SAWMILLING OF MALAPAPAYA [POLYSCIAS NODOSA (BLUME) …

SAWMILLING OF MALAPAPAYA [POLYSCIAS NODOSA (BLUME) SEEMAN]

Pablito L. Alcachupas

Senior Science Research Specialist,Technology Innovation DivisionFPRDI-DOST, College, Laguna 4031, Philippines

Carlos M. Garcia

Scientist I, Material Science DivisionFPRDI-DOST, College, Laguna 4031, Philippines

ABSTRACT

The lumber recovery and processing rate in the primary conversion of malapapaya [Polyscias nodosa (Blume) Seeman] were investigated using table-type and mobile horizontal band sawmill and two sawing patterns, i.e; modified live-sawing and conventional or sawing-around methods.

Results revealed that malapapaya was easy to saw. There was a significant difference in lumber recovery between the two sawing patterns in the table-type bandmill. Modified live-sawing yielded significantly higher lumber recovery than sawing-around.

On the other hand, sawing pattern did not affect lumber recovery in the horizontal bandmill. However, it influenced the processing rate in both types of bandmill. The processing rate was significantly higher in modified live-sawing than in sawing-around in both sawmill types.

There were no significant differences in the lumber recovery and processing rate between table-type and mobile sawmill in both sawing patterns.

Keywords: Polyscias nodosa (Blume) Seem., modified live-sawing, sawing-around, lumber recovery, processing rate

INTRODUCTION

The country’s wood industry used to rely solely on traditional timbers from the natural growth forests for housing, construction, furniture, woodworks and other wood products. However, because of the shrinking timber supply from natural growth forests, the need to stretch the country’s timber supply from other sources has become critical.

To address the problem, the government and the private sector have initiated measures such as searching for possible substitute tree species and conducting trials to evaluate the working properties of various industrial tree plantation species (ITPS) and lesser-used species (LUS).

Various ITPS are gaining more attention as they are now made to complement or replace in some cases the current supply of raw

Philippine Forest Products Journal 2013, Volume 4, pp. 1-9

2 Philippine Forest Products Journal Volume 4 January-December 2013

materials obtained from the natural growth forests. For instance, of the 2012 total log production of 862,429 m3, about 99.6% or 858,888 m3 came from tree plantation forests (FMB-DENR 2012).

One of the promising LUS/ITPS is malapapaya [Polyscias nodosa (Blume) Seeman] of the family Araliaceae. It is commonly found in low and medium altitudes often on level land, seldom on slopes. In Quezon Province, it grows abundantly particularly in old coconut plantations that have regenerated into forests associated usually with other LUS such as Alstonia, Artocarpus and Macaranga (Rojo et al. 1998).

Malapapaya is also available in the provinces of Benguet, Pangasinan, Zambales, Rizal, Bulacan, Laguna, Sorsogon, Palawan, Leyte and in Mindanao. For Tagalogs, malapapaya is commonly called “bias-bias” and “bongliw”, while in Pangasinan it is known as “panalatangen” (Rojo et al., PCARRD 2006; PROSEA 1998). Lately, it has been grown as an ITPS in Quezon, Laguna and Pangasinan.

Malapapaya is a medium-sized tree up to 30 m tall and attains a diameter at breast height (dbh) of 50 cm. The wood is lightweight with a density of 0.39 at 12% moisture content (Alipon et al. 2005, Tamolang et al. 1995). Its heartwood is pale to pinkish buff and not clearly differentiated from the sapwood. Its grain is straight, and its texture fine and even (Meniado et al. 1981, Rojo et al. 1998, PROSEA 1998).

The wood of malapapaya is primarily used for small products such as boxes, matches, pencil slats, popsicle sticks, toothpicks, chopsticks and ice cream spoons. Other uses include wooden shoes, fence posts and handles for rice-knives. Large diameter logs are suitable for veneer and plywood production (Meniado et al. 1981, PROSEA 1998, PCAARRD 2006).

Lumber recovery is affected by several interacting factors, which vary from one sawmill to another. The major factors are of two types. The first includes log form and quality, kerf width, sawing variation, rough-green and dry-dressed lumber size, and slabbing and edging practices. The second type is associated mainly with differences in log breakdown patterns. Other factors, which are managerial in nature, are product mix, decision-making by sawmill personnel, and condition and maintenance of equipment (Steele 1984, Hallock et al. 1976).

To bridge the gap between timber supply and demand by the wood industry, researchers have continuously studied the log breakdown of small diameter logs (SDL) including ITPS, lesser-known species (LKS) and tops and branches (Alcachupas & Lapitan 2007, FPRDI-ITTO 1998).

In sawmilling bagalunga (Melia dubia Cav.), Lapitan (1996) reported an average lumber recovery of 64% for modified live-sawing (MLS) and 55% for conventional or sawing-around using the FPRDI mobile horizontal band sawmill (Wood-Mizer LT40 HD). In addition, modified live-sawing has slightly higher productivity than conventional sawing (4.30 m3/hr vs.3.90 m3/hr). Lumber recovery of 56% and 54% for modified live-sawing and conventional sawing, respectively, is obtained from sawing mangium (Acacia mangium Willd.) using the same sawmill ( Alcachupas & Lapitan 1998).

While other LUS and ITPS have been the subject of intensive studies, information on the sawmilling techniques for better recovery and/or profitable use of malapapaya is wanting. The study was conducted to acquire benchmark information on the sawmilling characteristics of malapapaya. Specifically, it aimed to determine the lumber recovery and lumber processing rate of two types of sawing patterns using two types of sawmill, and recommend a sawing technique appropriate for malapapaya.

3Pablito L. Alcachupas, et al. .

MATERIALS AND METHODS

MATERIALS

Two hundred sixteen logs from 24 trees with diameter range of 12.5 to 35 cm and uniform length of 1 m were collected from the natural stand of malapapaya in Barangay Lubi, Atimonan, Quezon. The logs had an aggregate volume of 7.860 m3. Table 1 shows the number and sizes of logs used.

METHODS

• Scaling and CodingThe logs were hauled from the collection site to Barangay Lubi, Atimonan, Quezon and then to FPRDI in freshly-cut condition. Log samples per tree were identified by tree number and log position, e.g. 1-1 is the 1st log from tree number 1. The gross volume per log was determined based on the average of the big-end and small-end diameter inside bark (dib) using the Brereton formula:

V = 0.7854D2L

where:

V = gross volume, m3

D = average diameter, m (inside bark of the big and small-end diameters)

L = length, m

• Sawmilling and Data Collection

Prior to sawmilling, the individual logs underwent prophylactic treatment by spraying deltamethrin to prevent the

Sawmill TypeGross

Volume(m3)

No. of logs

(pieces)

Ave. Dia.(cm)

Ave. Length

(m)Table-type band sawmillMobile horizontal band sawmill (Wood-Mizer)

4.403.46

108108

22.4520.50

1.01.0

Total/Overall average 7.86 216 21.47 1.0

attack of staining fungi.

Sample logs for each sawing method were marked. The sawing patterns employed were the conventional or sawing-around (SA) and the modified live-sawing (MLS) methods described as follows:

Table 1. Characteristics of malapapaya logs sawn by type of sawmill

Fig. 1. Conventional or sawing-around pattern.

Fig. 2. Modified live-sawing pattern.

• Conventional or Sawing-around – All four faces of the log after slabbing are sawn. Log is turned 900 or 1800 for each sawing sequence depending on the presence of defects on each surface being sawn ( Fig. 1).

• Modified live-sawing – A slab and a board are cut, then turned 1800 with the slabbed side serving as footing then the log is sawn thru and thru the last board (Fig. 2).


The sawmilling trials were conducted using a typical table-type bandsaw in Barangay Lubi and the FPRDI mobile horizontal narrow band sawmill. Logs were sawn into 25-mm and 50-mm- thick boards.

The table band sawmill has a flywheel diameter of 650 mm and is run by a 5 HP, 3-phase motor with 1750 rpm. The blade used is an ordinary, N-type high speed steel blade, 412.50 mm long, 38.00 mm wide and 1.06 mm thick or gauge 19 (Fig. 3). Set, or the distance that a tooth is bent compared to the body of the blade, measures 0.53 mm.

The mobile horizontal narrow band sawmill is powered by a 24 HP twin cylinder, electric start with 61 amp alternator. It features a very heavy 100 mm x 200 mm structural steel frame that allows cutting of a log with diameter as large as 80 cm and length as much as 6.4 m. Its throat capacity allows lumber up to 700 mm wide to be cut. This sawmill uses an especially fabricated raker type bandsaw blade forged from special heat-treated alloy steel. The blade measures 31.35 mm x 3,950 mm and 1.06 mm thick (gauge 19), with a 22-mm tooth pitch, a gullet depth of 6.4 mm, 130 hook angle and 0.53 mm of set. Figure 4 shows the profile of the sawblade of a Wood-Mizer.

Fig. 3. Diagram of the sawblade used in the table-type sawmill.

Fig. 4. Diagram of the sawblade used in the mobile sawmill.

The resulting lumber pieces were marked consecutively with a lumber crayon based on the log number and sequence of cut to track the recovery per log. The lumber code indicated the sequence of cut, e.g., 3-1-1 meant tree number 3, log 1 and board 1. The volume of lumber per log was tallied to determine the percent lumber recovery based on the log gross volume:

Sawing time for each log was recorded starting from log loading into the sawmill bed or table and ending when log cutting was completed. Typical delays, which included log turning, belt and blade adjustment or replacement, blade sharpening, refueling and filling-up of water and fuel container, and removing small stones embedded in the bark and sawdust stuck on flywheels, were also recorded. Processing rate (m3/hr), discounting the delays, was determined.

Statistical Analysis

T-test was used to compare percent lumber recovery and processing rate using two band sawmill types and two sawing patterns.

RESULTS AND DISCUSSION

Lumber Recovery

For the table-type band sawmill, the average lumber recovery was 60.25% where 2.65 m3 were produced from 4.40 m3 of log samples (Table 2). In terms of bd ft per m3 recovery, this translates into a lumber recovery factor (LRF) of 255.45 bd ft/m3. Similarly, the lumber yield using the mobile sawmill averaged 60.61% with about 2.10 m3 lumber output from 3.46 m3 log input, for an LRF of 257 bd ft/m3. Considering the small-diameter size of the logs (20.50 to 22.45 cm), the 60% lumber recovery is an

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acceptable conversion factor based on the 55-71% lumber recovery in sawmilling some ITPS and LUS using the mobile horizontal sawmill (FPRDI-ITTO 1998).

Lumber Recovery and Processing Rate of Malapapaya Logs between Sawing Patterns

Table 3 shows the comparison of lumber recovery and processing rate for MLS and SA for each type of sawmill. For the table-type, the average recovery of 62% for modified live-sawing was significantly higher than the 58.5% recovery for the sawing-around method (tvalue 2.2).

The 4% increase in modified live-sawing indicates that a log capable of producing 0.236 m3 if sawn-around will produce 0.245

Sawmill Type

No. ofLogs

(pieces)

Ave.Dia.(cm)

GrossVolume(cu m)

Lumber Recovery

% Volume LRF (m3) (bf/m3)

Table-typeBand sawmill 108 22.45 4.40 60.25 2.65 255.45

MobileHorizontal

Band sawmill(Wood-Mizer)

108 20.50 3.46 60.61 2.10 257.00

Table 2. Average lumber recovery from malapapaya logs sawn by type of sawmill

Sawmill Type Ave % Recovery Ave. Processing Rate (m3/hr)

Table-type Sawing-around (Conventional)

Modified live-sawing

Mean tvalue

58.5 2.2* 62.0

Mean tvalue

0.506 3.24** 0.613

Mobile-horizontal Sawing-around (Conventional)

Modified live-sawing 59.0 1.95 ns

62.2 0.212 11.31**

0.384

Table 3. Comparative lumber recovery and processing rate of malapapaya logs between sawing-around and modified live-sawing using two types of band sawmill

*Significant at 5% level **Highly significant at 1% level ns Not significant

m3 if live-sawn. This increase was the result of producing wider boards even from smaller logs as the sawing system only requires one or two turnings then sawn thru and thru the last board. Also, the conservative edging allowed the generation of partially edged or wany, boards producing the widest possible board from a log. Also, lesser sawlines meant lesser sawmill wastes for modified live-sawing than when logs were sawn-around.

In the mobile horizontal band sawmill, lumber recovery was not significantly different between the two sawing methods (tvalue 1.95). Sawing-around resulted in 59 % lumber recovery, while modified live-sawing gave 62.2%. The results indicate that sawing pattern will not affect lumber recovery when the mobile band sawmill is used in the log conversion of malapapaya.

Pablito L. Alcachupas, et al. .


The processing rate in converting malapapaya logs to lumber, however, was affected by sawing method in both types of sawmill (Table 3). In the table-type sawmill, modified live-sawing resulted in significantly faster processing rate (0.613 m3/hr) than sawing-around (0.506 m3/hr) (tvalue 3.24). Likewise, in the mobile-horizontal band sawmill, the average processing rate was significantly higher in modified live-sawing (0.384 m3/hr) than sawing-around (0.212 m3/hr) (tvalue 11.31).

The higher processing rate in modified live-sawing can be attributed to the minimal handling of logs resulting in faster sawing after cutting a slab and a board. In sawing-around, the log has to be turned three or four times on the sawmill bed. This consumes more time, thus affecting processing rate.

Lumber Recovery and Processing Rate of Malapapaya Logs between Sawmill Types

The lumber recovery in converting malapapaya logs into lumber by table-type and mobile horizontal band sawmills was not affected by sawmilling pattern (Table 4). Recovery in the table-type mill (58.5%) and mobile horizontal mill (59%) using the sawing-around method was not significantly different (tvalue -0.26).

Likewise, the percent recovery in table-type mill (62.0%) and mobile horizontal band sawmill (62.2%) by modified live-sawing pattern was not also significantly different (tvalue -0.18). This might be due to the similarity in blade thickness (1.06 mm) and sawkerf ( 2.12 mm) for both sawmill types.

Sawmill type, however, influenced the rate of processing malapapaya logs into lumber in each method. The processing rate in sawing-around by table-type mill (0.506 m3/hr) (tvalue, 14.65) was higher than the mobile bandmill). Likewise, the processing rate in modified live-sawing by table-type (0.613 m3) was significantly higher than in the mobile horizontal band mill (0.384m3/hr) (tvalue 7.54).

The higher processing rate for the table-type mill may be due to the mill’s faster feed rate capability and the more lateral stability of the wider bandsaw blade used (37.5 mm) compared with the 31.35 mm wide blade used in the mobile sawmill. Also, due to more log handling, viz., loading, turning and fixing of small logs on the sawmill bed, more time was consumed using the mobile sawmill.

Because of higher productivity rate (vol/unit time) as well as less capital investment, the table-type sawmill is deemed suitable

Sawing Pattern Ave. % Recovery Ave. Processing Rate (m3/hr)

Sawing-around

Table-type band sawmill Mobile-horizontal band sawmill

Mean tvalue

58.5 -0.26ns

59.0

Mean tvalue

0.506 14.65**0.212

Modified live-sawing Table-type band sawmill

Mobile-horizontal band sawmill62.0 -0.18ns

62.20.613 7.54**

0.384

Table 4. Comparative lumber recovery and processing rate between table-type band sawmill and mobile band sawmill in sawing malapapaya

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for small-scale sawmilling of malapapaya. However, there is a need to enhance worker’s skills on sawmill operation and maintenance to ensure optimum efficiency. A detailed appraisal of the processing operation is also necessary before any investment decision is made.

Sawmilling Characteristics and Lumber Quality

Malapapaya is classified as easy to saw. Because of its low density, no significant blunting of the sawblades was observed during the sawmilling operation and no change of blade was required even after 4 hr of continuous sawing. In general, the ease of sawing wood varies directly with wood density. The lower the density, the easier it is to cut with a sharp tool (US FPL 1977, ITTO-FPRDI 1998, Alcachupas & Lapitan 2007).

Considering the soundness of the log samples, the occurrence of log end-splits was very minimal to nil. Also, because the logs were almost of the same size, the number of boards produced per log averaged six pieces, with an average width of 165 mm considering that 25-mm and 50-mm-thick boards were produced from each log.

Further, due to the nature of the log, some lumber containing pith (soft and thin-walled cells at the center of the log) exhibited 75 - 150 mm long end-splits at both ends. In some cases, the pith on the surface extended throughout the length of the lumber. This could have enhanced the occurrence surface checks or end-splits during lumber drying.

Every piece of lumber produced showed a smooth surface probably because of the close distance between tooth points in the bandsaw blades of the two sawmill types. The surface of the lumber resembled that of a planed board, thus it would need only light planing or sanding if it would be used for making such products as furniture components for instance.

The teeth of the blades were also properly sharpened and aligned and their gullet was sufficient to carry away the sawdust produced. This highlights the need for sawmill operators to give due attention to tooth setting and sharpening of the blades before the sawing operation.

Likewise, prophylactic treatment applied on the logs before sawmilling proved to be effective in preventing the attack of staining fungi on the lumber produced.

