About the Cover...About the Cover Mr. Juanito P. Jimenez, Jr. of the Technology Innovation Division...

About the Cover

Mr. Juanito P. Jimenez, Jr. of the Technology Innovation Division inspects the wood failure values of plywood specimens submitted from all over the country. Pages 43 to 58 of this issue feature Mr. Jimenez, Jr., et al.’s study on the profile of the wood species currently being used in local and imported plywood and their bond performance.

The Philippines’ Forest Products Research and Development Institute (FPRDI) under the Department of Science and Technology (DOST) is mandated to conduct basic and applied R&D to improve the utility and value of wood and non-wood forest products, undertake the transfer of technologies, and provide technical services and training.

Tels. (0063) 5362360/2586/2377Fax: (0063) 536-363website: www.fprdi.dost. gov.ph

PhilippineForest Products

Journal

A Publication of the Forest Products Research and Development InstituteDepartment of Science and Technology

College, Laguna 4031, Philippines

Philippine Forest Products JournalVolume 6January-December 2015

TABLE OF CONTENTS

Physical properties of 4-, 6- and 8-year-old falcata 1[Falcataria moluccana (Miq.) Barneby & J. W. Grimes]from Caraga Region, PhilippinesMarina A. Alipon & Elvina O. Bondad

Identification of naturally grown Philippine teak 12(Tectona philippinensis Benth. & Hook. f.) based onmorphological and anatomical featuresArsenio B. Ella, Emmanuel P. Domingo, Florena B. SamianoElvina O. Bondad & Anacleto M. Caringal

The taxonomy and wood anatomy of Philippine trees with included phloem 22Ramiro P. Escobin, Jennifer M. Conda & Fernando C. Pitargue, Jr.

Tow-grade abaca (Musa textilis Nee) fiber as 32reinforcement for packaging paperErlinda L. Mari, Adela S. Torres & Aimee Beatrix R. Habon

Profile of wood species used in local and 43imported plywood and their bond performanceJuanito P. Jimenez, Jr., Ramiro P. Escobin & Jennifer M. Conda

Resistance of thermally-modified kauayan-tinik 59(Bambusa blumeana Schultes f.) to termites and powder-post beetlesCarlos M. Garcia & Robert A. Natividad

Design and development of hydraulic type charcoal briquettor 68 Belen B. Bisana, Amando Allan M. Bondad, Dante B. Pulmano, Calixto Lulo & Ladylyn A. Cosico

Development of laminated buho 79[Schizostachyum lumampao (Blanco) Merr.] lumberRobert A. Natividad & Juanito P. Jimenez, Jr.

1Marina A. Alipon & Elvina O. Bondad

PHYSICAL PROPERTIES OF 4-, 6- and 8-YEAR-OLD FALCATA[Falcataria moluccana (Miq.) Barneby & J. W. Grimes]

FROM CARAGA REGION, PHILIPPINES

Marina A. Alipon & Elvina O. Bondad

Scientist I & Senior Science Research Specialist respectively, Material Science Division DOST-FPRDI, College, Laguna 4031, Philippines

Corresponding Author:MAAlipon ([email protected])

ABSTRACT

The physical properties (relative density, moisture content or MC and shrinkage from green to 12% and 5% MC), and oven-dry condition of 4-, 6- and 8-year-old falcata or Moluccan sau collected from three sites in the Caraga Region, plus the effects of different sources of variations particularly tree age and site on the physical properties, were evaluated to determine the species’ end-uses. The three sites were in Pating-ay, Prosperidad, Agusan del Sur (Site 1), Nong-nong, Butuan City (Site 2) and Las Nieves, Agusan del Norte (Site 3).

Three trees per age from each site were collected. From each tree, a 3-m log per height level (butt, middle and top) was cut. A 152-mm disc was cut above the 3 m per height level for physical properties determination. Three samples per property per height level were taken. Hence, there were three sites, three trees per age per site and three height levels per tree. All tests followed the procedure specified in ASTM D 143-52.

Based on the FORPRIDECOM guidelines for improved utilization and marketing of timbers, both relative density and volumetric shrinkage of falcata were deemed low (Group V). The ratio of tangential to radial shrinkage was also low, while the longitudinal shrinkage was abnormally high.

The effects of site and age on all physical properties were significant except in longitudinal shrinkage from green to 5% MC. Similarly, the effect of height was significant except in relative density and longitudinal shrinkage from green to oven-dry and at 5% MC.

Keywords: Falcata, relative density, moisture content (MC), shrinkage, static bending, compression parallel and perpendicular-to-grain, shear and hardness, ages, sites, Caraga Region-Philippines

Philippine Forest Products Journal Volume 6 January-December 2015

2 Philippine Forest Products Journal Volume 6 January-December 2015

INTRODUCTION

Plantation establishment for industrial tree plantation species (ITPS) is one major scheme used in the Philippines to meet the wood-based industries’ demand for a sustained volume of raw materials. Falcata or Moluccan sau [Falcataria moluccana (Miq.) Barneby & J. W. Grimes] is the most widely planted ITPS in the Caraga Region, particularly in private lands developed by families and communities. According to dela Cruz (2011), Caraga produced from 57% to 69% of the country’s total plantation logs in the last five years.

Falcata is a large tree attaining a height of up to 40 m and 20 - 100 cm diameter at breast height (dbh). It is found in primary and secondary forests, often on river flood terraces, sandy soils at 0 - 1,600 m altitude. It is widely cultivated in Moluccas, New Guinea, Solomon Islands, Bismarck Archipelago, and Admiralty Islands, and introduced elsewhere in Malesia (Rojo 1999).

Knowing the basic physico-mechanical properties of a wood is crucial in promoting the use of substitutes for traditional timbers that are no longer available in commercial quantities. Further, these properties can help determine the species’ end-uses for optimum utilization.

The more important physical properties of timber are moisture content (MC), relative density (RD) and shrinkage. MC affects almost all other properties of wood and the quality of end-products, while RD is a good indicator of many of the wood’s working properties such as strength, nail-holding, bolt-bearing, gluing and shrinkage characteristics. Shrinkage refers to the change from the original to the final dimensions as wood dries below the fiber saturation point (FSP). From a practical point of view, shrinkage, which accompanies a decrease in MC

below the FSP, is a serious setback in wood. Knowledge of shrinkage characteristics of any wood species enables the determination of the target cutting dimensions and uses, as well as preventive measures against drying defects.

Although information on the physical properties of falcata from other localities in the Philippines, specifically Regions 2 and 3, is available, it is based on only one 8-year-old tree per region. As the wood-using industries shift toward younger and smaller diameter trees such as falcata, it becomes imperative to evaluate the physical properties of younger trees (4 to 8 years old), particularly from the Caraga Region where the species abounds. Hence, this study aimed to: 1) test and evaluate the physical properties of falcata; and 2) determine its end-uses including the effects of tree site and age on its physical properties.

MATERIALS AND METHODS

Three trees per age were used: 4, 6 and 8 years old from three sites in Caraga: Pating-ay, Prosperidad, Agusan del Sur (Site 1); Nong-nong, Butuan City (Site 2) and Las Nieves, Agusan del Norte (Site 3). Information about the experimental trees and sites is shown in Table 1.

Statistical analysis

The Three-Factorial in Complete Randomized Design (CRD) was used in the statistical evaluation of data, while DMRT was used to determine the significance among mean values.

RESULTS AND DISCUSSION

The means of RD and MC of 4-, 6- and-8-year-old falcata trees from different sites in Caraga are shown in Figs. 2 and 3.


Features Site 1 Site 2 Site 3Elevation (masl)Soil typepHTextureClimate

Tree spacingSilvicultural treatments

Tree diameter at breast height (dbh, cm) 4-year-old 6-year-old 8-year-old

Average merchantable height (MH, m) 4-year-old 6-year-old 8-year-old

Average total height 4-year-old 6-year-old 8-year-old

136Clay loam5.4 – 6.0MediumType II (Rainfall July - December)3 x 3Clearing/weeding for 3 years, fertilizer application (complete) for 3 years, 50kg/sack, 2 sacks/ha

100-400Camansa series5.0 – 7.0MediumType II (Rainfall July-December)3 x 3None

200-700Clay loam5.3 – 6.0Medium and granulatedType II (Rainfall July-December)4 x 4None

171925

111414

131522

121617

91515

101518

202226

172022

192225

Note: Sites covered by Industrial Forest Management Agreement (IFMA).

Table 1 Information about the study sites and trees

From each tree, a 3-m log per height level (butt, middle and top) was cut. A 152-mm disc was cut above the 3 m height level

Fig. 1 Sampling scheme.

for physical properties determination. The sampling is shown in Fig. 1.


RD increased for the 4-, 6- and 8-year-old trees except in Site 1 where the values decreased for the 4- and 6-year-olds and increased for the 8-year-old. Mean RD values at 4, 6 and 8 years old from the three sites were 0.224, 0.248 and 0.270, respectively. The increasing trend could be due to the changes in the cross sectional dimensions of the wood cells. The studies of Lantican

Rela

tive

Dens

ity

(1976) and Tavita (1984) indicate that in most cells the cross sectional dimension exhibits systematic patterns of variation with increasing age or distance from the pith as in RD.

MC decreased for the 4-, 6- and 8-year-old trees except in Site 2 where the values slightly increased for the 6- and 8-year-old trees.

Moi

stur

e Co

nten

t (%

)

Fig. 2 Relative density of falcata at different ages and sites

Fig. 3 Moisture content (%) of falcata at different ages and sites.


Mean MC values at 4, 6 and 8 years old from the three sites were 252.28%, 219.29% and 208.0%, respectively. The findings conform to the established relationship between RD and MC (Skaar 1972, Panshin & de Zeeuw 1970).

Table 2 shows the ANOVA for physical properties of 4- to 8-year-old falcata at different sites in Caraga.

The effects of site and age and their interactions on physical properties were highly significant except in longitudinal shrinkage (LS) at 5% MC. The effect of height was also significant except in RD and LS from green to oven-dry and at 5% MC.

According to Panshin and de Zeuw (1970) the variability in wood properties arises from the effects of several systems on the physiological activities of the cambium. Among them are: 1) age or maturation changes in the cambium itself which are associated with variance within trees of a species; 2) genetic factors which are the basic causes for between-tree variations, and 3) environmental factors such as rainfall, temperature and silvicultural treatment which affect the net water and nutrient supply to the cambium.

In this study, the significant differences of properties between sites could be due to the predominant effect of ST (clearing/weeding, and fertilizer application for three years) on trees in Site 1 compared with those in Sites 2 and 3 with no ST. According to Klem (1968) and Echols (as cited in Shephard Jr 1982), RD has been found to increase after fertilization. Similarly, fertilizer application particularly the presence of nitrogen causes the increase in rate of diameter growth but does not decrease the RD (Shepard Jr. 1982), as also observed in this study.

Although other factors above were reported to affect between and within tree variations, the differences seemed insignificant probably because the characteristic features

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1

Tabl

e 2

AN

OVA

for ph

ysica

l pro

pertie

s of 4

-, 6-

and 8

-year

-old

falca

ta


Sourc

e o

f V

ari

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on

(6-y

ear-

old

)D

F

Shri

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Gre

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% M

C

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Site

(S

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ge (

A)

S x

AH

eigh

t (H

)S

x H

A x

HS

x A

X H

Err

or

2 2 4 2 4 4 846

5

5.27

91.

118

0.43

60.

374

0.25

50.

461

0.12

40.

152

34.6

3**

7.34

**2.

86**

2.45

ns1.

67ns

3.03

*0.

81ns

140.

1922

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11.9

1717

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1.07

14.

054

1.16

20.

950

147.

61**

24.1

7**

12.5

5**

18.5

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1.13

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1.22

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0.41

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173

0.55

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364

60.8

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1.14

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48ns

1.51

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24.6

92.

106

0.61

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320

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0.23

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261

94.7

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86ns

3.34

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212

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)S

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1

Tabl

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Co

ntinu

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Tabl

e 2

Co

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among sites were almost similar. These included elevation, soils, climate and spacing (Table 1). Wang and Shin (1995) reported no significant differences in RD of Japanese cedar plantation with spacing of 3 m x 3 m and 4 m x 4 m.

Conversely, RD has been found to decrease after fertilization (Erickson & Lambert, Gagnon & Hunt, Gooding & Smith all as cited in Shephard Jr 1982) or remain relatively constant (Einspahr et al., Megraw & Nearn all as cited in Shephard Jr 1982). According to Shepard (1982), variability in results of these studies is related, at least partly, to differences in species, age, stand conditions, site conditions and geographic location.

DMRT (Table 3) shows the differences in the mean physical properties among sites, ages and height levels. RD was significantly highest in Site 1, 8-year-old, followed by Site 2, 6-year-old and Site 3, 4-year-old. Similarly, VS from green to 12% and 5% MC and oven-dry conditions was significantly highest in Site 1, 8- year-old. Tangential shrinkage (TS), radial shrinkage (RS) and longitudinal shrinkage (LS) were also highest in Site 1, 8-year-old, and either with significant or no significant difference between Sites 2 and 3. Expectedly, MC was significantly lowest in Site 1, 8-year-old. The effect of height level was highly significant except in RD and LS from green to 5%MC.

Per FORPRIDECOM guidelines for improved utilization and marketing of timbers (1980), VS fell under low group (Group V, 7.8% and below), indicating small changes in dimension as wood dries below FSP. The TS to RS ratio was also below 2%. However, the LS of the sample was high. Individual values ranged from 0.25 to 1.35%, while mean values were from 0.45 to 0.76%.

According to Skaar (1972), the LS of normal wood from green to oven-dry ranges from 0.1 to 0.3%; RS is 2 to 3% and TS is about twice as great for a number of species. Panshin and de Zeeuw (1972) observed that TS for air-

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ite1 2 3

Age

, yea

rs 4 6 8

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But

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Mea

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0.25

9a0.

248b

0.23

6c

0.22

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127.

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278.

570a

273.

678a

252.

281a

219.

287b

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216.

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231.

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231.

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226.

287

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3.81

7b3.

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118a

4.15

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966b

3.77

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3.96

6

3.26

7a2.

440b

2.28

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2.56

7b2.

469b

2.49

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2.78

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2.48

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0.76

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0.61

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0.55

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6.04

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326b

6.94

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6.82

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574b

6.16

8c

6.52

2

Tabl

e 3

DM

RT fo

r phy

sical

prop

ertie

s of fa

lcata


Feat

ures

Phys

ical

Pro

pert

ies

Tang

enti

al

Shri

nkag

e f

rom

G

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% M

CR

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G

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% M

CLong

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inal

Shri

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from

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% M

CV

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ic S

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from

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% M

CS

ite1 2 3

Age

, yea

rs4 6 8

Hei

ght

But

tM

iddl

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p

Mea

n

3.65

5a2.

981b

3.09

7b

3.18

6b3.

372a

3.17

7b

3.35

4a3.

222b

3.15

8b

3.24

5

2.58

2a1.

973b

1.85

9c

2.06

4b2.

079b

2.26

7a

2.19

3a2.

187a

2.03

3b

2.13

8

0.61

6a0.

348b

0.29

9c

0.40

5a0.

411a

0.44

7a

0.43

1a0.

421a

0.41

1a

0.42

1

6.14

5a4.

890b

4.89

8b

5.17

8b5.

380a

5.37

3a

5.47

2a5.

337a

5.12

2b

5.13

0

Feat

ures

Phys

ical

Pro

pert

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Tang

enti

al

Shri

nkag

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G

reen t

o 1

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G

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o 1

2%

MC

Long

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inal

Shri

nkag

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from

Gre

en t

o 1

2%

MC

Volu

metr

ic S

hri

nkag

e

from

Gre

en t

o 1

2%

MC

Site

1 2 3

Age

, yea

rs4 6 8

Hei

ght

But

tM

iddl

eTo

p

Mea

n

2.33

4a1.

687b

1.78

9b

1.85

7b1.

954a

b1.

997a

2.04

1a1.

912b

1.85

8b

1.93

7

1.47

4a0.

991b

0.93

0b

0.99

0c1.

109b

1.29

1a

1.15

0ab

1.17

6a1.

068b

1.13

1

0.14

7a0.

140a

0.11

0b

0.13

1b0.

111b

0.15

4a

0.14

6a0.

133a

b0.

117b

0.13

2

3.77

5a2.

661b

2.70

2b

2.82

8c3.

040b

3.26

2a

3.16

7a3.

064a

2.90

5b

3.04

5

Tabl

e 3

Co

ntinu

ed . .

.

Tabl

e 3

Co

ntinu

ed . .

.


RD Group Industrial Tree Plantation Species Philippine Mahogany Species

I - High (above 0.700)

II - Moderately High(0.601 – 0.700)

III - Medium (0.501 – 0.600)

IV - Moderately Low (0.401 – 0.500)

V – Low

Satinwood (Chloroxylon swietenia DC)

Acacia crassicarpaAcacia cincinnataBenguet pine (Pinus kesiya Royle ex Gordon)Ipil-ipil[Leucaena leucocephala (Lam.) de Wit] Big leafed mahogany (Swietenia macrophylla King)

Acacia crassicarpaAcacia cincinnataBenguet pine (Pinus kesiya Royle ex Gordon)Ipil-ipil [Leucaena leucocephala (Lam.) de Wit]Big leafed mahogany (Swietenia macrophylla King)Yemane (Gmelina arborea Roxb.)

Para rubber [Hevea brasiliensis (HBK.) Muell.-Arg.]Bagras (Eucalyptus deglupta Blume)

Alnus spp.Ilang-ilang [Cananga odorata (Lamk.) Hook. f. & Thoms.]Kaatoan bangkal [Anthocephalus chinensis (Lamk.) A. Rich. ex Walp.]Kapok [Ceiba pentandra (L.) Gaertn.]Lumbang [Aleurites moluccana (L.) Willd.]Spanish cedar (Cedrela odorata L.)African tulip (Spathodea campanulata Beauv.)Gubas (Endospermum peltatum Merr.)Falcata [Falcataria moluccana (Miq.) Barneby & J.W. Grimes]

Bagtikan [Parashorea malaanonan (Blanco) Merr.]

Almon (Shorea almon Foxw.)Lauan, red (Shorea negrosensisFoxw.) Lauan, white (Shorea contorta Vidal)Mayapis [Shorea palosapis (Blanco) Merr.] Tangile [Shorea polysperma (Blanco) Merr.]

Tiaong (Shorea ovata Dyer ex Brandis

Table 4 Relative density classification of falcata and other plantation and Philippine Mahogany species

dried wood is about twice as large as RS at the same MC. Generally, woods that exhibit large differences between TS and RS or high ratio of TS to RS are more prone to drying defects (Alipon & Tamayo 1997, Panshin & de Zeeuw 1970, Skaar 1972).

Using the RD grouping of Philippine timbers for various uses (Alipon & Floresca 1990, 1991, Alipon et al. 2005), falcata and some plantation and “Philippine Mahogany” species, are classified and compared as follows (Table 4):


LITERATURE CITED

ADAY JU. 1988. Variations in some wood anatomical features, specific gravity, extractive content and transverse shrinkage in Benguet pine (Pinus kesiya Royle ex Gordon) from a second growth forest. Ph. D. thesis. UPLB CF Library. 143 pp.

ALIPON MA. 1990. Physical and mechanical properties of bagras (Eucalyptus deglupta Blume) from the Paper Industries Corporation of the Philippines (PICOP). FPRDI J. 19(1-4): 60-76.

ALIPON MA. 1991. Relative density and shrinkage of yemane (Gmelina arborea Roxb.) at different ages and height levels. FPRDI J. 20(3 & 4):50-60.

ALIPON MA, FLORESCA AR. 1991. Strength and related properties of three species of Acacia (Mimosoideae-Leguminosae). FPRDI J. 20(1-2): 67-72.

According to the FORPRIDECOM guidelines (1980), falcata fell under the low density (Group V), the same grouping as the 8-year-old trees collected by Alipon et al. (2005) from Regions 2 and 3. The possible end-uses for such trees include pulp and paper, toys, pencil slats, match sticks, toothpicks, ice cream spoons, popsicle sticks, venetian blinds, core veneer, wooden shoes and cigar boxes. The logs can be converted into lumber for construction purposes where strength and durability are not critical requirements.

CONCLUSIONS AND RECOMMENDATION

• Falcata’s RD and MC values obtained in this study can help determine its woodworking properties, charcoal and pulp yield, weight and tree biomass at 4 to 8 years old from different sites.

• Based on FPRDI’s RD grouping, falcata’s end-uses remain the same regardless of age and site. This means that plantation managers do not have to wait until the eighth year to harvest and utilize the species.

• The VS and ratio of TS to RS are low. However, high LS indicates the need for an appropriate kiln drying schedule to prevent warping, checking, splitting and even collapsing of the wood as it dries below FSP (25-30% MC). The MC and TS, RS and VS from green to 12% and 5% MC and oven-dry condition can help improve the drying schedules and provide cutting allowance in anticipation of the wood’s movement, particularly for uses requiring dimensional stability.

• Benefit-cost analysis of the use of 4 to 8-year-old falcata logs at different diameters is recommended to confirm the viability of harvesting the trees at a younger age.


ALIPON MA, TAMAYO GY. 1997. Interrelationships among shrinkage properties, seasoning and relative density in Philippine timbers. FPRDI J. 23(2): 1-13.

ALIPON MA, FLORESCA AR, TAMOLANG FB. 2000. Shrinkage characteristics of Philippine timbers for uses requiring dimensional stability. FPRDI Trade Bulletin Series No. 6. 22 pp.

ALIPON MA, BONDAD EO, CAYABYAB PC. 2005. Relative density of Philippine woods. FPRDI Trade Bulletin Series No. 7. 32 pp.

AMERICAN SOCIETY FOR TESTING MATERIALS. 2005. Methods of testing small clear specimens of timber. ASTM Designation: D143-52. 1972. Book of ASTM Standards. Part 16. Philadelphia, PA. 30 pp.

