgreat potential Industrial bamboo products will also result in alleviating the pressure on forestsas well as creating employment opportunities for ruraltribal poor particularly women Consideringthis the Government of India has launched an important national initiative for promotion of bambooproducts in mission mode Laminated bamboo boards are closest to wood both in appearance andproperties and are generally manufactured from the monopodial bamboo namely Phyllostachyspubescens The material is highly suitable for ooring and furniture Working on a project fundedby the Ministry of Environment and Forests Government of India IPIRTI has evolved a process formaking bamboo wood (laminates) from a sympodial bamboo found in several states of India namelyBambusa bambos Strength properties of bamboo wood are comparable to those of Tectona grandis(teak) A at-pack table and a wall stand were also designed and fabricated indicating the suitabilityof the material for furniture
Key words Laminates bamboo-wood wood substitute sympodial bamboo
INTRODUCTION
The development of wood substitutes is one of the important interventions enunci-ated in the 1988 National Forest Policy of India aiming at the conservation of naturalforests [1] Such substitution has necessarily to be done by the use of renewable -bres due to the fact that wood alternates made from non-renewable resources willnot be sustainable More over alternates based on plastics metals and such othermaterials are highly energy consuming non-biodegradable and are not conduciveto our environment [2 3] Of the several renewable bre resources bamboo is beingrediscovered throughout the world as a futuristic material Bamboo is perhaps oneof the fastest growing plants on the earth and sequesters atmospheric carbon most
currenTo whom correspondence should be addressed E-mail bansalkavsnlcom
14 A K Bansal and T R N Prasad
ef ciently Several panel products have been developed or are under developmentusing bamboo in different form including stripslaths slivers and particles [4 5]India has rich resources of bamboo both in terms of extent and variety In fact sev-eral species of bamboos occur naturally in the country and have been part of Indianculture with more than thousand traditional uses IPIRTI has been associated withdevelopment of several useful products from woven bamboo mats that are not onlyenvironment-friendly but also people friendly [6 7]
A new generation product made from bamboo strips known as bamboo laminatehas gained importance in Europe and America particularly as ooring materialin place of hardwoods due to the fact that it resembles wood in appearance andhas similar workability [8] Bamboo laminate can replace timber in many otherapplications such as doors and windows frames partitions and furniture Theselaminates are manufactured from a temperate zone monopodial bamboo namelyPhyllostachys pubescens referred to in the international technical literature also asmoso bamboo (Ref [9] and data not shown)
Working under a project funded by the Ministry of Environment and ForestsGovernment of India IPIRTI screened a number of Indian sympodial or clumpforming bamboo species and developed the technology for the manufacturingbamboo laminates from Bambusa bambos one of the common bamboo species inseveral parts of the country covering around 15 of the total bamboo bearing forestareas The species is also raised as plantations outside forests
MATERIALS AND METHODS
A generalized process ow chart for manufacturing bamboo laminates is given inFig 1 In simple terms the process involves conversion of bamboo into stripshaving uniform rectangular cross-section drying them to reduce the moisture todesirable level application of adhesive and hot pressing using both vertical and sidepressure to achieve proper bonding Some of the bamboo processing machines wereimported as they are not available in the country One of the available hydraulic hotpresses was modi ed so as to provide both vertical and side pressure required formaking bamboo laminates
The bamboo strips are required to have a uniform rectangular cross-section Thestrips are put side by side in two different fashions and accordingly they are termedas vertical and horizontal laminates (Fig 2) The normal minimum size (the lesserdimension of the cross-section) for use in furniture is 18ndash20 mm Moreover suchstrips are made from bamboo splits having a cross-section as shown in Fig 3From such a cross-section strips of rectangular cross-sections are cut by removingthe extra material in two stages of planing This speci c processing requirementputs a constraint on minimum diameter and wall thickness of bamboos that can beeconomically used for making laminates
Since culm diameter and wall thickness are two very important parameters thatlimit the conversion of bamboo into strips of suitable sizes for making laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 15
Figure 1 Process ow chart for manufacturing bamboo laminates
Figure 2 Bamboo laminates
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
14 A K Bansal and T R N Prasad
ef ciently Several panel products have been developed or are under developmentusing bamboo in different form including stripslaths slivers and particles [4 5]India has rich resources of bamboo both in terms of extent and variety In fact sev-eral species of bamboos occur naturally in the country and have been part of Indianculture with more than thousand traditional uses IPIRTI has been associated withdevelopment of several useful products from woven bamboo mats that are not onlyenvironment-friendly but also people friendly [6 7]
A new generation product made from bamboo strips known as bamboo laminatehas gained importance in Europe and America particularly as ooring materialin place of hardwoods due to the fact that it resembles wood in appearance andhas similar workability [8] Bamboo laminate can replace timber in many otherapplications such as doors and windows frames partitions and furniture Theselaminates are manufactured from a temperate zone monopodial bamboo namelyPhyllostachys pubescens referred to in the international technical literature also asmoso bamboo (Ref [9] and data not shown)
Working under a project funded by the Ministry of Environment and ForestsGovernment of India IPIRTI screened a number of Indian sympodial or clumpforming bamboo species and developed the technology for the manufacturingbamboo laminates from Bambusa bambos one of the common bamboo species inseveral parts of the country covering around 15 of the total bamboo bearing forestareas The species is also raised as plantations outside forests
MATERIALS AND METHODS
A generalized process ow chart for manufacturing bamboo laminates is given inFig 1 In simple terms the process involves conversion of bamboo into stripshaving uniform rectangular cross-section drying them to reduce the moisture todesirable level application of adhesive and hot pressing using both vertical and sidepressure to achieve proper bonding Some of the bamboo processing machines wereimported as they are not available in the country One of the available hydraulic hotpresses was modi ed so as to provide both vertical and side pressure required formaking bamboo laminates
The bamboo strips are required to have a uniform rectangular cross-section Thestrips are put side by side in two different fashions and accordingly they are termedas vertical and horizontal laminates (Fig 2) The normal minimum size (the lesserdimension of the cross-section) for use in furniture is 18ndash20 mm Moreover suchstrips are made from bamboo splits having a cross-section as shown in Fig 3From such a cross-section strips of rectangular cross-sections are cut by removingthe extra material in two stages of planing This speci c processing requirementputs a constraint on minimum diameter and wall thickness of bamboos that can beeconomically used for making laminates
Since culm diameter and wall thickness are two very important parameters thatlimit the conversion of bamboo into strips of suitable sizes for making laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 15
Figure 1 Process ow chart for manufacturing bamboo laminates
Figure 2 Bamboo laminates
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Manufacturing laminates from sympodial bamboos mdash an Indian experience 15
Figure 1 Process ow chart for manufacturing bamboo laminates
Figure 2 Bamboo laminates
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
16 A K Bansal and T R N Prasad
Figure 3 Bamboo splitting and sizing for laminates
of the several Indian bamboo species viz Bambusa balcooa B nutans B bambosand B tulda appear to be suitable Of these B bambos was taken up for the studydue to its availability close to the Institutersquos main research laboratory at BangaloreThe utilizable proportion of bamboo strips will greatly depend upon the diameterand wall thickness of the bamboo A preliminary estimation of yield of strips wasalso carried out
Conversion of bamboo into strips
Mature bamboo culms with outer diameter more than 100 mm and wall thicknessin the range of 10ndash15 mm were cross-cut to 1-m lengths using a cross-cuttingmachine External bulging at the nodes was removed manually A special splittingmachine that splits bamboo into strips with parallel edges was used to convertround bamboos into strips The strips were then immersed in boiling water towhich some preservative chemical was also added to remove the starch and enhancedurability of bamboo strips The colour of the strips can be darkened by steamingthem under 5ndash6 kgcm2 pressure for 2ndash4 h The intensity of the colour developeddepends on the temperature and duration of the steaming the higher the temperatureand longer the time the darker the colour These strips are then dried to 8ndash10moisture content in a hot air chamber at 80 sect 2plusmnC After drying the strips are passedthrough four side planing machine equipped with two side (vertical) and two face(horizontal) cutters to get strips with predetermined and uniform rectangular cross-sections with plane surfaces However some strips may have defects like bluestains cutter marks reining dents and ripples Defect-free strips were selectedfor further processing
Adhesive formulation
Three types of resin adhesives namely (1) urea formaldehyde (UF) forti ed withmelamine (the melamine is added after manufacturing of UF resin) (2) melamineurea formaldehyde (MUF the melamine is added during the resin manufacturingprocess before co-condensation stage) and (3) phenol formaldehyde (PF) were
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Manufacturing laminates from sympodial bamboos mdash an Indian experience 17
GNCP is Ground nut cake powder CSF is Coconut shell our
Table 2Pressing conditions
UF resin MUF resin PF resin
Temperature (plusmnC) 115 125 145Pressure perpendicular to glue-lines (kgcm2) 10 12 14Pressure parallel to glue lines (kgcm2) 25 25 25Pressing time (min) 12 15 20
used in the investigations Various parameters of the three resins are given inTable 1
Adhesive application assembly and hot pressing
Adhesive was applied to the four side planed strips through brush coating Adhesivecoated strips were assembled to make the desired thickness keeping in mind thecompression losses during hot pressing using two stacking types as depicted inFig 2 to make vertical and horizontal laminates The assembly was hot pressedin a hydraulic hot press generally used for making plywood modi ed to provideside pressure in addition to the vertical pressure The pressing conditions for threeadhesive resins are given in Table 2
Finishing or surface coating
Laminates manufactured in the pilot plant were planed in a planing machine to geta smooth nish The board is then lled with putty prepared with bamboo dust to ll the gaps and crevices and primer coating was given followed by coating withmelamine clear nish or polyurethane
Testing of bamboo laminates
Five samples each of the three types of vertical and horizontal laminates were testedat the Institutersquos testing lab for block shear strength modulus of rupture (MOR)modulus of elasticity (MOE) screw withdrawal strength compression strength
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
18 A K Bansal and T R N Prasad
and abrasion resistance The rst ve properties were tested according to IndianStandard IS 1708-1986 the last one according to IS 12823-1990 These propertieswere compared with those of teak (Tectona grandis) as it is a well-known andwidely used timber through out India for all sorts of work such as beams columnsroof work ooring planking paneling doors and windows furniture etc Teakis recognized as a standard species for evaluation of suitability indices of timberspecies in India [10ndash12]
RESULTS AND DISCUSSION
Yield
From the investigation carried out during the conversion of bamboo into stripsaverage yield came to 17 This utilisable portion of bamboo for manufacturinglaminates is rather low the remaining portion can be used for particle board or asfuel the outer layer can be used for basketry Proportions of residues not-utilizablefor making laminates in different stages are given in Table 3
Strength properties
One of the important properties of any composite material using resin or anyadhesive material is the bond integrity The bamboo laminates were tested for theirbond strength through cyclic wetting in hot water at 60 sect 2plusmnC for 3 h followed bydrying for 16 h It was seen that the laminates manufactured with the three typesof resins namely urea formaldehyde melamine urea formaldehyde and phenolformaldehyde remained intact without any signs of de-lamination after 3 6 and12 cycles respectively These results conform to expected quality of bonding forthe respective resins and indicate that only PF-bonded laminates can be suitable forexterior applications and UF- and MUF-bonded laminates are suitable for interioruses