CONCLUSIONS AND RECOMMENDATIONS

• Malapapaya wood is easy to saw.

• Sawmilling of malapapaya results in a 60% overall average lumber recovery, an acceptable conversion factor.

• The modified live-sawing method results in higher lumber recovery than sawing- around for both types of bandmill. The processing rate is influenced by sawing pattern in both types of band sawmill. Higher processing rate of logs is observed in modified live-sawing than in sawing-around.

• There is no significant difference in lumber recovery between the two types of bandmill regardless of sawing pattern. However, the table-type sawmill is able to process malapapaya logs to lumber faster than the mobile type.

• The modified live-sawing pattern is superior to sawing-around in converting malapapaya logs into lumber based on higher lumber recovery and production rate.



LITERATURE CITED

ALCACHUPAS PL and LAPITAN FG. 2007. Sawmilling characteristics of Auri (Acacia auriculiformis A. Cunn. ex Benth). Terminal Report. FPRDI, College, Laguna.

ALCACHUPAS PL and LAPITAN FG. 1998. Narrow bandsawing characteristics of Acacia mangium Willd. Terminal Report. FPRDI, College, Laguna.

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

FPRDI-ITTO. 1998. Compendium on low-cost houses from small-diameter logs, thinning, tops and branches. FPRDI, College, Laguna.

FOREST MANAGEMENT BUREAU (FMB)-Department of Environment and Natural Resources (DENR). 2012. Philippine forestry statistics. Diliman, Quezon City.

HALLOCK H, STERN AR and LEWIS DW. 1976. Is there a “best sawing method?”. USDA Forest Service Res. Paper. FPL 280. Madison, WI, USA.

LAPITAN FG. 1996. Sawmilling characteristics of bagalunga (Melia dubia Cav.) Terminal Report. FPRDI, College, Laguna.

MENIADO JA, AMERICA WM, DE VELA BC, TAMOLANG FN and LOPEZ FR. 1981.Wood identification handbook for Philippine timbers. Vol. II. FORPRIDECOM, College, Laguna.

PCAARRD. 2006. FARM NEWS. Volume 31, October-December issue. Los Baños, Laguna.

PROSEA. 1998. Plant resources of South-East Asia No. 5 (3). Timber trees: Lesser-known timbers. Backhuys Publishers, Leiden, The Netherlands. pp. 465-467.

ROJO JP, ARAGONES, JR EG, BELLO ED and MOSTEIRO AP. 1998. Field guide to the identification of important lesser-used species of Philippine timbers. FPRDI-ITTO Project PD 47/88 Rev. 3(I), Utilization of Lesser-Used Species as Alternative Raw Materials for Forest Based Industries. FPRDI, College, Laguna. pp. 22-23.

STEELE PH. 1984. Factors determining lumber recovery in sawmilling. USDA Forest Service Gen. Tech. Report. FPL 39.

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

US FPL. 1977. Encyclopedia of Wood: Wood as an engineering material. Drake Publishers Inc., NY, USA.

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ACKNOWLEDGMENTS

The authors would like to thank the Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAARRD), Los Baños, Laguna for the financial support granted to this study under the DOST-GIA funded project entitled, “Management of Post-Harvest Pests of Malapapaya [Polyscias nodosa (Blume) Seem.] from Malapapaya Farms”, under the Program on the Enhancement of Malapapaya Industry in Laguna and Quezon Provinces.



FABRICATION OF A BAMBOO FLATTENING MACHINE

Dante B. Pulmano 1, Robert A. Natividad1, Carolyn Marie C. Garcia2, Ruben A. Zamora1

and Eduardo M. Atienza1

1Researchers, Technology Innovation Division, FPRDI-DOST, College, Laguna 4031 Philippines

2Researcher, Technical Services Division, FPRDI-DOST, College, Laguna 4031 Philippines

ABSTRACT

This study aimed to design, fabricate and pilot test a bamboo flattening machine. The machine was designed to have an output of 100 m²/ day for an 8-hr operation. However, 200 m²/day was attained by increasing the speed of the rollers without significantly affecting quality of the flattened bamboo.

The flattener was made of steel rollers arranged in series with gradually decreasing radii of curvature from half round to flat. The drive was a 1.5 KW gear motor, 220 volts, 3-phase, 60 hertz connected to a frequency speed controller with 220 volts input.

Production of flattened and laminated bamboo products was achieved. However, the production process needs to be improved to reduce the production cost.

The production cost per square meter of flattened bamboo (6 mm average thickness) and laminated bamboo panel (12 mm) were USD 2.81 and USD 6.71, respectively.

The IRR, ROI, NPV and payback period of flattened and laminated bamboo were 50%, 38%, USD 125,580 and 4th year, and 79%, 80%, USD 189,290 and 3rd year, respectively.

Overall product diversity and market for bamboo products are expected to improve as the flattening machine is promoted and becomes available to the bamboo furniture and construction sectors.

Keywords: bamboo, flattening machine


11Dante B. Pulmano, et al. .

INTRODUCTION

The usefulness of bamboo to man has been immeasurable. Espiloy et al. (2002) listed almost 300 uses of bamboo including for furniture and handicrafts, construction and housing materials, ornaments, jewelries, farm and fishing implements, food and medicine, and airplane parts.

Bamboo has been traditionally used in round, split and woven forms. Recent trends in bamboo utilization indicate the need for new or innovative processing techniques to enhance product development and quality and promote competitiveness, especially in the world market. In the Philippines, continuous efforts are being exerted by research and development institutions to produce unique and high-value products including various forms of engineered bamboo.

Engineered bamboo products which serve as substitute for a number of wooden products have created a market niche in China, Japan, India, the United States and Europe (Natividad 2003). The processing system involves glue-lamination of slats, veneer and woven strips into panels for furniture, flooring and other construction components. Bamboo particleboard and medium density fiberboard have been also developed in China for housing and construction purposes (Natividad 2003).

Locally, flattened bamboo has been long used for walls of houses and buildings in the rural areas. Popularly known as “crushed bamboo”, the product has been recently used in modern furniture components (i.e. table tops, chair back rest and seat, siding and doors of cabinets, headboard of beds, etc.) which are in-demand in the export market. Flattened bamboo has been also used in glue-laminated form for flooring (3-5 plies) and walling (glued over plywood or medium density fiberboard) (Natividad 2003).

The flattening of bamboo is a tedious process because it is manually done. Round or half round bamboo culm is slowly incised along the length with an adze or bolo to make it soft and flexible for flattening. Thus, a flattening machine is essential to facilitate production.

Bamboo grows in almost every region of the Philippines (Table 1). A polymeric material like wood, bamboo can be plasticized (Tavita et al. 2003). Furniture producers worldwide steam solid wood furniture components to a prescribed length of time and temperature before they are subjected to bending. Studies have shown, however, that plasticizing wood using liquid ammonia is more effective than steaming (Schuerch 1964).

Laxamana and Tavita (1988) conducted a study in bamboo flattening using quarter-cut kauayan-tinik (Bambusa blumeana J.A & J.H Schultes) slats obtained from the butt,

RegionErect Species

Hectares %

CAR 12,286 32.62

R-I 1,750 4.65

R-II 4,566 12.12

R-III 816 2.17

R-IV 283 0.75

R-V 2,262 6.00

R-VI 3,996 10.61

R-VII 4,186 11.11

R-VIII 368 0.98

R-IX 95 0.25

R-X 1,437 3.82

R-XI 4,697 12.47

R-XII 601 1.59

R-XIII 320 0.85

SUB-TOTAL (R I-XIII)

25, 377

GRAND TOTAL 37,663 100.0

Source: Virtucio (2008)

Table 1. Regional distribution of bamboo stands in the Philippines (all species)


middle and top of the culm. The slats were subjected to steam at atmospheric pressure and soaked in 3% NaOH for 2, 3 and 4 hr before flattening by pressing them between steel plates heated over live charcoal. Another study conducted by Tavita et al. (2003) determined the effects of boiling time before flattening and which among the three experimental flattening devices was most effective. Both studies, however, were not successful enough to produce flattened bamboo without traces of cracks or splits.

The process involved in producing flattened bamboo tiles by Mr. Monoso from Iloilo Province was described in Garcia’s (1997) report. The tiles reportedly showed cracks or splits on the surface. No details were given on the design of the equipment.

In Japan, Toya et al. (1998) developed a flattening machine made of metal rollers with different curvatures aligned in series from round to flat. Half-split bamboo culms 500 mm long without nodal diaphragms were first boiled in water for 10-20 min then shaved to remove the inner and outer cortex, leaving a uniform thickness of 9 mm. The culms were then heated with an electric device from 120 to 130oC (inside culm temperature) and immediately flattened. Cracks and splits were also visible on the surface of the flattened bamboo. Alipon et al. (2002) made similar studies by flattening kauayan tinik and botong (Dendrocalamus latiflorus Munro) to produce laminated lumber. Their results corroborated Toya et al.’s claim. that the optimum temperature for unfolding was about 130oC bamboo culm temperature. In the Philippines, the technique for producing flattened bamboo with few or no checks or splits has not yet been determined.

This study was thus conducted to design, fabricate and pilot test a bamboo flattening machine and determine its cost of production. Although flawless flattened

culms are preferred, a few checks or splits on the surface are acceptable because these can serve as accents to the material once the cavities are sealed with an appropriate filler during finishing as commonly done in crushed bamboo.


One unit of flattening machine and its auxiliaries were designed and fabricated in cooperation with Aycafil Industrial Corp. (AICOR) in Sta. Rosa, Laguna using locally available materials.

A series of test runs was conducted with and without load. Corrections and calibrations were made at AICOR before the machine was delivered to FPRDI. At FPRDI, it was tested thru a series of production runs and to gather operational data.

Two species of bamboo, kawayan tinik and botong, were used for the test runs and actual production runs. Some prototype products from the flattened bamboo were produced, including a folding table, laptop table, school chair, and finger-jointed planks.

The financial viability of the machine was evaluated. Likewise, a technology forum cum demonstration was conducted among 31 participants from furniture and handicraft companies in the province of Pampanga to elicit comments for the improvement of the machine.


Machine Design

The flattening machine is shown in Figure 1. The machine was designed to have an output of 100 m² a day as per requirement of a former furniture producer and exporter based in Angles City, Pampanga.

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It was made of high carbon steel rollers arranged in series with gradually decreasing radii of curvature from half round to flat. The flattener rollers consisted of nine modules. Each module with one pair of opposite-shaped rollers was installed on a 12-mm-thick mild steel bracket on both sides. The roller shaft was mounted on the brackets and supported by a spring loaded take-up bearings to regulate the pressure exerted on the flattened bamboo.

The brackets were bolted on a 100-mm steel channel base frame. The modules were bolted to each other by 12 mm x 75 mm x 130 mm mild steel connector. In between modules, a total of 7 KW band heaters were installed to attain the desired 130oC bamboo culm temperature while flattening.

The whole length of the flattening chamber was covered with a 50-mm-thick insulation material cladded by a plain G.I sheet (gauge 18). After the flatteners, a series of 14 pairs of 50 mm diameter x 200 mm long roller

pipes were installed as retainers of flattened bamboo.

The machine drive was a 1.5 KW gear motor, 220 volts, 60 Hertz, three-phase output and single-phase input. A variable-speed controller was also installed to establish the optimum speed that would produce the desired output of the machine.

Test Operations

The machine first ran without load at AICOR to check all moving parts for any misalignment especially on the rollers, loose bolts and nuts, roller chains tension and electrical system. A water catch basin was provided under the rollers to prevent dripping of water during flattening.

Corrections and refinement of the machine were completed after three months at the plant site. The first trial with load was made using four halves of 100 mm diameter x 1.2 m long PVC pipe. The halved PVC pipes with

Dante B. Pulmano, et al. .

Fig. 1. The bamboo flatenning assembly


a total of 12 mm thickness were flattened at the same time.

Five trials (Table 2) were conducted at AICOR using kauayan tinik for the first and second trials. Bamboo culms with average diameter of 10 cm were cross-cut to 129 cm length from the near bottom of the culm with average thickness of 22 mm until a minimum of 10 mm thickness at the top was obtained. About four to six pieces of 1.29 m length each were obtained from one whole culm. After cutting, the culms were de-nodded and skinned, then split into halves and the nodal diaphragms were subsequently removed. The culms were boiled in water at 100oC from 30 min to 2 hr for softening or plasticizing treatment. After boiling, the plasticized materials were unloaded one after the other from the boiling tank. While still hot and moist, these were fed individually through the flattener at 20 hertz setting with an equivalent roller linear speed of 1.7 m per min. This setting was computed to give an average output of 100 m² for an 8-hr operation per day.

Heaters were switched on at a temperature setting of 150oC inside the flattening chamber. However, recorded bamboo culm temperature sampling at the outlet of the heated chamber ranged from 70oC to 72oC only. For the third trial using botong, the same procedure was used but with 180oC heater setting. The recorded outlet bamboo culm temperature was 79oC to 80oC.

For the fourth and fifth trials, the heaters were no longer used because the lubricant of the roller guides and bearings was observed being drained. The linear speed of the rollers was set to 4 m per min with an equivalent average output of 200 m² for an 8-hr operation per day. For each trial, the time from the start of flattening up to the last sample was recorded. Average recovered total area was computed for each run over the total time consumed equals the average output of the machine per unit time.

The machine was transferred to the FPRDI Laboratory and five trial runs (Table 3) were made using botong. The same procedure

TrialNo.

BambooSpecies

No. of Samples(halved culms)

Sample SizeBoilingTime,min

RunningTime,min

*Production Rate, m²/hr

Diameter,mm

(ave.)

Length, m

1Kawayan

tinik36 100 1.29 30 25 *14

2Kawayan

tinik36 100 1.29 30 22 *16

3 Botong 36 100 1.29 35 28 *13

4 Botong 36 100 1.29 60 14 **25

5 Botong 34 100 1.29 120 16 **21

Table 2. Results of the test conducted at AICOR

*20 hertz setting = 1.7 m/ min**40 hertz setting = 4.0 m/min

15

was followed with the roller speed set to 4 m per min. The number of cracks and splits was counted in about 37 samples of flattened bamboos for the bottom and top portions, and inner and outer parts of the culm. The first 3 m from the bottom and the next 3 m to the top were considered as bottom and top, respectively.

Observation was made to find out which part of the culm was susceptible to cracks and splits. ANOVA showed that the number of cracks and splits on the inner part of the culm did not significantly differ from those

TrialNo.

Bamboo Species

No. of Samples (halved culms)

Sample Size BoilingTime,min

Running Time, min

*Production Rate, m²/hrDiameter,

mm (ave.)Length,

m

1 Botong 64 100 1.29 30 26 24

2 Botong 64 100 1.29 60 30 21

3 Botong 70 100 1.29 75 28 24

4 Botong 60 100 1.29 120 40 15

5 Botong 74 100 1.29 71 30 24

Table 3. Results of the test conducted at FPRDI

*Production rate was computed as the maximum recoverable area per culm (0.1638m²) after edging or side trimming multiplied by the length and divided by the total running time.

*Roller speed at 4 m/min


at the bottom and top. In the outer part, however, the number of cracks and splits was significantly different from those at the bottom and top. The bottom inner part was more susceptible to cracks than the bottom outer part. Since the bottom of the culm is thicker, it is expected to be more vulnerable to cracks and splits than the other parts.

Financial Viability of the Equipment

Flattened laminated bamboo planks and some prototype products such as school desks were produced. (Fig. 2). The bamboo flattening

Fig. 2. Prototype of a school desk made of laminated bamboo


equipment is a viable addition to an existing bamboo processing or woodworking wood firm since the equipment needed in producing engineered bamboo products are almost the same as those used in woodworking. A firm’s decision to acquire the equipment rests mainly on its assessment of the additional costs and revenues expected from the productive use of the equipment.

Cost of Producing Flattened Bamboo and Bamboo Floor Planks

The flattening equipment can process at least 70 (6.45 m) bamboo poles per day. Assuming an average diameter of 100 mm, about 115 m² of flattened bamboo can be produced per day. Total operating cost (before interest) is estimated at USD 314.82 per day or USD 2.81 /m². Since the major cost components are the costs of labor and bamboo, production cost can be higher or lower depending on the location of the production facility. In Iloilo, for example, bamboo costs only between USD 0.67 to USD 1.11 per pole. Thus, without taking into account the cost of bamboo, the cost of flattening will be USD 1.66/m², with labor as the largest cost component.

Conversion of flattened bamboo into engineered products will further add value. Flattened bamboo can be laminated to produce tongue and groove (T & G) floor planks . The daily production of 115 m2 of flattened bamboo can be processed into 57 m² of 2-ply floor planks. Since this will entail additional costs for glue, labor and electricity, the total operating cost (before interest) will increase to USD 373.89 or USD 6.71/m² of T & G floor planks.

Profitability of the Flattening Machine

The profitability of the equipment depends not only on the costs but also on the expected revenues that can be derived from producing

flattened bamboo and converted products. Thus, a firm that decides to invest in the equipment should also commit to pursue product development, quality control, and aggressive marketing.