DELA CRUZ VC. 2011. Review and assessment of ITP production and utilization, and technology transfer and extension services for ITP clientele of Caraga. Project proposal for DOST-PCAARRD funding, College, Laguna, Philippines. 35 pp.

FOREST PRODUCTS RESEARCH AND INDUSTRIES DEVELOPMENT COMMISSION (FORPRIDECOM). 1980. Guidelines for the improved utilization and marketing of tropical wood species. RP/HQ 1979-5RO.FAO, Rome. 153 pp.

LANTICAN CB. 1976. Quality control should start in the woods. Asean Forest Industries Yearbook. 23-24:7374.

PANSHIN AJ, DE ZEEUW C. 1970.Textbook of wood technology. 3rd ed. Vol. 1. McGraw-Hill, New York. 705 pp.

ROJO JP. 1999. Lexicon of Philippine trees. FPRDI, College, Laguna, Philippines.

SKAAR C. 1972. Water in wood. Syracuse University Press. 128 pp.

SHEPARD, JR. RK. 1982. Fertilization effects on specific gravity and diameter growth of red spruce. Wood Sci. 14(3): 138 - 144.

TAVITA YL. 1984. Influence of sampling position and growth rate on the wood properties of

Benguet pine (Pinus kesiya Royle ex Gordon). Unpubl. MS Thesis. UPLB Graduate School, College, Laguna. 86 pp.

WANG SY, LIN SH. 1995. Effect of plantation spacings on the quality of visually graded lumber. Paper presented during the IUFRO World Congress held in Finland, 6-18 August 1995


IDENTIFICATION OF NATURALLY GROWN PHILIPPINE TEAK(Tectona philippinensis Benth. & Hook. f.)

BASED ON MORPHOLOGICAL and ANATOMICAL FEATURES

Arsenio B. Ella, Emmanuel P. Domingo, Florena B. SamianoElvina O. Bondad1 and Anacleto M. Caringal2

Scientist III, Science Research Specialist I, respectively Material Science Division (MSD), DOST-FPRDI

College, Laguna 4031, Philippines

2Assistant Professor, Batangas State University, Lobo Campus, Batangas, Philippines

Corresponding author:ABElla ([email protected]/[email protected])

ABSTRACT

The study addresses a gap in technical information that could help harness the potential of Philippine teak, one of the country’s endemic forest tree species of the family Verbenaceae (APG: Lamiaceae). A heavy and hard wood species with a relative density at 0.710, it is a promising source of structural timber. Dwarfing is usually observed in Philippine teak along rocky limestone and coral hills. Branching is sympodial, orthotropic and spreading to form a broad crown. Bark flaky, brown to grayish (similar to guava). The species has a high potential to regenerate by coppice method.

Macroscopic observations and other physical attributes showed that the wood of Philippine teak is light yellow, grain is slightly wavy and texture is fine, glossy, hard and heavy. Fibers are medium-sized and thin-walled. Rays are uniseriate and multiseriate and classified as extremely low. Philippine teak wood could be differentiated from teak (Tectona grandis L. f.) by its smaller pores and thinner rays. The distinguishing anatomical features of the two Tectonas are the presence of whitish deposits and tyloses, ring-porous, growth rings (early wood and latewood).

Keywords: Philippine teak, Tectona, morphology, wood anatomy

INTRODUCTION

At present there is a growing interest among Filipino scientists and forestry people to

utilize fully the country’s endemic forest tree species like the Philippine teak (Tectona philippinensis Benth. & Hook. f.). The species is predominantly found in dry exposed ridges


13Arsenio B. Ella, et al.

of southeastern Batangas, especially in the municipalities of Lobo and San Juan.

Less popular compared to teak (Tectona grandis L.) due to its small volume, it is a critically endangered species which was once believed to be extinct. The wood is classified as heavy and durable and can be used as substitute for molave (Vitex parviflora Juss.). During the Spanish era, the local people of Batangas used it for posts and general construction, and often substituted for molave and dungon (Heritiera sylvatica Vidal) in building Spanish galleons (Reyes 1938).

Philippine teak serves as a soil stabilizer particularly in deep ravines or areas susceptible to landslides, as well as coastal zone stabilizer. The wood is used locally for construction, as well as materials for tables, and benches (Caringal & Castillo 2002).

The wood of Philippine teak resembles those of teak and batitinan [Lagerstroemia pyriformis Koehne forma batitinan (Vidal) Furt. & Sris.] in structure, but the vessels are much smaller and the rays are narrower. However, the vasicentric parenchyma is distinctly aliform or confluent in batitinan. Moreover, the latter does not have the odor and the greasy feel of the former (Reyes 1938).

An earlier investigation conducted by Merill (1923) revealed that the species was found in thickets and secondary forests at low altitudes in Batangas and Iling Island (Mindoro). The species was first collected by English botanical collector Hugh Cuming in Batangas between 1836-1840 and verified to be extant in 1987 by Ridsdale and Reynoso and last observed extant by Madulid and Agoo in November 1989 (Madulid & Agoo 1990).

Lobo in Batangas is the documented habitat of Philippine teak. Natural stands of the species were observed in Barangays

Nagtoctoc, Banalo, Haybanga and Mabilog na Bundok by Pangga in 1993. Also, Madulid, et al. (2008) documented 100 individuals in Iling Island, in Barangays Katayungan and Baclayon, Occidental Mindoro.

Further, the species is still found in the remaining patches of molave forest while others are found in ravines and abysses or on the relief limestone hills with slopes ranging from 18 to 30%. No medicinal or other economic uses of the species have so far been recorded (Madulid & Agoo 1990).

Earlier studies focused more on the propagation of Philippine teak by direct seeding, barefoot wildlings and cuttings. Generalao and Lapitan (1970) revealed that propagation by cutting is more feasible than the two other modes of propagation.

A study by Pangga (1993) also on propagation showed that the nicking method for viability test may damage the seed of Philippine teak. Nicking is done to let water enter the viable seeds to break dormancy. She further suggested that wildlings be potted and allowed to harden for one month before field planting.

No comprehensive studies have been reported on the wood anatomy of Philippine teak. In the same manner, literature on the variations in structural, anatomical features and wood properties within and between trees of Philippine teak is nil. In other words, its potential as a first-class timber has not yet been studied. A study on the wood anatomy of the species may ultimately help lead to its optimum utilization.

This study was conducted to determine the morphological and wood anatomical characteristics, e.g., macroscopic and microscopic, of naturally grown Philippine teak and determine its distinct features that could help in its identification; and to identify other potential uses based on its wood anatomical properties.



Field and ocular inspection

Natural stands of Philippine teak were identified and assessed in Barangays Nagtoctoc, Banalo, Haybanga, Mabilog na Bundok and Sawang all in the municipality of Lobo, Batangas.

Field observation of freshly collected botanical materials and the species’ field characteristics was conducted. Morphological characteristics, viz., bark texture and color, leaf arrangement and flower characteristics, and the presence of fruits were noted. Observations on species ecology and seedling nursery adaptation were also noted.

Field sampling

Three trees of naturally grown Philippine teak were collected in Barangay Sawang,

Lobo, Batangas. The log samples were transported to the FPRDI sawmill, and processed into experimental materials. The sampling scheme used is presented in Figure 1. Specimens were prepared following the standard testing methods.

For each tree, 3-m long bolts were taken from the butt, middle and top portions. Each bolt was labeled with the tree number and height level. Discs 152 mm (6”) thick were cut from the end of each bolt where the anatomical (including fiber and vessel measurements) and physical properties specimens were taken.

Laboratory sampling

Anatomical observation and description

Blocks measuring 1cm X 1cm X 2 cm were cut from the six-inch disc and the true wood rays section was established. The blocks were cleaned and boiled in tap water until soft and then sectioned on slides.

Fig.1. Sampling scheme.


Samples normally 25 µm thick were cut from transverse, radial and tangential sections of the wood with a sliding microtome following the standard procedure. A 50-50 alcohol-glycerin solution was applied on top of the sample. The cut sections were placed on slides and covered with another slide prior to staining.

Transverse, tangential and radial sections of the wood were first washed with tap water to remove the glycerin-alcohol solution previously applied while cutting, and also other foreign bodies. Then the sections were stained with Safranine for greater visibility, then washed in 50, 75, 85 and 95% ethyl alcohol, respectively, and finally rinsed in tertiary butyl alcohol (TBA) and xylene.

The stained sections were mounted on slides using Entellan as mounting medium for microscopic observation. The section slides were placed in an oven set at about 50OC for about a week for complete drying.

The species was described using the terminology of the International Association of Wood Anatomists (IAWA 1989) and Standards and Procedures for Descriptions of Dicotyledonous Woods (Tamolang et al. 1963).

Fiber and vessel mensuration

Samples for fiber and vessel measurements were cut from the remaining wood samples used in the anatomical observation. Samples were cut into match-sized splints and placed in test tubes. The Franklin (1945) method of maceration was used. The test tubes were placed in a hot water bath for 1-2 hr or until the splints turned whitish and soft. The macerated samples were washed thoroughly with running water until they were acid-free.

The fibers and vessels were separated by shaking the sample in distilled water and were measured using Lantican’s method (1975). For each macerated sample, slides were prepared, and 25 whole fibers and

vessels were measured using a calibrated eye-piece micrometer in a light microscope at a magnification of 40x.

Macerated samples were stained with Safranine for greater visibility, pipetted into a slide and spread evenly on the surface. To ensure a uniform reference point for each fiber and vessel, measurement was taken at the widest portion. The average of the fiber dimensions was computed for each sample.

Details for microscopic examination followed those of IAWA (1989) and Tamolang, et al. (1963). Photographs of the wood blocks’ cross sections (magnified 10x) and transverse, tangential and radial sections (magnified 40x or higher) were taken to accompany species descriptions.


Morphological/botanical description of the species

The Philippine teak is a small to medium-sized tree (ave. 30 cm DBH) reaching a height of 8-27 m and a diameter of up to 80 cm. Branching is sympodial, orthotropic and spreading to form a broad crown. Trees, particularly on steep ridges, have low and narrow buttresses (Fig. 2). Dwarfing is observed along the rocky substrates of limestone relief and coral hills.

On disturbed localities where trees have been cut for lumber or house posts, the remaining trees have short boles, small to medium-sized and with irregular branches. Several saplings have been observed with numerous regrowths (20-30 sprouts). This indicates the species’ high potential to regenerate by coppice method.

The outer bark of Philippine teak is flaky, brown or grayish and sometimes pale green similar to that of guava (Psidium guajava L.) (Fig. 3). During dry months, the outer bark scrolls lengthwise and becomes reddish to


brown, leaving the bark surface whitish or gray. Inner bark is yellowish with 7-11 pale brown streaks.

Leaves (Fig. 4) are simple, glabrous or nearly so on the upper surface, the lower surface white verrucose, decussate and ovate to elliptic, 12-22 cm long x 6-10 cm wide. The base is cuneate and apex is acuminate. Leaf lamina is entire and sometimes denticulate. The petiole is 1-3 cm long. Veins are 5-8 pairs, alternate. Upper surface is dark-green but pale green underneath. The young apical leaves are yellow green.

The flower is terminal or axillary cyme inflorescence of 10-13 sets of flowers and each set is composed of 15 florets, usually triple. The flower is perfect, 10-15 mm x 5-10 mm in diameter arranged in dome-shape cyme; peduncle, 10-15 mm long; corolla, 5, whitish with very fine purple hair-like projections, 6-11 mm long at the center from which the 6 anthers bearing the yellow pollen sacs develop. The flowers give a white-purple impression but entirely purple when observed from a distance.

The fruit of Philippine teak is cyme of pale-brownish, hard and round drupes (46-148 per panicle), 10-13 mm x 4-6 mm in diameter (Fig. 5). Fruit maturity is perfectly

timed during the rainy season (July-August). Rainfall causes the mature drupes to fall, probably the species’ physiological response to perpetuate regeneration.

Field observation revealed that drupes remain dormant on the forest floor for almost a year. At the onset of the rainy season, the seeds burst from dormancy. During this time, hundreds of germinants (3.5-6.0 cm long) can be collected from the ground and tended in the nursery, where the optimum environmental conditions for the species’ regeneration and survival are present. Otherwise, leaving them on the forest floor will make it difficult for the germinants to survive during summer. After two to three years, the nursery-adapted wild seedlings can be re-introduced to their natural habitat. Physical propertiesand macroscopic observations

The wood is creamy, turning to light yellow (Fig. 6). The grain is slightly wavy; the texture is fine; slightly glossy, hard, heavy and tough.

Anatomical observations

Fibers of Philippine teak are classified as medium-sized with an average length

Fig. 3. Bark.

Fig. 4. Leaves.

Fig. 2. Buttress. Fig. 2. Buttress. Fig. 3. Bark. Fig. 4. Leaves.


Fig. 6. A typical wood (cross-section) of Philippine teak as seen by the naked eye.

Fig. 5. Fruits

Height Level Relative Density Moisture Content (%)

Butt 0.734 56.69

Middle 0.700 58.78

Top 0.698 60.32

Average 0.710 58.60

Table 1. Philippine teak’s relative density and moisture content.

of 1.02mm. Fiber diameter did not vary significantly among the three trees observed, with an average diameter of 20 µm (Table 2).

Cell wall thickness is considered “thin”, lumen width is greater than the cell wall, consistent with the IAWA standard for cell wall thickness of wood fibers. Vessels are numerous to very numerous, with an average 54 per mm2. Vessel length is very short. Tyloses and deposits are found in vessels.

Generally, parenchyma is observed in paratracheal pattern as evidenced by confluent to narrow vasicentric (Fig. 7). Rays (Fig. 8) are numerous to very numerous, 7-15 (ave. 9) per mm2; of two kinds, uniseriate and multiseriate; the uniseriate is composed mostly of square to upright cells; the multiseriate is heterocellular, 2-3

(mostly 3 cells wide); ray width is fine to moderately fine, 40-54 µ (ave. 47 µ); and ray height is extremely low from 0.23 to 0.37 mm (ave. 0.31 mm)


• Field observations showed that the Philippine teak’s drupes remain dormant in the forest floor for a year. At the onset of the rainy season, the seeds burst from dormancy. Large trees, particularly those on steep ridges, have low and narrow buttresses. Dwarfing is common along rocky limestone and coral hills.

• Identification of Philippine teak wood based on macro-anatomical structure is not complicated. Macroscopic


Fig. 7. Transverse section showing almost exclusively solitary pores with confluent parenchyma (35x).

Fig. 8. Tangential section showing rays mostly heterocellular multiseriate (35x).


Tabl

e 2. Im

porta

nt mi

crosc

opic

featur

es ob

serve

d in P

hilipp

ine te

ak.

Tree

N

o./

Por-

tion

Fibe

r D

imen

sion

(m

m)

Vess

elM

ulti

seri

ate

Ray

sU

nise

riat

e R

ays

Fibe

r Le

ngth

(R

ange

, av

e.)

Dia

met

er

(Ran

ge,

ave.

)

Lum

en

Wid

th

(Ran

ge,

ave.

)

Cel

l Wal

l Th

ick-

ness

(R

ange

, av

e.)

No.

per

m

m2

and

ave.

Ave

rage

Le

ngth

(m

m)

Ave

rage

Ta

ngen

-ti

al D

iam

-et

er

Pore

Siz

e C

lass

ifi-

cati

on

Hei

ght

(mm

)

No.

of

Cel

ls

Wid

e

Wid

th(m

m)

Hei

ght

(mm

)

No.

of

Cel

ls

Hig

h

10.

864-

1.15

31.

011

0.01

7-0.

023

0.02

0

0.00

6-

0.01

30.

010

0.00

48-

0.00

590.

0052

20-9

149

.31

0.21

70.

0903

20 µ

Extre

mel

y sm

all

0.24

2-3

0.04

10.

085

2-10

20.

965-

1.11

41.

070

0.01

6-0.

019

0.01

8

0.00

5-0.

008

0.00

7

0.00

47-

0.00

660.

0055

29-8

856

.59

0.23

10.

0884

18 µ

Extre

mel

y sm

all

0.26

2-3

0.04

20.

128

3-9

30.

828-

1.06

80.

977

0.02

0-0.

024

0.02

2

0.01

1-0.

013

0.01

2

0.00

47-

0.00

540.

0050

28-8

757

.09

0.24

50.

0900

22 µ

Extre

mel

y sm

all

0.27

2-3

0.03

50.

133

3-7

Ave

:1.

020

0.02

00.

009

0.00

5254

.33

0.23

10.

0895

20 μ

0.26

2-3

0.03

90.

115

2-10


LITERATURE CITED

CARINGAL AM & CASTILLO JR. 2002. Status and prospects of the Philippine teak research (Paper presented during the 1st Summit on Philippine Teak). 4 September 2002, San Jose, Batangas.

FRANKLIN FL. 1945. Preparations of thin sections of synthetic resins and wood-resin composites and a new macerating method for wood. In Biol. Abst. Vol. 20, No. 1 Sect. A, No. 118, 1946.

GENERALAO MM & LAPITAN F. 1970. Growing Philippine Teak (Tectona philippinensis) in Mt. Makiling. Research Note, Bureau of Forestry, Research Division, Los Baños Experimental Station, College, Laguna.

INTERNATIONAL ASSOCIATION OF WOOD ANATOMISTS (IAWA) COMMITTEE. 1989. IAWA List of Microscopic Features for Hardwood Identification. WHEELER EA, BAAS P and GASSON PE (Eds.). IAWA Bulletin 10(3):219-332.

LANTICAN CB. 1975. Variability and control of wood quality. Inaugural lecture given on 13 August 1975 at the UPLB College of Forestry, College, Laguna.

MADULID DA & AGOO EM. 1990. Conservation Status of Tectona philippinensis Benth. & Hook. f., A Threatened Philippine Plant. Acta Manila 38:41 – 55.

MADULID DA, AGOO EM & CARINGAL AM. 2008. Tectona philippinensis. The IUCN Red List of Threatened Species. (http://www.iucnredlist.org)

observations showed the wood is light yellow, grain is wavy, texture is fine. It is likewise glossy, hard and heavy.

• It is the smaller pores and thinner rays of Philippine teak that differentiate it from the more popular Tectona grandis. However, the most common anatomical features present in the two Tectonas are the whitish deposits and tyloses. With its fine texture, the Philippine teak is suitable for heavy-duty furniture and cabinets.

• With a relative density at 0.710, Philippine teak is a potential source of heavy construction and structural timber.

• Results of the study could possibly lead to the species’ propagation, resulting in increased population and established plantations. This would help conserve the critically endangered species. Plantations will eventually benefit Batangas tree farmers, and lead to the maximum use of the timber in its raw and engineered forms.

• It is recommended that Philippine teak woods from other sources where it abounds, e.g., Iling Island (Mindoro) and Verde Island (East Batangas), be collected for further wood anatomical studies.


MERRILL ED. 1923. An Enumeration of Philippine Flowering Plants 3: 403. Bureau of Printing, Manila.

PANGGA IC. 1993. Ex-Situ Genebark for Philippine Teak (Tectona philippinensis). Unpublished Report. PAWB, DENR, Diliman, Quezon City.

REYES LJ. 1938. Philippine Woods. Commonwealth of the Philippines. Department of Agriculture and Commerce. Bureau of Printing. Manila. Technical Bulletin 7.

TAMOLANG FN, VALBUENA RR, MENIADO JA & DE VELA BC. 1963. Standards and Procedures for Description of Dicotyledonous Woods. Forest Products Research Institute, College, Laguna, 46 pp.


THE TAXONOMY AND WOOD ANATOMY OF PHILIPPINE TREES WITH INCLUDED PHLOEM

Ramiro P. Escobin, Jennifer M. Conda & Fernando C. Pitargue, Jr.

Scientist I, Science Research Specialist I & Supervising Science Research Specialist, respectively

Material Science Division, DOST- FPRDICollege, Laguna 4031, Philippines

Corresponding Author:RPEscobin ([email protected])

ABSTRACT

A total of 43 species under three genera and three families exhibiting included phloem are presented. Three types of included phloem are recognized, i.e., a) complete bands, b) patches and c) diffuse. Of the more than 3,700 species, 124 families and 600 genera of Philippine woods, only three genera exhibited included phloem, namely: Avicennia [Verbenaceae (APG:Acanthaceae], Memecylon (Melastomataceae) and Aquilaria (Thymelaeaceae).

The standard procedure in wood anatomy was used to study the presence of included phloem and macro-physico-mechanical characters of the specimens. Three representative species for each of the three genera are presented in photographs.

The taxonomic status of the species is based on the currently accepted systems of classification; their current uses, distribution and ecology are also included. An artificial key to the identification of genera based on the character of included phloem is likewise presented.

Keywords: Plant taxonomy, wood anatomy, wood identification, included phloem

INTRODUCTION

To identify an unknown wood, wood anatomists always look for diagnostic characters unique to the species, genera or families. One of these useful characters is the occurrence of included phloem.

Included phloem is a type of secondary growth among plants with secondary thickening (usually, trees) considered anomalously developed. Esau (1977) defined it as the secondary phloem included in the secondary xylem of certain dicotyledonous plants. It may also be called interxylary phloem.

The International Association of Wood Anatomists (IAWA) defines the term as concentric, diffuse and variable phloem or cambial strands classified as cambial variants and should not be called “anomalous” since they regularly occur in taxa in which they are found (Wheeler et al. 1989).

Other authors (Escobin et al. 2014a, 2014b, Meniado et al. 1977) define it as phloem strands or layers included in the secondary xylem of certain dicotyledonous wood. Mauseth (2014) gave a similar definition and an extensive explanation of its development and apparent function.


23Ramiro P Escobin, et al.

Normally, the phloem consists of the living tissues found at the outer portion of the cambium (the meristem that produces the phloem tissues at the outer portion and the xylem tissues in the inner portion). Thus, the phloem tissues are found near the bark of a tree. On the other hand, the secondary xylem is technically comprised of dead tissues and in layman’s term it is called “wood”.