The physical and mechanical properties of laminates made from B bambos aswell as the relevant values for teak wood are given in Table 4 From Table 4 itis clear that the strength properties of bamboo laminates compare well with those
Table 3Waste during conversion of bamboo culms into strips
Process Waste ()
Cross-cutting 17Splitting 16Internal knot removing 36Shrinkage during drying 4Four side planning 10Total 83
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Manufacturing laminates from sympodial bamboos mdash an Indian experience 19
of teak wood Bamboos are generally understood to be not a strong material butthere are several species of bamboo which are quite strong Comparing variousIndian bamboo species with a view to classify and grade them for structuralutilization Rajput and Sharma [13] have observed that average strength of bamboois about 16 less than that of average wood but the MOR and MOE of somebamboo species including B bambos reported in the study are higher than those
a Average 3900 3235 4999 4006 4683b Standard deviation 3965 370 793 692c Variation coef cient () 123 70 198 148
ii Edgea Average 2881 5375 2333 3659 3216b Standard deviation 563 464 878 669c Variation coef cient () 105 200 240 208
a At 12 moisture contentb Made from B bambos culms obtained from Bangalore University Campusc Made from B bambos culms obtained from MM hills Karnataka
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
20 A K Bansal and T R N Prasad
Figure 4 Magazine holder
of teak Moreover strength of split bamboo is found to be more than roundbamboo [14] The strength properties of bamboo are known to increase with agebeing the maximum at maturity and decrease along the length within a culm In thepresent study only mature bamboo culms were used and in the course of processinggenerally the bottom portions of the culms were selected due to the requirementof minimum wall thickness for making laminates All these factors contribute inenhancing the strength properties of the laminates This also suggests that bamboospecies and selection of lower thick walled portions from mature culms is likely tohave signi cant effect on the properties of the laminates
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Manufacturing laminates from sympodial bamboos mdash an Indian experience 21
Figure 5 Centre table
The vertical bamboo laminates manufactured at the Institutersquos facilities were usedfor making consumer products and a centre table and a magazine holder weredesigned and fabricated at the Institute (Figs 4 and 5)
CONCLUSIONS AND RECOMMENDATIONS
From this it is seen that bamboo wood or laminates made from the Indian clumpforming or sympodial bamboo species Bamusa bambos has properties comparableto those of teak wood They are also suitable for making furniture The studyalso indicates that whereas UF and MUF resin bonded laminates are suitable forinterior uses for exterior applications PF resins are required to be used Furtherwork is in progress to screen other sympodial bamboo species for manufacturingbamboo wood
Considering that bamboo wood has properties comparable to teak a highly de-manded furniture wood and the fact that India has sizable quantities of bamboospecies suitable for processing into laminates the Institute is working in collabo-ration with the National Mission on Bamboo Applications for evolving a technol-ogy package encompassing critical aspects of the processing technology in terms ofcharacterization of bamboos primary processing including cross-cutting splitting
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
22 A K Bansal and T R N Prasad
four-side planing and yield of utilizable splits characterization of adhesive and itsapplication hot pressing nishing and evolving standards to facilitate industrialadoption of the technology
Acknowledgements
The work reported in this paper was undertaken as a part of a project fundedby the Ministry of Environment and Forests Government of India The authorsacknowledge the nancial support from the Ministry of Environment and ForestsThe authors also thank the scientists and technical staff of the Institute who wereassociated with various works for successful completion of the study
REFERENCES
1 Anon National Forest Policy of India (1988)2 A K Bansal and S S Zoolagud Plantation wood bamboo and lignocellulosics mdash a future
source of building materials in Proceedings of the International Conference on lsquoWaste andByproducts as SecondaryResources for Building Materialsrsquo BMTPC ICS-UNIDO and Ei NewDelhi pp 370ndash381 (1999)
3 A K Bansal Lignocellulosics as sustainable source of building materials paper presented atthe InternationalTraining Course on lsquoMaterials Design and Production Processes for Low CostHousingrsquo ICSICAMT Bangalore (2002)
4 H-M Zhu Bamboo based boards in China an introduction in Bamboo People and theEnvironment Volume 3 P M Ganapathy J A Janssen and C B Sastry (Eds) INBAR TechnicalReport 8 140ndash154 (1996)
5 P M Ganapathy H-M Zhu S S Zoolagud D Turcke and Z B Espiloy Bamboo panel boardsmdash a state of the art review INBAR Technical Report 12 (1999)
6 S S Zoolagud and A K Bansal Research on bamboo based panels present status and futureneeds in Proceedings of the National Seminar on Plantation Timbers and Bamboo IPIRTIBangalore pp 83ndash89 (1998)
7 A K Bansal and S S Zoolagud Bamboo composites material of the future Journal of Bambooand Rattan 1 (2) 119ndash130 (2002)
8 Q S Zhang and B Xu INBAR mdash NFU Transfer of Technology Model Bamboo FloorManufacturing Unit INBAR Beijing (2001)
9 The MOSO difference httpwwwMOSOcom10 V D Limaye Grouping of Indian timbers and their properties uses and suitability Indian Forest
Records Timber Mechanics 1 (2) 19ndash64 (1954)11 A C Sekhar and B S Rawat Physical and mechanical properties of teak from different local-
ities in India and neighbouring areas Indian Forest Records (New Series) Timber Mechanics1 (13) 195ndash212 (1966)
12 S S Rajput and A S Gulati Some considerations on the selection of reference timber forcomparison in the evaluation of suitability indices of Indian timbers Journal of the IndianAcademy of Wood Science 14 (2) 96ndash102 (1983)
13 S S Rajput V K Gupta and S D Sharma Classi cation and grading of bamboos for structuralutilization and their safe working stresses Journal of the Timber Development Association(India) 38 (2) 19ndash32 (1992)
14 N K Shukla R S Singh and S N Sanyal Strength properties of eleven bamboo species andstudy of some factors affecting strength Journal of the Indian Academy of Wood Sciences 19 (2)63ndash80 (1988)
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
J Bamboo and Rattan Vol 3 No 1 pp 23ndash26 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Effect of trimming of culms on growth and proliferationof bamboo (Dendrocalamus strictus Roxb) propagules
R KUMAR 1curren and M PAL 2
1 Plant Physiology Branch Botany Division Forest Research Institute Dehra Dun 248 006 India2 ICFRE Headquarters FRI Dehra Dun India
AbstractmdashA study was conducted to observe the effect of trimming of culms at the time ofmultiplication of propagules using macroproliferation technique on growth and proliferation ofbamboo (Dendrocalamus strictus Roxb) Results indicated that trimming of culms had the adverseeffect on growth and proliferation parameters of bamboo propagules The rst part of this studyappeared in Journal of Bamboo and Rattan 2 (3) on pages 241ndash248
Key words Bamboo trimming growth proliferation culm
INTRODUCTION
As a result of increasing demand over-exploitation poor natural regeneration anddestruction of natural bamboo forests by animals and forest re many bambooforests have become highly degraded Considering the problems associated withthe natural regeneration it has become necessary to supplement and raise bamboothrough arti cial regeneration Dendrocalamus strictus is one of the most importantbamboo species in India [1] This species is most widely used for its multifariousproperties
Due to long seeding cycles bamboo seed availability is a major problem for large-scale production of planting stock so there is a current need for establishmentof rhizome banks to meet the future demand of planting stock for plantationprogrammes There are many factors responsible to accelerate the growth andproliferation of bamboo propagules [2] Some silvicultural practices like manuringweeding etc have been applied to increase the growth and proliferation rate ofbamboo propagules [3] But some other practices are also required to meet theproblem of low proliferation rate Many workers have observed the effect of
currenTo whom correspondence should be addressed E-mail sajwalryahoocom
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
24 R Kumar and M Pal
trimming in different plant species Some authors [4ndash7] have reported the negativeeffect of trimming while on the other hand some [8 9] noticed a positive effect oftrimming on plant growth But no work was done to see the effect of trimming ongrowth and proliferation of bamboo seedlings at the time of multiplication
Bearing in mind the above contrasting results the present study was conducted tosee the effect of trimming of culms at the time of multiplication of propagules usingmacroproliferation method in Dendrocalamus strictus
MATERIALS AND METHODS
The study was undertaken in the nursery of Plant Physiology Branch Botany Divi-sion Forest Research Institute (Dehra Dun India) Six-month-old seedlings weretaken and separated in September 2001 using the macroproliferation technique Inthis technique the polybags were slit along the length the ball of earth carefullyremoved and soil loosened so as to expose the rhizome prior to rhizome separationThe entire plant along with culms and rhizomes was washed in a bucket containingwater The extra roots were cut off with scissors The rhizome sub-units were thenseparated with the help of a secateur taking care that each unit had at least oneculm its own roots and rhizome
The propagules thus obtained were planted in polybags lled with the mixture ofgarden soil sand and FYM (farmyard manure) in the ratio of 2 1 1 At this time30 propagules were selected keeping in view the uniformity for height and vigourThese 30 plants were divided into two sets of 15 plants each The culms of oneset were trimmed by cutting off from 50 cm above the level of potting mixture inthe polythene bag whereas in the other set these were left untrimmed The plantswere maintained under open nursery conditions After a period of six months theobservations on growth and proliferation were recorded
RESULTS AND DISCUSSION
The data of the present investigation are given in Table 1 The results of t-testsindicate that trimming of culm had an adverse effect on all aspects of growth andproliferation From these aspects the number of leaves the fresh weight of leavesand rhizome the dry weight of rhizome and roots and the total fresh and dry weightwere signi cantly affected by the practice of trimming at P 6 005
The results of the present study clearly showed that trimming of propagules sup-pressed their growth signi cantly More than 50 reduction was recorded in num-ber of leaves fresh weight of leaves and rhizome dry weight of rhizome and rootsand total fresh and dry weight parameters There was a reduction in culm numberhence in the rate of proliferation due to trimming but the differences were statisti-cally signi cant only at P 6 010 Arron [7] observed reduction in growth of silvermaple saplings suggesting that metabolism occurred in foliage and not in stem
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Effect of trimming of culms on growth and proliferationof bamboo propagules 25
Table 1The effect of trimming of culms on the growth and proliferationof Dendrocalamus strictuspropagules
Parameter Mean Variance Pooled P
Untrimmed Trimmed Untrimmed Trimmed variance value
NOC D number of culms HOC D height of culms BDC D basal diameter of culms NOL Dnumber of leaves NORSU D number of rhizome sub-units FWC D fresh weight of culms FWL Dfresh weight of leaves FWRZ D fresh weight of rhizomes FWRT D fresh weight of roots TFW Dtotal fresh weight DWC D dry weight of culms DWL D dry weight of leaves DWRZ D dry weightof rhizomes DWRT D dry weight of roots TDW D total dry weight
Signi cant at P lt 005
In bamboos Cheung et al [10] has reported that trimming followed by fertilizerapplication resulted in lateral shoot production only whereas the ndings of RamPrasad and Chadhar [11] support the results of the present study as they founda negative effect of repeated prunings on the rhizome weight in Dendrocalamusstrictus The retention of shoots at the time of seedling separation for vegetativemultiplication of planting stock generally provided more vigorous propagules in thestudy although intact shoot tops dried up within 4ndash6 days of seedling separationThe translocation of the nutrients from intact shoot tops to growing rhizome andshoot system apparently resulted in growth superiority of these propagules
The ndings of present study re ect that the effect of trimming in bambooseedling should be studied in detail to improve the growth and proliferation Theheight or level of trimming and time of trimming are the major factors which maybe studied
REFERENCES
1 S Kondas Biology of two Indian bamboos their culm potential and problems of cultivationIndian Forester 108 (3) 179ndash188 (1982)
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
26 R Kumar and M Pal
2 R Kumar Physiological analysis of the factors associated with the rooting of cuttings andproliferationof bamboo (DendrocalamusstrictusRoxb) DPhil Thesis Forest Research Institute(Deemed University) Dehra Dun (2002)