For higher profitability, the investor should produce products from flattened bamboo. Prototype school chairs specified by the Department of Education, as well as tables and floor planks were developed for this project, demonstrating just some of the possible end-products from flattened bamboo. Financial indicators for the flattening equipment will be higher if the flattened bamboo is further developed into finished products such as floor planks.

At full capacity production of 13,680 m2 of bamboo floor planks per year, internal rate of return (IRR) is 79%, net present value (NPV) is around USD 189,000 and return of investment (ROI) is 80%. Expected net income from the sale of bamboo floor planks is around USD 42,900 (without financing).

Tables 4 and 5 show the production and financial indicators for flattened bamboo and bamboo floor planks.

Technology Forum and Demonstration

A technology forum and demonstration on the operation of the bamboo flattening machine was held at the Philippine Furniture Testing Center, Paralayunan, Mabalacat, Pampanga in cooperation with the Department of Science and Technology Regional Office No. III. Thirty-one participants from the furniture and handicraft industries in Pampanga, members of the Chamber of Furniture Industries of the Philippines Pampanga Chapter, and the government sector attended the forum.

Fourteen attendees participated in the technology needs assessment. All of them

17Dante B. Pulmano, et al. .

Fabrication cost of flattening equipment USD 20,888.89Production per day Flattened bamboo 115 m² Flattened bamboo floor planks 57 m² Production Cost Flattened bamboo USD 2.8/m² Flattened bamboo floor planks USD 6.71/m²Selling Price Flattened bamboo (30% markup) USD 3.64/m² Flattened bamboo floor planks (50% mark up) USD 10.07/m²Net income per year (without financing) Flattened bamboo USD 28,000 Flattened bamboo floor planks USD 42,890 IRR Flattened bamboo 50 % Flattened bamboo floor planks 79 %ROI Flattened bamboo 38 % Flattened bamboo floor planks 80%NPV Flattened bamboo USD 125,580 Flattened bamboo floor planks USD 189,220 Payback period Flattened bamboo 4th year Flattened bamboo floor planks 3rd year

Table 5. Production and financial indicators for flattened bamboo and bamboo floor planks

COST ITEMS Flattened bamboo Flattened bamboo floor planks

USD PER DAY

% of total operating

costUSD PER DAY % of total

operating cost

Bamboo polesa 124.44 40 124.44 33

Preservative treatmentb 7.87 2 7.87 2

Electricityc 19.6 6 20.89 6

Fuelwoodd 34.91 11 34.91 9

Direct labore 128 41 142.22 38

Gluef - - 43.56 12

Total Operating Cost 314.82 100 373.89 100

Depreciation 8.36 8.36

TOTAL 323.18 382.24

Cost per m²Cost per m³

Cost per bdft

USD 2.81g

USD 468.38USD 1.10

USD 6.71h

USD 1,117.67 USD 2.64

Cost of flattening USD 1.66 per sq mi

a 70 poles/day @ USD 1.78 per poleb 75 ml (Dacroll) x USD 0.10/mlc 88.2 kWh for flattened bamboo; 940 kWh for bamboo floor planks; at USD 0.22/kWhd 3.14 cu m x USD 11.11/m³e 19 mandays for flattened bamboo only; 20 mandays for bamboo floor planks; at USD 7.11/mandayf 14 kg glue (Racoll) at USD 3.11/kgg based on a production rate of 115 m² (.69 m³) of flattened bamboo per dayh based on a production rate of 57 m² of flattened bamboo floor planks per dayI Less the cost of bamboo

Table 4. Cost of producing flattened bamboo and flattened bamboo floor planks (USD per day)


said that their company did not have an existing bamboo flattening machine. Eight expressed interest in immediately adding the equipment in their production system. However, some said they would have an urgent need for the equipment in two to six years yet. Others requested for different types of technology intervention including solid and bent bamboo lamination and an equipment for converting sawdust and wood shavings into useful products.

In terms of technical performance and viability, the bamboo flattening machine was rated ‘excellent’ by 2 respondents, ‘very good’ by 9 and ‘good’ by 1. Three participants suggested improvements on the machine, i.e., incorporate a planer immediately after flattening so that nodes will be removed while still soft, and integrate a jointer type machine to even out the inner side of the culm. The machine was considered affordable by five respondents while the others did not comment.

CONCLUSIONS

• The bamboo flattening equipment and its auxiliaries have been successfully designed and fabricated.

• The target output of 100 m² per day at 8-hr operation has been attained and even exceeded.

• Various types of engineered bamboo products can be made using the equipment, i.e., planks, folding table, laptop table, and school desk.

• The production cost per m² of flattened bamboo (6 mm average thickness) and laminated bamboo panel (12 mm) are USD 2.81 and USD 6.71, respectively.

• The IRR, ROI, NPV and payback period of flattened bamboo and bamboo floor planks are 50%, 38%, USD 125,580 and 4th year, and 79%, 80%, USD 189,290 and 3rd year, respectively.

RECOMMENDATIONS

• Conduct pilot scale or commercial operation of the flattening machine to validate its performance and durability.

• Design and fabricate other tools or equipment for bamboo culm de-skinning, splitting and diaphragm removal.

• Test the machine using other bamboo species such as buho (Schizostachyum lumampao), bolo (Gigantochloa levis) or giant bamboo (Dendrocalamus giganteus).

19

LITERATURE CITED

ALIPON MA, FLORESCA AR, FIDEL MM, and CAYABYAB PC. 2002. Strength of glue laminated bamboo and bamboo-wood combination. Terminal Report. (Part I) NRCP Bicutan, Taguig, Metro Manila.

ALIPON MA, SAPIN G and PULMANO DB. 2002. Development of insect-resistant glue-laminated bamboo and bamboo-wood combination for housing components. Project Proposal for PCIERD Funding. FPRDI, College, Laguna.

BISANA BB, PULMANO DB, TAMOLANG FB, GARCIA CMC and DOISO EN. 2004 Design and fabrication of bamboo veneer lathe. Terminal Report. FPRDI Library, College, Laguna.

ESPILOY ZB, VIRTUCIO FD, ALIPON MA, ROXAS CA, BONDAD EO, and APOLINAR CD. 2002. Abstract of literature on Philippine bamboos. Volume II (1980-2000). FPRDI Library, College, Laguna.

ESPILOY ZB, VIRTUCIO FD, ALIPON MA, ROXAS CA, BONDAD EO and APOLINAR CD. 2002. Handbook on Philippine bamboos. FPRDI Library, College, Laguna.

LAXAMANA M and TAMAYO GY. 1984. Development of suitable drying schedule of some Philippine bamboos. Project. No. FORD 8105 En. FPRDI Library, College, Laguna.

NATIVIDAD RA and ZAMORA RA. 2003. Wood bending technology. Terminal Report of Project 4.4, PCARRD-DOST GIA National Furniture R & D Program. FPRDI Library, College, Laguna.

SCHUERCH. 1964. Wood Plastization. Forest Products Journal Vol. 14(9):3:377-381.

TANGAN FT. October 16, 2010. Bamboo: For people and the environment. Paper Presentation. Sitio Tanza II, Brgy. San Jose, Antipolo City.

TAVITA YL, NATIVIDAD RA, ATIENZA EM, and EBRON TZ. 2003. Improvement of flattening techniques for bamboo. Terminal Report. FPRDI Library, College, Laguna.

TOYA R, YOMAZUMI T, YOMANOUCHI K and YONOKURA M. 1998. Manufacturing and utilization of flat board. Proceedings from the 5th Conference on Timber Eng’g. Swiss Federal Institue of Technology. Montreux, Switzerland. August 17-20, 1998. Vol. 2, pp. 282-287

VIRTUCIO FD. October 22-24, 2008. Assessment of bamboo resources in the Philippines. Proceedings on the National Bamboo Development Forum. PTTC, Roxas Blvd.,Pasay City.



ACKNOWLEDGMENT

The authors wish to thank the DOST Technology Incubation for Commercialization (TECHNICOM) for the financial support and Philippine Council for Industry, Energy and Emerging Technology Research and Development (PCIEERD) for monitoring the implementation of the project.

21

PARALLEL EVALUATION OF BOND TEST ON PHILIPPINE-MADE PLYWOOD USING PNS 196:2000 AND ISO 12465:2007 STANDARDS

Juanito P. Jimenez, Jr, Freddie M. Ordinario, Nathaniel A. Ramos and Rico J. Cabangon

Senior Science Research Specialist, Science Research Specialist II, Research Assistant and Supervising Science Research Specialist, respectively

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

ABSTRACT

This study compared the glue-bond quality conformance of Philippine-made plywood to PNS 196:2000 and ISO 12465:2007 standards. Fifteen manufacturing companies undergoing annual product audit of the Bureau of Products Standards of the Department of Trade and Industry (BPS-DTI) were tested for the bond quality of their plywood. Test procedures of the two standards were followed. Two sets of samples from the same panel were tested in parallel for bond quality.

Results showed that the shear strength and percent wood failure values for Type I (exterior) plywood evaluated using PNS 196:2000 had higher values than those evaluated using ISO 12465:2007. This could be due to the additional pre-treatment of 24 hr soaking in water at 23°C using the latter standard.

Some companies passed both standards, while others passed the former but failed in the latter and vice-versa. However, the majority of the companies passed the requirements of both standards. For Type II (interior) plywood, all companies evaluated except one passed both standards.

For the Type I plywood from the 15 companies, only 10 were sampled for evaluation. Of the 10, only 6 (60%) conformed to both PNS and ISO standards requirements; 2 (20%) failed ISO; 1 (10%) failed PNS, and 1 (10%) failed both standards.

For the Type II plywood from the 15 companies, only nine were evaluated. Of the nine, eight (89%) conformed to the two standards and only one (11%) failed the requirements of both standards.

The majority of the companies evaluated for both the Type I and Type II plywood passed the requirements of PNS and ISO standards for glue-bond quality. Hence, it is safe to assume that Philippine plywood manufacturers can meet the requirements of ISO 12465:2007, specifically ISO 12466-2:2007 standards.

Keywords: bond test, plywood, Philippine-made, PNS 196:2000, ISO 12465:2007



INTRODUCTION

Plywood is one of the most widely used wood-based panels in the world. In the Philippines, the commercial production started in the early 1950’s when value adding to timber harvested from natural growth forests became a necessity to generate more income and jobs.

With the current trend of globalization and the creation of tariff-free or reduced tariff market among World Trade Organization (WTO) and ASEAN Free Trade Area (AFTA) member countries, trading of goods has become almost free-flowing from one country to another. Two wood products traded frequently between the Philippines and other countries are veneer and plywood (Philippine Forestry Statistics 2011).

Due to Executive Order No. 23 issued on February 2011, which declared a moratorium on the harvesting of timber from natural growth forests, it has become difficult for most plywood plants to obtain their raw materials from local sources. Some companies have resorted to importation of logs or veneers from nearby countries such as Papua New Guinea, Solomon Islands, Malaysia and China (P. Chao, CEO, San Manuel Wood Products, Inc., Personal Communication 2012, and J. Garcia, Administrative Officer, Mt. Banahaw Wood Industries, Inc., Personal Communication 2012). Other companies have shifted to the trading business and importing plywood from China (AP Ong, Member, Board of Directors, Philippine Wood Producers’ Association (PWPA) and Administrative Officer, Republic Wooden Commodities, Inc., Personal Communication 2013).

Technical barriers to trade such as different national test standards for plywood may soon be eliminated by the eventual harmonization of such. By 2015, it is envisioned that ASEAN member countries will be using the ISO as the only standard for all their manufactured

goods (MTG Del Rosario, Technical Officer of Technical Committee (TC) 35, Bureau of Philippine Standards, Department of Trade and Industry (BPS-DTI), Personal Communication 2013).

At the request of the PWPA and through the BPS-DTI’s TC 35 (Wood-based Panels: Plywood), this evaluation of the bond quality of Philippine-made plywood was conducted to determine if locally made plywood which used to pass glue-bond quality requirements of PNS 196:2000 would also pass the requirements of ISO 12465:2007.

The output of this study would help TC 35 decide whether to adopt in toto the ISO requirements for plywood bond quality or modify them based on the results. This study aimed to compare the glue-bond quality conformance of locally made plywood to PNS 196:2000 and ISO 12465:2007 and if appropriate, recommend new criteria for evaluation of bond test based on the data gathered.


Bond Test The procedures specified in PNS 196:2000 and ISO 12465:2007 particularly ISO 12466-1:2007 were followed. Two sets of samples from the same panel were evaluated in parallel for their bond quality. This was measured in terms of shear strength and percent wood failure values using Type I and Type II tests.

The samples were obtained from plywood companies undergoing annual product audit of the BPS-DTI. From April 2012 to September 2013, 15 local manufacturing companies were evaluated for their conformance to the two standards. Since a single company can produce various thicknesses of plywood, two to three thicknesses for each type were selected for those producing four or more

23

and only one thickness for each type for those producing less than four.

Table 1 shows the assignment of codes for the 15 companies and the thicknesses sampled from them. The sequence of the alphabet code was based on the order by which the companies submitted their samples for the annual product testing. A company which was sampled in 2012 was not included in 2013 to eliminate duplication.

Table 1 shows that of the 15 companies, only 10 (A, B, C, D, E, I, J, K, L, M) were evaluated using the Type I test, while only 9 (A, B, C, F, G, H, M, N, O) were assessed using Type II. Only 4 (A, B, C, M) were evaluated for both types.

For Type I and Type II plywood, the common thicknesses, which are nominal of ¼”, ½” and ¾” were evaluated to determine the conformance of local manufacturing

companies to PNS 196:2000 and ISO 12466-2:2007. The thicknesses of Type I plywood evaluated were 5 mm, 10 mm, 12 mm and 18 mm, while those of Type II were 5 mm, 9 mm, 10 mm and 18 mm.

Table 1 shows that of the 15 companies, only 10 (A, B, C, D, E, I, J, K, L, M) were evaluated using the Type I test, while only 9 (A, B, C, F, G, H, M, N, O) were assessed using Type II. Only 4 (A, B, C, M) were evaluated for both types.

For Type I and Type II plywood, the common thicknesses, which are nominal of ¼”, ½” and ¾” were evaluated to determine the conformance of local manufacturing companies to PNS 196:2000 and ISO 12466-2:2007. The thicknesses of Type I plywood evaluated were 5 mm, 10 mm, 12 mm and 18 mm, while those of Type II were 5 mm, 9 mm, 10 mm and 18 mm.

No. Company Code Type I (Exterior Plywood) Type II (Interior Plywood)

1 A 18 mm 9 mm

2 B 18 mm 10 mm

3 C 5 mm 18 mm 5 mm 9 mm 18 mm

4 D 10 mm 18 mm

5 E 18 mm

6 F 10 mm 18 mm

7 G 5 mm

8 H 4.5 mm

9 I 5 mm 18 mm

10 J 18 mm

11 K 18 mm

12 L 5 mm 12 mm

13 M 18 mm 10 mm

14 N 5 mm

15 O 18 mm

Table 1. Assignment of codes for the 15 companies and the thicknesses sampled from them

Juanito P. Jimenez, et al. .


Evaluation of the Bond Quality Using PNS 196:2000 versusISO 12466-2:2007

The bond quality requirements of the two standards differ in the criteria for passing or failing a given batch of plywood samples. In PNS 196:2000 (Table 2), not only the average wood failure (column 3) of the specimen per panel is considered but also the wood failure of each (column 2).

In ISO 12466-2:2007 (Table 3), only the averages of the wood shear strength and wood failure per panel are considered. Because of the two standards’ different criteria for passing/failing, it was decided to use only their common criterion which was based on the panel’s average shear strength and percent wood failure. For a sampled lot to pass the requirements, at least 9 out 10 panels should conform. However, if only 8 out of 10 panels conformed, a retest should be made. Below that (7 out of 10 and down), the lot would be considered non-conforming to the two standards.

Comparison of Conformance to Bond Quality Requirements

Evaluation of the samples’ conformance to bond quality requirements was tabulated per thickness and per company. Table 4 shows the matrix of evaluation for Type I plywood. The results for Type II uses the same format except that under the PNS 196:2000 column, instead of shear strength and wood failure values, a single column labeled “Quantity of Delamination” was used. The 15 companies were coded with letters A to O. The t-test was used to determine mean differences in shear strength and wood failure.


Type I (Exterior/Marine) Plywood

Table 5 shows the summary of the 10 companies’ performance in the bond quality test.

Average Shear Strength, kg/cm2 Minimum Wood Failure % Average Wood Failure %

Below 17.48 25 50

17.58 to 24.6 10 30

Above 24.6 10 15

Table 2. Wood-failure requirements of PNS 196:2000

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

0.2 > ז not applicable

0.4> ז ≥ 0.2 ≥ 80

0.6 > ז ≥ 0.4 ≥ 60

1.0 ≥ ז ≥ 0.8 ≥ 40

ז > 1.0 no requirement

Table 3. Glue line requirements of ISO 12466-2:2007

25

Panel No.

PNS 196:2000 ISO 12466-2: 2007

RemarksAve. Shear Strength* (kg/cm2)

Ave. Wood Failure* (%)

Ave. Shear Strength* (kg/cm2)

Ave. Wood Failure* (%)

Lot. Ave.