Included phloem is considered an anomalous secondary growth because the cambium ceases to develop and reactivates again in time, producing secondary phloem tissues and secondary xylem tissues again and again until bands, incomplete or diffuse, and scattered included phloem are observed in the wood’s inner portion normally occupied only by secondary xylem tissues.

According to Mauseth (2014), the apparent function of included phloem is primarily protecting the phloem from insects and other pests thru one or several layers of wood (secondary xylem). However, this has not been studied yet.

Of the more than 3,700 species, 124 families and 600 genera of Philippine woods (Salvosa 1963, Rojo 1999, Co 2011), only three genera exhibit included phloem, namely; Avicennia [Verbenaceae (APG: Acanthaceae], Memecylon (Melastomataceae) and Aquilaria (Thymelaeaceae).

This study dealt with the identification and taxonomy of Philippine woods with included phloem, a diagnostic feature useful to both plant taxonomists and wood anatomists.


Macro-anatomy

Specimens were prepared following standard macro-anatomical procedure used by Escobin et al. (2014a, 2014b) and Meniado et al. (1977). Distinct features of

the heartwood, sapwood, grain, texture, density, growth rings, pores, included phloem, tyloses, parenchyma, resin canals and other secretory structures, rays, fibers, splinter test and ripple marks were observed. Macro-anatomical description was made for each taxon with the help of a Coddington hand lens (10x and 20x) and a Leica digital microscope.

Photographs of three representative species of each genus discussed were produced using a digital stereoscope. The types of included phloem presented were marked by arrows.

Taxonomy

The recently accepted nomenclature of the families and genera studied was obtained from existing widely accepted classification systems, i.e., Cronquist (1988) which is largely based on traditional plant systematic practices and methods, and the newly proposed APG (1998, 2003, PBG 2006) based on a species’ DNA. The similarities and differences among the various classification systems were discussed. The distribution and ecology, uses and other important botanical information were obtained from existing taxonomic and botanic literature. A key to the identification of taxa based on the type of included phloem was proposed.


Taxonomy

Table 1 lists the taxonomically accepted and valid names of families, genera and species exhibiting included phloem, a diagnostic character in wood structure and identification. The valid and accepted name in the APG classification system is enclosed in parenthesis as currently practiced. The table presents the type of included phloem as classified in this article, as well as uses of the species.


Figures 1 to 3 show macro-anatomical photographs of representative species exhibiting the three types of included phloem. The included phloem in the figures is indicated by pointers.

The taxonomic results are based on Escobin et al.’s studies (2014a, 2014b), which include all the families, genera and species of Philippine trees. In this article, 3 families, 3 genera and 43 species of Philippine woods exhibiting the included phloem are presented.

All the families and genera with included phloem mentioned in this report are currently taxonomically accepted and valid. However, the family Verbenaceae to which the genus Avicennia belongs has undergone significant changes as some genera are lumped with other existing families and genera, i.e., Vitex, Premna, Teijsmanniodendron, Tectona, Gmelina, Clerodendrum and Callicarpa, as an offshoot of a proposed new system of classification largely based on the DNA of a taxon (APG 1988, PBG 2006).

In fact, Avicennia has been proposed to become part of a new family named Avicenniaceae (Sosef et al. 1998). Currently, Avicennia is accepted to be under the family Verbenaceae (Rojo 1999) and/or family

Acanthaceae (APG 1998, APG II 2003, PBG 2003). The genus Memecylon is poorly known taxonomically and needs revision or a monograph once information becomes available.

The following key to the identification of genera of Philippine woods with included phloem is highly artificial and does not reflect phylogenetic relationships. Aside from included phloem, the physico-mechanical character of the genera is also used.

To use the key, one needs to start from the first couplet (contrasting features in 1) until the genus is identified. Then, confirmation is needed in the macro-anatomical description and the figures provided.

Current trends in plant classification

The Cronquist system of plant classification is based on all taxonomic evidences that include all available information on taxa and relates these evidences to build a truly phylogenetic system reflecting evolutionary relationships of taxa -- the ultimate goal of plant taxonomy. Similarly, the APG system of classification is based on a multidisciplinary approach, but is largely focused on DNA. Thus, it does not follow the traditional taxonomic hierarchy and instead uses clades.

Artificial Key to the Identification of Genera of Philippine Woods with Included Phloem

1a Included phloem appears as a complete band alternating with bands of secondary xylem; each band of xylem and the phloem just external to it are produced by one cambial initial, then the next set is produced by another initial ......................................................................................................................................................... Avicennia

b Included phloem otherwise ................ 2

2a Wood soft and light; included phloem not in complete band but in patches ........................................................................................................................................Aquilaria

b Wood hard and heavy (relative density 0.60-0.70 at 15% MC), included phloem diffusely scattered among the secondary xylem, usually 2-3x larger than pores ..................................................................................................................................... Memecylon


Table1 Philippine woods with included phloem (Meniado et al. 1977, Escobin et al. 2014a, 2014b, Rojo 1999, Sosef et al. 1998)

Genus/Official Common Name/Scientific Name Family

Type of Included Phloem

Uses

A. Memecylon

(34 species occurring in the country; only M. lanceolatum Blanco is taxonomically accepted; the rest unresolved or poorly known.)

1. Lantoganon (M. agusanense Elmer)

2. Balitiunan (M. apoense Elmer)

3. Kandong (M. azurinii Quis & Merr.)

4. Basilan gikayan (M. basilanense Merr.)

5. Sigai (M. brachybotrys Merr.)

6. Yayan (M. calderense A. Gray)

7. Bagobahi (M. cordifolium Merr.)

8. Kagigai (M. cumingii Naud.)

9. Agam (M. densiflorum Merr.)

10. Kalasgas (M. elliptifolium Merr.)

11. Anaba (M. elongatum Merr.)

12. Batingi (M.gitingense Elmer)

13. Agam-iloko (M. gracilipes C.B. Rob.)

14. Digeg (M. lanceolatum Blanco)

15. Kasigai (M. littorale Merr.)

16. Loher kulis (M. loheri Merr.)

17. Pupuntad (M. myrtilli Blume)

18. Gasgas-linis (M. obscurinerve Merr.)

19. Diok (M. obtusifolium Merr.)

20. Gas-gas (M.oligoneuron Merr.)

21. Timbaras (M. oligophlebium Merr.)

22. Kulis (M. ovatum Sm.)

23. Gikayan-putla (M. pallidum Merr.)

24. Pasagit (M. paniculatum Jack)

Melastomataceae Diffuse, usually 2-3x larger than the secondary xylem (pores)

Wood hard and heavy; applied for local house-building (poles, beams and rafters), temporary construction, ship and boat-building and other uses requiring high-strength wood. Also for furniture, paddles, tool handles, rice pestles, anchors, household utensils and walking sticks; yields good-quality charcoal and fuelwood.


25. Panaipai (M. phanerophlebium Merr.)

26. Sigai-pakpak (M. pteropus Merr.)

27. Ramos-agam (M. ramosii Merr.)

28. Babahian (M. sessifolium Merr.)

29. Kulis-kitid (M. stenophyllum Merr.)

30. Sagingsing (M. subcaudatum Merr.)

31. Dignek (M. subfurfuraceum Merr.)

32. Ambatiki (M. symplociforme Merr.)

33. Tayabas gasgas (M. tayabense Merr.)

34. Gikayan (V. venosum Merr.)

B. Aquilaria

(7 species occurring in the country; taxonomically well-studied)

1. Mangod (A. apiculata Merr.)

2. Binukat [A. brachyantha (Merr.) Hall.f.]

3. Butlo [A. cumingiana (Decne.) Ridl.]

4. Palisan [A. filaria (Oken) Merr.]

5. Bari (A. malaccensis Lamk.)

6. Butlog-liitan [A. parvifolia (Quis.) Ding Hou

7. Makolan [A. urdanetensis (Elmer.) Hall. f.]

Thymelaeaceae I n c o m p l e t e bands

Wood used for light construction, carvings and as source of the well-known agar wood for incense manufacture. More commonly used medicinally rather than for wood-based products and construction materials. The agar wood is the re s i n - c o n t a i n i n g h e a r t w o o d obtained from old, diseased wood used as incense for various ceremonial purposes. It is considered the most expensive natural raw material in the world (can exceed USD10,000/kg) . Moreover, the incense is used against certain types of cancer, especially of the thyroid glands, and a variety of illnesses. Due to


its importance, many studies have been done to sustain and improve its yield while preserving the tree. The resin is also used for perfumery, culinary arts, and aromatheraphy.

C. Avicennia

(2 species occurring in the country; classified by APG under the family Acanthaceae)

1. Bungalon [A. marina (Forsk.)

Vierh.]

2. Api-api (A. officinalis L.)

Ve r b e n a c e a e ( A P G : Acanthaceae)

Complete bands Wood used for h o u s e - b u i l d i n g (posts, columns, beams, roofing), mine props, inlaying, and other decorative purposes, furniture, paneling, boat-building, rice mortars and mallets, paving blocks, pulp manufacture for rayon production, firewood, smoking (curing) fish, smoking rubber, and charcoal production. Ashes of the wood yield salt. Bark is used to tan leather and to treat skin parasites and gangrenous wounds. Seeds are eaten after roasting, while the resin is used to treat ulcers and tumors.

In addition, the PBG system disregards traditional plant morphology so that the clades are not necessarily homogenous morphologically.

To reconcile this, the PBG (2006) uses the APG clades and the Cronquist-affected families and genera in the order level of the taxonomic hierarchy. For practical purposes, the Cronquist system remains useful in plant revisions and monographs of taxonomically poorly known taxa, but the APG system truly reflects the phylogenetic relationships of plants.

Macro-anatomy

1. Memecylon (Melastomataceae, Fig. 1) Digeg

Distinct Features: Heartwood yellow-brown to dark brown with dark streaks, sharply demarcated from the lighter-colored sapwood. Grain generally interlocked, sometimes irregular and wavy; texture fine to moderately fine (coarseness due to included phloem); slightly lustrous to lustrous; hard and heavy (relative density: 0.60-0.70 at 15% MC).


Growth rings usually indistinct to the naked eye, under a hand lens marked by dark bands due to denser tissues and less porous region.

Pores small, visible only with a hand lens, exhibiting a semi-ring-porous topography, round to oval, solitary and in radial multiples of 2-3, with a tendency to form clusters and exhibit oblique arrangement, scalariform perforation plates observed.

Included phloem usually associated with pores about thrice the size of pores, abundant, diffuse, round to oval, usually occluded with gummy deposits. Tyloses rare; deposits chalky white, yellowish or orange.

Parenchyma visible only with a hand lens, paratracheal, thinly to thickly vasicentric, aliform to confluent, continuous and regularly-spaced diffuse-in-aggregates (needs keen observation), interrupted in M. venosum (gikayan), M. elliptifolium (kalasgas) and M. paniculatum (pasagit), seemingly terminal bands associated with pores bordering growth rings.

Rays visible only with a hand lens, of two

Fig. 1 Digeg (Memecylon lanceolatum Blanco).

types: medium-sized and fine. Splinter burns to complete white to gray ash; in M. elliptifolium splinter burns to charcoal. Ripple marks absent.

Similar Woods: Memecylon wood distinctive due to the islands of occluded phloem scattered in transverse section about 2-3 or more times the area of the vessel elements (shown by arrow in 20x cross-section view).

Supply: Limited and uncertain due to overexploitation. Originally reported commonly occurring in thickets and second-growth forests at low and medium altitudes in all provinces of Luzon, Mindoro, Palawan, Polillo, Samar, Leyte, Panay, Negros and Mindanao; but an updated inventory of species verified in the field is needed to ascertain volume available for use. Also occurs in Borneo and Sulawesi.

2. Avicennia [Verbenaceae (APG: Acanthaceae), Fig. 2] Api-api

Distinct Features: Sapwood extremely thick, very distinct from the heartwood, which is reddish brown to light pinkish cinnamon; grain crossed, irregularly waxy


Fig. 2 Api-api (Avicennia officinalis L.).

or twisted with a characteristic ribbon-like figure on quarter-cut face due to the included phloem; texture moderately coarse owing to the presence of included phloem; taste slightly salty; moderately heavy to heavy and moderately hard (relative density 0.48 at 15% MC).

Growth rings distinct to the naked eye, indicated by concentric, anastomosing layers of included phloem. Pores not visible to barely visible to the naked eye, solitary, but mostly in radial multiples of 2-4.

Parenchyma visible only with a hand lens, appearing as indistinct sheath or narrow vasicentric to the pores. Rays not visible to the naked eye, with whitish streaks. Included phloem distinct to the naked eye, sometimes branching, with black deposits in some isolated strands.

Similar Woods: Avicennia wood distinctive due to the included phloem (shown by arrow in 20x cross section view).

Supply: Api-api used to be common along muddy seashores and tidal streams

in mangrove swamps throughout the Philippines. Used to be locally abundant in Quezon, Zambales, Bataan, Camarines, Polillo, Masbate, Mindoro, Palawan, Samar, Negros, Surigao, Zamboanga, Misamis, Cotabato, Davao, and Jolo.

Supply has significantly decreased due to overexploitation. Remaining supply is being preserved and cutting is currently restricted. Updated information as verified in the field is needed.

3. Aquilaria (Thymelaeaceae, Fig. 3) Bari

Distinct Features: Heartwood yellowish-brown, not clearly demarcated from the lighter-colored sapwood, with darker streaks on the tangential surface. Grain generally straight to slightly interlocked; texture moderately coarse; lustrous, soft and light. (Relative density not available).

Growth rings indistinct even under a hand lens. Pores small, visible only under a hand lens, predominantly oblong, some solitary, in radial multiples of 2-4 or more. Included phloem present, abundant, usually larger


than pores, tangentially arranged and a diagnostic feature.

Tyloses present; deposits chalky white. Parenchyma visible only under a hand lens, sparse, thinly vasicentric. Fibers loose.

Rays fine and narrow, visible only under a hand lens. Splinter burns to complete white ash. Ripple marks absent.

Similar Woods: Aquilaria wood distinctive due to the presence of included phloem (shown by arrow in 20x cross-section view).

Supply: Very rare and local in occurrence in the Philippines, up to below 270 m altitude (Camarines Provinces). Also found in India, Myanmar, Malesia: Sumatra, Malay Peninsula (common), N and E Borneo. The species is listed in Appendix II (potentially endangered species) of the Convention on International Trade in Endangered Species of Wild Fauna and Flora.


• Of the more than 3,700 species, 124 families and 600 genera of Philippine woods, only three genera exhibit included phloem, namely; Avicennia [Verbenaceae (APG: Acanthaceae], Memecylon (Melastomataceae) and Aquilaria (Thymelaeaceae).

• Included phloem is a diagnostic character useful in wood identification. It can be classified into three types, namely: a) complete bands, b) patches, and c) diffuse. However, the use may be limited when identifying small specimens due to the possibility that it may not be present or seen in such specimens.

• Other diagnostic characters useful in distinguishing Philippine woods are recommended to be re-studied and published.

Fig. 3 Bari (Aquilaria malaccensis Lamk.).


REFERENCES

APG. 1998. An ordinal classification for the families of flowering plants. Annals of Miss. Bot. Gard. 85: 531-553.

APG II. 2003. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants. Bot. J. Linn Soc. 141: 399-436.

CO L. 2011. Co’s digital flora of the Philippines. www.philippineplants.org.

CRONQUIST A. 1988. The evolution and classification of flowering plants. 2nd ed. New York Botanical Garden, NY. 555pp.

ESCOBIN RP, AMERICA, WM, PITARGUE JR. FC, CONDA JM. 2015. Revised wood identification handbook for Philippine timbers, vol. 1. DOST-FPRDI, College, Laguna, Philippines.

ESCOBIN RP, CONDA JM, AMERICA WM, PITARGUE JR FC. 2014. Wood identification handbook for Philippine timbers, vol. 2. Unpublished manuscript. DOST-FPRDI, College, Laguna, Philippines.

ESAU K. 1977. Anatomy of seed plants. 2nd edition. Reprint. Philippine Graphic Arts, Inc., 163 Tandang Sora, Samson Road, Caloocan City. 550pp.

SALVOSA FM. 1963. Lexicon of Philippine trees. Forest Products Research Institute, College, Laguna, Philippines. Bulletin No. 1. 136pp.

MAUSETH JD. 2014. Botany: An introduction to plant biology. 5th ed. Jones and Bartlett Learning, LLC. Ascent Company. 5 Wall Street, Burlington, MA. 695pp.

MENIADO JA, TAMOLANG FN, LOPEZ FR, AMERICA WM, ALONZO DS. 1975. Wood identification handbook for Philippine timbers, vol. 1. Govt. Printing Press. Manila. 370pp.

ROJO JP. 1999. Revised lexicon of Philippine trees. FPRDI-DOST, College, Laguna, Philippines. 484pp.

SOSEF MSM, HONG LT, PRAWIROHATMODJO S. 1998. Plant resources of South-East Asia 5(3). Timber trees: Lesser-known timbers. Backhuys Publishers, Leiden, The Netherlands. 859pp.

THE PLANT BIOLOGY GROUP (PBG). 2006. Orders and families of Philippine plants. J. Nature Studies 5: 1-11. Philippine Society for the Study of Nature.

THE PLANT LIST. 2013. Version 1.1 Published in the Internet; http://www.the plantlist.org/ (accessed 01 January 2013).

WHEELER EA, BAAS P, GASSON PE (eds.). 1989. IAWA list of microscopic features for hardwood identification (with an Appendix on non-anatomical information). IAWA Bulletin n.s. 10(3): 219-332. Rijksherbarium, Leiden, The Netherlands.


TOW-GRADE ABACA (Musa textilis Nee) FIBER AS REINFORCEMENT FOR PACKAGING PAPER

Erlinda L. Mari, Adela S. Torres & Aimee Beatrix R. Habon

Scientist 1, Supervising Research Specialist & Senior Science Research Specialist,respectively Technology Innovation Division

DOST-FPRDI, College, Laguna 4013, Philippines

Corresponding Author: [email protected]

ABSTRACT

To establish conditions for producing abaca fiber-reinforced packaging paper, handsheets were prepared from waste kraft paper and pulp from residual or tow-grade abaca fiber. Paper properties were evaluated against those of commercially available packaging paper. The amount of abaca pulp and starch significantly affected the properties of paper at 60-70 g/m 2 basis weight. Three to seven percent of pulp from tow-grade abaca fiber was sufficient to reinforce waste kraft paper for packaging. Properties significantly improved compared with paper without abaca pulp.

Keywords: abaca fiber, packaging paper

INTRODUCTION

The Philippine Paper Manufacturers’ Association, Inc. (PPMAI) (2012) reported that between 2001 to 2011, the number of paper mills in the country went down from 43 to 24, with production decreasing by 1% per year from 1.056 million MT to 0.950 million MT.

Thru the years, domestic consumption, increasing at an average of 2.2% per year, has been consistently greater than local production. The shortage in local supply has always been addressed by imports.

All recycle-based, most of the country’s paper mills manage to run on small and slow old machines (50-60 tons/day), high

energy costs, increasing competition for raw material (wastepaper and virgin fiber), and several other limitations. Only two mills, one producing newsprint, printing and writing paper and the other, corrugating medium and testliner, have developed facilities capable of running 70 and more tons/day.

The local pulp and paper industry depends heavily on imported recycled paper, as well as imported virgin fiber, for its paper products. Virgin fiber is freshly prepared fiber or pulp from lignocellulosic materials such as wood or plants processed by cooking or pulping to remove as much lignin, resins and other components as possible. It is said to be “activated” or rendered active for bonding formation with other fibers due to the removal of these hydrophobic components (Hubbe et al. 2007).


33Erlinda L. Mari, et al.

A certain amount of virgin fiber is needed to enhance the properties of paper from recycled paper as fiber quality diminishes with each recycling. In its proposed Road Map for the Pulp and Paper Industry, the PPMAI has identified as one major problem the absence of a local source of virgin pulp for the industry’s virgin fiber requirement.

Moreover, in the Philippines, there is increasing pressure to implement regulations on the use of plastic-based materials, such as those for packaging, for already known adverse impact on the environment. Currently, the country imports volumes of paper bags or paper for bags for this purpose.

A key strategy that the PPMAI has identified is to exploit abaca (Musa textilis Nee) fiber in the absence of local wood pulp for reinforcement of locally produced printing/writing and packaging paper.

The Philippines is known as the major supplier of abaca fiber in the world, producing on the average 67,000 MT from 2002 till 2011. The fiber is exported in various forms: raw, pulp, cordage, yarns/fabrics, and fibercrafts, for an annual average export earning of USD 89 M, of which about 60% is attributed to pulp. Since 1991, however, the country imports abaca fiber from Ecuador, the second largest abaca supplier, for processing into pulp as demand for it has increased. While other countries are enjoying the versatility of abaca fiber, particularly of its pulp, the Philippines’ paper industry has lagged behind, hardly benefiting from it. Abaca pulp is used by the importing countries to produce different grades of paper, but mainly specialty paper.

Importing allows paper millers to avoid the rigors of pulping and their country’s strict

environmental regulations (FIDA 2012). Specialty paper includes tea bags, cigarette paper, currency paper, meat sausage casings, filter paper, and others.

Abaca pulp obtained from residual or tow-grade (Y2) abaca by chemical and mechanical pulping reportedly exhibits properties superior to imported softwood chemical pulps (Torres et al. 1997). Thus, even a small amount (5%) of abaca pulp blended with wastepaper has been found comparable with abaca pulp mixed with 20% imported softwood chemical pulp (Estudillo et al. 1998).

On the other hand, with each recycling of fiber, both quantity and quality diminish (Kleinau 1993, Mari et al. 2011) due to breakage, decreased flexibility, hornification, and other changes (Hubbe et al. 2007). The local paper industry is thus heavily weighed down by its complete dependence on wastepaper (imported and local) and imported virgin fiber. In light of the increasing need for paper and the drive to revitalize the pulp and paper industry, PPMAI is proposing, among others, the commercial processing of abaca fiber as reinforcement for paper.