3 P Khullar Studies on growth attributes and proliferation behavior of seedlings of somesympodial bamboos as affected by silvicultural manipulations PhD Thesis Forest ResearchInstitute Deemed University Dehra Dun (1997)
4 H S Lin and Z S Lin A study on the use of New Century pear shoots grafted on Heng-shanpear trees Bulletin of Taichung District Agricultural Improvement Station 3 25ndash41 (1980)
5 J P Sterrett Plant response to injections of XE 1019 in Proceedings of the Plant GrowthRegulator Society of America Thirteenth Annual Meeting St Petersburg Beach FL p 165(1986)
6 V F Mukhina The regeneration rate of the aerial phytomass of Arctostaphylos uva-ursi (L)Spreng after raw material collection (Central Yakutia) Rastitelrsquonye-Resursy 24 (2) 199ndash207(1988)
7 G P Arron Translocation of uniconazole after trunk injection of silver maple saplings Journalof Plant Growth Regulation 9 (3) 141ndash146 (1990)
8 P Brown Morphological and physiological aspects of owering initiation and development inTanacetum cinerariaefolium L University of Tasmania online article httpwwwifaunimelbeduauabstractsphdabstract1992brown1992htm (1992)
9 G K Sharma and S K Chauhan Conditioning of Celtis australis seedlings and their eldperformance Annals of Forestry 7 (1) 90ndash99 (1999)
10 Y Y Cheung S G Cooper T J Hansken and Y C Cheung Research on raising ofPhyllostachys pubescens seedlings in Recent Research on bamboos Proc Int BambooWorkshop Hangzhou Peoplersquos Republic of China A N Rao G Dhanarajan and C B Sastry(Eds) pp 154ndash159 IDRC Ottawa ON (1985)
11 R Prasad and S K Chadhar Effect of trimming of aerial parts on rhizome development ofbamboo (Dendrocalamus strictus) seedlings Journal of Tropical Forestry 3 (1) 67ndash70 (1987)
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
J Bamboo and Rattan Vol 3 No 1 pp 27ndash34 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Phenology and culm growth of Melocanna baccifera(Roxb) Kurtz in Barak Valley North-East India
S NANDY1 A K DAS 1curren and G DAS 2
1 Department of Ecology Assam University Silchar 788 011 Assam India2 Centre for Applied Statistics North-Eastern Hill University Shillong Meghalaya India
AbstractmdashThe phenology and growth of culms of Muli bamboo (Melocanna baccifera) were studiedin the Hailakandi district of Barak Valley in North-East India The culms emerge during the monthsof August and September and the growth curve is S-shaped The growth continues for a period of245 days with rapid growth attained after 45 days The lea ng pattern is characterized by periodicgrowth leaf-exchange type The adaptive strategy of this growth pattern is discussed in the context ofrestoration of degraded lands
Key words Melocanna baccifera phenology culm growth growth rate North-East India
INTRODUCTION
Bamboo is an important non-timber forest product (NTFP) of subsistence andmeets several commercial social environmental and economical perspectives [1]Of the 78 species of bamboos distributed in the North Eastern region of India [2]Melocanna baccifera or Muli bamboo is an important forest resource of BarakValley [3] as also in other parts of North-East India [4] The species is also abundantin hilly tracts of Bangladesh [5] and is included as one of the 38 priority bamboospecies identi ed by INBAR and IPGRI [6 7] The species is characterized by awoody pachymorph diffuse type of rhizome system [8] with long rhizome necksable to spread and quickly cover vacant spaces of hill areas [9] The species is anef cient early colonizer in secondary successional vegetation resulting from shiftingcultivation or other anthropogenic disturbances The studies on phenology andgrowth pattern of bamboos are limited see for example Banik [5] Shanmughavelet al [10] Ueda [11] Rao et al [12] and Schlegel [13] Such studies are importantin developing scienti c management systems for optimum yield The present work
currenTo whom correspondence should be addressed E-mail asheshkdsancharnetin
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
28 S Nandy et al
assesses the phenology and growth of Melocanna baccifera in Barak Valley thatresulted after gregarious owering in the mid-1960s
MATERIALS METHODS AND RESULTS
Study area and climate
The study was conducted in Madhabpur Hailakandi district (24plusmn210N latitudeand 76plusmn130E longitude) from March 1999 to August 2000 The study site hasa warm humid climate with mean annual rainfall of 2660 mm most of whichduring the south-west monsoon season (May to September) The mean maximumtemperature ranges from 254plusmnC (January) to 326plusmnC (August) and the meanminimum temperature varies from 11plusmnC to 25plusmnC (August) The dry season usuallycorresponds to the period from December to February The soil at the studysite is udic hyperthermic with the following physico-chemical properties bulkdensity (114 gcm3) water holding capacity (5916) soil texture sandy loamsoil pH (578) and organic carbon (137) [3] The selected stand of Muli bamboo(Melocanna baccifera) resulted from gregarious owering in the year 1964 As therhizome system is a diffuse pachymorph type and culm growth results in a plantationlike appearance it was not possible to differentiate individual plants
Phenology and growth of culm
The phenological observations on different features of culms such as colour of culmand sheath presence of leaf and sheath on the culm were recorded from July 1999 toJune 2000 Four age classes of culm were selected (i) current culm (ii) 1 year old(iii) 2 years old and (iv) more than 2 years old From each age category ve culmswere randomly selected and tagged with aluminium foil Thereafter the differentphenophases were observed at monthly intervals
The culm growth was studied during August 1999 to May 2000 Because bamboois a quick growing plant and its height stabilizes over a comparatively short spanof time a longitudinal study was preferred rather than considering different randomsamples at different times [12] Forty newly sprouted culms were randomly selectedwith initial height ranging from 5 to 10 cm and identi ed with numbered aluminiumfoil tags The growth in height was studied for 266 days Height was measureddaily for the rst 25 days thereafter on alternate days for 108 days When in thelast phase growth was slower it was measured at weekly intervals It was observedthat from August it takes approximately eight months for height to be stabilizedMean heights over time are shown in Fig 1a
The rate of growth varies during the eight month period To measure the culmheight growth rate the average rate of change in height between any two-timeepochs (say t1 and t2 was measured as
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Phenology and culm growth of Melocanna baccifera 29
(a)
(b)
Figure 1 Culm height growth (a) and culm height growth rate (b) of Melocanna baccifera
y2 iexcl y1
t2 iexcl t1
where y1 and y2 are heights at time t1 and t2 The results are shown in Fig 1b
DETAILED PHENOLOGY
Detailed phenological observations of different age classes of culms in Melocannabaccifera are summarised in Table 1 The culms emerged during the period JulyndashAugust (rainy season) The leaves are absent on the newly emerged culms and start
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
30 S Nandy et alTa
ble
1Ph
enol
ogic
alfe
atur
esof
diff
eren
tage
clas
ses
ofM
eloc
anna
bacc
ifer
acu
lmdu
ring
July
1999
ndashJun
e20
00
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
New
culm
(i)
Lea
fA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tIn
itiat
ion
ofle
afbu
dfo
rmat
ion
Pres
ent
Pre
sent
(ii)
Col
our
ofcu
lmC
ulm
cove
red
by shea
ths
Cul
mw
rapp
edw
ith
shea
ths
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Lig
htgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thT
ippo
rtio
ngr
eeni
shlo
wer
port
ion
redd
ish
brow
n
Tip
port
ion
gree
nish
low
erpo
rtio
nre
ddis
hbr
own
Tip
port
ion
ligh
tbr
own
low
erpo
rtio
nre
ddis
hbr
own
Lig
htbr
own
Lig
htbr
own
Lig
htbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
Dar
kbr
own
1ye
arol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
25
fall
en75
fa
llen
New
leav
esst
artt
oap
pear
New
leav
esas
wel
las
old
leav
es(i
i)C
olou
rof
culm
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
Dar
kgr
een
(iii
)C
olou
rof
shea
thD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nD
ark
brow
nB
lack
ish
Bla
ckis
hB
lack
ish
Bla
ckis
h
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Phenology and culm growth of Melocanna baccifera 31
Tabl
e2
(Con
tinu
ed)
Age
Phe
nolo
gica
lO
bser
vati
onpe
riod
clas
sfe
atur
e19
9920
00
July
Aug
S
ept
Oct
N
ov
Dec
Ja
nF
eb
Mar
chA
pril
May
June
2ye
ars
old
(i)
Lea
fP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
ntP
rese
nt40
fa
llen
80
falle
nN
ewle
aves
appe
ar
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nD
ark
gree
nw
ith
whi
tesp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hbl
ack
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s
Dar
kgr
een
wit
hm
any
spot
s(i
ii)
Col
our
ofsh
eath
Bla
ckB
lack
Bla
ck
very
few
pres
ent
Bla
ckB
lack
Bla
ckB
lack
and
half
brok
en
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Bla
ckan
dha
lfbr
oken
Abs
ent
Abs
ent
gt2
year
sol
d(i
)L
eaf
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
Pre
sent
75
fall
en90
fa
llen
New
leav
esap
pear
New
asw
ella
sol
dle
aves
(ii)
Col
our
ofcu
lmD
ark
gree
nw
ith
spot
s
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Dar
kgr
een
wit
hsp
ots
Yel
low
ish
gree
nY
ello
wis
hgr
een
Yel
low
ish
gree
n
(iii
)C
olou
rof
shea
thA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
tA
bsen
t
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
32 S Nandy et al
appearing after about 8 months ie in the month of April The culms are initiallycovered by sheaths which are persistent in nature and retained on the culms forabout 2 years This persistent nature of culm sheath helps to protect soft culmsin early growth as reported by Chua et al [14] The emergence of new culmsduring rainy season was also reported in Melocanna baccifera by Banik [5] and inGigantochloa ligulata and G levis in Japan by Ueda [11] The new culms werevery soft and delicate During this early growth period monkeys damaged a largenumber of shoots The new shoots locally called koril are an important edibleresource which is gathered and sold in local markets
The leaves which appeared in the month of April were retained for a periodof almost one year and then started falling The fall of leaves in the month ofApril is followed by appearance of new leaves and thus lea ng pattern exhibitedlsquoperiodic-growth leaf exchangersquo type [15] This pattern of leaf renewal helpsthe species in retranslocation of nutrients from older leaves and this needs futureinvestigation Similar lea ng pattern was also observed in Neohouzea dullooaan early successional species in secondary vegetation after shifting cultivation inNorth-Eastern India [16]
DISCUSSION
The height growth curve of culms (Fig 1a) appears to have a smooth S shape Theshape of the growth curve is described by the rate of change of growth at differenttimes If the curve is changing in a non-linear fashion it may be possible to nd asimple mathematically de ned curve which describes the change and which can beestimated from the data The estimated parameters can then be treated as a summaryof the growth pattern These values may be used for comparison across species orvarieties or same species growing under different environmental conditions Theauthors in a separate study are investigating this
From the growth rate curve of culm height (Fig 1b) it is observed that during the rst three months the growth rate was increasing with maximum growth of 177 cmper day in November During the rst 25 days from the third week of August tothe middle of September growth was very slow only 02 to 20 cm of increment inheight per day In the next 20 days ie up to rst week of October the growth rateincreased very fast from 20 to 160 cm height growth per day During next 45 daysuntil the third week of November growth varied between 160 to 177 cm per dayThis period may be termed the peak growth period and has been reported in otherbamboo species by Rao et al [12] Nearly 60 of the total height growth is attainedduring this period From the fourth month onwards the growth rate progressivelydecreased Within rst 20 days up to December 10 it decreased very fast reducingto less than half and came down to 79 cm increment per day For the next 50 daysuntil the last part of January the growth rate remained more or less constant varyingbetween 675 cm to 858 cm per day After that during February March and April
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Phenology and culm growth of Melocanna baccifera 33
it decreased very slowly nally showing zero growth by the end of April ie theculms cease to grow in height any further at this point of time
Banik [9] reported the maximum rate of culm elongation in Melocanna bacciferaas 44 cm per day and the minimum as 15 cm per day Such a fast rate was observedduring the second half of the complete culm elongation period The total culmelongation period was 55ndash60 days Osmaston [17] reported that the daily extensiongrowth in the culms of Dendrocalamus gigantias was 10ndash30 cm with a maximumof 58 cm Similarly Shanmughavel and Francis [10] reported an average heightgrowth of 30 cm per day in Bambusa bambos In Bambusa tulda maximum growthof 70 cm per day was reported [18] The maximum height attained in the presentstudy was 1676 m exceeding the 13 m reported by Banik [5]