Table 4. Comparison of the mean shear strength and wood failure as per PNS 196:2000 and ISO 12466-2:2007

* Each panel’s shear strength and wood failure values come from the average of 18 specimens.Notes: Remarks:1 MPa = 10. 20 kg/cm2 A = Conformed to both PNS 196:2000 and ISO 12466-2:2007 0.6 MPa = 6.12 kg/cm2 B = Conformed only to PNS 196:20000.4 MPa = 4.08 kg/cm2 C = Conformed only to ISO 12466-2:20070.2 MPa = 2.04 kg/cm2 D = Did not conform to both standards

Thickness Company

PNS 196:2000 ISO 12466-2: 2007 t - Test of means

RemarksAve.

Shear Strength* (kg/cm2)

Ave. Wood

Failure* (%)

Ave. Shear

Strength* (kg/cm2)

Ave. Wood

Failure* (%)

t-valueShear

t-valueWood Failure

5 mm

C 11.95 86 10.49 80 -1.52 ns -1.50 ns 10A

I 6.80 69 5.06 74 -3.08 ns 0.91 ns 8A, 2B

L 12.17 93 11.81 94 -0.47 ns 0.37 ns 10A

10 mm D 16.49 83 16.00 84 -0.65 ns -0.23 ns 10A

12 mm L 9.86 83 9.47 79 -0.36 ns 0.88 ns 10A

18 mm

A 5.69 71 5.55 67 -0.30 ns -0.68 ns 8A, 2B

B 5.74 45 5.30 36 0.82 ns 1.53 ns 7D, 3B

C 10.49 76 9.38 72 -1.28 ns -0.53 ns 8A, 1C, 1D

D 12.66 93 12.13 93 0.64 ns -0.06 ns 10A

E 10.44 90 10.21 93 -0.45 ns 0.88 ns 10A

I 17.37 88 16.69 88 -0.63 ns 0.05 ns 10A

J 10.44 71 9.69 72 -1.20 ns 0.15 ns 9A, 1C

K 7.26 74 7.04 73 -0.32 ns -0.17 ns 9A, 1B

M 13.76 97 13.79 97 -0.03 ns -0.09 ns 10A

Table 5 Summary of bond quality of Type I plywood from 10 companies evaluated as per PNS 196:2000 and ISO 12466-2:2007 requirements

* Each average value of shear strength and wood failure per thickness and per company is the mean of the sampled lot with a total of 180 specimens.

ns – not significant



Type I, 5 mm samples. For the 5 mm samples, three companies (C, I and L) were evaluated for conformance to the two standards. Table 5 shows how each company differed in mean shear strength test and wood failure values. For Companies C and L, all panels received an A remark which means their samples passed both PNS and ISO standards. The lot mean values for shear strength and wood failure were also found to be not significant based on t-test although both were slightly higher in the PNS for Company C. However for companies I and L, only the shear strength was higher in the PNS.

For Company I, eight panels had an A, while two had a B remark. This means that all 10 plywood conformed to the requirements of PNS, while a retest was done for the ISO as only 8 out of 10 panels passed. The passing conformance should be 9 out of 10. The t-test also revealed that both lot mean shear strength and wood failure values were not significantly different although shear strength was higher in the PNS than in the ISO and the reverse was true for wood failure.

Type I, 10 mm and 12 mm samples. For the 10 and 12 mm plywood, only two companies (D and L) were evaluated. Company D had 10 mm, while Company L had 12 mm plywood (Table 5). Both companies received an A remark for the 10 panels which means they both conformed to the two standards. The t-test revealed that the shear strength and wood failure values for both companies did not significantly vary.

Type I, 18 mm samples. For the 18 mm specimens, nine companies (A, B, C, D, E, I, J, K and M) were evaluated for their conformance to PNS 196:2000 and ISO 12465:2007. Table 5 shows how each company differed in mean shear strength test and wood failure values.

Four companies - D, E, I and M - obtained A remarks for all their specimens. The mean values of the shear test and wood failure for

these four companies were also found not significant based on the t-test although shear strength and wood failure were generally slightly higher in the PNS than in the ISO.

For Companies J and K, 9 out of 10 plywood conformed to both standards. For Company J, all plywood samples conformed to ISO (9A and 1C), while for Company K all plywood conformed to PNS (9A and 1B). The mean values of the shear test and wood failure for the two companies were also found not significant based on the t-test although shear strength was slightly higher in the PNS than in the ISO and wood failure values were almost the same with just 1% difference.

Two companies, A and C, had a retest for both standards for having only 8 out of 10 conformances. Company A had a perfect 10 out of 10 conformances to PNS (8A and 2B) but had to have a retest for ISO for having only 8 out of 10. For company C, it was the reverse, having 9 out of 10 conformances to ISO (8A and 1C), the retest was only for PNS. The mean values of the shear test and wood failure for the two companies were also found not significant based on the t-test although shear strength and wood failure were slightly higher in the PNS than in the ISO.

Company B was the only one that failed both standards. Receiving 7D and 3B remarks, only three of its plywood out of 10 passed PNS, and 7 out of 10 failed both standards. The mean values of the shear test and wood failure for this company were also found not significant based on the t-test; although shear strength and wood failure were slightly higher in the PNS than in the ISO.

Type II (Interior/Ordinary) Plywood

Table 6 shows the summary of the companies’ performance in the bond test.

27

Thickness Company

PNS 196:2000 ISO 12466-2: 2007

RemarksQuantity of Delamination

Ave. Shear Strength * (kg/cm2)

Ave. Wood Failure*

(%)

4.5 mm H 0/150 14.1 91 10A

5 mm

C 2/150 9.18 94 10A

G 5/150 8.71 84 8A, 1B, 1C

N 0/150 12.3 99 10A

9 mmA 1/150 8.50 73 10A

C 3/150 9.18 94 10A

10 mm

B 40/150 6.26 53 3A, 1B, 2C, 4D

F 0/150 18.34 90 10A

M 0/150 16.77 83 10A

18 mm

C 5/150 12.15 84 10A

F 2/150 13.16 98 10A

O 0/150 13.80 95 10A

Table 6 Summary of bond quality of Type II plywood from 9 companies evaluated as per PNS 196:2000 and ISO 12466-2:2007

* Each average value of shear strength and wood failure per thickness and per company is the mean of the sampled lot with a total of 180 specimens.

Type II, 4.5 mm and 5 mm samples. Four companies (H, C, G and N) were evaluated (Table 6). Companies H, C and N had perfect A remarks for the 10 panels. Only company G had 9 out of 10 conformances to PNS (8A and 1B) and ISO (8A and 1C). Nevertheless, it still passed both standards.

Type II, 9 mm and 10 mm samples. Five companies (A, C, B, F and M) were evaluated (Table 6). Companies A, C, F and M obtained A remarks for the 10 panels. Only company B had either 4 out of 10 conformances to PNS (3A and 1B) or 5 out of 10 conformances to ISO (3A and 2C) standards. Still, company B failed the requirements of both standards.

Type II, 18 mm samples. Three companies (C, F and O) were evaluated (Table 6) and all received A remarks for the 10 panels, meaning they all conformed to the requirements of PNS and ISO.

SUMMARY AND IMPLICATIONS

For the Type I plywood, of the 10 companies evaluated, 6 out of 10 (60%) conformed to both PNS and ISO requirements; 3 out of 10 (30%) had a retest for either standard (2 for ISO and 1 for PNS) and 1 out of 10 (10%) failed to conform to both standards.

For the Type II plywood, of the 9 companies evaluated, 8 out of 9 (89%) conformed to the requirements of the two standards and only 1 out of 9 (11%) failed both standards.

The majority of the companies evaluated both for Type I and Type II plywood passed the requirements of PNS and ISO for glue-bond quality requirements. It is safe to assume that Philippine plywood manufacturers can meet the requirements of the ISO 12465:2007 specifically ISO 12466-2:2007. Hence, the ISO standards for the glue-bond



quality requirements may be adopted in toto by the BPS. CONCLUSIONS

The general glue-bond performance of the 15 companies tested shows that the shear strength and percent wood failure of Type I plywood evaluated using PNS 196:2000 have slightly higher values, though statistically not significant, than those tested using ISO 12465:2007. This is perhaps due to the

additional pre-treatment of 24 hr soaking in water at 23°C in the latter method. The majority of the companies have passed the requirements of both standards.

For the tests on Type II plywood, a company which failed in the delamination test using PNS 196:2000 also failed in the shear and wood failure evaluation using ISO 12465:2007. However, in general, Philippine-made Type II plywood can pass both standards.

REFERENCES

ISO 12465:2007. Plywood Specifications.

ISO 12466-1:2007. Plywood – Bonding Quality – Part 1: Test Methods.

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

Philippine Forestry Statistics. 2011. Forest Management Bureau, Department of Environment and Natural Resources. Quezon City.

PNS 196:2000. Plywood Specifications.

29

UTILIZATION OF SPENT TEA LEAVES AND WASTE PLASTICS FOR COMPOSITE BOARDS

Juanito P. Jimenez, Jr., Erlinda L. Mari, Edgardo M. Villena and Rico J. Cabangon

Senior Science Research Specialist, Scientist I, Science Research Specialist I, and Supervising Science Research Specialist, respectively


ABSTRACT

Single layer particleboards with densities of 0.45 g/cm3 (low) and 0.75 g/cm3 (medium) were made from mixtures of spent tea leaves (TL) and waste plastics (WP) at proportions of 30TL:70WP, 40TL:60WP and 50TL:50WP. Boards from pure tea leaves bonded with phenol formaldehyde resin were also produced for comparison. The boards were tested for the effects of board density and material proportion on mechanical properties [modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB) and face screw holding (FSH) strength] as well as physical properties [moisture content (MC), thickness swelling (TS) and water absorption (WA)]. Results were also compared with the existing Philippine Standard for Particleboard (PNS 230:1989).

The results showed that density was positively associated with MOR and IB, in both low and medium-density boards, and also with MOE and WA in medium-density boards. On the other hand, the ratio between TL and WP significantly affected all the properties, except MOE in low-density boards. In medium-density boards, the significant effect of TL and WP ratio was limited to FSH, IB and MC.

The results indicate that it is possible to produce TL-WP composite boards that warrant testing. The boards exhibited remarkable dimensional stability, had low MC and low TS after 24-hr immersion in water, but fared poorly in strength properties. Thus, this type of board might be suitable for exterior but non-load bearing applications such as eaves’ ceiling and kitchen partitions.

Keywords: spent tea leaves, waste plastic, particleboard



INTRODUCTION

The Philippine Republic Act 9003, or also known as the“Ecological Solid Waste Management Act of 2000”, established the National Solid Waste Management Commission (NSWMC), with the Department of Environment and Natural Resources (DENR) as lead agency.

The Commission is tasked to oversee the implementation of the country’s solid waste management plans and prescribe policies to achieve the objectives of the Act. As part of the Commission, the Department of Science and Technology (DOST) is tasked to promote and transfer available technologies on waste utilization, as well as develop new uses for recovered resources.

The NSWMC (NSWMC 2005 as cited by Atienza 2011) estimates the country’s solid waste generation at 19,700, 24,059, and 28,875 tons per day for the years 2000, 2005 and 2010, respectively, which are equivalent to roughly 7.2, 8.8 and 10.54 million tons per year, respectively. Several programs to address the solid waste management problem have been established in the Philippines. Among these is the Philippine Environment Partnership Program (PEPP) with industries in cooperation with environment-related agencies. The PEPP seeks to provide a package of incentives to industries involved in effective voluntary self-regulation of their wastes and improved environmental performance (EMB-DENR 2012)

Waste plastics (WP) from different sectors of the society make up about 16 % of National Capital Region’s solid waste (Atienza 2011) and a little more in other regions of the country (Aguinaldo 2012). Among the WP segregated at Material Recovery Facilities (MRFs), wrapping films, grocery and sandwich bags, and other containers made of low-density polyethylene (LDPE)

are considered of lower recyclability than the polyethylene terephthalate (PET) plastics used for soft drink and water bottles, juice bottles, mouthwash bottles, salad dressing containers, boil-in food pouches, and processed meat packages, as well as the high density polyethylene (HDPE) plastics for milk bottles, detergent bottles, oil bottles, toys, plastic bags (UNEP 2012). Of considerable volume, LDPE plastic wastes are cut or shredded and sold at a lower price. Though several recycling initiatives have been introduced in the country, the volume of wastes being generated appears to be greater than the capacity of these endeavors to recycle them. Waste disposal sites continue to increase with the expanding population and intensified development (Atienza 2011).

The industry sector is, thus, encouraged to self-regulate its wastes under the PEPP. As such, factories may not only look for ways to safely dispose of their wastes but also for means of recycling and possibly recovering the cost of disposal to the extent of even deriving earnings by adding value to their wastes.

The Universal Robina Corporation (URC) produces one of the country’s popular flavored tea drinks. The company has been searching for practical uses for the spent tea leaves wastes generated by its processing mills, which amount to 18 metric tons per day on wet basis (Paul Alexis A. Borgonia, Production Manager, URC, Personal Communication, 25 June 2011) or 3.6 metric tons per day (dry basis). A 200-day extraction per year would accumulate 720 metric tons of the dry waste, a volume large enough to consider a big-volume end-use. One end-use for such is the production of composite boards for the housing and construction industry.

The use of lignocellulosic wastes (wood and agricultural residues) in composite board manufacture is nothing new. In

31

China, Thailand, Vietnam and Japan where extraction plants for various kinds of tea drinks generate spent tea leaves in massive amounts, different studies have been conducted on the use of this waste in making particleboard as the sole material or in combination with wood. Yalinkilic et al. (2002) reported making spent tea leaves particleboard with urea formaldehyde (UF) as binder.

Their results showed that the high phenolic content of waste tea leaves board (WTLB) can make the boards resistant to decay fungi with only 3.5 – 8.6% and 6 – 12.1% mass loss against Tyromyces palustris and Coriolus versicolor, respectively. WTLB also exhibited termiticide property as the three-week exposure to Formosan subterranean termites Coptotermes formosanus showed a gradual but increasing mortality of the insects. Physical and mechanical properties of the WTLB were at par with the general purpose boards designated in BS 5669.

Other studies combined spent tea leaves with lignocellulosic material like wood using either UF or phenol-formaldehyde (PF) as binder. Li-Jen et al. (2009) made particleboard from waste tea leaves in combination with wood-based particles with PF as binder at 5% resin content.

The resulting physical and mechanical properties in general were affected negatively as the ratio of the mixed tea leaves increased. However, the amount of free formaldehyde decreased as the mixed ratio of tea leaves increased. All the boards conformed to F1 or F2 criterion of CNS 2215.

A similar study on formaldehyde abatement in WTLB was done by Jin-shu et al. (2006). Orthogonal experimental method showed that waste tea leaves had the ability to abate formaldehyde emission from boards. It also showed that density was a significant factor affecting mechanical properties (MOR, MOE and IB) of the board.

Meanwhile, Hojo, et al. (2001) found that an application of green tea extract containing 30% (w/w) catechin to the surface of the plywood manufactured using formaldehyde-based resin remarkably suppressed the emission of the formaldehyde from the plywood.

While FPRDI has also been conducting research on the use of different kinds of wood and agricultural residues for composite board manufacture, this present study was its first attempt using spent tea leaves and more so in combination with waste plastic. Dolores, et al.’s (2004) work may be a useful reference. One finding described a single layer particleboard with 30/70 bamboo particles to waste plastic ratio pressed for 15 min at 150oC surpassing the minimum requirement specified in the PHILSA 105 (Philippine Standard for Particleboard) for the MOR, IB and thickness swelling.

In another study, a first of its kind, composite board was produced by mixing waste plastic with cement and wood wool (Cabangon 2010). The resulting board, however, had lower strength properties than conventional wood wool cement board, limiting it to non-structural applications.

In view of the above, this study evaluated the potential of combining spent tea leaves and waste plastic to produce particleboard. Specifically, the effects of material ratio and board density on board properties were determined. Results were compared with those of pure tea leaves bonded with PF resin and with the standard specifications for particleboard (PNS 230-1989).


Materials

Spent tea leaves (TL) were obtained from URC’s flavored tea drink processing plant in Cabuyao, Laguna. With about 400% moisture content (MC), the very wet material was



first air-dried for two weeks to reduce MC to about 60%, screened to obtain particles over 2 mm in size, and then oven-dried to appropriate MC (8 to 12%).

The waste plastic (WP), mainly LDPE plastic bags cut into fragments about 5 mm x 5 mm in size, was obtained from the LGU-MRF of Los Baños, Laguna. PF adhesive was provided by RI Chemicals Corporation.

Methods

Board Manufacture

The experimental design below was followed in the preparation of materials and production of particleboards.Calculated amounts of TL and WP were

Board size (L x W x T), cm 30 x 30 x 1.2

Board density, kg/m3 450, 750

TL:WP 30:70, 40:60, 50:50

Platen temperature, oC 150

Pressure, kg/cm2 50

Pressing time, min (step-down) 15

No. of boards per treatment 5

mixed thoroughly in a large vat then formed into a mat using a forming box measuring 30 cm x 30 cm. The mat was hot pressed to 12 mm with thickness bars placed at the edges of the platen at 150°C and pressure of 50 kg/cm2 for 15 min. Hot pressing was followed by cold pressing for 24 hr to stabilize the board.