This present study aimed to address this concern by establishing the conditions, that is, proportions of abaca pulp, waste kraft pulp and starch, needed for the manufacture of packaging paper.


Material preparation

Waste kraft paper and pulp from tow-grade abaca fiber from Albay Industrial

VariableMaterial Waste kraft paperCanadian Standard Freeness (CSF), mL 251-300Basis weight, g/m2 60, 70, 80Abaca pulp, % 3, 5, 7Starch, % 1, 2, 3


Source of Variation DF

Mean Squares

Burst Tear Tensile Folds

Basis Wt (A)

Abaca Pulp (B)

A*B

Starch (C)

A*C

B*C

A*B*C

Error

Corrected Total

2

2

4

2

4

4

8

108

134

3.110*

0.944ns

0.477**

0.040ns

0.162*

0.056ns

0.099ns

0.056

58.676**

2.164**

4.122**

1.130ns

2.274**

2.607**

5.183**

0.374

423.190**

130.661**

135.381**

20.872ns

13.648ns

35.226*

11.746ns

13.708

487.439**

171.270**

236.914**

15.654ns

15.275ns

21.240ns

22.500ns

18.619

R2 0.624 0.833 0.572 0.566

CV 10.841 6.480 10.339 30.076

Table 1 ANOVA on the properties of abaca-reinforced handsheets

ns - not significant at α= 0.05

* - significant at α= 0.05

** - significant at α= 0.01

Development Corp. (ALINDECO) in Malinao, Albay Province were disintegrated and beaten in the Valley beater to arrive at the desired freeness of pulp slurry. The former was beaten for 11 min to a freeness of 253 mL CSF; the latter, for 30 min to a freeness of 288 mL CSF.

Handsheet Preparation and testing

Five handsheets were prepared following TAPPI/ISO procedures using the experimental design below:

The handsheets were tested according to TAPPI/ISO methods, as follows: basis weight or grammage (ISO 536:1995), thickness (ISO 534:1995), burst index (ISO 7263:1994), tearing index (ISO 1974:1990), tensile index (ISO 1924:1994), and folding endurance (ISO 5626:1993). Control handsheets (without abaca pulp and starch)

were also produced at 60 g/m2 basis weight and similarly tested.

Evaluation of data

Data were analyzed using the factorial design in completely randomized design (CRD). DMRT was used to compare treatment means, control handsheets and commercial packaging paper.


Table 1 shows the ANOVA on the four strength indices - burst, tear, tensile and folds - of the handsheets formed from the different treatment combinations.

As expected, basis weight significantly affected the four strength properties. The amount of abaca pulp in the mixes had a highly


Abaca Pulp, % 3 5 7 3 5 7 3 5 7 Basis Weight, gsm

60 70 80

Fig. 1 Effect of basis weight, starch and abaca pulp on burst index.

significant effect on tear, tensile and folds but not on burst, while the amount of starch did not affect any index. The interaction between basis weight and the fraction of abaca pulp was also highly significant on all properties, but the addition of starch limited the significance to tear index only.

Burst index

Fig. 1 shows the average burst index values (interaction of the three variables - basis weight, amount of abaca pulp and amount of starch) of the handsheets. The values did not significantly differ from each other. Compared with the control sheets, however, replacing with 5% abaca pulp and adding 1-3% starch doubled burst strength from 1.21 to 2.44 (at 60% basis weight).

The highest values had a basis weight within 60-70 gm2 with the amount of abaca pulp having a significant but varying effect. For practicality, however, for almost the same burst strength, the basis weight and abaca pulp need not go beyond 70 g/m2 and 5%, respectively (Table 2) and with only 1-2% starch (Table 3).

Tear index

For tear index, Fig. 2 shows minimal increases in values at 60 g/m2 compared to the control. Fiber length is generally recognized to affect tear index. The presence of abaca pulp hardly manifested this effect probably because its freeness was almost the same as that of waste kraft pulp. This could also indicate that the waste kraft obtained was mainly of virgin wood pulp.

It was only with the tear index that the interaction among the three variables was significant. Table 4 shows that the highest values generally had 80 g/m2 basis weight, 5% abaca pulp and 2% starch. This implies dependence of tear on mass. The presence of more abaca pulp or longer fibers (5-7% as shown in Table 5), as well as starch (2-3% as shown in Table 6), added resistance to tear.

Tensile index

In the case of tensile index, the average values (Fig. 3) or the interaction among the three variables was found insignificant. Compared to the control, however, there


0

2

4

6

8

10

12

14

1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3

Tear

inde

x, m

N.m

2 /g

% Starch at different proportion of abaca pulp


60 70 80

Control

Fig. 2 Effect of basis weight, starch and abaca pulp on tear index.

Table 3 Treatment means for interaction between basis weight and amount of starch on burst index of abaca-reinforced handsheets

Variables Burst Index, kPa.m2/g

DMRT RankBasis weight, g/m2 Starch, %

Control (60 g/m2) 0 1.2160 1 2.21 bc

2 2.30 bc3 2.19 c

70 1 2.32 bc2 2.36 b3 2.58 a

80 1 1.92 d2 1.92 d3 1.86 d

Means followed by the same letter(s) are not significantly different at α = 0.05

Table 2 ANOVA on the properties of abaca-reinforced handsheetsVariables Burst Index,

kPa.m2/gDMRT RankBasis weight, g/m2 Abaca pulp, %

Control (60 g/m2) 0 1.2160 3 2.00 c

5 2.40 b7 2.31 b

70 3 2.59 a5 2.39 b7 2.29 b

80 3 1.86 c5 1.93 c7 1.92 c

Means followed by the same letter are not significantly different at α = 0.05


Variables Tear Index mN.m2/g DMRT RankBasis weight

g/m2Abaca pulp

%Starch

%Control

(60 g/m2) 0 0 7.99

60

31 8.54 fghij2 8.85 fghij3 8.61 fghij

51 9.04 fgh2 7.42 k3 8.10 ijk

71 8.08 ijk2 8.13 hijk3 8.67 fghij

70

31 9.06 fg2 8.34 ghij3 8.94 fgh

51 9.15 efg2 9.29 def3 8.87 fghij

71 9.11 efg2 10.04 cd3 10.57 c

80

31 10.79 c2 9.13 efg3 10.41 c

51 9.22 defg2 12.73 a3 11.65 b

71 10.24 c2 11.66 b3 9.99 cde

Table 4 Treatment means for interaction among basis weight, proportion of abaca pulp and amount of starch on tear index of abaca-reinforced handsheets

Means followed by the same letter(s) are not significantly different at α=0.05

Table 5 Treatment means for interaction between basis weight and proportion of abaca pulp on tear index of abaca-reinforced handsheets

Variables Tear Index, mN.m2/g

DMRT RankBasis weight, g/m2 Abaca pulp, %

Control (60 g/m2) 0 7.9960 3 8.66 de

5 8.19 f7 8.30 ef

70 3 8.78 d5 9.10 d7 9.90 c

80 3 10.11 c5 11.20 a7 10.63 b



Table 6 Treatment means for interaction between basis weight and amount of starch on tear index of abaca-reinforced handsheets


Variables Tear Index, mN.m2/g

DMRT RankBasis weight, g/m2 Starch, %

Control (60 g/m2) 0 7.99

60 1 8.56 e

2 8.13 e

3 8.46 e

70 1 9.11 d

2 9.22 d

3 9.46 d

80 1 10.08 c

2 11.17 a

3 10.68 b

0

5

10

15

20

25

30

35

40

45

50

1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3

Tens

ile In

dex,

N.m

/g

% Starch at different proportion of abaca pulp


60 70 80

Control

Fig. 3 Effect of basis weight, starch and abaca pulp on tensile index.

was a notable increase even with only 3% abaca fiber and the addition of starch.

Table 7 shows that the highest values were from handsheets with 70 g/m2 basis weight with 3% abaca pulp. Two to three percent starch resulted in an insignificant difference between 3% and 7% abaca pulp. The

coefficient of regression, R2, for these data was just a little over 50%, which suggests wide variation in values.

Folding endurance

Folding endurance (Fig. 4) exhibited the most remarkable effects among the treatments.


Table 7 Treatment means for interaction between basis weight and proportion of abaca pulp on tensile index of abaca-reinforced handsheets


Variables Tensile Index,N.m/g

DMRT RankBasis weight, g/m2 Abaca pulp, %

Control (60 g/m2) 0 25.42

60 3 30.49 e

5 33.14 de

7 36.73 c

70 3 43.03 a

5 35.04 cd

7 39.76 b

80 3 34.96 cd

5 33.69 d

7 35.44 cd

Any combination of a small amount of starch with 3-7% abaca pulp for basis weights 60 and 70 g/m2 significantly improved folding endurance, surpassing those of the reference packaging materials by two-fold.

Folding endurance is a more sensitive measure of effect of changes in paper due to pulp furnish or to deterioration. Accordingly, “the increase in folding endurance produced by a small increase in beating is so great

Fig. 4 Effect of starch and abaca pulp on folding endurance.


that significant differences are indicated when no significant difference is found in either tensile or bursting strength” (ASTM 1963). Based on the results and considering that only tow-grade abaca fiber was used, 3-7% of abaca pulp was sufficient to reinforce packaging paper of 60-70 g/m2 basis weight. Adding starch at 1-3% was needed for greater strength (Table8).

Table 9 shows the notable increase in the number of folds from the control with 3% abaca pulp and with more abaca pulp. However, this seemed effective only up to 70 g/m2 as the values tapered off at higher basis weights. Thus, 60 g/m2 with 7% abaca pulp compared well with 70 g/m2 with 3% abaca pulp.

In an earlier study where the fraction of

abaca pulp mixed with old corrugated carton ranged from 5% to 20%, results notably improved in all properties up to 10%, but tapered off with higher amounts of abaca (Nicolas et al. 1997).

In Table 10, the properties of handsheets at 60.5 g/m2 with 3% abaca pulp and 1% starch are compared against the properties of two commercial packaging materials with an average basis weight of about 65 g/m2.

The lower tensile strength of the handsheet may be due to the lower density resulting from its thickness. With better pressing/calendering attainable in commercial production and at lower grammage, packaging paper with higher strength may possibly be produced using tow-grade fiber and the addition of minimal starch.

Variables Tensile Index,N.m/g

DMRT RankAbaca pulp, % Starch, %

Control (60 g/m2) 0 25.42

1 34.66 de

3 2 37.37 abc

3 36.44 abcd

1 35.19 cde

5 2 34.02 de

3 32.66 e

1 35.47 bcd

7 2 38.01 ab

3 38.45 a

Table 8 Treatment means for interaction between proportion of abaca pulp and amount of starch on tensile index of abaca-reinforced handsheets



Table 10 Properties of handsheets and commercial kraft packaging paper compared


Properties Abaca-Reinforced

Kraft Paper

A B Ave

Basis weight, g/m2 60.5 64.94 64.79 64.87

Thickness, mm 0.142 0.115 0.111 0.113

Density, g/cm3 0.430 0.565 0.584 0.575

Burst index, kPa.m2/g 2.02 1.85 1.71 1.78

Tear index, mN.m2/g 8.54 9.74 5.30 7.52

Tensile index, N.m/g 28.52 32.22 32.46 32.34

Folding endurance 7.48 9.60 5.62 7.61

Table 9 Treatment means for interaction between basis weight and proportion of abaca pulp on folding endurance of abaca-reinforced handsheets


VariablesFolds DMRT

RankBasis weight, g/m2 Abaca pulp, %

Control (60 g/m2) 0 6.62

60 3 9.30 f

5 13.03 cde

7 19.76 a

70 3 21.64 a

5 15.13 bc

7 16.58 b

80 3 10.04 ef

5 10.33 def

7 13.30 cd


LITERATURE CITED

American Society for Testing and Materials (ASTM). 1963. Paper and paperboard. Characteristics, nomenclature and significance of tests. 3rd ed. July 1963. Philadelphia, PA.

ESTUDILLO CP, TORRES AS, AUSTRIA CO. 1998. Production of abaca mechanical pulp as extender to waste paper for printing and writing paper. For. Prod. J. 24(1): 11-24.

Fiber Industry Development Authority (FIDA). 2012. Abaca fact sheet. FIDA, Quezon City, Philippines.

HUBBE MA, VENDITTI RA, ROJAS OJ. 2007. What happens to cellulosic fibers during papermaking and recycling? A review. Bioresources 2(4): 739-788.

KLEINAU JH. 1993. Chapter X. Secondary fibers and recycling. In: Pulp and Paper Manufacture. Vol. 3. Secondary Fibers and Non-Wood Pulping. Hamilton F, Leopold B (Technical eds.); Kocurek MJ (Series ed.). Joint Textbook Committee of the Paper Industry, TAPPI USA & CPPA & Canada.

MARI EL, TORRES AS, AUSTRIA CO, HABON ABP. 2011. Recycling mimeograph-printed newsprint paper. ASEAN J. Sci. Technol. Dev’t 28(2): 156-167.

TORRES AS, ESTUDILLO CP, AUSTRIA CO. 1997. High yield pulping of abaca (Musa textilis Nee). For. Prod. J. 23(1): 23-32.


• The amounts of abaca pulp and starch significantly affect paper properties at 60-70 g/m2 basis weight.

• Three to seven percent pulp from tow-grade abaca fiber with minimum starch is sufficient to reinforce waste kraft paper

for packaging. Significantly improved properties are achieved even with lower grammage compared with paper without abaca pulp.

• Further research is recommended to include pulp from abaca wastes and the new hybrid of abaca, and to cover more variables (pulp freeness, basis weight, pulp proportions).

43Juanito P. Jimenez, et al.

PROFILE OF WOOD SPECIES USED IN LOCAL AND IMPORTED PLYWOOD AND THEIR BOND PERFORMANCE

Juanito P. Jimenez, Jr.1, Ramiro P. Escobin2 & Jennifer M. Conda2

1Senior Science Research Specialist, Technology Innovation DivisionDOST-FPRDI, College, Laguna 4031, Philippines

2Scientist I & Science Research Specialist I, respectively, Material Science DivisionDOST-FPRDI, College, Laguna 4031, Philippines

Corresponding Author: JPJimenez ([email protected])

ABSTRACT

The wood species currently used in local plywood production, as well as the dominant species used in imported plywood, was determined. The bond performance of both local and imported plywood was also assessed using PNS 196:2000 and ISO 12466-2:2007 standards.

With a 20x hand lens and a Leica digital stereoscope, identification was done by examining the physico-mechanical and macro-anatomical properties of the samples and comparing them with wood samples lodged at the FPRDI Wood Library.

Results showed that the majority of the local companies especially those from Mindanao used Falcataria moluccana as the dominant species for plywood production. Depending on veneer quality, this species was used as outerply, core, cross bands and lumber core.

Shorea sp., Artocarpus blancoi, Weinmannia sp., Heritiera sp., Pinus sp. and Endospermum peltatum were not only used for outer plies, but also as core and cross bands depending on veneer quality. On the other hand, imported plywood used only Populus sp. as cross band and core. Helicia sp. and an unidentified species (too thin for identification) from the family Anacardiaceae or Burseraceae were usually used as outer plies.

The bond test revealed that local plywood conformed to both PNS and ISO standards for Type I exterior plywood regardless of the species used in the layers as long as the adhesive used was phenol formaldehyde. In contrast, though imported plywood used only Populus sp. in the cross band and core, it did not conform to both standards due to the use of melamine glue, a weaker exterior adhesive than phenol formaldehyde.

Keywords: Local plywood, imported plywood, species profile, bond test



INTRODUCTION

Plywood is one of the most widely used wood-based panel products in the building industry. In the Philippines, despite decreasing raw material supply, plywood production is still high despite a decreasing trend from 1990-2014. From 1990-1999, plywood production averaged 335,100 m3; from 2000-2009, it declined to 306,500 m3 and from 2010-2014, it further went down to 247,200 m3 (Philippine Forestry Statistics 2010, 2011, 2012, 2013, 2014).

The declining production can be attributed to the cancellation or expiration of Timber License Agreements (TLAs) of most companies, competition with other panel products, and the imposition in 2011 of Executive Order No. 23, which declared a moratorium on the cutting and harvesting of timber in the natural and residual forests and creating an anti-illegal logging task force. The resulting dearth of raw materials led to the closure of some veneer and plywood plants. Because of the current boom in the Philippine construction industry, local demand for plywood remains high. The sector registered an annual growth rate of 12.01% from 2009-2013. This growth was supported by government and private investments in the infrastructure and residential markets, and expected to be the main growth drivers from 2014 to 2018 (Timetric 2014). According to the Philippine Statistics Authority, local construction activity has been growing as shown by the 20.8% increase in number of approved building permits -- from 24,400 new constructions in the first quarter of 2013 to 29,468 for the same quarter in 2014. Residential building projects recorded a faster expansion (17.1%) compared with non-residential buildings (15.2%) (Timetric 2014). This kind of growth raises concerns over its impact

on the supply of materials such as plywood.The insufficient supply of local plywood has resulted in some trading firms importing the product from other countries such as China, Malaysia and Vietnam for ready disposal to the market (PWPA 2012). Influx of imported plywood rose from an average of 1,167 m3 (1990-1999) to 2,904 m3 (2000-2009), then to a very high 171,376 m3 (2010-2014) (Philippine Forestry Statistics 2010, 2011, 2012, 2013, 2014). On the other hand, some local manufacturers import logs from Malaysia, Papua New Guinea and Indonesia for veneer production, while others simply import veneers from China and New Zealand for plywood production (Philippine Forestry Statistics 2011, 2012, 2013, 2014). In boat or building construction utilizing plywood, it is important to know the identity of the wood species as this will determine the panel’s estimated service life, as well as expected strength properties. The species tapped for plywood nowadays have changed due to the shift towards fast-growing plantation species with short rotation cutting cycle, i.e., 10 to 15 years old (Orwa et al. 2009). The bond type of the plywood should also be considered as incorrect use can later result in delamination of the veneers and failure in service.

This study was conducted to distinguish between local and imported plywood currently sold in the market thru profiling of the wood species identity and assessment of their bond performance.

Specifically, it aimed to determine: (1)the species being used in local plywood production and the dominant species used in imported plywood; (2) the extent by which various species are used in the plywood layers. Lastly, it aimed to determine whether or not the bond performance of the local and imported plywood conformed to Philippine National Standards (PNS) and ISO requirements.



Plywood samples

The plywood samples came from local manufacturing companies applying for Philippine Standard (PS) license or from importers applying for Import Commodity Clearance (ICC) with the Bureau of Philippine Standards-Department of Trade and Industry (BPS-DTI).

The samples were limited to those submitted to the FPRDI Plywood Testing Laboratory from January to July 2014. Eight out of 14 companies that applied for PS license within the study period were selected – 3 from Luzon and 5 from Mindanao.

On the other hand, four out of nine companies were selected from the importers that applied for ICC: 2 companies in Luzon, 1 in the Visayas and 1 in Mindanao. Hence, geographically, both manufacturers and importers were represented.

To keep the results confidential, the companies were coded A, E, O for those based in Luzon and B, C, D, F, G for those in Mindanao. The four importers were coded W, X, Y, Z.

The plywood samples drawn by the DTI Regional Offices (DTI-RO) or the DTI’s

accredited sampling body thru its own method of random sampling (Fig. 1) were used.

Ten panels for a particular size were obtained following PNS 196:2000 method. From each panel, three portions were cut and labeled as top, middle and bottom. Hence, 30 samples per size were submitted for testing and subsequently identified per layer of veneer. Fig. 1 shows how the samples were selected, while Tables 1 and 2 show their specifications.

Identification of plywood layers

The layers of the 30 plywood samples per size were identified up to the species level when possible, or to the genus level when the identity could not be ascertained, or to the family level when it was not possible to identify the layer due to the very thin width of the face and back.

Using a 20x hand lens and a Leica digital stereoscope, identification was done per company by examining the samples’ physico-mechanical properties (Alipon et al. 2005) and macro-anatomical properties using wood identification handbooks (Escobin et al. 2015, Escobin et al. 2014, Meniado et al. 1981, Meniado et al. 1975). Identification was confirmed by comparing them with the wood samples lodged at the FPRDI Wood Library (CLP)1.

Plywood Batch/size (for PS applicant) or Plywood Bill of Lading per size (for ICC applicant)

10 randomly selected panels from various crates/pallets

Top

MiddleBottom

30 samples per batch or Bill of Lading/size

Fig 1. Method for selecting the plywood samples.

1International abbreviation of the FPRDI Wood Collection at College, Laguna 4031 as recognized in the Index Herbarium by Holmgren and Holmgren (1990) and Index Xylariorum by Stern (1988).


No.

Com

pany

Cod

e/

Reg

ion

Loca

tion

Typ

e I

(E

xteri

or

Ply

wood

)Ty

pe I

I (I

nte

rior

Ply

wood

)

3-p

ly5

-ply

7-p

ly9

-ply

11

-p

ly1

3-

ply

3-p

ly5

-ply

7-p

ly9

-ply

11

-ply

13

-ply

1A

/3

Luzon

25 m

m6

mm

9 m

m,

12 m

m

2E

/ 4

4 m

m9

mm

18 m

m8

mm

,

18

mm

PB

17 m

m

3O

/ 4

5 m

m11

mm

18 m

m

4B

/ 1

0

Mindanao

4.5

mm

5

mm

5C

/ 9

5 m

m10

mm

18 m

m6

D /

11

18 m

m P

B

7F

/ 13

4.5

mm

10 m

m18

mm

4 m

m9

mm

,

18

mm

PB

8G

/ 1

35

mm

9 m

m18

mm

10 m

m,

18 m

m P

B18

mm

Tabl

e 1

S

pecifi

catio

ns of

samp

les su

bmitte

d for

PS

appli

catio

n

Tabl

e 2

S

pecifi

catio

ns of

samp

les su

bmitte

d for

ICC

appli

catio

n

No.