The growth strategy exhibited by Melocanna baccifera with periodic growthlea ng pattern and rapid height growth is an adaptation as an early colonizerThis along with its special rhizome architecture makes this species valuable forrestoration of degraded land
Acknowledgements
One of the authors (A K D) wishes to thank Dr R L Banik Advisor INBARproject of ce at Tripura India for the useful discussion during the preparation ofthis manuscript
REFERENCES
1 I V Ramanuja Rao Bamboo for sustainable development an agenda for action INBARMagazine 6 (3-4) 35ndash39 (1998)
2 D K Hore Genetic resources among bamboos of Northeastern India Journal of EcologyTaxonomy and Botany 22 (1) 173ndash181 (1998)
3 S Nandy Studies on the ecology of Muli bamboo mdash Melocanna baccifera (Roxb) Kurz mdashin Barak Valley North-East India MPhil thesis Department of Ecology Assam UniversitySilchar Assam India (2001)
4 K Haridasan Bamboos in North East India mdash their distribution and conservation draft paperon bamboo distribution commissioned by the NEHHDC INBAR presented at TERI-CBTCSeminar Guwahati (2001)
5 R L Banik Investigationon the culm productionand clump expansionbehaviourof ve bamboospecies of Bangladesh Indian Forester 114 576ndash583 (1988)
6 J T Williams and V S Rao (Eds) Priority species of bamboo and rattan INBAR TechnicalReport No 1 INBAR and IBPGR New Delhi (1994)
7 A N Rao V R Rao and J T Williams Priority species of Bamboo and Rattan IPGRI-APOSardang (1998)
8 M Watanabe A proposal on the life form of bamboos and ecological typi cation of bambooforests in Bamboo Production and Utilization Proceedings of the Project Group P 504 18thIUFRO World Congress T Higuchi (Ed) Publ Japan Society of Bamboo Development andProtection (1986)
9 R L Banik Annual growth periodicity of culm and rhizome in adult clumps of Melocannabaccifera (Roxb) Kurz Bangladesh Journal of Forest Science 28 (1) 7ndash12 (1999)
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
34 S Nandy et al
10 P Shanmughavel and K Francis Above ground biomass production and nutrient distributionin growing bamboo (Bambusa bambos (L) Voss) Biomass and Bioenergy 10 (56) 383ndash391(1996)
11 K Ueda Studies on the physiology of bamboo Bulletin of Kyoto University 30 169 (1960)12 K S Rao P S Ramakrishnan and K G Saxena Architectural plasticity of bamboos and its
signi cance in the succession Bamboo Journal 8 92ndash99 (1990)13 F M Schlegel Growth behaviour of Chusquea culeou in South Central Chille Journal of the
American Bamboo Society 8 (1-2) 59ndash64 (1991)14 M Hills (Ed) in Statistics for Comparative Studies pp 194 Chapman and Hall London
(1974)15 K S Chua B C Soong and H T W Tan The Bamboos of Singapore IPGRI-APO Singapore
(1996)16 K A Longman and J Jenik Tropical Forest and its Environment Longman London (1987)17 B B Osmaston Rate of growth of bamboos Indian Forester 44 (2) 52ndash57 (1918)18 S Drans eld and E A Widjaja Plant Resourcesof South East Asia CD-versionETI and Prosea
Foundation Indonesia (2001)
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
J Bamboo and Rattan Vol 3 No 1 pp 35ndash43 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Basic density and strength properties of cultivated Calamusmanan
R WAHAB 1curren O SULAIMAN2 and H W SAMSI 3
1 University Malaysia of Sabah (UMS) Locked Bag 2073 88999 Kota Kinabalu Sabah Malaysia2 University Science of Malaysia (USM) Penang 11800 Malaysia3 Forest Research Institute Malaysia (FRIM) Kepong 52109 Kuala Lumpur Malaysia
AbstractmdashThis research investigates the basic density of Calamus manan cane grown in plantationand its relationship to strength Cane samples were obtained from two plantation area in MalaysiaThe results indicate that the lower part of the cane shows to have higher basic density compared to thehigher part of the cane The older canes (18 and 24 year-old) show a higher basic density comparedto young canes (7 and 11 year-old) Samples with higher basic density show to have higher strengthcompared to those with lower basic density Older canes indicate to have a 7ndash8-times higher strengthcompared to young canes
Key words Calamus manan cane basic density strength MOR
INTRODUCTION
Canes are the main source of raw materials for furniture and weaving industry Theycan be used to make furniture baskets mats hunting and shing utensil itemsfor adornment etc One of the most popular canes found in Malaysia is Calamusmanan It is sometimes called lsquoking of the canersquo by the local furniture industry Itis strong very exible versatile and possesses higher quality over the other canespecies
Utilization of C manan is considered over-exploited This led to resource exhaus-tion and the species become scarce and expensive In the mid-1980s the govern-ment of Malaysia encouraged the establishment of cane plantations in the forestand intercropping between the rubber trees The Forestry Department in Peninsu-lar Malaysia (and FRIM at that time under Forest Department) Sarawak and Sabahtook the leading role in initiating by establishing the cane plantation in forest reserve
currenTo whom correspondence should be addressed E-mail drrazakwyahoocom
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
36 R Wahab et al
areas Several private companies with the support of several government agensiesfollowed this later Aminuddin and Supardi [1] reported that under this programmedmore than 13 000 ha of land was planted with canes
After more than a decade these planted canes have reached the recommendedharvesting age [1 2] Early observations based on the growth performance of thecanes show promising returns As a result some of these canes were harvested
Some fundamental studies on wild C manan have been performed by severalresearchers [3ndash5] Ani and Lim [3] studied 11-year-old cultivated C manan andfound out that there were differences in the bre wall thickness between the forestand the cultivated one However the bre length was almost similar To ourknowledge no study has been carried out on the strength of cultivated canes Studieson other cane species mostly focused on the physical and mechanical properties ofmatured with canes of unknown age [6ndash9]
MATERIALS AND METHODS
Twenty-four stems of planted Calamus manan consisting of six from each agegroup of 7 11 18 and 24 years were used in the study Stems of age-group 7and 11 were taken from the Paka Trengganu and stems from age-group 18 and 24were taken from Temerluh Pahang The sites where these canes were cultivatedwere noted to have similar soil characteristics The determination of age is basedon date of planting as provided by the planters
Each stem was sampled and labelled at six levels of height A height levelor namely a portion consists of a length of 3 meters Portion 1 represents culmheight from 0 to 3 meters portion 2 represents culm height 3 to 6 meters portion3 represents culm height 6 to 9 meters portion 4 represents culm height 9 to12 meters portion 5 represents culm height 12 to 15 meters and portion 6 representsculm height 15 to 18 meters This length is considered to be a standard lengthwhich is commonly practiced by the canes industry in the country for processingand utilization purposes Only portions 1 2 3 4 5 and 6 have been taken and usedin the studies due to dif culties in extracting the rest of stem portions and to getuniform characteristics
Within a week after harvesting these canes were cured in diesel oil as this isnormal practice in the cane industry This is also being outlined by Razal et al [10]The duration of the process was about 20 min All processed canes were air-driedfor about 14 days These canes were cut into smaller sizes according to size requiredfor physical and mechanical studies These samples were kept in a conditioningchamber of about 20plusmnC and 65 RH to produce an equilibrium moisture contentof about 12sect1 The mechanical tests were conducted using Shimadzu UniversalTesting Machine in accordance to BS 373 [11] and ASTM 143-53 [12]
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Basic density and strength properties of cultivated Calamus manan 37
RESULTS AND DISCUSSION
The cross-section of 11-year-old and 24-year-old canes from portion 1 from thesame height are shown in Fig 1 It shows variation in culm density between theouter and inner part of the culm The outer part of older canes (24 years old) showsa much higher density compared to younger one (11 years old) Figure 2 showsvariation in density along the height of canes Portion 1 that is near the base issmaller in diameter compared to portion 6 The diameter of the canes increasesfrom the bottom portion to the top
The basic density is a measure of the relative amount of solid cell wall materialThe results of basic density studies are shown in Table 1 The trend of therelation of basic density with portion is shown in Fig 3 This result indicatesthat the basic density is signi cantly higher as the canes mature The analysis ofvariance (ANOVA) of the results is summarized in Table 2 The multiple range
Figure 1 Cross-section showing a distinct variation in density between outer and inner portion ofcultivated 11-year-old C manan (panel A) An image of 24-year-old C manan which consideredmatured is seen in panel B
Figure 2 Cross-section showing the variation in density between the outer and inner portion ofcultivated7-year-oldC manan at different height A represents portion1 B portion 3 and C portion 6
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
38 R Wahab et al
Table 1Means value for basic density of age-group 7 11 18 and 24-year-old culm
Table 2Summary of analysis of variance on basic density of planted C manan at different ages culms andportions
Source of variation df F -value and statistical signi cance
Age 3 80155
Culms 4 194ns
Portion 5 8744
ns not signi cant at P lt 005 currencurrensigni cant P lt 001
Figure 3 Trend of basic densities in portions of C manan from different agegroups
tests (MRT) on effects of age portion and culm on basic density of cultivatedC manan are shown in Table 3 The basic densities signi cant decrease from thebasal to the upper portions These ndings were in agreement with previous studies[10 13ndash15] This relationship is probably related to the percentage amount of bre
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Basic density and strength properties of cultivated Calamus manan 39
Table 3Multiple range tests (MRT) on effects of age portion and culm on basic density of planted C manan
Basic density
Age 7 11 18 24043a 047b 061c 070d
Culm 1 2 3 4 5055b 055b 054a 054a 056b
Portion 1 2 3 4 5 6062f 058e 056d 054c 051b 047a
ns not signi cant at P lt 005 currencurrenhighly signi cant P lt 001 Means in the same rows followedby the same letter are not signi cantly different at the 005 probablity level
Table 4Relationship between basic density and age-groups
Equation Intercept (a) Slope (b) R2 Standard error P -value
Basic density D a C b pound age 0302 00164 081 00121 lt00000
base on height of the canes The lower portion contain higher amount of bres ascompared to the upper part of the canes
The relationship of basic density and age factor was analysed using regressionas shown in Table 4 The correlation coef ent indicated a moderately strongrelationship between both variables This value can be used to predict limits fornew observations in age and even for the strength properties
The results of mean values of modulus of rupture (MOR) modulus of elasticity(MOE) for static bending tests and modulus of rupture (MOR) for compression testsare tabulated in Figs 4ndash6 and Table 5 Generally the mean strength values of canesdecrease with the portion Portion 1 shows the highest strength value while portion6 has the lowest strength Canes from the 24-year-old group exhibited the higheststrength value as compared to other age-groups The MORs from static bendingranged from 1683 MPa to 1678 MPa These are expected as they possess thehighest basic density This is followed by 18 year-old age-groups having the MORfrom static bending range from 305 MPa to 429 MPa However there was a suddendecrease in strength values for the 11-year-old and 7-year-old age-groups canesThe strength values ranged from 47 MPa to 77 MPa and 39 MPa to 66 MParespectively These strength values for both age-groups are considered as too lowand might not be suitable for industrial utilization The strength properties relatedvery well with the density as discussed earlier
CONCLUSIONS
The lower part shows to have higher basic density compared to higher part ofthe canes The older canes (18 and 24 years old) have a higher basic density
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
40 R Wahab et al
Table 5Means value for modulus of rupture for compression modulus of rupture and modulus of elasticityfor static bending tests at 12 moisture content for C manan of age-groups 7 11 18 and 24-year-old
ns not signi cant at P lt 005 currencurren highly signi cant P lt 001
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Basic density and strength properties of cultivated Calamus manan 41
Figure 4 Modulus of rupture on compression tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
Figure 5 Modulus of rupture (MOR) on bending tests at different age-group of planted C manan atportions 1 2 3 4 5 and 6
compared to young canes (7 and 11 years old) Samples with higher density have ahigher strength compared to canes with lower density Older canes indicate to havehigher strength compared to younger canes generally it can be concluded that the
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
42 R Wahab et al
Table 7Duncan multiple range test (MRT) of MOR bending MOE bending and MOR compression tests onplanted cane manau
Compression Bending strengthAge strength MOR (MPa) MOE (MPa)
7 65a 931a 2860a
11 73b 932a 2890a
18 398c 1043a 4120b
24 437d 1349b 5830c