For comparison, 12 mm-thick PF-bonded boards were produced from 100% TL at 6% resin content and similar hot-pressing conditions. All the boards were left in a humidity-controlled room (RH 60-65%, room MC 12%) for about 6 weeks before testing the properties.

Testing of Board Properties

Following PNS 230:1989 (Philippine National Standard: Specification for Particleboards), the boards were tested for MOR and MOE, IB, face screw-holding strength (FSH), MC, 24-hr WA and TS.

Statistical analysis Analysis of co-variance (ANACOVA with board density as co-variate) in completely randomized design (CRD) was conducted separately for the low and medium-density boards. Significant effects were further analyzed by comparing the treatment means using DMRT. Simple comparison of property values was done against PF-bonded TL boards.


Physical Observations on the

Boards

Material ratio (TL:WP) and board density were the variables of the study. However, the boards were observed to be below the target thickness of 12 mm and this would have a bearing on the target density, too, as shown in Table 1. The target densities of 0.45 and 0.75 g/cm3 were not achieved, the actual being higher and lower than the targets, respectively.

Moreover, the low-density group indicated decreasing density with increasing TL, while the reverse was true for the medium-density group. Material ratio appeared to affect board density. TL and WP are two entirely different materials. TL is polar; WP, non-polar. Since both materials were not finely ground, as what is done with commercial wood-plastic composites (WPC), a completely homogeneous board would be difficult to obtain.

33

Ratio Tea Leaves (TL):

Waste Plastic (WP)

Low Density Target = 0.45 g/cm3

Medium Density Target = 0.75 g/cm3

Actual Mean Density (g/cm3)

Actual Mean Thickness

(mm)

Actual Mean Density (g/cm3)

Actual Mean Thickness

(mm)

30 : 70 0.55 9.11 0.66 10.04

40 : 60 0.53 10.04 0.69 10.66

50 : 50 0.50 10.80 0.72 11.15

Table 1. Board density of the TL-WP composites

Plastic bags, like the WP gathered in MRFs, are usually LDPE type, a thermoplastic with an average density of 0.920 g/cm3 and a melting point of 120oC (Dynalab 2013). In this study, it is likely that much of the WP, after melting during hot-pressing, fused and solidified back upon release from the hot-press and subsequent conditioning, with only a portion binding with the TL.

This resulted in boards with lower thickness and therefore higher density than the target density, particularly for low-density boards. However, as WP decreased, the thickness increased due to the greater volume but lower specific gravity provided by TL, which also blocked fusion between plastic particles. By the density formula which is the ratio of mass over the volume, higher volume can result in lower density if mass is held constant.

For the medium-density boards, compaction of more TL and WP might have resulted in less fusion of the WP and more surface contact with TL. The thickness difference from the target was not as big as the difference in the low-density boards hence, actual density moved closer to the target.

Effect of Material Ratio and Board Density on Board Properties

ANACOVA on the different properties of the boards shows that density was positively associated with MOR and IB, in both low and medium density boards, and with MOE and WA in the medium-density boards (Table 2).

On the other hand, the ratio between TL and WP had a more significant effect on all the properties, except MOE, in the low-density boards.

MOE in the low-density group did not show any effect of density and material ratio due to the wide variation in values resulting probably from the localized fusion of plastic particles. In the medium-density boards, effect of material ratio was limited to FSH, IB and MC.

Table 3 shows the means of the different properties after factoring in the effect of the varying densities. DMRT on the means indicates differences due to material ratio. Also shown in the table are the average values obtained for the PF-bonded pure TL boards, as well as the values set by the PNS 230:1989 for comparison purposes.

For the low-density group, the material ratio 30/70 significantly differed from the other two ratios in most of the properties (Table 3). In general, greater strength properties (MOR, MOE, FHS, and IB) were observed with more WP. Reducing the proportion of WP (to TL/WP 40/60), however, still gave strength properties that compared well with the PF-bonded TL board, except for MOE.

Unfortunately, except for IB, the boards’ strength properties, including those of PF-bonded TL boards, were way below the strength specifications for Type 100 particleboard. On PF-bonded boards from TL and wood particles, Li-Jen et al. (2009) also



Source DF

LOW-DENSITY

MORMS

MOEMS

FHSMS

IBMS

WAMS

TSMS

MCMS

Corrected Model 3 99.41 1538418.11 113.95 15.57 947.95 32.03 4.98

Ratio 2 24.65* 2277735.71 ns 98.82** 2.80* 421.78** 30.53** 2.87**

Density 1 80.76* 1708513.83 ns 8.27 ns 5.41* 14.50 ns 2.08ns 0.05 ns

Error 20 4.28 870331.42 12.64 0.76 8.20 1.09 0.11

Corrected Total 23

R2 (%) 77.20 20.96 57.48 75.46 94.55 81.53 86.75

CV 19.76 91.67 23.74 33.44 6.32 30.77 6.64

MEDIUM-DENSITY

Corrected Model 3 191.35 2813266.53 347.06 6.32 301.76 8.93 2.26

Ratio 2 9.56 ns 4916.09 ns 268.05**

2.07** 26.93 ns 12.18 ns 2.87**

Density 1 498.88 ** 71335872.03** 56.65 ns 5.81* 889.18** 7.97 ns 0.07 ns

Error 20 15.85 59403.22 25.92 0.25 14.77 5.71 0.06

Corrected Total 23

R2 (%) 64.42 87.66 66.76 78.94 75.40 19.00 84.77

CV 19.34 11.31 21.76 34.81 10.84 42.60 4.53

Table 2. Summary of ANACOVA on properties of TL-WP composite boards.

** - highly significant * - significant ns – not significant

Table 3. Mean values of the different properties of TL-WP composite boards.

TL:WP

LOW-DENSITY

MOR, kg/cm2

MOE,kg/cm2

FHS,kgf

IB,kg/cm2 WA,% TS,% MC,%

30/70 12.56 a 1736.21 a 20.20 a 3.43 a 37.77 c 1.27 b 4.06 c

40/60 10.55 ab 760.84 b 15.34 b 2.77 a 42.89 b 2.22 b 5.06 b

50/50 8.30 b 555.91 b 9.39 c 1.62 b 58.27 a 6.68 a 6.16 a

TL:WP MEDIUM-DENSITY

30/70 21.78 a 2185.07 a 21.28 b 1.44 a 33.34 a 4.17 a 4.74 c

40/60 19.54 a 2143.99 a 18.08 b 0.90 b 37.04 a 6.64 a 5.67 b

50/50 20.47 a 2134.23 a 30.83 a 1.99 a 36.00 a 6.01 a 5.94 a

PF-bonded TL boards 10.76 2149.75 23.12 3.74 94.83 25.27 13.66

PNS 230-1989 Type 100 80 15000 30 2 none ≤ 20 5-13

Mean values with same letters (in a column) are not significantly different.

35

observed enhanced IB with less TL.

On the other hand, the boards’ physical and dimensional properties (MC, WA and TS) were much better. The hydrophobic property of the plastic component was manifested in the very low MC, WA and TS values. Here, the PF-bonded TL boards still failed.

In the medium-density group, ANACOVA has shown FHS, IB and MC to be significantly affected by material ratio (Table 2). However, only MC showed an increasing trend with decreased WP (Table 3). Compared to the low-density boards, MOR, MOE, TS and MC increased but IB decreased, even failing the PNS minimum limit.

Visual observation indicated that in the low-density boards, the WP was well molten up to the core. This was not true in the medium -density group. This should explain the increase in MOR and MOE resulting from a plasticized and densified surface, which might have prevented sufficient heating into the core layer, thus the decrease in IB due to incomplete melting of WP. The two-fold increase in TS values, specifically for 30/70 and 40/60 ratios may also be partly due to the greater swelling in the poorly-bonded core layer and partly to the greater volume of the hygroscopic TL.

It is unfortunate that a more thorough observation of the boards under a scanning

electron microscope (SEM) was not possible at the time of study. TL underwent physical extraction at the factory and the extent of change in its physical and chemical structure might have something to do with its reaction, in this case its ability to bond with resin, such as PF, or to bond with other materials, such as WP. In addition, the WP used was also a mixture of different types of plastic bags, though mainly LDPE. A micrograph that would show the “bond” between TL and PF as well as TL and WP should further explain the results of the study.

CONCLUSION AND RECOMMENDATION

• The study has produced composite boards from the mixture of TL and WP that warrant testing. The boards exhibit remarkable dimensional stability, low moisture content and low thickness swelling after 24-hr immersion in water, but poor strength properties. Thus, this type of board may be used for exterior but non-load bearing applications such as eaves’ ceiling and kitchen partitions.

•A thorough analysis on TL is necessary to better understand its properties and design its workability with other materials for certain end-product.

LITERATURE CITED

AGUINALDO E. 2012. Country Presentation. Republic of the Philippines. Second Meeting of the Regional 3R Forum in Asia.Kuala, Lumpur, Malaysia. Retrieved from <http://www.uncrd.or.jp/env/3r_02/presentations/BG2/2-5%20Philippines-2nd-3R-Forum. pdf.> on October 30, 2012

ATIENZA V. 2011. Chapter 5. Review of the waste management system in the Philippines. Initiatives to promote waste recycling and segregation through good governance. Economic integration and recycling in Asia. An interim report. Chosakenkyu Hokokusho. Institute of Developing Economies. Kojima and Michida, eds. Retrieved from <http://www.ide.go.jp/Japanese/Publish/Download/Report/2010/pdf/2010_431_05.pdf.> on October 29,2012.



BUREAU OF PRODUCT STANDARDS (BPS) 1989. Philippine National Standard (PNS 230:1989). Specifications for Particleboards. Department of Trade and Industry. Makati.

CABANGON RJ. 2010. Development of wood-wool cement plastic composite. Terminal Report. FPRDI-DOST Library, College, Laguna.

EMB-DENR (Environmental Management Bureau-Department of Environment and Natural Resources). 2012. Philippine Environment Partnership Program (PEPP). Retrieved from <http://www.emb.gov.ph/pepp/> on 29 October 2012.

DOLORES HC, FIDEL MM, MALLARI VC and NICOLAS AV. 2004. utilization of waste plastics as binder for plywood and particleboard production. Terminal Report. FPRDI-DOST Library, College, Laguna. 49 p.

DYNALAB CORP. 2013. Plastic properties of low-density polyethylene (LDPE). Retrieved from <http://www.dynalabcorp.com/technical_info_Id_polyethylene .as0> on 07 January 2013.

HOJO H, FUKAI K, NANJO F. 2001. Application of green tea catechins as formaldehyde scavengers. Retrieved from <http://www.o-cha.net/english/conference2/pdf/2001/files/ PROC/III-072.pdf.> on 09 January 2013.

LIJEN H, HONGDING S, TIENTIEN C, SONGLIN W and WUNJUENG H. 2009. Manufacture and properties of particleboards by mixing green tea leaves waste with wood-based particles. Abstract. Retrieved from <http://cabdirect.org/abstracts/20093360346.html;jsessionid=9FE948523789E7FFAA0E729FED58B2A1> on January 9, 2013.

JIN-SHU S, JIAN-ZHANG L, YONG-MING F, and HONG-XIA M. 2006. Preparation and properties of waste tea leaves particleboard. Abstract. Retrieved from <http://link.springer.com/article/10.1007/s11632-006-0008-5#page-1> on January 9, 2013.

UNEP (UNITED NATIONS ENVIRONMENTAL PROGRAM). 2012. Training module for the assessment of plastic wastes. Submitted to United Nations Environmental Program. Division of Technology, Industry and Economics, International Environmental Technology Centre Osaka/Shiga Japan. Retrieved from <http://www.unep.org/ietc/Portals/136/Other%20documents/Waste%20Management/Waste%20Plastic/WP_1_1_PlasticWaste_TrainingModule.> on November 5, 2012.

YALINKILIC MK, IMAMURA Y, TAKAHASHI M, KALAYCIOGLU H, NEMLI G, DEMIRCI Z, and OZDEMIR T. 1998. Biological, physical and mechanical properties of particleboard manufactured from waste tea leaves. International Biodeterioration and Biodegradation. Abstract. Retrieved from <http://www.sciencedirect.com/science/article/pii/S0964830598800103> on April 7, 2011

37

COMPARISON OF CHEMICAL PROPERTIES OF A CLIMBING BAMBOO [DINOCHLOA sp.] AND A SOLID BAMBOO [DENDROCALAMUS STRICTUS]

Maria Salome R. Moran1, Aimee Beatrix R. Habon1 and Alfinetta B. Zamora2

1Senior Science Research Specialist (ret.) and Science Research Specialist II, respectively


2ResearcherInstitute of Plant Breeding

UP Los Baños, College, Laguna 4031, Philippines

ABSTRACT

The chemical properties (ash, starch, 1% NaOH solubles, ethanol-benzene solubles and hot water solubles) of two lesser used bamboo species were analyzed to determine their end-use potential and compare them with other species.

Bikal (Dinochloa sp.), a climbing bamboo was collected from San Teodoro, Oriental Mindoro Province while Dendrocalamus strictus, an erect and tissue culture-derived solid bamboo, was collected from the Institute of Plant Breeding, College, Laguna.

Sampling at three height levels was done after four internodes. The samples were analyzed using TAPPI Standard Method of Analysis, and the internodes and nodes were analyzed separately.

Results showed significant variations in chemical composition within (at different culm heights, between culms, and between internodal and nodal portions of the culm) and between species.

Keywords: climbing bamboo, Dinochloa sp., Dendrocalamus strictus, chemical properties

INTRODUCTION

Across Asia, bamboo is extensively used as a raw material in the handicraft, furniture, and construction industries. Some Asian countries use bamboo in the manufacture of pulp and paper and other cheap disposable products such as skewers, chopsticks and joss paper for religious purposes (Abd. Latiff et al. 1992).

The chemical properties of bamboo vary according to species, growing condition, age, and part of the bamboo culm, as well as external factors such as topographical and seasonal effects (Abd. Razak et al. 1994).

Studies have shown that age influences the anatomical, physical and mechanical properties of some Philippine bamboos, with the 3-year-old culms being the most suitable



for maximum utilization in furniture-making and general construction work (Espiloy 1991).

Bikal (Dinochloa sp.) is a climbing bamboo, about 7.8 m tall with internodes 36.94 cm long and a diameter 3.56 cm wide (Espiloy et al. 2001). In terms of average culm wall thickness, bikal is sometimes observed to be almost solid (10.40 mm) at the basal part. On the average, its anatomical properties (fibrovascular bundle frequency, fiber length and diameter, lumen width, cell wall thickness, and length and diameter of vessel elements) do not significantly differ as sampled at every four internodes starting from the 2nd up to the 18th internode.

Similarly, its physical properties (moisture content, specific gravity and shrinkage characteristics) do not significantly differ as sampled at every four internodes interval along the culm. The mechanical properties (static bending, maximum crushing strength and shear value) of the different portions of the culm also do not vary significantly except for modulus of rupture (MOR). This indicates that the basal portion of the bamboo which is observed solid up to almost the middle of the culm, has higher maximum bending load than the top which has thinner culm wall.

Espiloy et al. (2001) characterized and differentiated the anatomical and physico-mechanical properties of young (1-year-old) and mature (5-year-old) solid bamboo. The young and mature culms are located at the outer and inner portions of the clump, respectively. Because they overcrowd inside the clump, the mature culms have smaller diameter, shorter internodes, shorter height, lesser internodes per culm and thinner culm wall than the younger ones.

Thus, all anatomical properties except for fibrovascular bundle frequency and vessel diameter of solid bamboo generally do not differ significantly between height levels and ages. With regards to the physical

properties, the 1-year-old bamboo has significantly higher moisture content and shrinkage values than the 5-year-old. Along culm height (butt, middle, top), there are no significantly variations in the physical properties for both ages.

Most of the mechanical properties of solid bamboo do not differ significantly with age and height level. The presence of nodes in the specimens does not affect significantly the maximum crushing strength and shear values both in height and age levels.

Roxas et al. (2003) reported that the butt portions of solid bamboo (untreated and treated with fungicide) are not stained by fungi after six months of exposure. The middle and top portions of treated samples are stain free, while those of the untreated samples are heavily stained on the first month. Both treated and untreated bikal culms are slightly attacked by staining fungi on the first week. Solid bamboo and bikal samples (untreated and treated with insecticide) are not attacked by powder-post beetle.

This study was conducted to determine the chemical properties of bikal and an erect and tissue culture-derived solid bamboo species; and to determine the end-use potential of the two bamboo species.

MATERIALS AND METHODS Materials

Four culms each of mature bikal and solid bamboo were collected from San Teodoro, Oriental Mindoro Province and Institute of Plant Breeding, College, Laguna, respectively. Sampling was done at every 4- internode interval starting from the 2nd internode at the lower portion up to the 13th internode at the upper portion. The 4-internode interval taken at three height levels represented the butt, middle and top

39

portions. The internodes and nodes were analyzed separately.