Com

pany

Cod

e/

Loca

tion

Typ

e I

(E

xteri

or

Ply

wood

)Ty

pe I

I (I

nte

rior

Ply

wood

)

3-p

ly5

-ply

7-p

ly9

-ply

11

-ply

13

-ply

3-p

ly5

-ply

7-p

ly9

-ply

11

-ply

13

-ply

1W

/ L

uzon

18 m

m18

mm

2X

/ L

uzon

4.85

mm

17.5

mm

4.85

mm

3Y

/ V

isay

as5.

0 m

m

4Z

/ M

inda

nao

4.85

mm

17.5

mm

4.85

mm

17.5

mm


Average Shear Strength (kg/cm2) Minimum Wood Failure (%) Average Wood Failure (%)Below 17.58 25 5017.58 to 24.6 10 30Above 24.6 10 15

Table 3 Wood failure requirements of PNS 196:2000

Mean Shear Strength (ז), MPa Average Apparent CohesiveWood Failure, %

0.2 > ז not applicable0.4 > ז ≥ 0.2 ≥ 800.6 > ז ≥ 0.4 ≥ 601.0≥ ז ≥ 0.6 ≥ 40ז > 1.0 no requirement

Table 4 Glue line requirements of ISO 12466-2:2007

Each veneer layer of a panel was identified and tallied in a table to compute for the average percentage use of the species. To guide the identification, the local manufacturers were asked where they sourced their raw materials. For the imported plywood, traders were asked the samples’ country of origin.

Bond test

The bond performance of the local and imported plywood followed the procedures specified in Annex C of PNS 196:2000. The samples were selected following the scheme in Fig.1.

A previous study by Jimenez et al. (2013) showed that there is no statistical difference between shear strength (SS) and wood failure (WF) values obtained in parallel testing of plywood using both PNS and ISO standards and as such can be used for evaluation in the present study. As the thrust of BPS-DTI is to harmonize its standards with internationally accepted ones, the bond test was evaluated using the criteria of both PNS and ISO.

Table 3 shows the SS - WF requirements wherein the minimum WF and average WF of all specimens per test piece (top, middle, bottom) were considered. On the other hand, in Table 4, only the average SS and WF were considered in determining the samples’ conformance to the standards.


Identification of the plywood layers

• Luzon companies

Three companies from Luzon (Table 5) were included: 2 from Region 4 and 1 from Region 3. Company A from Region 3 produced not only plywood but also laminated veneer lumber (LVL). It imported only Pinus veneer from only one country. Table 5 shows that 100% Pinus sp. was used on the outer ply, cross band and core of all the plywood it made.

Company E from Region 4 produced Types I and II plywood. Shorea sp. made up 71.32%


of the material for the face and back, including low grade Shorea veneers for cross band and core.

Other local species used as cross band and core were Endospermum peltatum Merr., 13.50%; Falcataria moluccana (Miq.) Barneby & J.W. Grimes, 8.94%, and Artocarpus blancoi (Elmer) Merr., 4.54%. Other lesser-known species were occasionally used as inserts or as cross band such as Aleurites moluccana (L.) Willd. and Parkia timoriana (DC.) Merr. Company O, also from Region 4, produced largely Type I plywood with a variety of species combination in the core and cross band as spliced species for maximum material recovery. The outer ply or face and back used purely Weinmannia sp., 45.10%, but this veneer, probably the rejects for outer plies, was also found spliced with

other species as cross band or core. Other species used substantially as cross band and core were A. blancoi (22.47%), Endiandra sp. (18.10%) and F. moluccana (8.07%). Like Company E, it also tapped other lesser-known species such as A. moluccana and Duabanga moluccana Blume as occasional core and cross band and sometimes as spliced veneer with other species.

The plywood made by the three companies contained imported veneers. Company A used 100% Pinus sp. from New Zealand, while Companies E and O had a mix of imported and local veneers. The majority of imported veneers were harnessed as outerply by Companies E and O.

As there were log and veneer importation from Malaysia, Papua New Guinea and Solomon Islands in recent years (FMB-DENR 2011, 2012, 2013, 2014), the identified

Table 5 Identity of wood veneers used in Luzon plywood.

Identification/Family Name

CompaniesAve. %

UseCompany A Company E Company O

F B CB C % Use F B CB C % Use F B CB C %

Use

Pinus sp. (Pinaceae) Y Y Y Y 100 N N N N 0 N N N N 0 33.3

Shorea sp.(Dipterocarpaceae) N N N N 0 Y Y Y Y 71.32 N N N N 0 23.8

Weinmannia sp.(Cunoniaceae) N N N N 0 N N N N 0 Y Y Y Y 45.10 15.0

Artocarpus blancoi (Moraceae) N N N N 0 N N Y Y 4.54 N N Y Y 22.47 9.0

Endiandra sp. (Lauraceae) N N N N 0 N N N N 0 N N Y Y 18.10 6.0

Falcataria moluccana*(Mimosaceae) N N N N 0 N N Y Y 8.94 N N Y Y 8.07 5.7

Endospermum peltatum (Euphorbiaceae) N N N N 0 N N Y Y 13.50 N N N Y 3.33 5.6

Aleurites moluccana (Euphorbiaceae) N N N N 0 N N Y N 1.3 N N Y Y 1.83 1.0

Duabanga moluccana (Sonneratiaceae) N N N N 0 N N N N 0 N N Y Y 1.10 0.4

Parkia timoriana (Mimosaceae) N N N N 0 N N Y N 0.4 N N N N 0 0.1

TOTAL 100 100 100 100

Legend: F = Face, B = Back, CB = Cross Band, C = Core, Y = Yes, N = No*Synonym – Paraserianthes falctaria (Source: www.theplantlist.org)


Shorea sp. might have come from these countries, while the identified lesser-known or lesser-used local species probably came from nearby local sources, i.e., Quezon, Batangas, Laguna and Rizal provinces.

The top three genera used by Luzon companies for plywood, namely: Pinus sp., Shorea sp. and Weinmannia sp., were largely from imported logs or veneers based on interviews with the company managers and data from Philippine Forestry Statistics (FMB-DENR). Local woods used in significant amounts for veneer manufacture such as A. blancoi, Endiandra sp., F. moluccana and E. peltatum were probably sourced from the nearby provinces of Quezon, Batangas, Laguna and Rizal. Company O management, however, said that their F. moluccana veneer came from Palawan.

Mindanao companies

Five companies from Mindanao (Table 6) were included in the study. Two, F and G, were from Region 13, while the rest were from Region 10 (B), Region 9 (C) and Region 11 (D).

Company B produced only Type II plywood. Table 6 shows that F. moluccana was the most used species as core (33.35%), followed by A. blancoi (28.35%), Heritiera sp. (16.70%) and Pinus sp. (16.60%) as outerply.

Another species used as core was A. mangium at 5%. The core layer was sometimes not made up of only one but two species, i.e., F. moluccana and A. mangium, spliced together. This kind of mixed species splicing often resulted in variable properties of the plywood especially in the bond strength as F. moluccana has low density while A. mangium has medium to high density.

Company C produced largely Type I plywood. Surprisingly, the outer plies were made up

of a variety of species including Populus sp. and an unidentified species from either the family Anacardiaceae or Burseraceae. These two were assumed to be imported as according to the manager, the company bought their outerply veneers from China.

The most used species whether as core, crossband and even outerply was F. moluccana at 26.60%, followed by Shorea sp. at 18.20% which was used mostly as outerply but occasionally spliced with other species as core or crossband.

Two imported species followed – Populus sp. and an unidentified very thin veneer from the either the family Anacardiaceae or Burseraceae both at 16.65% and used as outerply. The least tapped was A. blancoi (11.45%) processed mainly as core and crossband.

Other species used by Company C as outerply were E. peltatum (3.70%) and Celtis sp. (3.10%). The former was sometimes found spliced with F. moluccana as core and crossband. A few species were found in small amounts as core or crossband such as Octomeles sp. (2.25%), Duabanga mollucana (0.55%), Dipterocarpus sp. (0.50%), Anisoptera sp. (0.25%) and Palaquium sp. (0.10%). Company D produced only 18-mm Type II plyboard. Unlike other companies, it utilized only one species - Weinmannia sp. (40%) – for outer ply. The lumber core and crossband veneers were all F. moluccana at 60%. According to company management, they imported the outerply veneer, while F. moluccana was sourced locally. Company F made both Types I and II plywood. F. moluccana was the most used species at 56.58% for outerply, crossband and core. The majority of its use, however, was for crossband and core. The second most used species was Shorea


Ident

ificati

on/Fa

mily

Name

Comp

anies

Ave. % Use

Comp

any B

Comp

any C

Comp

any D

Comp

any F

Comp

any G

FB

CBC

% Use

FB

CBC

% Use

FB

CBC

% Use

FB

CBC

% Use

FB

CBC

% Use

Falca

taria

molu

ccan

a* (M

imos

acea

e)N

NN

Y33

.35N

YY

Y26

.60N

NY

Y60

.0Y

YY

Y56

.58N

YY

Y58

.9347

.09

Shor

ea sp

. (Di

ptero

carp

acea

e)N

NN

N0

YY

YY

18.20

NN

NN

0Y

NY

Y32

.35Y

YN

N19

.3313

.98

Arto

carp

us b

lanco

i (Mor

acea

e)Y

NN

N28

.35N

NY

Y11

.45N

NN

N0

NN

YY

3.15

YY

YY

16.64

11.92

Wein

man

nia sp

. (Cu

nonia

ceae

)N

NN

N0

NN

NN

0Y

YN

N40

.0N

NN

N0

NN

NN

08.0

0

Herit

iera s

p. (S

tercu

liace

ae)

NY

NN

16.70

NN

NN

0N

NN

N0

NN

NN

0N

NN

N0

3.34

Popu

lus sp

. (Sa

licac

eae)

NN

NN

0Y

NN

N16

.65N

NN

N0

NN

NN

0N

NN

N0

3.33

Unide

ntifie

d (ve

ry thi

n)An

acar

diace

ae or

Bur

sera

ceae

NN

NN

0N

YN

N16

.65N

NN

N0

NN

NN

0N

NN

N0

3.33

Pinu

s sp.

(Pina

ceae

)N

YN

N16

.60N

NN

N0

NN

NN

0N

NN

N0

NN

NN

03.3

2

Endo

sper

mum

pelt

atum

(Eup

horb

iacea

e)N

NN

N0

NY

YY

3.70

NN

NN

0N

YY

Y3.7

0N

YY

N1.3

31.7

5

Aniso

pter

a sp.

(Dipt

eroc

arpa

ceae

)N

NN

N0

NN

NY

0.25

NN

NN

0N

YY

Y2.0

0N

NY

N3.7

71.2

0

Acac

ia sp

. (Mi

mosa

ceae

)N

NN

Y5.0

0N

NN

N0

NN

NN

0N

NN

Y0.2

0N

NN

N0

1.04

Celtis

sp. (

Ulma

ceae

)N

NN

N0

NY

NN

3.10

NN

NN

0N

NN

N0

NN

NN

00.6

2

Octo

mele

s sp.

(Dati

scac

eae)

NN

NN

0N

NN

Y2.2

5N

NN

N0

NN

NN

0N

NN

N0

0.45

Leuc

aena

leuc

ocep

hala

(Mim

osac

eae)

NN

NN

0N

NN

N0

NN

NN

0N

NN

Y1.5

0N

NN

N0

0.30

Duab

anga

molu

ccan

a (So

nner

atiac

eae)

NN

NN

0N

NN

Y0.5

5N

NN

N0

NN

NN

0N

NN

N0

0.11

Lage

rstro

emia

pyrif

orm

is (L

ythra

ceae

)N

NN

N0

NN

NN

0N

NN

N0

NN

NY

0.52

NN

NN

00.1

0

Dipt

eroc

arpu

s sp.

(Dipt

eroc

arpa

ceae

)N

NN

N0

NN

YN

0.50

NN

NN

0N

NN

N0

NN

NN

00.1

0

Palaq

uium

sp. (

Sapo

tacea

e)N

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sp. (32.35%) largely as outerply and occasionally spliced as core and crossband with F. moluccana. The spliced Shorea veneers were factory rejects and tapped as outerply.

Also used by Company F as outerply were E. peltatum (3.70%) and Anisoptera sp. (2%). These two, however, were also found spliced with other species as crossband or core. Other species observed as crossband or core were A. blancoi (3.15%), Leucaena leucocephala (1.50%), Lagerstroemia pyriformis (0.52%), and A. mangium (0.20%).

Like the other four Mindanao companies, Company G also utilized F. moluccana the most at 58.93% as outerply, crossband and core both for Types I and II plywood. However, the majority of its use was for crossband and core. In second place was Shorea sp. (19.33%) primarily as outerply. A. blancoi ranked third at 16.64% used in all layers either as outerply, crossband or core depending on where the veneer was most suitable to use based on surface quality. Another species used as outerply and crossband was E. peltatum (1.33%). Anisoptera sp. (3.77%) was used as crossband only.

The top three species tapped by Mindanao companies for plywood were F. moluccana (47.09%), Shorea sp. (13.98%) and A. blancoi (11.92%). The use of F. moluccana as outerply veneers depended on the quality of veneer from rotary cutting of the bolt. Lapitan and Eusebio (2010) found that only F. moluccana logs from trees 16 years old or older are made into outerply by some Mindanao veneer and plywood companies. Otherwise the logs are processed as core stock. In Indonesia, F. moluccana is also a peeler grade log owing to a straight bole of up to 20 m (Krisnawati et al. 2011).

On the other hand, Shorea sp. is a traditional species used for plywood as outerply

especially face thinstock. Its limited supply owing to the ban in cutting from natural growth and secondary growth forests in the Philippines was probably augmented by importation of Shorea peeler grade logs from Malaysia, Papua New Guinea and Solomon Islands (FMB-DENR, 2013). A. blancoi, an endemic species in the Philippines, is also rotary cut and has been long used for veneer and plywood manufacture (The Technical Committee on Veneer and Plywood 1999). Unlike in Luzon, the widespread processing of F. moluccana for plywood production in Mindanao is due to its abundance in the island. Philippine Forestry Statistics showed that 851,629 m3 and 743,687 m3 of F. moluccana logs were produced in 2013 and 2014, respectively. This was followed by Gmelina arborea with 93,043 m3 in 2013 and 110,397 m3 in 2014, while A. mangium had 80,676 m3 in 2013, but surpassed the 2014 production of G. arborea with 111,566 m3 for the same year (FMB-DENR 2013, 2014). These two species, however, are not widely used for plywood because they are traditionally tapped mostly for lumber intended for construction and furniture-making (Escobin et al. 2015, Tamolang et al. 1995).

• Importers

Four plywood importing companies (Table 7) were included in the study. Only three species were identified from the four species used in imported plywood. These were Helicia sp. for outer plies, Populus sp. for cross band and core, and Firmiana simplex for occasional inserts. The other species of outer ply used in imported plywood by importers X and Z could not be identified due to the very thin veneer which made pore topography difficult to discern.The most used species as core and cross band in imported plywood was Populus sp.


at 67.4%. It was followed by the unidentified outerply (17.2%), which was paper-thin but with beautiful grain. The limited topography of the pores seen on the cross section made it difficult to identify the outerply layer. However, this was believed to belong to either the family Anacardiaceae or Burseraceae. The third most used species was the Helicia sp. (14.4%) largely as outerply and occasionally as insert or spliced with Populus sp. as crossband. The least used and found as mere inserts and spliced as crossband was F. simplex at only 1%.

The widespread use of Populus sp. in imported plywood was most likely due to the species’ abundance in the exporting country. According to the importers, peeler logs considered as premium owing to their beautiful grain were sourced from other countries and veneered as thinly as paper or about 0.15 mm thick. The high-tech veneer lathe made it possible to produce a thin layer.Another feature of imported plywood was the use of similar thickness for the core and crossband that made possible sizes of 5-ply 4.5 mm and 11-ply or 13-ply 18 mm.

Bond performance

• Luzon companies

All samples of the three companies from Luzon subjected to the bond test passed the SS – WF requirements of PNS 196:2000 and ISO 12466-2:2007 (Table 8). Except for the 9-ply 25-mm Type I sample of Company A that reached an average SS of 18.1 kg/cm2

or 1.77 MPa, all Type I samples of Companies E and O gave values below 17.58 kg/cm2 SS.

Identification of Company A’s plywood layers showed that only one species, i.e., Pinus sp., was used. This explains why there was no variability in the average SS values of the top, middle and bottom of the samples. According to the company’s management, they imported radiata pine veneer from New Zealand. This species is a medium density softwood (RPBC 2003), which may explain its high SS values. The high average WF value of 88% may be due to the good quality of the veneer, as well as the company’s high gluing standards. Further, softwood species like Pinus sp. are commonly used as exterior plywood in temperate countries.

Identification/Family Name

CompaniesAve %

Use

Importer W Importer X Importer Y Importer Z

F B CB C % Use F B CB C %

Use F B CB C % Use F B CB C %

Use

Populus sp.(Salicaceae) N N Y Y 78.5 N N Y Y 60.0 N N Y Y 60.0 N N Y Y 70.9 67.4

Unidentified (very thin outer ply)Anacardiaceae orBurseraceae

N N N N 0 Y Y N N 40.0 N N N N 0 Y Y N N 29.1 17.2

Helicia sp.(Proteaceae) Y Y Y N 17.4 N N N N 0 Y Y N N 40.0 N N N N 0 14.4

Firmiana simplex (Malvaceae) N N Y N 4.1 N N N N 0 N N N N 0 N N N N 0 1.0

TOTAL 100 100 100 100 100

Table 7 Identity of wood veneers used in imported plywood

Legend: F = Face, B = Back, CB = Cross Band, C = Core, Y = Yes, N = No


Thickness(mm)

Company

Bond Test *

RemarksTop Left Middle Bottom Right

Panel Ave. SS

Panel Ave. WF

SS (kg/cm2)

WF (%)

SS (kg/cm2)

WF (%)

SS (kg/cm2)

WF (%)

25 A 18.2 87 18.1 97 18.1 79 18.1 88 A 4 E 6.0 89 5.4 92 4.8 91 5.4 91 A 9 E 6.7 65 7.5 72 5.8 62 6.7 66 A18 E 12.2 59 12.6 71 10.2 61 11.7 64 A 5 O 7.4 69 7.9 79 6.2 52 7.2 67 A11 O 6.3 51 7.2 50 9.5 61 7.7 54 A18 O 8.6 65 7.7 61 8.4 63 8.2 63 A

Table 8 Bond performance of Type I plywood from Luzon

Legend: * Bond Test values presented are average of 10 panels SS = shear strength, WF = wood failure

Company E samples except for the 7-ply 18-mm Type I had SS values below 10.2 kg/cm2 or 1 MPa. The 3-ply 4-mm panels had an average of 5.4 kg/cm2 or 0.53 MPa SS and 91% WF, while the 5-ply 9-mm had an average of 6.7 kg/cm2 or 0.66 MPa SS and 66% WF. The 7-ply 18-mm panels had an average of 11.7 kg/cm2 or 1.15 MPa SS and 64% WF. Compared with Company A, the average SS of Company E was very variable for all the sizes tested. This might be due to the various species used in plywood manufacture. The high average WF (91%) of 3-ply 4-mm samples could be attributed to the core species used, which were mostly F. moluccana and E. peltatum.

For the 5-ply 9 mm and 7-ply 18 mm sizes, the majority of the species used as crossband and core was a mixture of low density species (F. moluccana, E. peltatum and A. moluccana) and medium density species (A. blancoi and Shorea sp.) which resulted in varied SS and WF values.

For Company O, all samples had an average SS below 17.58 kg/cm2, with WF of more than the minimum 50% required by PNS 196:2000. Evaluation using ISO 12466-2:2007 showed that all samples had SS above 0.6 MPa but less than 1 MPa, meaning they conformed to the ISO requirement of more than 40% WF. Like Company E, the values of SS and WF were quite variable for all parts of the panels due to the variable species used. The relatively low WF (54 % - 67%) might have been caused by several factors such as surface quality (i.e., rough veneer, surface contaminants) of the veneer used – not only of the core but also of the outer plies; gluing (i.e., spread rate and resin content), and pressing conditions. Also, the use of A. blancoi as core layer could have resulted in lower % WF as the species is of medium density and has numerous deposits that occlude the cavities of parenchyma cells, blocking the mechanical anchorage of the adhesive in the wood.

Notes: Remarks: 1 MPa = 10.20 kg/cm2

0.6MPa = 6.12 kg/cm2

0.4MPa = 4.08 kg/cm2

0.2 MPa = 2.04 kg/cm2

A = Conformed to both PNS 196:2000 and ISO 12466-2:2007B = Conformed only to PNS 196:2000C = Conformed only to ISO 12466-2:2007D = Did not conform to both standards


• Mindanao companies

All samples from Mindanao which underwent the bond test passed the SS – WF requirements of both standards (Table 9).

Company C samples except for the 3-ply 5-mm Type I had average SS values above 10.2 kg/cm2 or 1 MPa. The 3-ply 5mm had an average of 7.1 kg/cm2 SS or 0.7 MPa and 98% WF. The high WF value was probably due to the use of low density species like F. moluccana and E. peltatum as core.

For the 5-ply 10-mm and 7-ply 18-mm panels, the above 1 MPa average SS was attributed to the use of some medium density species as cross band and core, such as A. blancoi, Shorea sp., Octomeles sp. Dipterocarpus sp. and Palaquium sp. The high average WF (above 85%) of all the samples could be because of the veneer’s good surface quality and the company’s good gluing practices.