Means in the same rows followed by the same letter are not signi cantly different at the 005probablity level
Figure 6 Modulus of elasticity on static bending tests in different age-groups of planted C manan atportions 1 2 3 4 5 and 6
cultivated Calamus manan of age 18 and above possess mechanical characteristicsthat makes them suitable for utilization
REFERENCES
1 M Aminuddin and N Supardi Opportunity and prospects for large-scale planting of rattans inPeninsular Malaysia Cane Imformation Center Bulletin 10 (2) 1 6ndash81415 (1991)
2 M N Salleh and M Aminuddin Canes as a supplementary crop in rubber plantation inProceedings of Rubber Growerrsquos Conference C Rajarao and L L Amin (Eds) pp 261ndash273Rubber Research Institute Malaysia Kuala Lumpur (1986)
3 S Ani and S C Lim Anatomical and physical features of 11-y-old cultivated C manan inPeninsular Malaysia Journal of Tropical Forest Science 3 (4) 372ndash379 (1991)
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Basic density and strength properties of cultivated Calamus manan 43
4 G Weiner and W Liese Anatomical structures and differences of canes genera from SoutheastCanes Information Center Bulletin 1 (12) 122ndash132 (1987)
5 G Weiner and W Liese Anatomical features of canes Canes Information Center Bulletin 6 (2)6ndash7 (1988)
6 M A Latif A K Roszaini and N Supardi Anatomical features and physical properties ofCalamus palustri ba Malaccensis Journal of Tropical Forest Science 2 (1) 6ndash15 (1996)
7 K M Bhat and C Renuka Variation in physical characteristic of Kerala grown rattans ofPeninsular India Malaysian Forester 49 185ndash197 (1986)
8 K M Bhat P K Thulasidas and C P Mohamed Strength properties of ten South Indian canesJournal of Tropical Forest Science 5 (1) 26ndash34 (1992)
9 K M Bhat A Mathew and I Kabeer Physical and mechanical properties of canes of Andamanand Nicobar Islands (India) Journal of Tropical Forest Science 2 (1) 16ndash24 (1996)
10 W Razak M Tamizi and O Arshad Cane oil curing bleaching and preservation in Transferof Technology Model Series INBAR Beijing (2001)
11 Standard Method for Testing Small Clear Specimen of Timber British Standard 373 p 71British Standard Institution London (1957)
12 Annual book of ASTM Standards D 143ndash52 (1974)13 W Razak W S Hashim W A Wan Tarmeze and M Tamizi Properties and products quality
of cane manau from plantation Paper presented at the National Cane Seminar 2000 FRIMMalaysia (2000)
14 W Razak W S Hashim and H Hamdan Comparative strength properties between planted andwild Calamus manan Presented at the Malaysian Science and Technology Conferences 2001Kota Kinabalu Sabah Malaysia (2001)
15 A K Roszaini The physical properties of Calamus scipionum and Daemonrops angustifolia atdifferent ages and height Joumal of Tropical Forest Science 4 (2) 153ndash158 (1998)
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
J Bamboo and Rattan Vol 3 No 1 pp 45ndash56 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Characteristics of three western Nigerian rattan speciesin relation to their utilisation as construction material
E B LUCAS 1 and B I O DAHUNSI2curren
1 Department of Agricultural Engineering University of Ibadan Nigeria2 Department of Civil Engineering University of Ibadan Nigeria
AbstractmdashPhysical and mechanical properties of three rattan cane species Calamus deerratusEremospatha macrocarpa and Laccosperma secundiorum were evaluated The objective was todetermine their suitability for construction especially for structural members Proximate analyses aswell as mineral contents were also determined The moisture content and density of green sampleswere 155 (dry basis) and 587 kgm3 respectively L secundiorum had the highest carbohydratecontent while C deerratus had the least Radial shrinkage and swelling exceeded longitudinalshrinkage and swelling in all the rattan species suggesting high anisotropism in movement Moisturecontent had signi cant effect (P lt 005) on the moduli of elasticity and rupture of all the rattanspecies The moduli of elasticity of C deerratus E macrocarpa and L secundiorum were 3396 516and 11 106 Nmm2 respectively The strength properties of the rattan canes were found to be lowerthan those of timber species of comparable densities The physical and mechanical properties of therattan canes studied were found to be adequate for use as reinforcement in lowly stressed concreteelements such as frameworks for ferrocement and complex shaped formworks
Key words Rattan species physical properties mechanical properties construction material proxi-mate analysis mineral analysis
INTRODUCTION
Rattans are non-wood forest products whose economic value is well exploitedin the far Eastern Countries especially Malaysia Indonesia Singapore and thePhilippines More than 700 million people spread all over the world trade in oruse rattan for a variety of purposes [1] Furniture however is the most popularrattan product In Nigeria rattans remain a great potential only now being slightlytapped The share of rattan and cane products in Nigeriarsquos gross domestic productsis negligible [2] Knowledge of their properties should enhance industrial utilization
currenTo whom correspondence should be addressed E-mail biodahunsiengineercom
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
46 E B Lucas and B I O Dahunsi
locally and improve on its possible contribution to Nigeriarsquos economy There areabout 600 species of rattan belonging to 13 genera Sunderland [3] reported that 20species from 4 genera have been identi ed in West and Central Africa He furtherstated that the four genera of African rattan are easy to differentiate particularlythrough the morphology of their climbing organs The rattan stem diameter variesgreatly from 2 to 3 mm among the smallest species to 100 mm in exceptionallylarge species [4] Rattans with a stem diameter of 18 mm and above are classi ed aslarge-diameter canes while the others are the small-diameter canes Rattans havebeen found to grow to great heights usually around 46 m but may reach as muchas 150 m [5]
Rattan canes when soaked in water for a day or two depending upon thetemperature of the water become a softer and more pliable material that can bereadily bent into contorted curved shapes [6] The cortical or outer portion of rattanstem is extremely hard and durable while the medullary or inner portion is soft andsomewhat porous [7] The toughness and appreciable tensile strength of rattan caneshave been harnessed to produce highly-stressed articles such as nooses for catchingelephants [8] Purseglove [9] reported the use of rattan for the construction of aswinging bridge over the gorge in Assam India He further mentioned the use ofrattan as tether- guy- and tow-ropes Rattan bridges have also been encountered insome parts of West and Central Africa [3] Rattans have also been utilized as dragrope for hauling timber and tethering buffaloes [10] The use of rattan canes forbuilding and general construction works in Southern and Western parts of Nigeriahas been observed [2 11] The areas of application include frames walls partitionsrafters and ceilings of mud houses They have been used in the construction ofarticles such as barn granaries shing traps sieves and winnowers mats andtrays and also as reinforcement for wall partitions and frames of structures usedas stores market stalls and residential abodes of forest communities The excellentperformance of some rattan canes under stress led Burkill [10] to conclude that thereis no natural product that would be able to compete with rattan if adequate supplycan be guaranteed at a reasonable price Drans eld [4] stated that few productshave the strength and exibility for utilization as material for furniture productionlike those of true rattan
Drans eld [12] reported that studies on the physical properties of rattan are intheir infancy He stated that the diameter of the internodes and indeed the stemitself does not usually vary signi cantly along their length and that the cross sectionis usually more-or-less circular An investigation to determine the steady state waterpermeability of some rattan species [13] showed that they obeyed Darcyrsquos lawand that permeability of internodal and nodal samples did not differ signi cantlyThe Reynolds number (Re) obtained for rattans was 044ndash238 indicating that the ow of liquid in rattan was laminar A study by Goh [14] concluded that thestrength properties of the species of rattan studied by him (Calamus manan) weregreater in the air-dried condition than those in green condition He further observedthat air-dried material (144 moisture content) had a density of 750 kgm3 and
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Characteristicsof three rattan species 47
compression strength parallel to grain of 30 MPa Kadir [15] mentioned thatmechanical properties of rattan canes as observed in two species investigated byhim (C scipionum and Daemonorops angustifolia) decreased from the basal to thetop portion of the stem The mechanical properties are also signi cantly affected bythe age of the plant with the highest values obtained in 12-year-old plants
The speci c and interactive properties of Nigerian canes are hardly documentedunlike in Asia where much work has been done on the properties of Asian rattanspecies of economic importance Most of the research efforts on rattan canes inNigeria have been on its trade and utilization especially for furniture [2 16ndash18]No records of the physical and mechanical properties of Nigerian rattan canesappear in published works Sunderland [3] reported that recent research on Africanrattan has concentrated on providing information on the taxonomy ecology andutilization Kadir [15] mentioned that there is a dearth of information on theproperties of rattan species Hence some of them have remained unutilised Furtherresearch is needed to determine the properties and also the appropriate utilizationtechnology of such species The chemical and mineral compositions of biologicalmaterials are known to have effect on their physical and mechanical propertiesKnowledge of the properties of Nigerian rattan canes would indicate the extentto which they can be adopted for structural usage including as reinforcement inconcrete and framework for ferrocement These areas appear presently untouched
MATERIALS AND METHODS
The canes from three species of rattan palms were studied The species areC deerratus Eremospatha macrocarpa and Laccosperma secundiorum Maturedsamples from wild stocks whose actual ages could not be determined wereobtained from Epe (Lagos State) and OkadaSapoba (Edo State) forests in WesternNigeria The rattan samples were carefully collected and their morphologicalcharacteristics studied for the purpose of identi cation References were made tothe stocks of rattan samples kept in the herbarium of the Department of BotanyUniversity of Ibadan Nigeria
The following physical properties were determined for the three species of rattancane moisture content density and shrinkage and swelling coef cients The testsamples used in this study were mainly from the middle portions of the harvestedplants Moisture content was determined using the oven-drying method Thedimensions of the rattan canes were measured with vernier calliper and micrometerscrew gauge while the weight was determined using an electronic balance
Proximate and mineral analyses were carried out Moisture and dry mattercontents fat crude bre content protein content ash content carbohydrate contentand energy value were determined by the methods recommended by Associationof Of cial Analytical Chemists (AOAC) [19] The mineral contents determinedinclude calcium magnesium potassium sodium manganese iron copper zincand phosphorous All the minerals except phosphorous were determined by use
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
48 E B Lucas and B I O Dahunsi
of atomic absorption spectrophotometer as recommended by the AOAC [19] Thephosphorous content was determined using the Vanado-Molybdate method [19]
Static bending tests were carried out on 40 test samples of each species atfour different moisture content levels (20 16 12 and 8) and perpendicular todirection of grains to determine bre stress at elastic limit and moduli of rupture andelasticity This was done by adapting the method used by Sekhar and Rawat [20]in their experiment on the strength properties of an Indian cane (C tenuis) Oneset was tested with node at the centre while the other was tested without nodes atthe centre For each test a sample measuring 250 mm was prepared and mountedon two supports of an adapted test jig at a span of 150 mm Load was appliedat the centre of the specimen till it failed as recommended by ASTM D143 [21]De ection of the neutral plane at the centre of the specimen was recorded againstload through a dial gauge and load-de ection characteristics were determined foreach test specimen The loads and de ections at the elastic limit were used toevaluate the bre stresses at elastic limit and modulus of elasticity while the loadthat caused complete failure was utilised for modulus of rupture
RESULTS AND DISCUSSION
Physical properties
The moisture contents and densities of green rattan samples are as shown in Table 1Green samples of E macrocarpa had the highest average moisture content (188)while C deerratus had the lowest average moisture content (135) The resultsobtained in this study were close to the general values of between 130 and 160recorded for rattan canes by Liese [22] The high moisture content of greensamples of rattan cane has implications on the weight of freshly harvested rattancane materials Therefore it would be good management practice to season freshrattan canes before transporting them High moisture content could also makethem susceptible to attack by fungi and insects It may also result in dimensionalinstability