Methods

The starch content of the ground samples was determined using the method developed by Humphrey and Kelly (1961). Other chemical components were analyzed using the Technical Association of the Pulp and Paper Industry (TAPPI) Test Method (TAPPI 1944-1995).

The test methods used in the analysis are listed below. All computations were based on the oven-dry weight of the sample.

• Moisture content (T264 om-88)

• Ash (TAPPI T211 om-85)

• 1% Sodium hydroxide solubility (TAPPI T212 om-88)

• Ethanol-benzenesolubility (TAPPI T204 om-88)

• Hot water solubility (TAPPI T207 om-93)

• Starch - The procedure used was a calorimetric method which depends ultimately on the reaction of the amylase in the sample with iodine. A standard reference curve was obtained using A.R. potato starch wherein varying quantities of starch were weighed and treated using the following procedure.

The sample was treated with 7.2M perchloric acid to react for 10 min, transferred to a 50-ml volumetric flask, and diluted with distilled water up to the 50-ml mark. The solution was centrifuged and a 10-ml aliquot was placed in a 50-ml volumetric flask together with a drop of phenolphthalein and made alkaline with sodium hydroxide.

Acetic acid was added to discharge the color, followed by 10% potassium iodide and 0.1N potassium iodate. The color was allowed to develop for 15 min brought to volume

with distilled water and the absorbance measured at 650 nm using a blank prepared without starch. The percentage starch was calculated based on the standard reference curve.


NaOH Solubles

The internodes at the butt or top of bikal had the highest 1% NaOH solubles, while the nodes at the butt gave the highest value (Tables 1 & 2). The difference in the results obtained between the internodes and nodes could be due to the different ages of the four bikal culms used. With solid bamboo, the internodes at the top had the highest 1% NaOH solubles (Table 3).

Abd. Latiff and Khoo (1994) found that 1% NaOH solubles of 3-year-old G. scortechinii increase significantly from the butt to the top portion with the top having the highest value. This is attributed to the photosynthetic process in the upper culm.

Variations between culms and at different culm portions for both species were significant (Tables 5 & 6). Bikal internodes had significantly higher alkali solubles than the nodes. Between species, the alkali solubles were not significantly different (Table 7).

The 1% NaOH solubles contents of bikal and solid bamboo (27.64% and 27.84%), respectively, were higher than that of wood’s (16.9%). Malaysian (19.2 - 26.8%), Chinese (26.91 - 35.32%) and other Philippine erect (22.3 - 39.52%) bamboo species have also high level of 1% NaOH solubles.

High alkali solubles content is an inherent characteristic of bamboo which can be associated with the level of carbohydrate content or degree of cellulose degradation. This can result in lower pulp yield and higher

Maria Salome R. Moran, et al. .


Culm Portion1%NaOHSolubles

%Ash%

Alcohol-BenzeneSolubles

%

Hot waterSolubles

%Starch

%

1

ButtMiddleTopAverage

27.0027.0227.9027.30

3.563.542.74

3.28

3.152.962.052.72

8.918.748.388.68

0.460.370.300.38

2


31.1729.8830.0530.37

3.363.042.913.10

2.362.752.732.61

9.439.199.539.38

0.670.140.150.32

3


26.9626.3225.4726.25

3.293.302.252.95

2.422.301.432.05

8.358.077.848.09

0.170.110.160.15

4


29.0228.0629.4428.84

3.924.775.334.67

1.942.252.082.09

11.2210.2010.7710.73

0.180.110.120.14

Average of 4 culms 3.50 28.19 2.37 9.22 0..25

Table 1. Chemical properties of bikal internodes at different culm portions

Culm Portion1%NaOHSolubles

%Ash%


%

Hot waterSolubles

%Starch

%

1


26.2725.7225.9025.96

1.902.042.082.01

2.152.212.472.28

6.316.636.446.46

0.290.380.320.33

2


31.1129.1927.9429.41

-2.432.152.29

2.302.382.012.23

8.007.185.086.75

0.400.370.780.52

3


26.3724.0725.1625.20

1.761.581.681.67

2.512.301.892.23

7.075.165.625.95

0.260.210.09

4


-26.3929.1427.77

----

2.362.061.582.00

8.856.938.167.98

0.160.180.200.18

Average of 4 culms 1.99 27.09 2.19 6.79 0.31

Table 2. Chemical properties of bikal nodes at different culm portions

41

Table 3. Chemical properties of solid bamboo internodes at different culm portions

Culm Portion

1% NaOH

Solubles%

Ash%


%

Hot waterSolubles

% Starch%

1


28.2328.4325.7027.45

6.557.426.426.83

6.505.614.645.58

11.8611.309.7210.96

0.601.051.521.06

2


25.1226.8427.2726.41

3.964.724.864.51

5.364.173.604.38

10.9611.0511.0211.01

0.330.200.230.25

3


29.6030.1432.7430.83

10.089.359.829.75

4.144.785.744.89

8.959.1211.429.83

0.230.170.630.34

4


26.2426.8426.9126.66

6.246.126.236.20

5.644.353.314.43

10.439.788.639.61

0.290.330.230.28

Average of 4 culms 6.82 27.84 4.82 10.35 0.48

Culm Portion Ash%


%

Hot waterSolubles

%Starch

%

1


4.965.606.505.69

-3.542.613.08

-9.728.489.10

1.111.832.301.75

2


2.823.003.703.17

2.582.99

-2.79

7.767.77

-7.77

0.170.560.690.47

3


6.685.606.906.39

3.112.78

-2.95

8.978.60

-8.79

0.500.982.571.35

4


4.234.424.724.46

3.382.51

-2.95

8.228.54

-8.38

0.400.440.540.46

Average of 4 culms 4.93 2.94 8.51 1.01

Table 4. Chemical properties of solid bamboo nodes at different culm portions.



alkali demand in chemical pulping. Hot 1% NaOH solution extracts low molecular weight carbohydrates consisting mainly of hemicellulose (TAPPI 1995). High level of alkali solubles may mean high degree of fungal decay or cellulose degradation. The alkali solubles content increase as the material decays or degrades.

Ash Content

Increasing ash content of the nodes from the butt to the top of the culm was observed for solid bamboo (Table 4). The internodes and nodes of both bikal and solid bamboo differed significantly in ash content within (at different culm portions) and between culms (Tables 5 & 6). In both species, the internodes had higher ash content than the nodes. Bikal’s average ash content was significantly lower than that of solid bamboo (Table 7).

The ash contents of bikal (2.75%) and solid bamboo (5.86%) were higher than those of Chinese bamboo, Phylostachys pubescens (1.1 - 1.2%), the commonly used monopodial bamboo for making machine-intensive products such as skewers and chopsticks in Taiwan and China and those of Malaysian

bamboo, 1-3-year-old G. scortechiinii (1.09 - 1.18%) used in making incense sticks in Peninsular Malaysia (Abd. Latiff & Khoo 1994). The ash contents were comparable with other Philippine erect bamboo species (2.4 - 9.7%).

Ash represents the non-volatile, non-combustible inorganic matter of the raw material and is a measure of the mineral salts and other inorganic matter (TAPPI 1995). High ash content is undesirable if the material is to be used for making machine-intensive products and dissolving pulp.

Alcohol Benzene Solubles

Alcohol-benzene mixture extracts fats, waxes, some resins and some portions of wood gums (TAPPI 1995). The internodes at the butt portion gave the highest alcohol-benzene soluble content among the different portions of the solid bamboo culm (Table 3). The alcohol-benzene solubles of bikal and solid bamboo varied significantly at different culm portions but not between culms (Tables 5 & 6).

Bikal internodes (2.37%) had comparable alcohol-benzene solubles with the nodes

Source of Variation

Degree of Freedom

Mean squares and statistical significance

Ash%

1%NaOHSolubles

Alcohol-benzene solubles

Hot water solubles Starch

Internodes Culm Portion (culm) R2 (%) CV

38

6.16**0.80**95.965.93

26.88** 1.33**

95.37 1.57

1.08** 0.54**

75.11 13.6

11.66** 0.32ns

74.47 8.12

0.14ns

0.08** 83.79 36.74

Nodes Culm Portion (culm) R2 (%) CV

38

0.47**0.03** 97.86 2.81

31.60** 4.15**

98.84 0.99

0.18ns

0.27** 61.51 12.0

6.70ns

2.78** 99.24 1.78

0.22** 0.05**

90.20 22.64

Table 5. Summary of ANOVA on the chemical properties of bikal

**highly significant at α = 0.01 *significant at α = 0.05 ns-not significant

43

Source of Variation

Degree of

Freedom

Mean squares and statistical significance

Ash 1% NaOHSolubles

Alcohol-benzene Solubles

Hot water Solubles Starch

Internodes Culm Portion (culm) R2 (%) CV

38

38.71** 0.49**

99.94 0.92

26.11* 3.73**

99.04 0.93

2.69ns

2.41** 80.26 12.02

4.08ns

2.36** 95.00 2.75

1.34* 0.21**

98.19 13.75

Nodes Culm Portion (culm) R2 (%) CV

38

12.04** 0.68**

99.18 3.44

-

0.06ns

0.47** 83.15 7.77

1.32ns

0.45** 97.27 1.67

3.79ns

1.21** 97.20 15.73

**highly significant at α = 0.01 *significant at α = 0.05ns-not significant

Table 6. Summary of ANOVA on the chemical properties of solid bamboo.

Species Portion 1% NaOHSolubles

%Ash%


%

Hot waterSolubles

%Starch

%

BikalInternodesNodesAverage

28.19a

27.09b

27.64

3.50a

1.99b

2.75

2.37a

2.19a

2.28

9.22a

6.79b

8.01

0.25a

0.31a

0.28

Solid bamboo

InternodesNodesAverage

27.84-

27.84

6.82a

4.93b

5.86

4.82a

2.94b

3.88

10.35a

8.51b

9.43

0.48b

1.01a

0.75

Table 7. Mean values of the chemical properties of internodes and nodes of bikal and solid bamboo

(2.19), while solid bamboo internodes (4.82%) had significantly higher alcohol-benzene solubles content than the nodes (2.94%). Bikal (2.28%) and solid bamboo (3.88%) had low levels of alcohol-benzene extractives which were within the range of values for Malaysian (1.7 - 4.5%), Chinese (3.88 - 9.11%), and Philippine erect (3.1 - 5.4%) bamboo species.

Hot Water Solubles

The hot water solubles include tannin, starch, sugar, pectin, and phenolic compounds within the woody materials. Abd. Latiff

et al. (1992) reported that the amount of hot water soluble is also related to mold, fungal and insecticidal infestation and may influence the durability of bamboo. The amount of water-soluble materials is higher in the dry season than in the rainy season (Abd. Latiff et al. 1995).

The hot water solubles contents of bikal internodes and nodes were highest at the butt of the culm (Tables 1 & 2). These significantly varied across culm portions (for nodes) and between culms (for internodes) while those of solid bamboo internodes and nodes varied across portions and not between

For each property and for each species, means with the same letter are not significantly different at α = 0.05



culms (Tables 5 & 6). The internodes of bikal and solid bamboo had significantly higher hot water solubles than the nodes (Table 7).Bikal had lower water solubles content (8.01%) than solid bamboo (9.43%). Solid bamboo’s hot water solubles were higher (9.43%) than those of Malaysian (3.7 - 8.5%) and Philippine erect bamboo (3.4 - 5.12%) but both species’ hot water solubles contents were within the range of values for Chinese bamboos (5.41 - 15.94%).

Starch

The amount of starch also influences bamboo’s durability and service life. The starch content of bikal internodes varied significantly at different culm portions while those of the nodes differed significantly across portions and between culms (Table 5). The internodes (0.25%) and nodes (0.31%) of bikal had comparable starch values.

Solid bamboo internodes varied significantly at different portions of the culm and between culms while the nodes differed only at the culm (Table 6). The nodes of solid bamboo showed increasing starch content from the butt to the top (Tables 3 & 4), and had significantly higher values than the internodes. Between species, bikal (0.28%) had significantly lower starch content than solid bamboo (0.75%) (Table 7).

A study on Malaysian bamboos B. vulgaris and B. blumeana, Gigantochloa levis (Blanco) Merr (1.14 – 8.66%) showed that as the culms matured from one to three years, the starch content increases, with the 3-year-old having the highest amount of starch (Abd. Latiff et al. 1992). The starch content of bikal (0.28%) and solid bamboo (0.75%) were much lower than those of 3-year-old Malaysian bamboos (1.14 – 8.66%).

Low starch content of the two bamboo species indicated less susceptibility to infestations as found by Roxas et al. (2003)

in their studies where the treated and untreated bikal and solid bamboo samples were not attacked by powderpost beetles after six months of exposure. This indicates the need for milder preservation treatment of these bamboo species should they be used for furniture and handicraft products.

The significant differences in chemical properties of bikal and solid bamboo observed within and between species concur with the results of Liese (Abd. Latiff et al. 1992) that bamboo’s chemical composition may vary according to species, age, culm height, growing conditions, and topographical and seasonal effects.

Based on the results obtained, bikal and solid bamboo are potential materials for pulp and paper production due to their similarity in chemical properties (except for ash content of solid bamboo) with Chinese bamboos that are extensively used for pulp and paper production in China. Both species are also suitable for furniture and handicraft production due to their low starch content that would make them less susceptible to insect attack.


• There are significant variations in chemical composition of bikal and solid bamboo within (culm height, between culms and between internodes and nodes and between species).

• Bikal internodes have significantly higher ash, 1% NaOH solubles, alcohol-benzene and hot water solubles content than the nodes, while solid bamboo internodes have higher ash, alcohol-benzene solubles and hot water solubles than the nodes.

• The average chemical properties of bikal (ash, alcohol-benzene

45

solubles, hot water solubles and starch content) are significantly lower than those of solid bamboo.

• Bikal and solid bamboos are comparable in chemical properties with Philippine erect bamboo species except for hot water solubles.

• The similarity in chemical properties of bikal and solid bamboo with

Chinese bamboos that are widely used for pulp and papermaking makes them potential materials for pulp and paper production.

• Both species are suitable materials

for furniture and handicraft production as they have low starch content that will make them less susceptible to insect attack.

LITERATURE CITED

ABD. LATIFF M, KHOO KC and ALI NA. 1992. Carbohydrates on some natural stand bamboos. J. Tropical For. Sci. 4(4): 310-316.

ABD. LATIFF M and KHOO KC. 1994. Fiber morphology and chemical properties of

Gigantochloa scortechiinii. J. Tropical For.Sci. 6(4): 397-407.

ABD. RAZAK, ABD. LATIFF M, LIESE W and HARON. 1995. Utilization of bamboos. Part III. Planting and utilization of bamboo in Peninsular Malaysia. Research Pamphlet. No. 118. pp. 50-60.

ESPILOY ZB. 1982. Silica content in spiny bamboo Bambusa blumeana, (Blume) ex Schultes]. NSTA Technology Journal. Oct-Dec. pp. 38-43.

ESPILOY ZB. 1991. Effect of age on the physico-mechanical properties of some Philippine bamboos. Presented in the 4th International Bamboo Workshop in Changmai, Thailand.

ESPILOY ZB, MARUZZO M, CAYABYAB P, ZAMORA AB and RODIS G. 2001. Physico-mechanical properties and anatomical structure relationship of bikal and solid bamboo. Terminal Report. FPRDI, College, Laguna.

HUMPHREYS EFR and KELLY J. 1961. A method for the determination starch in wood Anal. Chem. Acta 24: 66-70.

ROXAS ML, REYES AV, ESPILOY ZB, TAMAYO JP, SAN PABLO MR and CAYABYAB P. 2003. Resistance of bikal and solid bamboo against staining fungi and powder-post beetles. Terminal Report. FPRDI, College, Laguna.

TECHNICAL ASSOCIATION OF THE PULP AND PAPER INDUSTRY TEST METHODS. 1994-95. TAPPI Press. Atlanta, GA.



PRELIMINARY STUDY ON THE SUITABILITY OF SOME INDUSTRIAL TREE PLANTATION SPECIES

AND FRUIT TREES FOR FRUIT WINE BARREL

Simplicia B. Katigbak, Ceazar A. Cuarezma, Erlinda L. Mari and Robert A. Natividad

Senior Science Research Specialist, Senior Science Research Specialist, Scientist I & Chief Science Research Specialist, respectively


ABSTRACT

Three industrial tree plantation species (ITPS), namely big-leafed mahogany (Swietenia macrophylla King), river red gum (Eucalyptus camaldulensis) and mangium (Acacia mangium), and two fruit trees, namely santol [Sandoricum koijape (Burma) f.] and mango (Indian)(Mangifera indica) were evaluated for their suitability as wood material for fruit wine barrel.

Staves from the five species were fabricated into 15 L capacity barrels wherein laboratory-prepared pineapple wine was aged for 2 weeks. The aged wines, together with water aged similarly in separate barrels, were first subjected to sub-chronic toxicity test on rats, which included histopathological examination of the rats after the test. The organoleptic or sensory test by wine tasters followed immediately.