For Company F, all Type I samples had average SS values below 17.58 kg/cm2 for

PNS and below 1 MPa for ISO. This could be due to the extensive use of F. moluccana veneer (56.6%) in almost all the layers. For WF, only the 3-ply 4.5mm had a low value of 63% in spite of having F. moluccana veneer as core. This might be because of the same factors at work in Company C samples. Nevertheless, the 5-ply 10-mm and 7-ply 18-mm samples passed the WF requirements of both standards.

For Company G, only the 7-ply 18-mm plywood had SS above 1 MPa, meaning that WF evaluation was no longer required for ISO but still required for PNS. The %WF, however, of the 7-ply 18 mm was higher than the minimum 50% required by PNS, which means the samples conformed to both standards. The species used in the core of the 7-ply samples varied from panel to panel. Some had F. moluccana, while others were spliced with F. moluccana and A. blancoi. The major species used in all layers, however, was F. moluccana which comprised 58.93% of

Thickness(mm) Company

Bond Test

Remarks

Top Left Middle Bottom Right Panel Ave.SS

Panel Ave. WFSS (kg/

cm2)WF (%)

SS (kg/cm2)

WF (%)

SS (kg/cm2)

WF (%)

5 C 7.1 99 7.5 96 6.8 98 7.1 98 A10 C 12.4 77 12.1 87 12.3 92 12.3 85 A18 C 11.5 98 11.4 95 11.6 94 11.5 96 A

4.5 F 5.5 58 5.5 68 6.2 63 5.7 63 A10 F 6.6 79 8.6 84 7.7 81 7.6 81 A18 F 6.8 76 7.9 83 5.1 74 6.6 78 A 5 G 7.3 84 7.6 80 6.1 80 7.0 81 A 9 G 6.9 74 8.8 74 8.8 81 8.2 76 A18 G 11.9 98 11.8 94 12.1 95 11.9 96 A

Table 9 Bond performance of Type I plywood from Mindanao



0.6MPa = 6.12 kg/cm2

0.4MPa = 4.08 kg/cm2

0.2 MPa = 2.04 kg/cm2



the total. The other two sizes, i.e., 3-ply 5 mm and 5-ply 9 mm, had 7 and 8.2 kg/cm2 average SS, respectively. The samples conformed to both standards, with more than 40% WF for ISO or more than 50% WF for PNS. The major species used in the layers was F. moluccana, which could explain their relatively high WF but relatively low SS.

• Importers

All samples of the four importing companies (Table 10) did not conform to the requirements of Type I exterior plywood. The species used could be assumed to have no relation to the %WF obtained as most of the failures had very few wood fibers adhering to the surface of the sheared test pieces.

The failure of the imported plywood in conforming to the two standards may have been due to the type of adhesive used. Local Type I exterior plywood uses phenol formaldehyde adhesive, while

imported plywood, as stated in the product information, uses melamine glue.

Although melamine glue could be considered as an exterior type of glue being weather- and boil-proof also, it did not meet the minimum requirements of the two standards. Lower quality melamine-glued plywood can sustain 4-8 hr boiling without delamination, while higher quality melamine can last between 10 – 20 hr in the boil test.

In contrast, phenol formaldehyde is more resistant as it can withstand 24 – 72 hr of boiling without delamination (De Merchant nd). After the boiling test, plywood adhesives should maintain residual strength to overcome the wet shear tests. In the case of melamine, no more residual strength was observed, resulting in low WF values apart from some delamination observed on the outer plies after the cyclic boil test. Compared to phenol formaldehyde

Thickness(mm) Company

Bond Test

Remarks

Top Left Middle Bottom RightPanel Ave.SS

Panel Ave. WF

SS (kg/cm2)

WF (%)

SS (kg/cm2)

WF (%)

SS (kg/cm2)

WF (%)

18 mm W 7.7 6 8.9 7 6.6 8 7.7 7 D

4.85 mm X 7.3 20 6.5 16 4.4 6 6.1 14 D

17.5 mm X 8.5 10 7.8 8 7.6 15 8.0 11 D

4.85 mm Z 4 7 4.3 11 5.1 14 4.5 11 D

17.5 mm Z 6.9 20 7.6 18 5.1 15 6.5 18 D

Table 10 Bond performance of Type I imported plywood



0.6MPa = 6.12 kg/cm2

0.4MPa = 4.08 kg/cm2

0.2 MPa = 2.04 kg/cm2



REFERENCES

ALIPON MA, BONDAD EO, CAYABYAB PC. 2005. Relative density of Philippine woods. FPRDI Trade Bulletin Series No. 7. DOST-FPRDI, College, Laguna 4031, Philippines. 42pp.

DE MERCHANT C. nd. Glue used in exterior and marine plywood manufacture. www.christinedemerchant.com/marine_plywood_glues.html. Retrieved on Oct. 23, 2015.

E.O. 23. 2011. www.gov.ph/2011/02/01/executive-order-no-23-4/. Retrieved on May 2, 2015.

which could meet the WF requirements of the two standards, the melamine glue did not conform to PNS and ISO bond requirements for exterior type plywood. The use of melamine as exterior adhesive in imported plywood might be due to the very thin layers of the inner and outer plies that could sustain a reddish brown blemish if phenol formaldehyde was used. To protect the surface of the very thin outer plies from degradation due to glue bleed-through, the manufacturer resorted to using melamine glue.

CONCLUSIONS

• Due to the scarcity of raw materials for plywood production brought about by EO 23, local companies included in this study especially those from Mindanao have shifted to using tree plantation species such as F. moluccana, which comprises the majority of the material for veneer and lumber core.

• For Luzon companies, the major species,

i.e., Pinus sp. and Shorea sp., used as peeler logs for veneer and plywood are apparently imported from New Zealand, Malaysia, Papua New Guinea and Solomon Islands. The absence of large tree plantation areas in Luzon has resulted in the use of various lesser-known or lesser-used species available locally such as Endiandra sp.

• Imported plywood is mainly made of Populus sp. as cross band and core. Another identified major species as outerply of imported plywood is Helicia sp. Other species are used for outer plies in imported plywood but these can no longer be identified due to the very thin layer which makes it impossible to discern pore topography. However, they are believed to belong to Family Anacardiaceae or Burseraceae.

• The majority of the local companies’ plywood can be distinguished from the imported ones by their core and cross band veneer. Local producers, especially those from Mindanao, use plantation species mainly F. moluccana while imported ones tap Populus sp. for core and cross band veneer.

• In imported plywood, the very thin layer (about as thin as paper) of the outer plies and its having more layers of about the same thickness in the core and cross band can also delineate it from local plywood.

• The bond test reveals that local plywood can conform to both PNS and ISO glue bond requirements for Type I exterior plywood regardless of the species used as long as the adhesive used is phenol formaldehyde. In contrast, imported plywood does not conform to PNS and ISO glue bond requirements due to the use of melamine glue, a weaker exterior adhesive than phenol formaldehyde.


ESCOBIN RP, AMERICA WM, PITARGUE, JR. FC, CONDA JM. 2015. Revised wood identification handbook for Philippine timbers, Vol. 1. DOST-FPRDI, College, Laguna 4031, Philippines. 320pp.

ESCOBIN RP, CONDA JM, AMERICA WM & PITARGUE JR. FC 2014. Wood Identification Handbook for Philippine Timber Vol. II. Unpublished manuscript. FPRDI, College, Laguna 4031, Philippines.

HOLMGREN PK, HOLMGREN NH. 1990. Index Herbariorum: Part 1. The herbaria of the world. Regnum Vegetabile. Vol. 120. New York Botanical Garden. 704 pp.

ISO 12466-2:2007. Plywood – Bonding quality – Part 2: Requirements.

JIMENEZ JR. JP, ORDINARIO FM, RAMOS NA, CABANGON RJ. 2013. Parallel evaluation of bond test on Philippine-made plywood using PNS 196:2000 and ISO 12465:2007 standards. Philipp. For. Prod. J. 4: 21-28.

KRISNAWATI H, VARIS E, KALLIO M, KANNINEN M. 2011. Paraserianthes falcataria (L.) Nielsen: Ecology, silviculture and productivity. CIFOR, Bogor, Indonesia. www.cifor.org.Books.BKrisnawati1103. Retrieved on May 2, 2015.

LAPITAN FG, EUSEBIO DA. 2010. Utilization of small diameter logs from sustainable source for bio-composite products: Addressing technical gaps in producing bio-composite products. Activity 2.1.3. Quality Control. Project Code: CFC/ITTO62-PD 40/00 Rev 4(1). www.itto.int>files>Technical Retrieved on May 2, 2015.

MENIADO JA, AMERICA WM, DE VELA BC, TAMOLANG FN, LOPEZ FR. 1981. Wood identification handbook for Philippine timbers, vol. II. Apo Production Units, Inc., Quezon City. 186 pp.

MENIADO JA, TAMOLANG FN, LOPEZ FR, AMERICA WM, ALONZO DS. 1975. Wood identification handbook for Philippine timbers, vol. I. Gov’t. Printing Press, Manila. 370 pp.

PHILIPPINE FORESTRY STATISTICS. 2010. FMB-Department of Environment and Natural Resources.






PHILIPPINE WOOD PRODUCERS ASSOCIATION (PWPA). 2012. How to defend against the imported plywood siege. Woodstock 10(1): 3.

PHILIPPINE NATIONAL STANDARD 196:2000. Plywood Specifications. BPS-Department of Trade and Industry.

ORWA C, MUTUA A, KINDT R, JAMNADASS R, SIMONS A. 2009. Agroforestry database: A tree reference and selection guide version 4.0 http://www.worldagroforestry.org/af/treedb/. Retrieved on May 2, 2015.

RADIATA PINE BREEDING CO, LTD. (RPBC) 2003. Radiata pine wood density. Information Bulletin No. 2. www.rpbc.co.nz/pdfs/RPBC%20Bulletin%202.pdf. Retrieved on Sept. 26, 2015.

STERN WL. 1988. Index Xylarium: Institutional wood collection of the world. Reprinted from IAWA Bulletin n.s. 9(3). IAWA, Rijksherbarium, Leiden, The Netherlands.

TAMOLANG FB, ESPILOY EB, FLORESCA AR. 1995. Strength grouping of Philippine timbers for various uses. FPRDI Trade Bulletin Series No. 4. 31 pp. FPRDI, College, Laguna. Philippines.

THE TECHNICAL COMMITTEE ON VENEER AND PLYWOOD. 1999. The Philippines recommends for veneer and plywood. 111 p. PCARRD, Los Baños, Laguna., Philippines.

TIMETRIC. 2014. Construction in the Philippines – key trends and opportunities to 2018. 72 pp. www. reportlinker.com. Retrieved on Sept. 26, 2015.

59Carlos M. Garcia & Robert A. Natividad

RESISTANCE OF THERMALLY-MODIFIED KAUAYAN-TINIK (Bambusa blumeana Schultes f.) TO TERMITES AND POWDER-POST BEETLES

Carlos M. Garcia & Robert A. Natividad

Scientist 1, Material Science Division & Chief, Technology Innovation Division, respectivelyDOST-FPRDI, College, Laguna 4031, Philippines

Corresponding Author:CMGarcia ([email protected])

ABSTRACT

The resistance of thermally modified (TM) quarter split culms of kauayan-tinik to subterranean termites (Microcerotermes losbañosensis), drywood termites (Cryptotermes dudleyi) and powder-post beetles (Dinoderus minutus L.) was determined following standard procedures. Resistance of TM bamboo was based on insect attack and degree of termite damage or number of beetle holes on the samples.

Results showed that thermal modification of kauayan-tinik at 200oC and heating time of 60 min provided better protection than the rest of the treatments, and thus the TM bamboo samples at these conditions were classified moderately resistant to the attack of M. losbañosensis. Improved resistance to drywood termites and powder-post beetles was likewise observed.

Although all samples including the control were found resistant to drywood termites and powder-post beetles, the TM samples incurred lower weight losses than the control. Further studies are needed to improve kauayan-tinik’s resistance against wood-destroying insects.

Keywords: Resistance, thermal modification, Bambusa blumeana Schultes f., termites,powder-post beetles

INTRODUCTION

Known as the “grass of life”, bamboo is arguably one of the most versatile natural materials on earth, with multitudes of documented end-uses. However, it is susceptible to the attack of bio-deteriorating organisms. Insect or fungal attack may occur before, during or after processing or while in

storage and during transport (Garcia et al. 1996, Giron & Garcia 2005).

The application of chemicals thru prophylactic treatment has been widely used in the prevention and control of biodegrading agents in bamboo (Abdurrohim1982, Xu 1984, Latif



et al. 1987, Zhou et al. 1987, Varma et al. 1988, Tang & Yuan 1989). Spraying, brushing, dipping or soaking of bamboo in chemical solution result in the reduction of powder-post beetle and fungal attack in round or split culms.

The rise of the green movement, however, has prompted research institutions to shift focus on technologies that will reduce, if not completely stop, the use of harmful chemicals as practiced by the industry.

An alternative control strategy is non-chemical treatment using heat, also called thermal modification treatment, first employed to wood. Thermal modification involves controlled pyrolysis of wood at 180oC in the absence of oxygen, thus inducing chemical changes in the wood (Burmester 1973).

Studies on thermal modification of wood emphasized its effects on the wood’s physical and mechanical properties (Bekhta & Niemz 2003, Esteves et al. 2008, Salim et al. 2010, Hill 2006, Fojutowski et al. 2011, Wang et al. 2013). The encouraging results made possible the commercial production of thermally modified (TM) wood such as ThermoWood of Finland, Plato-Wood and Retified Wood of Netherlands and Oil-Heat Treated Wood of Germany (FTA 2003).

A pioneering study on thermal modification to improve the durability of five Philippine wood species was done by Mailum and Arenas (1974) at DOST-FPRDI, Philippines. Samples of rain tree [Samanea saman (Jacq.) Merr.], bagtikan (Parashorea plicata), guijo (Shorea guiso Blume), mayapis [(Shorea squamata (Turcz) Dyer] and palosapis [Anisoptera thurifera (Blanco) Blume] were subjected to thermal modification at 130o, 150o and 1750C using a high temperature oven with dry air. Results showed an increase in the natural decay resistance of the five species against the white rot fungus, Fomes lividus, and brown rot fungus, Lenzites striata.

Thermal modification was also used in non-wood forest products like bamboo. Bamboo thermally modified in a hot oil bath of seed hemp at 180oC to 220oC for 30, 60 and 120 min increased in durability against basidiomycete and soft rot attack (Leithoff and Peek 2001).

The improved durability of bamboo in ground contact was also shown in a similar study using heat treatment at 1400, 1800 and 2200C and durations of 30, 60 and 90 min (Wahab et al. 2007). Although the strength properties were reduced, the values were still acceptable based on EN 252:1989 and ISO 22157: 2004 standards.

Thermal modification of Dendrocalamus asper using virgin coconut oil at 140oC to 200oC for 30 to 120 min significantly improves the species’ resistance to Microcerotermes losbañosensis (Manalo & Garcia 2012). Also, temperature had a more dominant effect than treatment time on D. asper’s resistance to termites.

Previous studies by Manalo (2007), Salim et al. (2010) and Nguyen et al. (2012) focused on the effects of oil treatment on bamboo’s physico-mechanical properties. In the Philippines, thermal modification by boiling in virgin coconut oil at 1800C for 60 and 120 min improved bamboo’s resistance to fungal decay. However, there was considerable loss in TM bamboo’s bending strength above 1800C (Manalo 2007). Thermal modification caused changes in EMC level. As temperature and treatment duration increased, the degree of change in EMC also increased.

The EMC of untreated samples significantly differed from that of TM bamboo. The lowest EMC change was observed in TM bamboo at 150oC for 30 min, while the highest was noted in TM samples at 200oC for 60 min (Natividad & Jimenez 2015). The results were similar to those obtained by Salim et al. and Nguyen et al.


Likewise, the process influenced the change in color of bamboo from light to darker brown. The color difference in two TM Vietnamese bamboo species is influenced more by temperature rather than treatment time (Nguyen et al. 2012).

With the above promising results from applying thermal modification on bamboo, this study was conducted to: 1) determine the resistance of TM kauayan-tinik to subterranean termites, drywood termites and powder-post beetles, and 2) classify the TM kauayan-tinik subjected to different temperatures and treatment times based on their resistance to the three wood-destroying insects.


Preparation of bamboo samples

The color, texture and appearance of the TM kauayan-tinik samples were noted, while data on the initial physico-mechanical properties were obtained from FPRDI’s Technology Innovation Division (Natividad & Jimenez 2015).

One hundred and fifty bamboo pieces with dimension of actual thickness x 2 cm x 6 cm were cut from quarter-split TM bamboo and assigned to the various temperature and treatment time combinations (T1 - 150oC at 30 min; T2 - 1500C at 60 min; T3 - 175oC at 30 min; T4 - 1750C at 60 min; T5 - 200oC at 30 min; T6 - 2000C at 60 min). The same number and measurement of untreated bamboo samples were kiln-dried to a moisture content (MC) of 8%, the same MC level as the TM bamboo.

Resistance test

Resistance of TM bamboo to the attack of three kinds of insects under laboratory conditions was evaluated. The insects included subterranean termites (M. losbañosensis),

drywood termites (C. dudleyi), and powder-post beetles (D. minutus).

A nest of M. losbañosensis containing active populations was established in a termite chamber prior to the exposure of TM bamboo, while workers of C. dudleyi were collected from infested wood. Bamboo infested with active populations of D. minutus were prepared and served as source of population.The TM bamboo slats were conditioned to 8% MC.

Test against M. losbañosensis

TM slats were exposed on top of concrete blocks previously laid out in a termite chamber with an active nest of M. losbañosensis. Termite tunnel formation was monitored monthly for four months. Resistance of TM bamboo was classified based on the rating system by Garcia and San Pablo (2011)(Table1).

Test against C. dudleyi

One hundred workers plus two soldiers of C. dudleyi were introduced into a petri dish serving as termite chamber and containing a single TM bamboo sample. The degree of termite damage and the occurrence of pellet-like materials coming out of the slats were observed quarterly for 12 months. The rating system and classification of resistance of TM bamboo against drywood termites were the same as that used in subterranean termites.

Test against D. minutus

TM blocks were placed in between two pieces of infested bamboo containing active beetle populations. The set-up was kept in a plastic tray serving as beetle chamber.

The occurrence of beetle holes and powdery masses on the surface of the samples was monitored quarterly for one year. The level of resistance of TM bamboo to beetle attack was rated based on the rating system by Garcia and San Pablo (2011) (Table2).


No. of Beetle Holes Classification

0 (no hole or boring attempts)

1 - 5

6 - 10

11 or more

Highly Resistant

Resistant

Slightly Resistant

Not Resistant/Susceptible

Experimental design

A 2-factor Factorial in Completely Randomized Design was used to evaluate the effects of each treatment on the physico-mechanical properties of TM bamboo. There were six replicates for each treatment.


The color of bamboo samples was influenced by the thermal modification process. Bamboo

% Termite Damage

% Degree of Termite Attack Classification

0

1 – 25

26 – 50

51 – 75

76 - 100

No evidence of termite attack

Slightly attacked, from initial nibbling to almost ¼ of the TM-bamboo is lost

Slightly attacked, from initial nibbling to almost ¼ of the TM-bamboo is lost

Severely attacked, > 50% but less than 75% of TM bamboo is lost

Destroyed, > ¾ of TM-bamboo is lost

Highly Resistant (HR)

Resistant (R)

Resistant (R)

Slightly Resistant (SR)

Not Resistant (NR)

samples subjected to thermal modification at 150oC was light beige, which turned light to dark brown at 175oC and dark brown at 200oC. Color change was likewise observed in one of two TM Vietnamese bamboo species and this could possibly be due to temperature rather than treatment time (Nguyen et al. 2012).

Resistance to M. losbañosensis

All samples - both TM and untreated - were invaded by subterranean termites

Table 1. Classification of TM bamboo’s resistance to termite attack

Source: Garcia & San Pablo (2011)

Table 2. Classification of TM bamboo’s resistance to powder post beetles

Source: Garcia & San Pablo (2011)


as evidenced by the presence of earthen tunnels on their surface after one month. Tunnel formation started from the concrete blocks and extended towards the top of the TM samples. Termite invasion, on the other hand, was initiated at the bottom of the TM blocks, while tunnel formation extended towards the cut ends and sides of the TM samples.

Thermal modification at 200oC and 60 min provided the best protection among all the treatment combinations, making the bamboo slats moderately resistant to the attack of subterranean termites. TM bamboo had the lowest incidence of termite damage (45%) and lowest weight loss (32.9%) after four months (Fig. 1). The parenchymatous tissues in the inner wall of the samples were almost consumed, but the outer fibrovascular bundles remained intact.

The epidermis of bamboo had no damage

which might be due to its silica content. The epidermal portion is more durable than the inner part which has high starch content that makes it more attractive to termites. However, the chemical changes in the bamboo cells caused by thermal modification apparently made TM bamboo unpalatable, thus improving their resistance against termite attack. The previously active insect population became inactive and eventually abandoned the bamboo samples.

TM slats subjected to lower temperatures of 150oC and 175oC for 30 and 60 min, respectively, and 200oC for 30 min were severely destroyed by subterranean termites. The degree of damage ranged from 62% to 72% with weight losses of 55.4% to 62.1%. Based on the rating scale of 51-75% damage, the TM specimens at the said temperature levels were classified slightly resistant to the subterranean termites.

Fig. 1. Percent damage and weight losses in TM bamboo caused by M. losbañosensis after four months of exposure


Untreated kauayan tinik samples were destroyed by termites, sustaining 85% damage and weight loss of 70.1%. With thermal modification, however, an increase in resistance was observed -- from slightly to moderately resistant.

Resistance to C. dudleyi

All TM bamboo samples except those subjected to 200oC for 60 min had termite nibbling or initial attack after three months. The degree of damage caused by drywood termites ranged from 1% to 5% (Fig. 2). Bamboo thermally modified at 200oC for 60 min was free from termite attack compared with the 3% damage of its untreated counterpart. The degree of damage on treated slats did not increase remarkably after six months of exposure.