Density of green samples of the rattan species ranged from 487 to 667 kgm3 withC deerratus having a density value of 648 kgm3 while those for L secundiorum
Table 1Moisture content (green) and density of rattan canes
Rattan species Moisture content (green) () Density (kgm3
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Characteristicsof three rattan species 49
and E macrocarpa were 573 and 539 kgm3 respectively The density of biologicalmaterials could give an indication of their strength properties although some lighterspecies have been known to possess higher strength than denser materials
Radial shrinkage was higher than longitudinal shrinkage for all the rattan species(Table 2) The average value of radial shrinkage coef cient found to be 72037 pound10iexcl6 mmmm per 1 change of moisture content was lower than the averagevalue of 1730 pound 10iexcl6 mmmm per 1 change of moisture content obtainedby Lucas and Ogedengbe [23] in their study of the shrinkage characteristicsof bamboo (Bambusa vulgaris) Radial shrinkage coef cient of E macrocarpawas 42324 pound 10iexcl6 mmmm per 1 change in moisture content while those forL secundiorum and C deerratus were 62224 pound 10iexcl6 and 11562 pound 10iexcl6 mmmmper 1 change of moisture content The values of longitudinal shrinkage coef cientof the rattan cane species was relatively small ranging from 6108 pound 10iexcl6 to13091 pound 10iexcl6 mmmm per 1 change of moisture content Radial shrinkage ofrattan canes was from 00948 to 01534 mmmm This was higher than the averagevalue of 5 (005 mmmm) recorded by Wijensinghe [24] for woods dried fromgreen to oven-dry condition The longitudinal shrinkage ranged from 00137 to00180 mmmm This compared well with the value of around 1 estimated byWijensinghe [24] Anisotropic shrinkage of rattan canes may cause distortion thatcould lead to incipient failure Some samples of L secundi orum were observed tohave cracks on their surfaces along their lengths when dried from green to oven-drymoisture levels These cracks which are areas of incipient structural failure can beattributed to differential drying rate of the core to the outer parts of cane resultingin shrinkage stresses at the outer portions whose drying rates were lower leading tocrack propagation
The swelling characteristics of the rattan canes are as shown in Table 3 The ra-dial swelling values are 01371 01422 and 00829 mmmm for L secundiorumC deerratus and E macrocarpa respectively The radial swelling of L secundi- orum was observed to be higher than the corresponding longitudinal shrinkagewhile those for the other rattan species were found to be lower The longitudinalswelling was found to be lower than radial shrinkage for all the rattan species The
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
50 E B Lucas and B I O Dahunsi
Table 3Swelling characteristics of rattan canes
Rattan species Radial Longitudinal Rs=Ls Radial Longitudinalswelling Rs swelling Ls swelling rate swelling rate(mmmm) (mmmm) (mmmm per (mmmm per
differential swelling and shrinkage characteristics may set up stresses within thecane leading to cracks warping and loss of integrity
Proximate and mineral analyses
The results of the proximate analyses of rattan canes are given in Table 4 whilethose of mineral analyses are shown in Table 5 Samples from all the rattanspecies have more than 70 carbohydrate content with L secundiorum havingthe highest value of 7944 while C deerratus had the least value of 7690Tests using iodine indicated that the carbohydrate content of L secundiorum wasconcentrated mainly in its inner portions Dahunsi [11] reported that the innerportion of L secundi orum was the main target of subterranean termite due toits high concentration of carbohydrates The termites ate the inner portions whileleaving the outer portions relatively untouched
The protein content of the rattan canes tested was found to range from 294to 462 while the percentage ash ranged from 096 to 193 The dry mattercontent of air-dried rattan canes was 8516 8598 and 8384 for L secundiorumC deerratus and E macrocarpa respectively Fat content of rattan cane sampleswas between 046 and 082
Calcium magnesium and potassium were the major mineral constituents of thethree species of rattan investigated This is similar to the mineral composition ofwoody plants in which the above minerals constitute up to 70 of the mineralcontent [25]
The energy values of the three species of rattan are as given in Table 6 Theaverage energy value of 1340 MJkg at 16 moisture content for rattan canewas less than the average of 1815 MJkg estimated for oven-dried wood byDinwoodie [26] This was attributed to the fact that the analysed samples werenot oven-dried Dinwoodie [26] con rmed that when wet wood is burnt the oven-dry energy value is reduced due to extra energy required removing the extra waterpresent in the wood The theoretical energy value for the three species of rattancalculated from Dulong Petitrsquos equation used by Lucas and Fuwape [27] was 17001702 and 1700 MJkg for L secundi orum C deerratus and E macrocarpa
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Characteristicsof three rattan species 51
Table 4Proximate composition of samples from three rattan species
Rattan species Constituents ()
Protein Crude oil Ash Fat Moisture Dry matter Carbohydratecontent
Calculated from Dulong Petitrsquos equation by Lucas and Fuwape [27]
respectively The energy value of rattan canes which compared well with thosefor other wood products indicated that their waste products could be used as fuelwood However the high ash content (096ndash193) compared to domestic fuel-woods show that much residue would be left after combustion This may result indisposal problems Rattan canes are therefore not expected to be a popular sourceof energy except during emergencies when shortage of more ef cient fuel sourcesexists The use of rattan canes as fuel would therefore not be expected to be asource of competing demand since more ef cient fuel sources exist This wouldtherefore not put pressure on availability of canes for structural applications
Mechanical properties
The moduli of elasticity (MOE) for the rattan canes are given in Fig 1 At 12moisture content L secundiorum C deerratus and E macrocarpa have MOE
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
52 E B Lucas and B I O Dahunsi
Figure 1 Modulus of elasticity (Nmm2) of rattan cane samples at four moisture content levels
values of 11 106 3396 and 518 Nmm2 respectively The MOE of L secundiorumfalls within the N3 strength group when compared to wood [28] The MOEfor L secundi orum and C deerratus were higher than the values of 1143 and1430 Nmm2 obtained by Kadir [15] for 12-year-old samples of C scipionum andD angustifolia respectively from the middle portion of rattan stems The meanMOE for C deerratus and E macrocarpa were found to be lower than those of theN7 strength group [28] The MOE values were higher in nodal specimens comparedwith internodal samples with the exception of that for L secundiorum at 20 andE macrocarpa at 8 MC However it was found that the differences in the MOEvalues of nodal samples compared to MOE values of internodal samples were notsigni cant (P lt 005) for both L secundi orum and E macrocarpa The presenceof node had signi cant effect (P lt 005) in the MOE values of C deerratus Themodulus of elasticity is a measure of the stiffness of material High stiffness wouldbe required to confer appreciable resistance to de ection resulting from imposedload
The moduli of rupture (MOR) for L secundiorum C deerratus and E macro-carpa at 12 MC were 9115 407 and 1066 Nmm2 respectively as shown inFig 2 The MOR values were higher than those for C scipionum and D angustifo-
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Characteristicsof three rattan species 53
Figure 2 Modulus of rupture (Nmm2) of rattan cane samples at four moisture content levels
lia [15] Moisture content was found to have a signi cant effect (P lt 005) on theMOR of rattan canes MOR of nodal samples was generally higher than those forinternodal samples This nding was at variance with the observations of Sekharand Rawat [20] that nodal samples of rattan have lower MOR values than intern-odal samples Statistical analysis however did not show any signi cant difference(P lt 005) in the MOR of the rattan species for nodal and internodal samples Thehigher MOR and MOE values of nodal samples could be attributed to the morphol-ogy of the rattan stem The stems of rattan at the node could be likened to twocylindrical drums being tightly tted into one another The point of attachment thusbecoming strengthened due to the thickening of this region containing high quantityof mechanical supportive tissues
The bre stresses at elastic limit of the rattan species are illustrated in Fig 3The relationship between the bre stresses at elastic limit and moisture content wassimilar to those obtained for moduli of elasticity and rupture
The failure mode of samples from L secundiorum was by sliding shear mainlythrough gradual propagation of cracks along its length especially in samples withmoisture content less than 16 The other type of failure notice in some samplesfrom this species was that of brittle failure without complete detachment of the
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
54 E B Lucas and B I O Dahunsi
Figure 3 Fibre stress at elastic limit (Nmm2) of rattan cane samples at four moisture content levels
cane The cane being held together by bre strands of the epidermis which havebeen shown by anatomical studies to be made up of largely mechanical tissues [11]Failures in both C deerratus and E macrocarpa were of plastic type with initiallinear load-de ection characteristics and then predominant plastic deformation untilthey could support no further increase in load At this point the rattan canescontinue to de ect even without further application of load
The performance of forestry products under applied loads is closely related totheir physical and mechanical properties Several Investigators including Panshinand de Zeeuw [25] have reported that the strength properties of forestry materialsare related to their speci c gravity In this study the density of the rattan specieswas found to relate to their mechanical properties
CONCLUSIONS
From the study the following conclusions on the technical properties of rattan canescould be drawn
i The rattan species studied have high amount of carbohydrate that can causethem to be susceptible to attacks by termites and other insects
ii Mineral composition of rattan canes is similar to those of woody plants
iii The strength properties of the rattan species are lower than those of timberspecies that have comparable densities
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
Characteristicsof three rattan species 55
iv The result of the various physical and mechanical properties shows that rattancanes may be used in reinforcing lowly stressed concrete elements such asframework for ferrocement concrete casings slabs on grade and for complexshaped formwork frame
v Moisture content has effect on the mechanical properties of rattan canespecies Improvements in mechanical properties were achieved by reductionsin moisture content level
vi Knowledge of the physical and mechanical properties of rattan canes wouldbe needed in order to design machines required for the mechanization of theharvesting and processing operations The values obtained from this workcould also be used to predict the behaviours of rattan canes when subjected toloading
REFERENCES
1 C B Sastry Rattan in the twenty- rst century mdash an overview Unasylva 52 (205) 3ndash6 (2001)2 O O Olubanjo Extensive Rattan Production-To-Consumption System in Southern Nigeria
A Case Study InternationalNetwork for Bamboo and Rattan (INBAR) Beijing (2002)3 T C H Sunderland Rattan resources and use in West and Central Africa Unasylva 52 (205)
18ndash23 (2001)4 J Drans eld Taxonomy biology and ecology of rattan Unasylva 52 (205) 11ndash13 (2001)5 P O Strausbaugh Rattan in Encyclopedia Americana Vol 23 M Cumming (Ed) p 269
Grolier Danbury CT (1997)6 H S Rao and B Lal Modelling with Cane The Indian Forester 94 (8) 630ndash634 (1968)7 L L Bram (Ed) Rattan and reed in Funk and Wagnalls New Encyclopedia Vol 22 p 127
Funk and Wagnalls New York NY (1996)8 T C Whitmore (Ed) in Palms of Malaya pp 13ndash52 Oxford University Press Oxford (1977)9 J W Purseglove Tropical Crops Monocotyledons Vol 2 pp 421ndash422 Longman London
(1972)10 I H Burkill (Ed) in A Dictionary of the Economic Products of the Malay Peninsula pp 1869ndash
1885 HorticulturalBooks (1966)11 B I O Dahunsi The properties and potential application of rattan canes as reinforcement
material in concrete PhD Thesis Faculty of Technology University of Ibadan Nigeria (2000)12 J Drans eld Rattan and cane in Encyclopedia of Material Science and Engineering Supple-
mentary Vol 2 R W Cahn (Ed) pp 61ndash65 Pergamon Press Oxford (1990)13 Z Ashaari and J A Pretty Steady-state water permeability of rattan (Calamus spp) part 1
longitudinal permeability J Tropical Forest Products 4 (1) 30ndash44 (1998)14 S C Goh Testing Rotan manau strength and machining properties Malayan Forester 45 (2)
275ndash277 (1982)15 R A Kadir Variation of Strength Properties of Locally Grown Calamus scipionum and
Daemonorops angustifolia Journal of the Institute of Wood Science 15 (6) 289ndash296 (2001)16 A B Morakinyo The Commercial rattan trade in Nigeria Forest Trees and People Newsletter
25 22ndash30 (1995)17 J P Pro zi Notes on West African rattans RIC Bulletin 5 (1) 1ndash3 (1986)18 D Komolafe Cane makers face raw material scarcity Daily Times (Nigeria) (5 August) 30