The sub-chronic toxicity test ended in zero mortality. Analyses of the rats’ blood chemistry specifically blood urea nitrogen (BUN), creatinine (CREA) and alanine aminotransferase (ALT) before and after the test generally showed no significant difference among species, except for the BUN of rats in the water set for big-leafed mahogany. Histopathological analysis of the animals’ kidneys and livers, however, showed none to only mild lesions for all treatments.

Except for the wines’ color and clarity, the organoleptic test revealed that generally there were no significant differences among wood species as wine barrels. Santol did not change the wine’s color, while mahogany imparted the darkest color, followed by Acacia mangium. Mango, on the other hand, caused the most turbidity while santol the least. Nonetheless, all the aged wines including the control were rated moderately acceptable.

Keywords: industrial tree plantation species, Swietenia macrophylla King, Eucalyptus camaldulensis, Acacia mangium, fruit trees, Sandoricum koetjape (Burma) f , Mangifera indica, wine barrel


47Simplicia B. Katigbak, et al. .

INTRODUCTION

A barrel or cask is a hollow cylindrical container traditionally made of assemblies of staves (curved wooden members) and bound with iron wire or strap steel hoops. The primary and original purpose of barrels is for storage and transport. In wine-making, however, the flavor imparted to wine during storage in the barrel is also considered essential (Mosedale & Puech 1998).

There are two distinct methods of constructing barrels, namely; American and European. The American barrel makers use kiln-dried wood while the European or French coopers always air-dry (season) the wood for 10 to 36 months. Moreover, the French barrel makers split the wood along the grain to make the staves while the Americans produce staves by sawing the wood.

Dharmadhikari describes that wooden staves for wine barrels “should be straight- grained, strong, resilient, free of defects, easy to work/bend and do not contribute undesirable flavor”. He claims that only oak wood possesses the wood structure and chemical composition to satisfy these qualities.

The large, multiseriate medullary rays of oak wood make it tough, resilient and dimensionally stable. Further, the wood is essentially impervious to movement of liquid due to tyloses that plug the pores. On the other hand, phenols within the wood interact with the wine to produce vanilla-type flavors. The time or aging spent in the barrel is considered essential to the taste and aroma of the aged wine (Mosedale & Puech 1998).

Dharmadhikari further reports of earlier attempts to use other wood species for wine barrels such as redwood, Douglas fir, spruce, and pine. Being conifers, these impart a resinous flavor to wine. If these were to be used, the inside of the barrels would have to be coated with wax or another material.

Similarly, the more porous red oak, ash, gum and chestnut also need to be coated to prevent leakage. Other suitable wood species include maple and cherry wood, which have an off-putting smell; acacia, which imparts yellow tint to wine, and rauli (Nothofagus alpina), which also gives off a musky scent to wine .

According to Simon (2009) extracts from the wood of acacia, European ash, American ash, chestnut, cherry and three oak species (Quercus pyrenaica, Quercus alba and Quercus petraea) contain the volatile composition that may give characteristic flavors to wines. In the Philippines, an organoleptic test as well as chemical and gas chromatographic analyses of kasoy (Anacarduim occidentale) wine aged in barrels from almon (Shorea almon Foxw.) and bagtikan (Parashorea plicata Brandis) gave results comparable to oak. This BPI-FORPRIDECOM (now FPRDI) cooperative project reported that bagtikan is a promising substitute to oak (Laroya et al. 1975). Classified as commercial timbers in the country, almon and bagtikan belong to the “Philippine Mahogany group” or prime dipterocarp timbers which comprise the bulk of logs harvested from the natural growth forests (Kochummen et al. 1993, America et al. 1993). With the implementation of Executive Order No. 23, there has been moratorium on the harvesting of timber from natural-growth forests in the Philippines since February 2011.

In early 2007, the Department of Science and Technology (DOST) launched a national program on tropical wines and spirits to bridge the disparity between supply and demand ( Veluz & Guevarra 2007). The DOST noted the inadequacy of local wine-making barrels despite the prospect of increasing wine consumption.


Since the early 1970s, the same problem was identified by the local fruit wine-makers - the need for locally available wooden barrels for the aging of wine.

At present, local fruit wine-makers use glass and plastic containers to ferment and age fruit wines. Accordingly, the quality and taste of wine produced are far from that of oak wine barrel. Despite the general belief that glass-lined containers will eventually displace wooden barrels in fruit wine and liquor production, brew masters still believe that wooden containers are best for high quality products.

This study evaluated the suitability of industrial tree plantation species (ITPS) and fruit trees for fruit wine barrel. The cost of fabricating the wine barrels was also estimated.


Wood from three ITPS, namely: big-leafed mahogany (Swietenia macrophylla King), river red gum (Eucalyptus camaldulensis Dehnh.) and mangium (Acacia mangium Willd.), and two fruit trees, namely, santol [Sandoricum koetjape (Burma) f.] and Indian mango (Mangifera indica) were selected based primarily on their availability and partly on their having moderately straight grain and multi-seriate rays.

Barrel Production

One log each of the five tree species was cut and sawn into 6.5 cm and 2.5 cm thick pieces for the stave and cover, respectively. The lumber pieces were piled with 2 cm x 3 cm spacers then air-dried to about 45% moisture content (MC). These were then kiln-dried in a 2.35-m3 capacity furnace-type lumber dryer to a final MC of 12%.

Using a table saw, jointer planer, thickness planer, sandpaper and bandsaw, 20 staves (45.72 cm long x 5.71 cm thick) were

prepared per 15 L capacity barrel (Fig. 1). For the barrel’s cover, 2.2 cm thick x 24.1 cm diameter lumber pieces were prepared using a band saw and wood lathe.

To assemble the staves into barrels, ring binders were prepared from flat bars, 1.2 mm thick x 1.27 cm wide. Twenty staves were arranged inside the ring binder to form a barrel. Top and bottom cover were positioned at their respective slots before fitting. The barrels were formed by forced-fit jointing system, (without using glue or nail).

Fig. 1. Band sawing of dried lumber into uniform staves.

49

The barrels were rinsed with tap water to remove dust, then partially filled (1/3) with tap water. Into each barrel, citric acid (1 g/L of water) and sodium metabisulfite (0.25 g/L of water) were then added. The barrels were left to stand until the head was tight, and then turned for the other head.

The barrels were then laid horizontally on blocks and filled with tap water until they were tight or swollen enough and did not leak. This took about five days. To further ensure the barrels would not leak, these were coated with paraffin wax. After this, the barrels were drained and rinsed with filtered mineral water.

Aging of the Fruit Wine

Fruit wine (Fig. 2) was prepared from fresh pineapples at the laboratory of the Institute of Food Science and Technology (IFST), University of the Philippines Los Baños. The fabricated wooden barrels were brought to the IFST laboratory and filled with the fruit wine. Three barrels per species were filled with the wine; one barrel per species was filled with purified water. These were left for the contents to age for 14 days (Fig. 3), after which samples for organoleptic and sub-chronic toxicity tests were taken through the bung holes. Control wine and control purified water came from plastic jars.

Sub-Chronic Toxicity Test

Sixty female Wistar rats were purchased from the Department of Science and Technology- Industrial Technology Development Institute (DOST-ITDI) Laboratory Animal Resource Center, Bicutan, Taguig City, Philippines. Acclimatization was done for seven days at the Biological Research and Testing Facility of ITDI before the conduct of the study.

The rats were divided into 12 groups, with five rats per group. Six groups were administered the aged fruit wines; the other six, the barrel-stored water. All rats were given 1 mL each of the sample or control daily for 28 days.

Fig. 2. Pineapple wine

Fig. 3. Aging of wine in the barrels

Simplicia B. Katigbak, et al. .


Blood samples were collected before and after the 28-day test. The rats were fasted for 14 to 16 hr prior to blood collection. The blood samples were analyzed for blood urea nitrogen (BUN), creatinine (CREA), and alanine aminotransferase (ALT) following the dry chemistry slide method using Vitros 250 Clinical Chemistry Analyzer (Ortho-Clinical Diagnostics, USA).

After the last day of dosing, the rats were euthanized using the carbon dioxide suffocation method. The liver and kidney were taken and fixed with 10% buffered formalin and the tissue processed and evaluated by a veterinary pathologist.

Histopathological findings were rated as follows:

No lesions 1Mild 2

Mild to moderate 2.5

Moderate 3

Moderate to severe 3.5

Severe 4

Organoleptic Evaluation of Aged Wines

Quality scoring of the aged wines was conducted by a panel of 15 wine tasters immediately after the results for sub-chronic toxicity test were made available. Samples were placed in identical containers with three-digit random code numbers and presented to each panelist in random order.

The panelists were asked to evaluate each sample and indicate the perceived intensity of the specified attribute by writing the code number of the sample on the appropriate point in the scale. The test was conducted in three replications.

Seven quality attributes, namely: color, bitterness, sweetness, clarity, flavor,

Color 1 = Extremely pale yellow 9 = Extremely dark yellow

Bitterness 1 = Very weak 9 = Very strong

Sweetness 1 = Very dry 9 = Very sweet

Clarity 1 = Very cloudy 9 = Very clear

Flavor 1 = Weak alcoholic taste 9 = Strong alcoholic taste

Aftertaste 1 = Not perceptible 9 = Highly perceptible

Gen. Acceptability 1 = Highly unacceptable 9 = Highly acceptable

aftertaste, and general acceptability were each scored on a 9-point scale as follows:

Data Analysis

Data (difference before and after) in BUN, CREA and ALT from the toxicity test were analyzed using ANOVA in CRD followed by DMRT. Histopathy data served to indicate physical observation on the toxicity of the aged wines. Data from the wine and water sets were separately analyzed.

Scores on the seven quality attributes from the organoleptic test were statistically analyzed using Kruskal-Wallis Test followed by Duncan Multiple Range Test (DMRT).

Results of both tests were used to evaluate the effect of wood species on the quality of the wines and the corresponding effects on the health of the rats.

Estimated Cost of Barrel Production

The cost of producing fruit wine barrel was estimated based on the amount and cost of materials used ( wood, metal hoops, jigs ) and cost of labor.-


Basic Comparisonof the Wood Species

Available literature indicated that the properties of the five wood species seem to be no match to the properties of oak wood (Table 1), particularly its straight grain.

51

SpeciesSpecific Gravity

Grain Rays TylosesWater

Solubles (%)

Reference

Oak (Quercus alba)

0.75 Straight

Medullary,

multiseriate, 19-

32% of volume of

wood

Pores

plugged

with

tyloses

5-10

D.Dharmadhikari

http://www.extension.

iastate.edu/NR/

rdonlyres/173729E4-

C734-486A-AD16-

778678B3E1CF/73970/

WoodenCooperage.pdf

Big-leafed Mahogany (Swietenia macrophylla)

0.5-0.85

Interlocked

;sometimes

straight

(1-)3-4-seriate;

prismatic

crystals present

Tyloses

absent 6.88-7.52*

S. Prawirobatmadjo,

et al. Swietenia. In:

PROSEA 1993. Timber

Trees. Major Commercial

Species;

*Torres et al. 2013

River red gum (Eucalyptus camaldulensis)

0.90-0.98Straight to

interlocked1-3-seriate

Moderate

to very

abundant4.16**

D. Lamb et al.

Eucalyptus. In: PROSEA

1993. Timber Trees.

Major Commercial

Species;

** Mabilangan &

Decena 2002

Mangium(Acacia mangium Willd.)

0.45

Straight to

shallowly

interlocked

1-2(-3)-seriate;

prismatic

crystals in

chambered

parenchyma

strands

Tyloses

absent 2.03***

F. Arentz et al. Acacia.

In: PROSEA 1993.

Timber Trees. Minor

Commercial Species;

***Fidel & Tamayo 1999

Santol(Sandoricum koetjape)

0.29-0.59

Straight

or slightly

wavy

Rays moderately

fine, barely

visible to the

naked eye-

S. Idris. Sandoricum. In:

PROSEA. Timber Trees.

Lesser Known Timbers.

1998

Mango (Mangifera indica)

0.41-0.80Somewhat

wavy

1-3-seriate;

prismatic

crystals

Tyloses

commonly

present-

E. Boer et al. Mangifera.

In: PROSEA. Timber

Trees. Lesser Known

Timbers. 1995

Table 1. Comparison of some physical properties and water solubles (%) of oak and the five wood species studied

As to rays, all the five species appeared to be multi-seriate. Tyloses, which are said to be important for oak barrels, are also present in river red gum and mango but absent in big-leafed mahogany and mangium, while gum-

like deposits are reported for santol. Among the species, santol may be the lightest (sp. gr = 0.29-0.59, Idris 1998) and river red gum, the heaviest (sp. gr. = 0.90-0.98, Lamb et al. 1993).



For chemical composition, oak was noted to have bigger amounts (5-10%) of water extractives than big-leafed mahogany (6.88-7.52%) and the locally-grown mangium (2.03%) and river red gum (4.16%).

In the case of santol and mango, information gathered was limited to reports on the anti-cancer, anti-inflammatory, and anti-oxidant activity of some extracts from their stems, barks and/or leaves (Kaneda et al. 1992, Rasadah et al. 2004, Nuñez et al. 2002, Rodeiroa et al. 2006, Barreto et al. 2008). This may suggest similar properties in the wood albeit at different levels.

Effect of Wood Species on Wine Quality

Sub-chronic toxicity evaluation. Rats and mice have been used as substitutes for humans/mammals in toxicological tests due to physiological, biochemical and anatomical similarities (Rhomberg & Lewandowski 2004). In this study, the toxicity test was completed with zero mortality. Figure 4 shows the average values of the BUN, CREA and ALT of the rat subjects before and after the 28-day toxicity test. Normal levels of BUN, CREA and ALT for humans are reported at 8-23 mg/dL, 0.7-1.3 mg/dL, and 5-60 IU/L, respectively (http://www.thebody.com/content/ art14473.html). In healthy rats, BUN, CREA and ALT are about 15-21mg/Dl, 0.2-0.8mg/dLand17.5-30.2 IU/L, respectively (http://www.ratfanclub.org/values.html).

At the outset, the test rats had BUN values lower (8.4-12.2 mg/dL) and ALT values higher (41-52 IU/L) than the reported normal values for rats but which are within the normal range for humans. The CREA values, however, are within the rats’ normal range.

The concern was on the level of change due to the administration of the experimental wines to the rats.The graphs indicate increases in average values after the toxicity test except for the ALT of rats served with water.

BUN and creatinine are both by-products of metabolism in the body manifested in the blood or serum. Both are indicators of kidney function. BUN is formed as the body gets rid of ammonia from protein break up while creatinine is a protein produced by muscle and released into the blood (Hosten 1990).

An increase in BUN from the normal values may indicate renal disease, while a decrease may suggest a malabsorption state or even liver damage, among others (http://www.austincc.edu/mlt/chem/clinicalsignificancelabtestguide.pdf).Serum creatinine may vary by about 10% margin of error and further due to dehydration or other illnesses (Hosten 1990).

ALT, on the other hand, is an enzyme which is a measure of damage in the liver. Increases in the normally low ALT level in the blood are usually attributed to liver damage (http://www.webmd.com/digest ive-disorders/alanine-aminotransferase-alt) or necrosis of hepatocytes (liver cells) (http://www.austincc.edu/mlt/chem/clinicalsignificancelabtestguide.pdf). A decrease is typically dismissed as being of no toxicological significance. Nonetheless, analysis of statistical significance of values obtained is suggested (May_2007.pdf).

Results of ANOVA based on the change in values in the rats’ blood chemistry generally showed no significant difference among species, except for the BUN of rats in the water set (Table 2). The very low R2 in all parameters measured indicates large variation in the treatment means (Tables 3 & 4).

Although not statistically significant, a closer look at the BUN data in Table 3 revealed

53

Source of Variation

dF

Mean Squares

Wine Water

BUN CREA ALT BUN CREA ALT

Barrel Material 5 33.553 ns 0.0181 ns 139.953 ns 108.901* 0.0046 ns 49.92 ns

Error 24 24.016 0.0073 86.717 32.527 0.0039 72.02

Corrected Total 29

R2 (%) 22.54 34.00 25.16 43.21 20.96 15.43

CV 43.89 6.22 115.92 48.24 60.60 -92.24

s – not statistically significant at α = 0.05* - statistically significant at α = 0.05

* - statistically significant at α = 0.05

Table 2. ANOVA on the difference between baseline and endline values of BUN, CREA and ALT of Wistar rats after the 28-day toxicity test

Fig. 4. Effect of wood species on the rats’ of blood chemistry.

Note: Each value is the average of three replicates with five observations per replicate. In healthy rats, BUN,CREA and ALT are about 15-21mg/Dl,0.2-0.8mg/dL and17.5-30.2IU/L,respectively (http://www.ratfanclub.org/values.html).