Damage on TM bamboo ranged from 3% to 5% after nine months. The termite population remained active, and a few pellet-like materials were evidence of attack. TM

samples at 200oC for 60 min remained sound, while untreated bamboo sustained slight damage of 3% to 6% after 3 to 9 months.

The degree of termite damage did not increase significantly in TM bamboo regardless of temperature and heating time combinations. The damage caused by drywood termites was slight (5% to 7%) after 12 months (Fig. 3) and with corresponding minimal weight losses (3.7 – 4.4%). The untreated slats exhibited 14% damage for the same period. Regardless of recording the highest weight loss of 7.5%, the untreated bamboo, together with treated samples, was classified resistant to drywood termites. Thermal modification plus the inherent resistance property of kauayan-tinik to the insects caused the very low damage in treated slats.

All TM specimens except those exposed to 200oC for 60 min had initial powder-post beetle attack after 3 to 9 months. Insect

Fig. 2. Percent damage in TM bamboo caused by C. dudleyi after 12 months of exposure


nibbling was evident on the cut-ends or along the samples’ radial surface.

The number of beetle holes in TM bamboo did not increase remarkably, and ranged from 0 to 1.7, 0 to 2.3 and 0 to 3.6 after 3, 6 and 9 months, respectively. However, all beetle holes were inactive, indicating that there was no active beetle population to cause further damage to the bamboo.

The results suggest the cessation of the powder-post beetle feeding activity, leading to the very low damage to TM bamboo. The presence of insect nibbling on the slats might be due to the beetles’ probing while foraging for food. The substrate was most likely abandoned when the insects perceived it unpalatable. The unpalatability could be because of the changes in the bamboo’s chemical structure as previously mentioned.On the 12th month, the number of beetle holes in TM bamboo at 200oC slightly increased to 2.1, but the rest of the treatments, on the

average, had more beetle holes (2.7 – 3). TM bamboo was thus classified resistant to beetle attack. The very low number of holes resulted in limited weight losses of 0.3% to 0.8%.

Weight loss in untreated bamboo was a very low 0.9%, which consequently caused minimal damage on the samples. The control showed 1, 2.4, 2.5 and 4.6 holes, which were recorded quarterly for 12 months. Untreated B. blumeana was thus classified resistant to powder-post beetles. Its inherent resistance resulted in fewer beetle holes in all TM bamboo.


• Thermal modification of B. blumeana at 200oC for 60 min provides the best protection against subterranean termites among the combinations of temperature and treatment time, thus rendering TM

Fig. 3. Number of beetle holes in TM bamboo caused by D. minutus after 12 months of exposure.


LITERATURE CITED

ABDURROHIM S. 1982. Cold soaking treatment of twelve bamboo species. Laporan, Balai Penelitian Hasil Hutan, Indonesia 159: 5 - 11.

BEKHTA P, NIEMZ P. 2003. Effect of high temperature on the change in color, dimensional

stability and mechanical properties of spruce wood. Holzforschung 57: 539 - 546.

BURMESTER A. 1973. Einfluß einer Wärme-Druck Behandlung halbtrockenen Holzes auf seine Formbeständigkeit. Holz als Roh- und Werkstoff 31: 237 - 243.

ESTEVES BM, DOMINGOS IJ, PEREIRA HM. 2008. Pine wood modification by heat treatment in air. BioResources 3(1): 142 - 154.

FINNISH THERMOWOOD ASSOCIATION (FTA). 2003. ThermoWood handbook. Helsinki, Finland. Retrieved from <http://www.thermowood.fi> on 18 May 2006.

FOJUTOWSKI AA, KROPACZ A, NOSKOWIAK A. 2011. The susceptibility of poplar and alder wood to mould fungi attack. Annals of Warsaw University of Life Sciences. Forestry and Wood Technology. No. 74: 56 - 62.

GARCIA, CM, SAN PABLO MR. 2011. Resistance of plantation grown Benguet pine (Pinus kaesiya Royle ex Gordon) to decay fungi and insect attack. Philipp. For. Prod. J. 2: 67 - 75.

GARCIA CM, GIRON MY, MABILANGAN LC. 1996. Non-chemical treatment of bamboo strips for the manufacture of woven products. FPRDI J. 23(1): 39 - 46.

GIRON MY, GARCIA CM. 2005. Protection and preservation manual on bamboo, rattan,

vines and twigs. DOST-FPRDI, College, Laguna, Philippines.

HILL C. 2006. Wood modification: chemical, thermal and other processes. John Wiley & Sons Ltd., The Atrium, Southern Gate, Chichester, West Sussex, England.

LATIF MA, DASGUPTA SR, DE BC, ZAMAN YU. 1987. Preservative treatment of bamboo for low cost housing. In Forest Products Abstracts 1990.013- 01516.

bamboo moderately resistant to M. losbañosensis attack.

• TM bamboo subjected to 200oC for 60 min is also free from drywood termites (C. dudleyi) attack compared to the 14 % damage incurred by untreated B. blumeana after 12 months.

• Only TM bamboo at 200oC for 60 min is resistant to powder-post beetles (D. minutus), while the rest exhibit slight

nibbling after 3 to 9 months of exposure.

• Although both treated and untreated bamboo are resistant to drywood termites and powder-post beetles, lower weight losses in TM bamboo indicate improved resistance against the two insects.

• Field test on TM bamboo is recommended to verify the results of the laboratory test.


LEITHOFF H, PEEK RD. 2001. Heat treatment of bamboo. Paper presented to the International Research Group on Wood Preservation (IRG). Nara, Japan. Retrieved from http://www.irg-wp.com/Documents/IRG_01-40216.pdf on 2008 November 26.

MAILUM NP, ARENAS CV. 1974. Effect of heat on the natural decay resistance of five

species of Philippine woods. Philipp. Lumberman 20(10): 18 - 19, 22 - 24.

MANALO RD. 2007. Effects of hot oil treatment on properties and durability of three species of Philippine bamboo. MS Thesis. University of the Philippines Los Baños, College, Laguna.

MANALO DR, CM. GARCIA. 2012. Termite resistance of thermally-modified Dendrocalamus asper (Schultes f.) Backer ex Heyne. Open Access Insects Journal. ISSN 2075-4450. www.mdpi.com/journal/insects. 6pp.

NATIVIDAD RA, JIMENEZ, JR. JP. 2015. Physical and mechanical properties of thermally modified kauayan-tinik (Bambusa blumeana Schultes f.). In Proceedings of the 10th World Bamboo Congress. Damyang, Korea. 10pp. http://www.worldbamboo.net/proceedings/wbcx

NGUYEN TC, WAGENFUHR A, PHUONG LX, DAI VH, BREMER M, FISCHER S. 2012. Effects of thermal modification on the properties of two Vietnamese bamboo species, Part I: Effects on physical properties. BioResources 7(4): 5355 - 5365.

SALIM R, ASHAARI Z, SAMSI HW, WAHAB R, ALAMJURI RH. 2010. Effect of oil heat treatment on physical properties of semantan bamboo (Gigantochloa scortechinii Gamble). Modern Appl. Sci. 4(2): 107 - 113.

TANG Y, YUAN Y. 1989. Anti-mould study on bamboo. J. Bamboo Res. 8(4): 1 - 11.

VARMA RV, MATTHEW G, MONAHADAS K, GNANAHARAN R, NAAIR K. 1988. Laboratory evaluation of insecticide for the control of the bamboo borers, Dinoderus minutus and B. ocellaris (Coleoptora: Bostrychidae). Material und Orgnismen 23(4): 281 - 288.

WAHAB R, SAMSI HW, SULAIMAN O, SALIM R, HASHIM R. 2007. Properties of oil-cured cultivated Bambusa vulgaris. Int. J. Agric. Res. 2(9): 820 - 825. http://www.academicjournals.net/fulltext/ ijar/2007/820-825.pdf. Retrieved 2008 December 3.

WANG W, YUAN Z, CAO J. 2013. Combined effects of thermal modification and ACQ-D impregnation on properties of southern yellow pine wood. In Proceedings of the 44th Annual Meeting of the International Research Group of Wood Preservation. Stockholm, Sweden. Document No. IRG/WP 13-40637.

ZHOU HM, WANG AF, WANG SH, QUIAN DZ, ZHANG HW. 1987. Studies of reasonable application of insecticide to control and cure bamboo and bamboo wares damaged by Dinoderus minutus. J. Nanjing For. Univ. 4: 48 - 51.


DESIGN AND DEVELOPMENT OF HYDRAULIC TYPECHARCOAL BRIQUETTOR

Belen B. Bisana, Amando Allan M. Bondad, Dante B. Pulmano, Calixto T. Lulo and Ladylyn A. Cosico

Supervising Science Research Specialist, Senior Science Research Specialist, Science Research Assistants, respectively

Technology Innovation DivisionFPRDI-DOST, College, Laguna, Philippines 4031

Corresponding Author:BBisana ([email protected])

ABSTRACT

A hydraulic type briquetting machine was fabricated at the FPRDI’s Bio-Energy and Equipment Development machine shop using mild steel plates, angle bars, flat bars, black iron (BI) pipes, galvanized iron (GI) sheets, directional valve, hydraulic cylinder, hydraulic pump, hydraulic oil, electric motor, pressure gauge, and other fittings. The machine is equipped with a hopper to feed the charcoal fines- binder mixture to the mold. It delivers 300 kg of briquettes per 8 hr of operation.

Charcoal briquettes from coco shell charcoal fines were produced at two cassava starch binder levels (6% and 8%) using the hydraulic briquettor. The performance of the experimental briquettes was compared with the briquettes produced using the FPRDI improved manual briquettor.

The crushing strength (CS) of the 6%-bound charcoal briquettes was statistically the same for manual and hydraulic briquettors. Meanwhile, the CS, density, and time to completely burn the 6%- and 8%-bound briquettes improved with the hydraulic type briquettes having statistically superior qualities compared to the manual type.

Production cost was USD 0.36/kg and USD 0.25/kg for manual and hydraulic briquettor, respectively. The manual type is more suited to end-users with limited resources while the hydraulic type is ideal for those with enough capital.

Keywords: hydraulic, charcoal briquettor


69Belen B. Bisana, et al.

INTRODUCTION

Biomass technologies in the country vary from the use of bagasse as boiler fuel for co-generation, rice hull and coconut husks for crop drying, biomass gasifiers for mechanical and electrical uses, fuel wood and agro-forestry wastes for oven to furnace and cook stove for domestic purposes.

In the Philippines, the household sector will remain the largest user of biomass energy particularly fuel wood, with a share of 66.9%. From 11.5% share of biomass energy in the total energy mix in 2008, fuel wood use increased to 13.6% in 2009 (http://.doe.gov.ph/ER/Renergy.htm).

As there is a predicted increase in fuel wood consumption in the next 10 years, the government is instituting measures that would wisely utilize this resource while reducing its negative impact on the environment (http://.doe.gov.ph/ER/Renergy.htm). These measures would include encouraging rural households to shift to alternative fuels.

The use of fuel wood, rice hull, sawdust and bagasse for cooking is hampered by a number of drawbacks including difficulty in handling and storage, high moisture content, health hazards generated by smoke and the wide variability in raw material properties.

Converting biomass into charcoal briquettes is one way to upgrade the quality of biomass fuel. Briquetting is the conversion of ground charcoal fines into large compact pieces by mixing a suitable blend of binders and applying pressure to produce the desired uniform sizes (Estudillo 1983).

Briquettes are more economical than lump charcoal because they have higher density and thus burn more slowly and last longer with more even heat release. Transport is

likewise less expensive because of their low friability (Bisana 2002).

Turning charcoal into briquettes requires the use of a briquettor. This machine creates pressure either manually or by the use of a motor that will drive the piston that compresses the mixture of charcoal fines and binder. FPRDI has developed the mechanized and manual versions of the charcoal briquettor.

The manual type is a boon to areas with no electricity and easy to transport to places where the raw material abounds (Estudillo 1986). Meanwhile, the mechanized type is not suited to small stakeholders as it requires a huge capital investment.

Bisana (2008) improved the manual briquettor and varied the size and shape of the briquettes. The unit produces briquettes measuring 3.8 cm long and 3.8 cm in diameter with a 1.2 cm cavity diameter at 15 kg/hr. The two briquettors cost about the same but the new unit has a higher capacity than the old one.

In a survey among 16 of the country’s briquette producers, Cortiguerra, et al. (2014) found that two users of the manual briquettor shifted to the semi-mechanized version for two reasons: the old equipment was not cost-effective and corrodes easily.

According to the users, production was slow and ergonomically problematic. The operator has to exert much effort to produce briquettes of uniform sizes and before the target quantity is met, he or she would already be exhausted from stomping on the pedal rod. Women especially found the manual type hard to use as they could not exert as much effort as men when stomping on the pedal.

Cortiguerra, et al’s. survey likewise assessed the strengths, weaknesses,


opportunities and threats of the charcoal briquetting industry. The strengths listed were high quality of charcoal briquettes and innovative producers who can meet buyers’ requirements.

The weaknesses, on the other hand, were the slow movement of the products from the briquette plant to the target markets and the industry’s slow response to customer needs, such as easy-to-ignite briquettes. Despite these weaknesses, the survey indicated that the industry has a number of opportunities to grow. One is the government’s focus on alternative sources of fuel in the rural areas. Another is the big market for briquettes abroad, something which our producers are simply too limited to take advantage of.

Threats to the industry included climate change which might alter the production of coconut in the Philippines and thus shrink the supply of coco shell, one of the industry’s main raw materials.

In view of the growing number of livelihood cooperatives across the country interested in charcoal briquetting and the increasing involvement of women in the venture, an easier-to-operate machine such as a hydraulic type briquettor may be in order.

A hydraulic machine consists of a cylinder fitted with sliding piston that exerts force upon a confined liquid (usually oil) which in turn, produces a compressive force upon a stationary base plate. The liquid is forced into the cylinder by a pump. A hydraulic-type briquettor is easy to operate but entails electricity as an added input. As such, output needs to be increased to compensate for the increased production cost.

This study aimed to develop a medium-size hydraulic-type briquettor with an estimated output of 35 kg briquettes/hr, evaluate the performance of the machine, determine its cost and prepare an operation and maintenance schedule.


A drawing of the briquetting machine was prepared. It was patterned after the improved FPRDI manual briquettor that produces briquettes with a center cavity. The unit was fabricated at the FPRDI’s Biomass Energy and Equipment Development (BEED) machine shop based on the following guides:

a) Steel plates, angle bar, round bars, H beam, hydraulic pump, valves, and cylinder were primarily used as materials in the fabrication.

b) The briquette produced was approximately 3.8 cm high, 5 cm diameter with cavity diameter of 1.25 cm.

The performance of the machine was evaluated based on crushing strength (CS) (kg), density (g/cm3) (Fig.1) and time (min) to completely burn the briquettes. Using 10 replicates, CS was tested using the Universal Testing Machine (ASTM Designation D 143-152), while density was calculated from the determined weight and the displaced volume.

Two levels (6% and 8%) of cassava starch were used as binder. The means of the 6% and 8%-bound briquettes using the improved manual and hydraulic briquettors were statistically evaluated by t-test.


Description of hydraulic briquettor

The hydraulic briquettor which can produce 300 kg of briquettes/8hr was fabricated using locally available steel plates, angle bars, round bars, electric motor, hydraulic pump, hydraulic cylinder, and directional valve. The briquettes measured 3.8 cm long, with a 5 cm in diameter and a 1.25cm diameter.


The unit (Fig. 3) is equipped with a hopper to feed the mixed charcoal fines-binder to the mold. Powered by a 3-Hp electric motor (single phase, 220 volts, 60 Hz, 1700 rpm), it has a central panel for the on and off switch. It consists of 33 cylindrical molds made of black iron (BI) pipes with a center cavity welded to a plate which serves as cover during pressing.

The motor is connected by a chain coupling to the hydraulic pump which applies a maximum pressure of 24.14 MPa (3,500 psi) on the fluids into the cylinder. This pushes the piston and compresses the charcoal-binder mixture into briquettes. The hand lever type directional valve has a maximum flow rate and pressure of 45.42 li/min (12 gpm) and 20.7 MPa (3,000 psi), respectively.

Fig 3. Hydraulic type briquetting machine

Fig 1. Determination of charcoal briquette density Fig 2. Determination of time to completely burn the charcoal briquette


Briquettor CS (kg)a/ Density (g/cm3) a/ Time (min) a/

Improved Manual 108.45 ± 5.2175 0.77 ± 0.0117 40.00 ± 0.2108

Hydraulic Briquettor 126.69 ± 10.186 1.101 ± 0.0106 77.1 ± 3.4751

t-value 1.59 20.94 10.66

Pr > | t | 0.1284 <.0001 <.0001

ns ** **

a/ Average of 10 replicates. Mean ± Std Errns - not significant different.** - highly significant different at alpha= 0.01.

Table 1 Summary of t-test for 6%-bound charcoal briquettes.

Machine performance

Table 1 shows the summary of the t-test for the 6%-bound briquettes using the improved manual and hydraulic briquettor. Between the two machines, the difference in the density and time to completely burn the briquettes was highly significant. Briquettes made from the hydraulic briquettor were heavier than those from the manual model.

Ideally, briquettes should be sold by weight and not by piece to ensure fair marketing. Using the hydraulic equipment, one kilogram means fewer briquettes than using the manual type.

Samples densified using the hydraulic machine took longer to completely burn. This

shows that the amount of heat emitted by the samples can be maximized.

CS did not significantly differ between the two briquettors when the 6% binder was used.

Table 2 shows the summary of the t-test for the 8%-bound charcoal briquettes. The means of the CS, density, and time differed significantly between the two briquettors. Using the hydraulic machine, the CS of 8%-bound briquettes almost doubled (Fig. 4a). The density increased by some 10% (Fig.4b) and the time to completely burn was about 25% higher (Fig.4c).

High CS implies that the briquettes cannot easily be broken during transport. The sample briquettes were more dense, and this made for longer burning time.


Briquettor CS (kg)a/ Density (g/cm3) a/ Time (min) a/

Improved Manual 144.44 ± 8.8489 0.81 ± 0.0123 45.00 ± 0.2108

Hydraulic Briquettor 279.04 ± 27.838 1.237 ± 0.0078 107.00 ± 0.8165

t-value 4.61 29.38 73.52

Pr > | t | 0.0008 <.0001 <.0001

** ** **

a/ Average of 10 replicates. Mean ± Std Errns - not significantly different.** - highly significantly different at alpha= 0.01.

Table 2 Summary of t-test for 8%-bound charcoal briquettes.

0

50

100

150

200

250

300

350

Manual Hydraulic

CS (K

g)

6%

8%

Fig 4a. Comparative crushing strength (CS) of 6% and 8%-bound briquettes for manual and hydraulic briquettor


0

20

40

60

80

100

120

Manual Hydraulic

Tim

e (m

in)

6%

8%

Fig 4c. Comparative burning time of 6% and 8%-bound briquettes for manual and hydraulic briquettor

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Manual Hydraulic

Dens

ity(g

/cm

3 )

6%

8%

Fig 4b. Comparative density of 6% and 8%-bound briquettes for manual and hydraulic briquettor


Hydraulic briquettor cost of fabrication

* Materials ------------------------------------------------------------------------USD 4,035.40

*Materials Price, USDHydraulic cylinder 577.78Directional valve 844.44

Hydraulic oil 66.66Hydraulic pump 555.56

Hydraulic hose and fittings 177.78Angle bar 3” (7.5cm) 14.44Angle bar 2” (5 cm) 25.78

Flat bar 3/8” (.94 cm) 10.00Bolts and nuts (assorted) 7.78

Royal Cord 21.11B.I pipe 2” dia (5 cm) 151.11

B.I pipe 5/8” dia (1.56 cm) 124.44CRS Shafting 2” dia (5 cm) 88.88

CRS Shafting 5/8” (1.56 cm) 14MS Plate ½” (1.25 cm) 255.56MS Plate 3/8” (.94 cm) 100

Magnetic switch 100Circuit breaker 13.33

G.I Cap 2” dia (5 cm) 1.0Nipple 2” dia (5 cm) 1.33Electric Motor (3 HP) 173.33

B.I Pipe” Sched 80 217.78B.I pipe ¾” (1.9 cm) 128.88

Roller Chain Coupling 26.66G.I Sheet 311.11

Pressure Gauge 26.66Total 4,035.40

Labor (40% of materials) -------------------------------------------------------------USD 1,614.16Other expenses -------------------------------------------------------------------------USD 133.33 (grinding disc, oxyacetylene gas, welding rods, paint, hacksaw blade and etc.)

TOTAL ---- USD 5,782.89


Operation and maintenance schedule

Operation

1. Prepare the charcoal fines–binder mixture.

2. Place the pre-mixed charcoal-binder materials into the feeder.

3. Pull down and lock the cover plate.

4. Push the directional valve to apply pressure and compress the mixture in the mold.

5. Open the cover plate and push the directional valve to release the charcoal

Production cost comparison

Assumption: Daily basis @ 300kg/day and 8hr/day1. Price of coco shell charcoal fines USD 0.178/kg2. Price of cassava starch USD 0.67/kg3. Electricity USD 0.26/kw-hr4. Binder 6% for hydraulic type and 8% for manual type5. Labor: 1 operator for hydraulic; USD 7.78/day 2 operators for manual type 6. Manual type capacity 120 kg/day7. Hydraulic type capacity 300 kg/day

Hydraulic type Manual type

Charcoal fines USD 0.178 kg x 300kg USD 53.40 USD 0.178/kg x

120 kg/day USD 21.36

Binder 300 kg x 0.06 x 0.67/kg USD 12.06 120 kg x .08 x USD 0.67/kg USD 6.43

Electricity3 Hp x 0.745kw/Hp x2 hrs x USD 0.26/kw-hr USD 1.16 ---

Labor 1 person x USD 7.78 USD 7.78 2 persons x USD 7.78

USD 15.56

Total USD 74.40 USD 43.35

Production cost per kg

USD 74.40/ day x 1 day/300 kg = USD 0.248/kg

USD 43.35/day x 1 day/120kg= USD 0.361/kg

briquettes

Maintenance Schedule

Activities Frequency

1. Check the alignment Before and of cylinder and piston. after use

2. Clean the cylinder Every after and piston. use

3. Lubricate the moving Monthlyparts.

4. Check the level of Quarterlyhydraulic fluid.


LITERATURE CITED

AMERICAN STANDARD FOR TESTING MATERIALS. 1996. Method of selecting small clear specimens of timber (ASTM) Designation D 143-152).