(1992)
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
56 E B Lucas and B I O Dahunsi
19 Association of Of cial Analytical Chemists (AOAC) Of cial Methods of Analysis 15th ednAOAC Arlington VA (1990)
20 A C Sekhar and B S Rawat Strength tests on Indian canes (1) Calamus tenuus The IndianForester 91 (1) 70ndash72 (1965)
21 American Society for Testing and Materials Standard Test Methods for Small Clear Specimensof Timber ASTM D143-94 (2000) e1 ASTM InternationalWest Conshohocken PA (2000)
22 W Liese Challenges and constraints in rattan processing and utilisation in Asia Unasylva 52(205) 46ndash51 (2001)
23 E B Lucas and K Ogedengbe Shrinkage Characteristics of Bamboo (Bambusa vulgaris)Nigerian Journal of Forestry 17 (1-2) 7ndash11 (1988)
24 L C A Wijensinghe The Differential Shrinkage of Wood The Ceylon Forester 4 (3) 281ndash285(1960)
25 A J Panshin and C de Zeeuw Textbook of Wood Technology 4th edn McGraw-Hill New YorkNY (1980)
26 J M Dinwoodie (Ed) in Wood Naturersquos Cellular Polymeric Fibre mdash Composite pp 14ndash133Institute of Metals London (1989)
27 E B Lucas and JA Fuwape Combustion-relatedand some other characteristicsof six nigerianplant species concerning their suitability as domestic fuels Nigerian Journal of Solar Energy 289ndash97 (1982)
28 Standards Organisation of Nigeria (SON) NCP2 The Use of Timber for Construction SONLagos (1973)
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
J Bamboo and Rattan Vol 3 No 1 pp 57ndash65 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Bonding characteristics of Gigantochloa scortechinii
A ZAIDON 1curren M T PARIDAH 1 C K M SARI 1 W RAZAK 2
and M Y N YUZIAH 3
1 Department of Forest production Faculty of Forestry Universiti Putra Malaysia 43400 SerdangSelangor Malaysia
2 Forest Product Division Forest Research Institute Malaysia 52109 KepongKuala Lumpur Malaysia
3 Malaysian Adhesive amp Chemicals Sdn Bhd Lot 9 Jalan Utas 157 40702 Shah AlamSelangor Malaysia
AbstractmdashThe adhesion and bonding propertiesof bamboo Gigantochloascortechinii were studiedThe variables studied were adhesive types grain orientation (parallel-ply or cross-ply) and bondingproperties of strips taken from different parts of bamboo culm ie strips taken near the periphery ornear the inner layer or a combinationof both Commercially availableadhesivesphenol formaldehyde(PF) urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were used to bond thebamboo strips The bonded specimens were subjected to plywood shear test in both dry and wetconditions The study showed that PF resin formulationsuitable for the productionof tropicalplywoodwas found to be most compatible for bonding bamboo strips neverthelessa slightly longer press timeis required to ensure suf cient curing of resin All shear strengths and wood failure percentage of thePF-bonded laminates met the minimum requirement of British standards The bonding properties ofUF-bonded laminates achieved the standard only when tested in dry conditions Hot press parametersemployed for pressing the MUF-bonded laminates was not suf ced to cure the resin The grainorientation (parallel or cross-ply) of the strips bonded with either PF or UF had no signi cant effecton the glue bond quality when tested dry In extreme wet conditions the parallel-ply laminates wereapparently more stable than the cross-ply laminates Different parts of the bamboo culm signi cantlyaffect the resulting glue bond quality In all conditions laminates made from peripheral strips gavemore stable products than those made either from inner strips or from the combination of both
Key words Bamboo Gigantochloa scortechinii strips bonding parallel-ply cross-ply
INTRODUCTION
Bamboo has been getting attention as a substitute material for wood [1] It hassimilar morphological properties to wood Due to its fast growth and availability
currenTo whom correspondence should be addressed E-mail zaidonputraupmedumy
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
58 A Zaidon et al
having an attractive and unique appearance this material can be converted intoengineered products such as composites laminated boards and plywood Theseproducts have gained commercial importance in China and Japan In Malaysia thismaterial has been used intensively in cottage industry like poultry cage vegetablebasket incense stick and joss paper skewer and chopstick and handicraft [2 3]
Due to the nature of the plants the utilization of bamboo culm can only be throughlamination In wood lamination bonding characteristics ie the surface wettabilitybuffering capacity and adhesive formulation are important since they determine therate of adhesive penetration into the wood surface the rate of adhesive curing andthe degree of adhesion developed between the substrate and the adhesive
Wettability of a wood surface refers to the rate or how fast a liquid can wetand spread on it The study of the wetting of solids by the contact anglemeasurements has become an important tool in the study of adhesion Accordingto Minford [4] wetting can be quanti ed by the equilibrium contact angle formedby the intersection of the solid liquid and gas phases When good wetting occursthe contact angle becomes very small and the liquid spread or ows spontaneouslyacross the surface Earlier study showed that the wetting angle of Gigantochloascortechinii (Buluh semantan) was 15plusmn [5] compared to 39plusmn for rubberwood after1 min of water droplet spreading [6]
Buffering capacity measures the resistance of wood to change in acidity or inalkalinity Both the pH and buffering capacity of the wood at the glueline affectthe cure of the resin Knowing the buffering capacity of wood helps determine theamount of buffering agent required in the adhesive to prevent changes in pH at theglueline These changes if not prevented will in uence the rate of curing of theresin Subsequently the working parameters ie assembly time press time andpress temperature will have to be adjusted and this could be very costly
This paper reports the bonding characteristics of bamboo strips (Gigantochloascortechinii) in terms of adhesion properties of the bamboo and the glue bondquality of the laminated board made from it An understanding of the bondingcharacteristics of this species is essential to ensure good bond quality is achievedand for bamboo to be able to complement wood
MATERIALS AND METHODS
Materials
Three-year-old culms of Gigantochloa scortechinii (Buluh semantan) were obtainedfrom Forest Research Institute Kepong Only culms having at least 7 mm wallthickness were selected to produce a minimum of 4-mm-thick strips after naldressing The culms were cross cut into 125 m long and converted into splits of20 mm wide using a splitting machine The epidermis and the inner parts of thesplits were removed Strips of 4 mm thickness were prepared from two separatezones of the split ie close to the periphery and close to the inner side All strips
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
were initially air-dried and then equalized in a conditioning room until it reached12 MC
Determination of buffering capacity of bamboo
Bamboo strip was ground to pass through a sieve with 53 sup1m mesh Theaqueous bamboo extract was prepared by re uxing 1 g bamboo particle in 100 mldistilled water for 1 h After re uxing the mixture was ltered using lterpaper The distillate was diluted to 400 ml and cooled to room temperature beforetitration Fifty ml was drawn from the solution and it was again diluted to 500 ml(concentration 002) Then 50 ml was taken and the initial pH of the solution wasrecorded The solution was titrated rst with 001 M HCl until it reached pH 30The procedure was repeated using another sample titrated with 001 M NaOH untilit reached pH 110 The pH value was recorded at every 5 ml of titration Theexperiment was done in triplicates and the values were maintained less than 5deviation
Gluing of bamboo strips
Gluing study was carried out on 150 mm long pound 20 mm wide pound 4 mm thickbamboo strips The MC of the bamboo strips was maintained at about 12Three types of commercial adhesives were used (a) phenol formaldehyde (PF)(b) urea formaldehyde (UF) and (c) melamine urea formaldehyde (MUF) Theseadhesives were supplied by a local manufacturer The adhesive formulations wereslightly modi ed from that of original formulation which was speci cally madefor plywood The modi ed adhesive formulation had acceptably high viscosityto control the penetration of adhesive into the strips Earlier study showed thatsurface wettability of this bamboo was markedly higher than most of the tropicalhardwood [5] Table 1 summarises the adhesive formulations
Three layers of bamboo strips were glued at different grain combinations(a) parallel to the grain (parallel-ply laminate) (b) perpendicular to the grain (cross-ply laminate) (c) peripheral to peripheral to peripheral layers (P-P-P) (d) inner toinner to inner layers (I-I-I) and (e) peripheral to inner to peripheral layers (P-I-P)
Table 1Glue mixing formulation for commercial adhesives
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
60 A Zaidon et al
Table 2Requirement for shear strength and wood failure
Average shear strength iquest Average wood Minimum average wood(Nmmiexcl2 failure () failure in any test piece ()
To produce cross-ply laminates a bamboo ply was rst prepared Strips were gluededge to edge using polyvinyl acetate resin to produce 15 mm pound 15 mm pound 4 mm plyThe ply was then glued perpendicular to each other producing three plies boardThe glue spread rate was 230 gm2 single glue line (SGL) for PF and 390 gm2 forboth UF and MUF resins
The assemblies were cold pressed at 10 kgcm2 for about 10ndash20 min andhot pressed at predetermined parameters speci ed in the resin manufacturerrsquosspeci cations [7 8] However the pressing time for PF-bonded laminates wasincreased by 17 to ensure optimal curing of resin The reason for this is discussedin the following section The laminated bamboos were conditioned at 20plusmnC and65 relative humidity for a week
A plywood shear test was conducted on 25 mm pound 25 mm pound 100 mm sheared areain accordance with BS 6566 [9] This includes dry test cyclic boil resistance (CBR)weather and boil proof (WBP) moisture resistance (MR) and interior immersion(INT) At least 12 specimens from each grain alignment and adhesive categorieswere tested
Upon completion of the test the specimens were dried and examined for theestimated percentage of wood failure along the glue line The wood failures ofindividual specimens were recorded to an accuracy of 10 and the average shearstrength and wood failure were compared with the standard requirement given inTable 2
An analysis of variance (ANOVA) was used to detect any shear strength changesbetween laminates from different grain alignment and between laminates fromdifferent pattern lay-up The means were separated using least square difference(LSD)
RESULTS AND DISCUSSION
Buffering capacity
The buffering capacity of a substrate is important in many gluing processesespecially if the adhesive is pH sensitive This property is governed by the pH of
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
Initial pH 714 594Volume of NaOH (001 M)required to reach pH 11 120 ml 130 mlVolume of NaOH (001 M)required to change 1 unit pH 031 ml 026 mlVolume of HCl (001 M)required to reach pH 3 120 ml 065 mlVolume of HCl (001 M)required to change 1 unit pH 29 ml 022 ml
a Data for rubberwood from Ref [6]
the material and an extreme value of wood pH had been reported to be troublesomefor achieving good adhesive bonds [10]
The buffering capacity of G scortechinii was found to be more sensitive towardsalkali than towards acid (Table 3) implying that G scortechinii has lower resistancetowards a change in alkaline than in acid Compared to rubberwood [6] bamboohas greater buffer capacity towards alkali Since bamboo is sensitive to alkali-basedadhesives such as PF a buffer is required in the adhesive formulation to ensuresuf cient curing of the resin [11] In this study however a longer press timewas employed to bond the PF-based boards The pressing time was increased to7 min instead of 6 min as speci ed by the resin manufacturerrsquos speci cation forcommercial plywood [7] For acid-based adhesives such as UF and MUF a normalhot press time for plywood was used [8]
Effects of grain orientation on glue bond quality
Information on the shear strength and wood failure percentage is important toevaluate the glue bond quality of bonded products Theoretically when both theshear strength and wood failure percentage values are high a good bonding hasoccurred If one of them is high and the other is low it indicates that either thewood or the adhesive is poor Nevertheless for heavy hardwood species like balaukasai and chengal (Shorea spp Pometia spp and Neobalanocarpus heimii) lowwood failure is acceptable as long as the strength is acceptable for the intendedend-use [6]
The mean shear strength and wood failure percentage of the laminated bamboosbonded with different types of adhesive are summarized in Tables 4 and 5 Thestatistical analysis showed no signi cant difference (P 6 005 in dry shearstrengths between parallel-ply laminates (236 Nmmiexcl2) and cross-ply laminates(268 Nmmiexcl2) when bonded using PF resin (Table 4) The dry wood failurepercentage however was relatively higher in the parallel-ply laminates (75) thanin the cross-ply laminates suggesting that the former is relatively superior
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
62 A Zaidon et al
Table 4Performance of phenol formaldehyde adhesive on G scortechinii laminated strips in dry cyclicboiling and weather boiling conditions
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