BISANA B. 2002. Training on charcoal production and briquetting. Unpublished Report. FPRDI Library, College, Laguna, Philippines.

BISANA B. 2008. Modified manual briquettor. Terminal Report. FPRDI Library, College, Laguna, Philippines.

CORTIGUERRA EC, GARCIA CMC, EUSEBIO GA, REYES MC, LONTOK PQ. 2014. Marketing strategy for FPRDI-developed technologies: charcoal briquetting technology. Terminal Report. FPRDI Library, College, Laguna, Philippines.

ESTUDILLO CP.1983. Charcoal production and briquetting research at FPRDI. Paper presented during the 20th Anniversary Celebration of FPRDI, July 15, 1983. FPRDI, College, Laguna, Philippines.

ESTUDILLO CP. 1986. Simple technology for the production and briquetting research of charcoal briquettes from sawdust and ricehull. Paper presented during the Regional Workshop on Energy from Biomass. King Mungkut Institute of Technology, Bangkok, Thailand. 3-7 March 1986.

FENGEL D. 1989. Carbonization and Gasification in Wood: Chemistry ultrastructure reactions. Walter de Gruyter. New York.

http://www.doe.gov.ph/ER/Renergy.htm 2010. Renewable Energy.

CONCLUSIONS

• The hydraulic type briquettor has been successfully fabricated using local materials.

• Six percent binder is sufficient in producing cocoshell charcoal briquettes using the hydraulic type briquettor.

• The crushing strength (CS) of the 6%- bound charcoal briquettes is statistically the same for both briquetting equipment but the hydraulic type briquettes have significantly higher density and burning time.

• For the 8%-bound briquettes, the CS, density, and time to burn are significantly higher in those made using the hydraulic briquettor than the manual.

• The hydraulic machine can produce 300 kg cocoshell charcoal briquettes/ day compared to the 96-120 kg cocoshell charcoal briquettes/ day for the manual type.

• The production costs are USD 0.36/kg and USD 0.25/kg for manual and hydraulic type briquettor, respectively at PhP 45 per USD.

• The technology is ready for piloting.

78 Philippine Forest Products Journal Volume 6 January-December 2015Philippine Forest Products Journal Volume 6 January-December 2015

DEVELOPMENT OF LAMINATED BUHO[Schizostachyum lumampao (Blanco) Merr.] LUMBER

Robert A. Natividad & Juanito P. Jimenez, Jr.

Chief Science Research Specialist and Senior Research Specialist, respectivelyTechnology Innovation Division

DOST-FPRDI, College, Laguna 4013. Philippines

Corresponding Author:[email protected]

ABSTRACT

The potential of buho bamboo for making laminated lumber was investigated. Internodes of the poles’ middle portion with almost uniform diameter and culm wall thickness were sorted, coded and quarter split with a bolo. Lamination and pressing with improvised clamps were done using polyurethane (PUR D4) glue at three spreads: 60 g/m2, 120 g/m2 and 240 g/m2. The laminated samples were conditioned to 10% MC prior to testing of physico-mechanical properties.

Results indicated that the buho lumber with the 120 g/m2 glue spread exhibited the best physical properties and static bending strength. However, the samples could be used for non-structural purposes only because they failed to satisfy the 80 MPa minimum standard MOR for engineered bamboo products.

The laboratory production cost of laminated buho was USD 5.66/bd ft. Decorative prototype table top and picture frames were fabricated from the samples.

Keywords: Laminated bamboo, Schizostachyum lumampao

79Robert A. Natividad & Juanito P. Jimenez, Jr.

INTRODUCTION

During the past decade, the Philippines has made significant inroads in the development and commercial production of various glue-laminated bamboo collectively known as engineered bamboo products. Notable among the engineered bamboo products made locally is the glue-laminated bamboo planks and panels for flooring (Alipon et al. 2011), walling and furniture. Another local panel product is the crushed or flattened bamboo culm (Pulmano et al. 2013) overlaid over plywood for walling, furniture components and handicrafts.

In 2013, the global bamboo market was estimated at USD 16.8 B and the share of engineered bamboo products was 20.2% or about USD 3.4 B (PBFI 2012). From 2007 to 2011, Philippine imports of engineered bamboo products (flooring, shaped products and panels) averaged USD 447,245 per year.

Glue-laminated bamboo slat panels are made from the butt portion of thick-culmed bamboo species such as kauayan-tinik (Bambusa blumeana J.A. & J.H. Schulter), bayog (Bambusa merrilliana (Elmer) Rojo & Roxas comb. nov.) and giant bamboo (Dendrocalamus giganteus Wallich ex Munro). In China, the same part of moso bamboo (Phyllostachys pubescens Mazel ex H. de Leh.) is also used for glue-laminated slat panels. However, the middle portion’s outer part is processed into strips and wickers for making bamboo curtains, while the inner part is converted into “pressed bamboo timber”. The top is mainly used for making chopsticks and toothpicks.

Buho [Schizostachyum lumampao (Blanco) Merr.] is one of the less tapped local bamboo species with significant volume in natural stands. Native to the Philippines (Roxas 2012, Rojo et al. 2000), it occurs extensively in the provinces of La Union, Pangasinan, Northern Palawan, Ilocos Norte and Ilocos Sur, Leyte and Panay.

Among the local bamboo species, buho has the widest area coverage at 6,544 ha. Next in rank is anos [Schizostachyum lima (Blanco) Merr] with 5,010 ha and kawayan tinik with 4,210 ha (PBFI 2012).

Buho is traditionally used in making “sawale”, which is a common housing material in the rural areas. It is also woven into baskets and other handicrafts and made into spears and flutes. In the late 1960s, the Bataan Pulp and Paper Mills, Inc. used buho as alternative raw material for printing and writing paper. Plyboo panels from buho were also manufactured in Abra in the late 1980s (Bamboo Information Network, undated).

FPRDI (2007) reported the following physico-mechanical properties (average values) of buho: culm height, 8.6 m; internode length, 52 cm; culm diameter, 5.2 cm; culm wall thickness, 0.5 cm; specific gravity, 0.461; maximum crushing strength, 29.3 MPa; MOR, 31.2 MPa and MOE, 6.1 GPa. It is classified as moderately resistant to biodeterioration.

Many innovative applications have been developed for engineered bamboo particularly the production of composite panel products which have received worldwide acknowledgement as substitute for wood-based panels. These include laminated bamboo veneer and laminated bamboo veneer lumber, laminated bamboo slats, bamboo mat board, particleboard and fiberboard.

The popular method of slat lamination into panel by horizontal or vertical orientation involves drying and planing the four sides into uniform width and thickness prior to gluing and pressing. The panel is finally planed and trimmed to final dimensions, making the process laborious and wasteful. It consumes a lot of energy and requires various equipment which local micro, small and medium enterprises can hardly afford.


The glue-lamination of quarter-split bamboo culm is more advantageous than bamboo slat lamination as gluing is done without planing. The four sides of the product are trimmed and planed only once to the required dimension, thus minimizing raw material wastage.

This project was designed to develop laminated bamboo lumber for various applications using buho, a thin-culmed species, to improve its utility and the value of its products. It likewise developed a process for gluing buho which could be replicated on other bamboo species and the middle portion of major species used in engineered bamboo. Prototype decorative products were also fabricated, and the cost of producing buho lumber in a laboratory setting was computed.


Materials collection and preparation

Buho poles were purchased along the highway in Victoria, Laguna. These were cross-cut with a handsaw based on internode length and then sorted by culm diameter and thickness for drying to the required moisture content (MC). Dried specimens were rubbed with a steel wool to remove dirt and slightly roughen their outer and inner portions prior to splitting and gluing. Gluing of the quarter-split internodes

The quarter-split buho internodes prepared for gluing were applied with D4 (PUR) glue using a 25-mm paint brush. The amount of glue was pre-computed based on the required glue spread. A quarter-split buho was put on the pan of a digital top loading balance. Then the balance was tared to zero and the required amount of glue poured in a controlled manner along the length of the internode.

Five to seven internodes were assembled and pressed with improvised bar clamps based on the curing time of the adhesive used. Six replicates per glue spread treatment were made. After pressing, the glued splits were conditioned for two weeks in an air-conditioned room with temperature of 23°C and RH of 55% - 65% prior to testing.

Physical and mechanical properties testing

The conditioned samples were machined to obtain the required sizes for testing using ASTM D 143-94, ASTM D 2395-93 and ASTM D 1037-99 procedures.

The physical property tests conducted were MC and relative density (RD) at test, water absorption (WA) and thickness swelling in radial (SR) and tangential (ST) sides. The mechanical property test comprised of static bending to measure the modulus of elasticity (MOE) and modulus of rupture (MOR).

Six replicates per glue spread (60g/m2, 120g/m2 and 240g/m2) were prepared. Half were used for the physical property tests and the other half for mechanical property tests.

Statistical analysis

The effects of glue spread on the samples’ physical properties and static bending strength were determined using ANOVA in simple CRD. Significant effects were further analyzed by comparing the treatment means using DMRT.

Prototype products

Based on the results, additional lumber samples from glue-laminated buho splits were made from the glue spread with the best strength and related properties. These were used to determine the laboratory production cost of laminated buho and to fabricate prototype products.


Fig. 1 Side view and cross-section of laminated buho lumber (top product) and traditionally laminated (vertical orientation) bamboo slats (bottom product).

Source DFMC

RELATIVEDENSITY WA

SWELLING

RADIAL (SR)

TANGENTIAL (ST)

MS Pr>F MS Pr>F MS Pr>F MS Pr> MS Pr>

Treatment 2 0.164 0.379ns 0.0011 0.509ns 7.297 0.579ns 1.189 0.090ns 0.800 0.114ns

Error 6 0.144 0.0015 12.202 0.322 0.251

Total 8

R2(%) 27.58 20.15 16.62 55.16 51.46

CV 3.84 6.35 15.29 22.29 34.07

Table 1 ANOVA on the effect of glue spread on the physical properties of buho lumber

ns - not significant


Physical appearance

The glue-laminated buho lumber looked similar, particularly on the side view, to traditionally laminated bamboo slats. The number of layers of glued lamina was noticeable in both products. However, the end grain was different in laminated buho

lumber (Fig. 1). The layers of arc split culms created a decorative pattern resembling growth rings commonly observed at the cross section of pine wood.

ANOVA on physical properties

The ANOVA on the effects of glue spread on the physical properties of laminated buho lumber is shown in Table 1. Statistical


Fig. 2 Average MC for test of samples by glue spread.

Fig. 3 Average RD of samples by glue spread.

analysis shows that glue spread did not significantly affect MC, RD, WA, SR and ST.

Moisture content at test

Based on the MC at test (Fig. 2), which averaged 9.9%, the laminated buho lumber did not significantly vary in MC (Table 1).

Hence, this property should not affect the strength test.

Relative density at test

The RD of the glue-laminated samples which averaged 0.62 (Fig. 3), was slightly higher than that of natural buho culms


Fig. 4 Average WA of laminated samples by treatment.

Fig. 5 Average SR and ST of samples by glue spread.

which averaged 0.461 (FPRDI 2007). The slight difference on the RD values, though not significant (Table 1), could be due to the slight variation in the culm wall thickness of the laminated quarter-split buho. The samples’ RD, however, should not affect the strength property test.

Water absorption.

After soaking for 24 hr in water, the percentage WA for the three glue spreads (60g/m2, 120g/m2 and 240g/m2) averaged 22.4%, 21.6% and 24.6,%, respectively (Fig. 4). Although the values varied slightly, the differences were not significant (Table 1).


Source DFMOE MOR

MS Pr>F MS Pr>F

Treatment 2 0.2350 0.8885ns 158.902 0.0059**

Error 6 1.9485 11.705

Total 8

R2(%) 3.86 81.90

CV 18.19 9.32

**Highly significant at α = 0.01.

Table 2 ANOVA on the effect of glue spread on the mechanical properties of buho lumber

Table 3 DMRT on the effect of glue spread on MOR of buho lumber

Glue Spread (g/m2) MORa (MPa)

60 28.404b

120 42.102a

240 39.518a

a Average of 3 replicates.Means with the same letter are not significantly different at α = 0.01

Swelling

The percentage swelling in the radial and tangential directions of the samples after 24 hr soaking in water is presented in Fig. 5. ANOVA (Table 1) shows that although there were variations in values, they were not significant.

Another factor is the foaming characteristics of PUR on glue lines prior to hardening of the glue. The foaming effect might have contributed to lower percentage of WA by filling any possible gaps or starved glue lines in the laminated samples.

The SR for all samples was more or less 50% higher than the ST regardless of glue spread. The swelling values can perhaps be correlated with the published values of individually split culms.

FPRDI (2007) reported the average SR and ST of split buho culms (not laminated) at 11% and 6%, respectively. This means that movement is around 40% higher in the radial direction than in the tangential. In Fig. 5, this is exactly what is shown. The SR is about 40% higher than ST in the quarter-split laminated buho culms.

Strength properties

ANOVA on MOE and MOR. Table 2 shows the ANOVA on the effect of glue spread on the samples’ MOE and MOR. Results indicate a highly significant effect of glue spread on MOR but not on MOE.

Further analysis by DMRT (Table 3) shows that only the 60 g/m2 spread differed significantly. The two other treatments did


Fig. 6 Average MOE of samples by glue spread.

Fig. 7 Average MOR of samples by glue spread.

not, although the 120 g/m2 had a higher value than the 240 g/m2 spread.

Modulus of elasticity

The MOE of the 120 g/m2 spread was the highest among the three treatments (Fig. 6). However, the ANOVA shows that the MOE

values for the three spreads did not vary significantly (Table 2).

Modulus of rupture

The same trend as that of the MOE was observed on the samples’ MOR with respect to glue spread (Fig. 7). However, as per


ANOVA (Table 2), the MOR values differed significantly.

DMRT (Table 3) shows that among the three glue spreads, 120 g/m2 gave the highest MOR, but it varied significantly only from 60 g/m2 and not 240 g/m2.

It is notable that in the conduct of the static bending strength tests, no breakage occurred in the laminated samples. Failures during the test resulted from the separation of bonded layers in the glue line or horizontal shear. This might be because of the low glue bond between the lamina due to the presence of the cutin layer on the culms’ rind.

Although it can be assumed that as the amount of glue spread increases the strength also increases, this was not true in the present study. Increasing glue spread means having a thicker glue line. Reinhart (1954) stated that there is greater probability for a flaw to occur in thick layers of adhesive than in thin layers, and consequently thin layers will give stronger bonds than thick ones. In general, an increase in adhesive layer results in a decrease in tensile and shear strength. This theory is also supported by various studies. Mara (1992) said that there is a strong relationship between glue line thickness and loss of joint strength. The strength of all glue joints decreases with a thick glue line.

Ramazan (2006), on the other hand, studied the effect of glue line thickness on shear strength of wood-to-wood joints. Findings showed that shear strength is significantly affected by glue line thickness. Strength decreases as the glue line thickness increases. Hajdarevic and Sorn’s (2012) study which looked into the effect of adhesive thickness on surface strength and joint stiffness revealed the same findings. Joint stiffness

and strength increase with increasing bonding surface and decrease with increasing adhesive thickness.

In the present study, the best glue spread was 120 g/m2 as it gave the optimum strength and physical properties. However, gauging from the MOR of the laminated samples, this glue spread is not suitable for structural applications as it failed to satisfy the 80 MPa minimum standard MOR required for general purpose engineered bamboo (BPS 2013).

Prototype products

The production cost of laminated buho lumber at laboratory-scale was USD 5.65/bd ft or USD 60.95/m2 for a 25-mm-thick board. This is broken down as follows based on the listed assumptions: Raw materials = USD 1.086 Glue (PUR) = 3.67 Labor cost = 0.90 Total USD 5.66

Assumptions:

1. Cost of buho was USD 10.86/bundle @ 25 pcs/bundle and USD 0.434/pole. An average of seven internodes from the middle portion of each pole were used and 2.5 poles could produce 25 mm x 240 mm x 400 mm (1” x 9.5” x 16.75’) sample or one bd ft.

2. Cost of polyurethane (PUR) glue was USD 26.08 per tube @ 850 g/tube = USD 0.0306/g. Laminated stock for one bd ft lumber (including allowances for trimming and planing) consume 120 g of glue @ USD 0.0306/g = USD 3.67.

3. One laboratory aide can process 6 bd ft of laminated buho (from cross-cutting, cleaning and splitting, gluing and pressing including trimming and planing); drying time of PUR was 20 min/assembly; thus, labor cost @ USD 5.43/day divided by six boards = USD 0.89/ bd ft.


Glue was the costliest item in the expenditures, contributing 65% to the production cost per unit volume. This was mainly due to the thin buho culm (about 4 mm) which accounted for numerous glue lines. Aside from this, PUR was quite expensive at USD 26.08 per 850 g tube.

Based on the physico-mechanical properties of laminated buho, some prototype items were fabricated (Figs. 8 & 9). These included one table top with cross-cut laminated buho as decorative centerpiece and two picture frames.

Fig. 8 Table top with decorative centerpiece made of cross-cut laminated buho.

Fig. 9 Picture frames from laminated buho lumber.


LITERATURE CITED

ALIPON MA, BAUZA EB, SAPIN GN. 2011. Development of floor tiles from Philippine bamboos. Philipp. J. Sci. 140(1): 33-39.

AMERICAN STANDARD FOR TESTING METHODS. 2000. Standard method of testing small clear specimens of timber. ASTM D143-94. Section 4. Vol. 4.10.

AMERICAN STANDARD FOR TESTING METHODS. 2000. Standard test methods for evaluating properties of wood-based fiber and particle panel materials. ASTM D1037-99. Section 4. Vol. 4.10.

AMERICAN STANDARD FOR TESTING METHODS. 2000. Standard test methods for specific gravity of wood and non-wood based materials. ASTM D 2395-93 (reapproved 1997). Section 4. Vol. 4.10.

BUREAU OF PRODUCT STANDARDS. 2013. Philippine National Standard FDPNS 2099:2013, Final draft. Engineered bamboo for general purpose-specification. DTI.

BAMBOO INFORMATION NETWORK. n.d. http://maidon.pcarrd.dost.gov.ph/cin/bamboo. Retrieved 2011.

FPRDI. 2007. Monograph on production and utilization of Philippine bamboos. FPRDI, College, Laguna 4031, Philippines.

HAJDAREVIC S, SORN S. 2012. Effect of the spread adhesive thickness and surface on strength and stiffness of joint. In: Proc. of the 16th International Research/Expert Conference, “Trends in the Development of Machinery and Associated Technology”. TMT Dubai, UAE. 10-12 September 2012.


• The internodes of the middle portion of buho culms, when sorted by diameter and culm thickness before quarter splitting, are promising raw materials for making glue-laminated lumber.

• Based on the physico-mechanical properties of laminated buho lumber, the recommended glue spread is 120 g/m2.

• The laminated buho lumber can be used only for non-structural or decorative purposes because its MOR is lower than

the standard minimum specification for general purpose engineered bamboo products.

• The laboratory production cost of laminated buho lumber is USD 5.66/ bd ft;.

• The technology is recommended to be tested on other bamboo species to reduce processing wastes and improve bamboo’s utility for engineered products. However, to improve glue bond strength, the cutin layer on the rind of bamboo culms must be removed prior to lamination.


MARRA AA. 1992. Technology of wood bonding, principles in practice. Van Nostrand Reinhold, NY. 454 pp.

NATIONAL ECONOMIC RESEARCH and BUSINESS ASSISTANCE. n.d.. Bamboo Industry Profile. www.investinr/2.net.

PHILIPPINE BAMBOO FOUNDATION, INC. 2012. Philippine bamboo industry roadmap. Progress Report. Sept. 2012.

PULMANO DB, NATIVIDAD RA, GARCIA CMC, ZAMORA RA, ATIENZA EM. 2013. Fabrication of a bamboo flattening machine. Philipp. For. Prod. J. 4: 10-19.

RAMAZAN K. 2006. Effect of glueline thickness on shear strength of wood to-wood joints. Wood Res. 51(1): 59-66.

REINHART FW. 1954. Survey of adhesion and types of bonds involved. In Adhesion and Adhesives Fundamentals and Practice. John Wiley and Sons, Inc., NY. 229 pp.

ROJO JP, ROXAS CA, PITARGUE, JR FC, BRIÑAS CA. 2000. Philippine erect bamboo species: A field Identification guide. FPRDI, College, Laguna.

ROXAS CA. 2012. Handbook on erect bamboo species found in the Philippines. Ecosystems Research and Development Bureau, Department of Environment and Natural Resources. College, Laguna.

Philippine Forest Products Journal 2015

Editor Ms. Rizalina K. Araral

Editorial Adviser Ms. Emerita R. Barile

Technical Reviewers

For. Robert A. NatividadDr. Dwight A. EusebioDr. Wilfredo M. AmericaEngr. Felix C. Moredo

Produced by the Technical Services DivisionForest Products Research and Development Institute

Department of Science and TechnologyCollege, Laguna 4031 Philippines

November 2016

Dr. Florentino O. TesoroDr. Magdalena Y. GironMs. Eleanor C. JacintoMs. Maria Socorro R. Dizon

Technical Advisers

Dr. Romulo T. AgganganFor. Felix B. Tamolang

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