Table 4 also shows that there were sharp decreases in the shear bond strength andwood failure percentage after the boards were exposed to cyclic boiling test (CBR)and weather boiling proof test (WBP) This has been expected due to extensivestress developed during boiling and drying treatments speci ed by the tests Stripsarranged perpendicular to each other experienced a relatively higher reduction inshear strength after cyclic soaking in boil water and after long soaking in boilwater CBR test was observed to be more severe than WBP test In terms of shearbond strength and wood failure percentage parallel-ply laminates was relativelymore stable when soaked repeatedly in boil water with higher wet shear strength(151 Nmmiexcl2 and wood failure percentage (79) compared to cross-ply laminates(124 Nmmiexcl2 and 62 respectively)
As shown in Table 2 all the shear strengths and wood failure percentages ofbamboo laminates meets the minimum standard requirement
Statistical analysis in Table 5 shows no signi cant difference between grainorientation in dry shear strength when bonded with UF ie 194 Nmmiexcl2 and236 Nmmiexcl2 for parallel-ply and cross-ply laminates respectively However whenbonded with MUF the shear strength for the parallel-ply laminates (291 Nmmiexcl2)was signi cantly higher (P lt 005 than cross-ply laminates (180 Nmmiexcl2) Drywood failure percentage was relatively higher in the former when bonded eitherusing UF or MUF resin Generally all parallel-ply laminates bonded with UFand MUF produced signi cantly higher wet shear strength compared to cross-plylaminates Wood failure percentage after soaking in warm water (MR test) was54 for UF-bonded parallel-ply laminates but no wood failure was found in UF-bonded cross-ply laminates In most cases MUF-bonded laminates failed at theglueline after warm water soaking even though they had considerably higher wetshear strength (151 Nmmiexcl2 parallel-ply laminates and 082 Nmmiexcl2 for cross-plylaminates)
Visual examination on the samples revealed solid traces of MUF adhesive in theglueline indicating that the resin was not properly cured This phenomenon suggeststhat the pressing parameters used for this resin may not be suitable since it followedthat of commercial plywood manufacture Thus a new process parameters forbonding bamboo materials with MUF is worth investigation
The results also show that the UF-bonded parallel-ply laminates meets theminimum shear strength and wood failure when tested either in dry or wet (bothINT and MR tests) conditions (Table 2) whilst UF-bonded cross-ply met only theminimum standard of dry test
Glue bond quality of different parts of bamboo culm
Gluing of strips from different parts of bamboo culm signi cantly affects (P lt
005 both the dry shear strength and wood failure percentage of the laminates(Table 6) Strips cut near the peripheral layer of the culm possess higher gluebond quality (shear strength 317 Nmmiexcl2 and 100 wood failure) than strips cutat the inner layer (217 Nmmiexcl2 and 67) Lower bonding quality was also found
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
64 A Zaidon et al
Table 6Mean shear strength and wood failure percentage of parallel-ply laminates from different parts ofbamboo culm when bonded with PF
Pattern Density of Dry conditions Cyclic boil Weather and boillay-up individual strips resistant (CBR) proof (WBP)
Means with different superscript (a b c) across rows differ signi cantly at P lt 005Values in parentheses are standard deviationsn number of specimens
for the mixed strips (185 Nmmiexcl2 60) In weather boil proof test a similartrend of shear strength and wood failure percentage for the laminates was notedThe peripheral strips had the highest shear strength and wood failure percentage(216 Nmmiexcl2 and 100 respectively) followed by the inner strips (184 Nmmiexcl293) and the mixed strips (173 Nmm2 63Even though a relatively lower shearstrength and wood failure percentage found in cyclic boiling test the values amongthe strips did not differ signi cantly (154ndash166 Nmmiexcl2) except for a markedreduction of wood failure percentage in the mixed strips (67)
The above results suggest that material cut at different part of the bamboo culmhad a signi cant effect on the glue bond quality This is true since the density atperipheral layer (660 kgmiexcl3) of the bamboo culm was higher than at the inner layer(487 kgmiexcl3 The higher density zone consists much higher ber contents than theinner layer and this would provide higher cohesive bonding to the adhesive
CONCLUSIONS
Gigantochloa scortechinii can be used in the wood lamination industry to compli-ment wood A phenol formaldehyde formulation speci ed for commercial plywoodwas found suitable to be used for bonding bamboo strips The results on bufferingcapacity of G scortechinii shows that the bamboo is sensitive to alkali-based PFand a slightly longer press time is needed to ensure suf cient curing of resin Anurea formaldehyde formulation and hot press parameters speci ed for commercialplywood manufacture were found to be compatible with that of laminating bam-
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
boo However the MUF adhesive used in this study requires a different pressingvariables than UF and PF resins
The grain orientation of the strips bonded with either PF and UF had no effect onthe glue bond quality when subjected to dry conditions When subjected to extrememoisture conditions regardless of adhesives used parallel-ply laminates had higherglue bond quality
Material cut at different parts of the bamboo culm had a signi cant in uence onthe glue bond quality Laminates made from peripheral strips had higher glue bondshear strengths and wood failure percentages than those made either from innerstrips or from the combination of both in either dry or wet conditions
REFERENCES
1 M N Salleh The global environment debate The role of bamboo in Proceedings of theInternational Bamboo Workshop and the IV International Bamboo Congress I V Romanujaand E Widjaja (Eds) Vol 1 pp 1ndash6 Ubud Bali (1995)
2 M Azmy and O Razak Field identi cation of twelve commercial Malaysian bamboo FRIMTechnical Information No 25 Forest Research Institute of Malaysia Kepong (1991)
3 M Aminuddin Bamboo in Malaysia Conversation status biodiversity base and strategicprogramme for improvementFRIM Report No 6 Forest Research Instituteof Malaysia Kepong(1995)
4 D J Minford Treatise on Adhesion and Adhesives Vol 7 Marcel Dekker New York NY(1991)
5 A Zaidon K A Uyup R Wahab M T Paridah and E D Wong Properties of structuralplywood made from bamboo (Gigantochloa scortechinii) Paper presented at IUFRO mdash All 5Division Conference 2003 Rotorua New Zealand (2003)
6 M T Paridah A M E Chin and A Zaidon Bonding propertiesof AzadirachtaExcelsa Journalof Tropical Forest Products 7 (2) 161ndash171 (2001)
7 Phenol-formaldehyde Resin for WB Grade Plywood Malaysian Adhesive and Chemical SdnBhd Shah Alam (1999)
8 Urea-formaldehydeResin for Plywood MalaysianAdhesive and Chemical Sdn Bhd Shah Alam(2001)
9 Specication for Bond Performance of Veneer Plywood BS 6566 Part 8 British StandardInstitutionLondon (1986)
10 E J William and A N Khan Effect of pH and buffering capacity of wood on gelation time ofresin Wood and Fibre 12 (4) 225ndash263 (1980)
11 T Sakuno and C C Moredo Bonding of selected tropical woods Effect of extractives andrelated properties in Adhesive Technology and Bonded Tropical Wood Products Y H ChungS J Branham and C Chun (Eds) pp 166ndash189 Taiwan Forest Research Institute Taipei (1993)
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
J Bamboo and Rattan Vol 3 No 1 p 67 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
The Bamboos of the World
D Ohrnberger Annotated nomenclature and literature of the species and thehigher and lower taxa 596 pages Elsevier Amsterdam 1999 rst reprint 2002Hardbound ISBN 0 444 50020 0 USD 207 world-wide except Europe and JapanEUR 207 Europe and Japan
This monumental book needs to be more widely used because it represents theresults of a massive effort by Prof Ohrnberger to compile a list of all the names thathave been used for the many species of bamboo It clari es the validly publishednames and synonyms of all ranks from family to infraspeci c taxa The bookincorporates all taxonomic treatments whether they have used narrow or widede nitions of categories This is the only approach which can be taken with thecurrent slow rate of revision especially of genera and the still relatively poorapplication of experimental taxonomic methodologies
The author clearly states that the book is aimed not only at botanists but alsoat people involved in horticulture forestry and ecology For these latter users itis a useful checklist of acceptable names thereby if used avoiding a great dealof confusion in publications For instance foresters still use the name Bambusaarundinacea with no author citation when B bambos (L) Voss is meant and thereis frequent confusion in the literature for the species of Phyllostachys such as edulisheterocycla and pubescens where there are a host of taxa to be correctly pinpointedThe same applies to horticultural specimens the reviewer recently saw one labelledlsquodwarf Himalayan Arundinariarsquo when it was most likely African Yushania alpina(Schumann) L
The book also points out something that needs to be more widely stressed and thatis that data on habitat and ecology are often not available Here a great deal morework is required especially for the species widely used by humans The reviewerwould take this opportunity to add the urgent needs for cytology and karyotypeanalysis as well as use of molecular methods of comparison
This book is a must in the library of every institute dealing with bamboo
J T WILLIAMS
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
J Bamboo and Rattan Vol 3 No 1 p 68 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Book review
Bamboo Preservation Compendium
Walter Liese and Satish Kumar 232 pages 121 photographs appendices 2003ISBN 81-901808-0-0 Published as Technical Report No 1 by the Centre for IndianBamboo Resource and Technology in cooperation with the American BambooSociety (ABS) and the International Network for Bamboo And Rattan (INBARas INBAR Technical Report 22) Price USD 20 can be ordered from PAN mailorder system which can be accessed on the INBAR website (httpwwwinbarint)
This is one of the very best books which came on my desk in the last years Theauthors share with us years and years of experience (they worked together for the rst time in 1966) in projects in nearly all bamboo-growing countries
The rst chapter deals with the structure of the bamboo culm illustrated withmany beautiful photographs of culm tissue cells and vessels Next the attention isfocussed on natural durability and on factors which reduce the quality of bambooillustrated with colour photographs of cracks fungi beetles and termites Oncethis foundation for our knowledge and insight is complete the book goes onwith non- chemical protection the link with experience in the eld is shown byphotographs of bamboo stored on the ground resulting in decay All traditionalmethods and structural details are dealt with Chemical treatment is the next itemwith information over all chemicals available followed by safety precautions andby the methods to apply the chemicals This text and the photographs remind meof many days I had the pleasure to work with Walter Liese in several projectsand reading these pages I feel again how impressed I was during those days byhis expertise Treatment of furniture and other products is the next subject in thebook followed by quality control environmental consequences the economics ofpreservation and nally how to deal with infested bamboo In appendices we nddata on chemicals a glossary lists of addresses bibliography and an index
Once more this book contains a wealth of information about a most importantaspect of bamboo It is a must on the desk (and in the hands) of everybody who isworking with bamboo It is a rich source of good information for both people in the eld and researchers It is a treasure
JULES JANSSEN
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
J Bamboo and Rattan Vol 3 No 1 pp 69ndash70 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
World bamboo and rattan
Dear Reader
We continue publishing the Table of Contents of the journal World Bamboo andRattan On the next page please nd the Table of Contents of Vol 1 No 3
JULES JANSSEN
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
70 World bamboo and rattan
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
JULES JANSSEN
72 Historical column
Historical column 73
74 Historical column
Historical column 75
76 Historical column
Historical column 77
78 Historical column
J Bamboo and Rattan Vol 3 No 1 pp 71ndash78 (2004)Oacute VSP 2004Also available online - wwwvsppubcom
Historical column
Alois Herzog Zur Mikroskopie der Bambusfaser (in German in English Aboutthe microscopy of bamboo bres) Wochenblatt fuumlr Papierfabrikation 49 1025ndash1031 (1938)
Dear reader once more I selected an old publication which shows to us howinteresting the results of scienti c research were in years long ago I am sorry thetext is in German but the article contains many gures From the text I derived the gure captions given below
Figure 1 Chinese paper made using a 1900-years-old procedureFigure 2 A detail of this paperFigure 3 A node with the diaphragmFigure 4 Cross-section of the culm wallFigures 5ndash11 Fibres after chemical treatment causing swellingFigure 12 Some cells with and without silicaFigure 13 Some cellsFigure 14 How the cells form a network
Remarkably no mention is made of the enlargement of the photographs Todaythis would be considered as unacceptable