Table 3. Treatment means (difference between baseline and endline values) of BUN, CREA and ALT of Wistar rats after the 28-day toxicity test

SPECIES BUN BUN CREA ALT

Big-leafed mahogany 10.20 0.14 2.80

River red gum 13.20 0.18 12.40

Mangium 11.60 0.16 9.80

Santol 6.80 0.06 8.20

Mango 11.00 0.06 14.20

Control 14.20 0.20 0.80

F-Value 1.40 ns 2.47 ns 1.61 ns

ns - not significantly different

In Table 4, water from the big-leafed mahogany barrel caused the largest difference in BUN value. This was followed by river red gum and santol, at the same level with the control. The use of barrel-stored water was an attempt to eliminate the effect of wine and somehow find how the barrels’ leaching into water would affect the test rats.

Inspecting the average values, big-leafed mahogany, river red gum, santol and the control plastic jar consistently caused a large increase in BUN, whether with wine or water; while mangium, and mango had

interchanging effects. This implies that the wine and any leaching from the barrel may have had some blending which altered the properties of the wine. Such effects were not very evident on CREA.

However, the ALT values increased with wine (Table 3) but decreased with water (Table 4). As earlier mentioned, an increase in ALT may indicate liver damage while a decrease may be of no toxicological significance (http://www. pesticides. gov.uk/Resources/CRDMigrated-Resoues/Documents/alt_ast_v8_May_2007.pdf).

SPECIES BUN CREA ALT

Big-leafed mahogany 18.80 a 0.12 -11.00

River red gum 14.60 ab 0.08 -8.80

Mangium 7.80 bc 0.08 -8.80

Santol 12.00 Abc 0.12 -9.00

Mango 5.80 C 0.08 -5.20

Control 12.00 Abc 0.17 -18.00

F-value 3.35 * 1.17 ns 0.69 ns

For each parameter, means followed by the same letters are not significantly different at α= 0.05* - significant at α = 0.05ns - not significantly different

Table 4. Treatment means (difference between baseline and endline values) of BUN, CREA and ALT of Wistar rats after the 28-day toxicity test (using the barrel-stored water)

55

Other than the above analyses, pathologists normally refer to histopathological analysis for an evaluation of the effects of substances on test animals. The histopath report (Table 5) on the rats’ kidneys and livers shows none to only mild lesions for those in the water set and mild lesions for those in the wine set, including the controls.

Thus, whether using wooden or plastic containers, wine would have generally a similar level of effect. Among the species studied, it appears that mangium had the least adverse effect on the liver while river red gum and santol had further impact on the kidney. Incidentally, Australian wine makers had used acacia wood for wine barrels (Dharmadhikari undated).

It is rather difficult to correlate the results obtained with secondary information on the chemical composition of the wood species. Unfortunately, actual analyses of the chemical components of the wood species and the resulting wines, which could give light on these findings, were not conducted.

Organoleptic evaluation. With the encouraging results from the sub-chronic toxicity test, that is, no lethal or immediate adverse effect on the rats administered with the wine samples, the organoleptic test was pursued. Table 6 shows the summary of scoring of the wine tasters on the wines aged in the different barrels.

Wood SpeciesWine Water

Kidney Liver Kidney Liver

Big-leafed mahogany

River red gum

Mangium

Santol

Mango

Control

2

2

2

2

2

2

2

2

1

2

2

2

1

2

1

2

1

1

1

1

1

1

1

1

Table 5. Histopath report on 28-day oral toxicity test on rats

Barrel Material (Wood Species)

Color Bitterness Sweetness Clarity Flavor Aftertaste General Acceptance

Big-leafed mahogany 7.8 a 6.3 a 4.2 a 5.5 b 6.0 a 5.3 a 5.1 a

River red gum 4.0 d 5.2 b 4.3 a 5.3 bc 5.6 a 4.6 a 5.3 a

Mangium 6.4 b 5.5 ab 4.2 a 5.6 b 5.5 a 5.4 a 4.1 b

Santol 2.4 e 5.5 ab 3.9 a 7.1 a 5.2 a 4.6 a 5.3 a

Mango 5.3 c 5.0 b 3.9 a 4.7 c 5.6 a 4.4 a 5.1 a

Control 2.4 e 5.6 ab 4.1 a 7.0 a 6.1 a 4.6 a 5.6 a

X2

c (Kruskal-wallis) 80.1 ** 8.5 ns 1.8 ns 37.7 ** 6.4 ns 8.1 ns 9.7 ns

Table 6. Summary of organoleptic evaluation

** - highly significant at alpha =0.01ns - not significantly different

For each attribute, means (ave. of 15) with same letter are not significantly different at alpha=0.05



Kruskal-Wallis values generally indicated no significant difference in the attributes except color and clarity. DMRT results indicated that the wine from the santol barrel was comparable in color with the control wine stored in plastic jar, i.e., no change in the wine’s color while big-leafed mahogany imparted the most color, followed by Acacia mangium.

Mango, on the other hand, caused the most cloudiness; santol, the least which was even a little clearer than the control wine. Although not significantly different, big-leafed mahogany was rated the most bitter, and mango, the least bitter.

For the rest of the attributes (sweetness, flavor and aftertaste), all the aged wines were rated moderate. Finally, despite the poor rating of big-leafed mahogany, mangium, river red gum, and mango in terms of color compared with santol, all the wines aged in barrels from all the species tested were rated moderately acceptable.

Results of the organoleptic test somehow signify that wine aged in wood species other than oak may be acceptable even to expert wine tasters. Therefore, the non-availability of oak barrels in the country should not be a limiting factor to the growth of the local wine industry. New wood species may even introduce new wine tastes which hopefully

may challenge the traditionally preferred taste from oak wood.

Cost Estimates

Based on laboratory costs for materials and labor to fabricate the barrels (Table 7), each 15-L capacity barrel was estimated to cost USD57.92. This is expected to go down if mass production is done. In comparison, the price of an equivalent 15-L capacity imported oak barrel from US is USD86.52; and from France, USD144.20.


• Five local wood species, namely, big-leafed mahogany, river red gum, mangium, santol and mango, can be fabricated into 15-L capacity barrels for fruit wine. Based on laboratory costs of materials and labor, each barrel is estimated to be 50 to 150% cheaper than the equivalent imported oak barrel.

• The sub-chronic toxicity test using Wistar rats have shown that the barrel aged wines have no observable adverse effect

Direct Materials

Wood (30 bd. ft. @ USD1.38/bd. ft.)

Metal rings (4 rings @ USD2.52/ring)

Wax and adhesive

USD41.20

USD10.07

USD 3.21

Direct Labor

2 workers @ USD3.44/barrel USD3.44

Cost per barrel USD57.92

Table 7. Direct costs for wine barrel production*

*Based on laboratory costs

57

and do not cause blood chemistry values to go beyond normal limits. Generally, the changes in the rats’ blood chemistry do not differ significantly among wood species and the control. Damage to kidney and liver is also generally mild for all containers used. Based on this, the wood species may be deemed safe for use as wine barrels.

• Organoleptic or sensory evaluation tests have shown that the barrel-aged wines are moderately acceptable; therefore, the wood species studied are moderately acceptable for use as wine barrels. However, santol wood appears to have the edge in terms of color and clarity.

• Though the study has somehow established that wood species other than oak can be used to age fruit wines that are safe and acceptable for consumption, it is suggested that spin-off studies or actual chemical analysis of the wood species and the aged wines be conducted to identify the chemical compounds or markers for the particular taste imparted by each wood species on wine.

• Further improvement in the preparation of the wood materials (including toasting which was not done in this study), fabrication and treatment of the barrels is also deemed necessary as each stage may be critical in the utmost utility of the barrels.

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ACKNOWLEDGMENT

The authors wish to thank the Department of Science and Technology – Region IV for funding the study; Ms. Lolita Villavelez and Ms. Irma I. Palanginan for their technical inputs; and Ms. Cynthia N. Ochona, Head of ITDI’s Biological Laboratory, and Ms. Erlinda I. Dizon, Professor of Food Science and Technology, University of the Philippines Los Banos for their help in the experiment.



PRESERVATION OF THE GREEN COLOR OF KAUAYAN TINIK (BAMBUSA BLUMEANA SCHULTES F.) AND KAUAYAN KILING (BAMBUSA VULGARIS

SCHRAD EX WENDLE)

Shirley A. Pelayo and Robert A. NatividadSupervising Science Research Specialist, Material Science Division,

and Chief Science Research Specialist, Technology Innovation DivisionFPRDI-DOST, College, Laguna 4031 Philippines

ABSTRACT

The effectiveness of a methanol-based copper nitrate Cu(NO3)2 in preserving the green color surface of fresh kauayan tinik (Bambusa blumeana Schultes f.) and kauayan kiling (Bambusa vulgaris Schrad ex Wendle) was evaluated. The wettability of the treated bamboo was likewise assessed. Bamboo samples were divided into two groups - those with the cutin kept intact (without pre-treatment) and those with the cutin removed (with pre-treatment). The samples were soaked in 1.5% methanol-Cu(NO3)2 solution at 25°, 40° and 60°C and placed in a water bath for 1 and 2 hr.

Results showed that L* (lightness), a* (green color) and b* (yellow color) were not affected by solution temperature and treatment duration for kauayan tinik samples without pre-treatment. For those with pre-treatment, the green color (a* = -10.10) and lightness (L* = 38.02) were affected by treatment duration. The green color of kauayan tinik surface was obtained in 2 hr.

For kauayan kiling without pre-treatment, lightness was significantly affected by solution temperature and treatment duration, while the green color was not affected by any of the variables. The values obtained, however, were comparable with those of kauayan tinik. On the other hand, treatment duration affected the a* value of kauayan kiling with pre-treatment. The green color (a*= -10.38) was observed in samples treated for 2 hr.

The surface of fresh kauayan tinik with and without cutin exhibited a green color that did not significantly differ from the treated samples while treated kauayan kiling showed a greener color than the fresh ones.

Wettability of all the treated samples did not significantly differ from the fresh samples. Contact angle values obtained were all >90˚, meaning the treated samples were non-wetting like the fresh bamboo.

Keywords: color preservation, Bambusa blumeana Schultes f., Bambusa vulgaris Schrad ex Wendle


61

INTRODUCTION

Bamboo is one of the most important non-timber forest products in the Philippines and other Asian countries. Known as the “Grass of Life”, it is used for a vast range of purposes especially in the rural areas because of its wide distribution, rapid growth, easy handling and many desirable properties. In recent years, bamboo has been used in the highly competitive world market in the form of pulp for paper, parquet, plywood, laminated veneer lumber and other engineered bamboo products. At present, there are 70 erect and climbing bamboo species in the Philippines (Virtucio 2008). About eight of them are commercially important and used as materials for construction, furniture, basketry and decorative articles. Among them are kauayan tinik (Bambusa blumeana Schultes f.) and kauayan kiling (Bambusa vulgaris Schrad ex Wendle), which are extensively cultivated for their excellent flexibility and machining properties and widely used as raw materials for furniture and handicrafts.

The green color of bamboo culms fascinates most bamboo users. However, the green skin of bamboo fades after drying, turning yellowish brown or dark brown. Many local bamboo handicraft manufacturers have long been looking for a technique to retain the natural color of bamboo even after the culm has already dried up. Several chemical treatments have been developed by Taiwanese researchers to preserve the green color of different bamboo species. However, the said techniques may be applicable only to species endemic to Taiwan.

Early studies on preserving the green color in bamboo used inorganic salts such as chromates, nickel salts and copper salt (Chang & Lee 1996, Chang 1997). After a while, Chang and Wu (2000) developed the chromated copper phosphate (CCP) or chromated phosphates (CP) formulations

which gave a greener color to bamboo than chromated copper arsenate (CCA).

The negative effect of arsenic in CCA on factory workers and the environment prompted the use of arsenic-free chemical reagents (Chang & Yeh 2001). Studies were likewise conducted in search of better chemicals, treatment procedure and appropriate conditions for protecting the green color in bamboo.

In 2002, Chang et al. used chromated phosphate and copper-phosporous salt treatments to treat ma bamboo and found that CP-treated bamboo exhibited excellent green color. They further studied the effect of CP on green-color protection of ma bamboo to understand better the treatment sequence of CrO3 and H3PO4 and their interactions. They found that green-color protection of ma bamboo culm could not be achieved by treating it with the CrO3-H3PO4 alone or with the H3PO4-CrO3 two-step treatment, but only by the CrO3-H3PO4 two-step treatment or the H3PO4-CrO3-H3PO4 three-step treatment.

Wu et al. (2002), on the other hand, obtained an attractive green color in culms treated with 1% CuP at 60ºC for 3 hr, using a 60:40 ratio of CuSO4 to H3PO4 in an aqueous solution. Compared with untreated bamboo culms, the CuP-treated samples had brighter greenish skin and also better green-color fastness.

The many experiments conducted on the preservation of bamboo’s green color prompted the above researchers to investigate the influences of the various green color protection treatments and treatment conditions on bamboo. Wu et al. (2004) came up with a technique on bamboo color preservation without alkali-pretreatment. They found that an excellent green-color protection can be obtained in makino bamboo culms treated with 2% methanol-borne copper chloride (CuCl2) in a 60ºC water bath for 2 hr.

Shirley A. Pelayo & Robert A. Natividad .


Having been successful in protecting bamboo’s natural color without pre-treatment, Wu et al. (2005) evaluated further the effectiveness of alkali pretreatment-free process in protecting the green color of ma and moso bamboos. Excellent green color was achieved in both species by treating them with 0.5% methanol-borne copper nitrate [Cu(NO3)2] at 60ºC for 2 hr and 1% methanol-borne copper acetate [Cu(Ch3COO)2] at 60ºC for 30 min, respectively.

This green color should adhere on the bamboo’s surface and should not be easily wiped out when wetted by water. Thus, wettability of the bamboo surface is an important property in color, finishing and chemical applications.

Wettability or wetting is the process when a liquid spreads on a solid substrate or material. It is defined by the contact angle of the liquid with the solid phase. When the droplet of the liquid “beads up” and the contact angle measurement is higher than 90˚, then it is classified as non-wetting. But when the droplet ‘wets out” across the surface and the contact angle is less than 90˚, it is classified as wetting (http://www.attension.com/wettabilityz) .

Wettability plays a crucial role in many industrial products and processes and plays an important role in the stabilization and performance of many products such as composites, paints and coatings, inks, cosmetics, pharmaceuticals and food products (http://www.attension.com/wettability and http://spec2000.net/09-wettability.htm).

This present study aimed to determine the effectiveness of a methanol-based copper nitrate [Cu(NO3)2] in preserving the green color of two of the most important bamboo species in the Philippines, kauayan tinik and

kauayan kiling, and evaluate the treated bamboo based on the color and wettability of the surface.


Determination of Appropriate Treatment

Sample preparation. Two culms each of kauayan tinik and kauayan kiling were collected from a bamboo plantation in Pililla, Rizal Province. These were cut into 4 mm x 40 mm x 150 mm samples, immediately wrapped in a black plastic bag and temporarily stored inside a refrigerator for 48 hr to retain the freshness and green moisture content prior to treatment. A control was provided for each species.

Chemical treatment. The samples were divided into two groups, the first group underwent pre-treatment following Palisoc’s procedure (Josefina G. Palisoc, FPRDI retiree with specialization in finishing, Personal Communication 2009) in the chemical removal of cutin using 10% disodium octaborate tetrahydrate (DOT) while the other group had no pre-treatment. Each group was composed of 30 pieces of fresh bamboo specimens. Following the procedure by Wu et al. (2005) with slight modification on pre-treatment, the specimens in five replicates were placed in a stainless container to which 1.5% methanol-copper nitrate solution [Cu(NO3)2] prepared at varying temperatures (25, 40 and 60°C) was poured to soak the specimens. Then, without cooling, the stainless containers were placed over a water bath with a temperature of 60˚C maintained for 1 and 2 hr.

After treatment, all the samples were oven-dried at 60ºC for 12 hr before measurement of surface color and wettability.

63

Evaluation of Treatment

Measurement of surface color. Almost flattened epidermis wafers were cut from the treated and fresh bamboo samples. These were submitted to the Philippine Textile Research Institute to measure color variation using the equipment called Data Color Spectraflash SF600 CT which measures the color difference in CIELAB units.

CIELAB is an opponent color system based on the 1942 system of Richard Hunter called L, a, b. CIELAB indicates these values with three axes, i.e., L*, a*, and b*. The L*, which is located in the central vertical axis, represents lightness whose values run from 0 (black) to 100 (white). The color axes represent opposing colors wherein values on each axis run from positive to negative. On the a-a’ axis, positive values indicate amounts of red, while negative values indicate amounts of green. On the b-b’ axis, yellow is positive and blue is negative. For both axes, zero represents neutral gray (http://dba.med.sc.edu/price/inf/Adobe_tg/models/cielab.html).

Wettability test. The wettability of the bamboo samples was determined using a simple apparatus called dinolite microscope attached to a personal computer with a software application for the purpose. Owned by the Plasma Physics Laboratory of the National Institute of Physics in UP Diliman, Quezon City, the equipment measured the contact angle of the treated and fresh bamboo samples.

Statistical Analysis

The data were consolidated and analyzed using Analysis of Variance (ANOVA) to determine the effect of the variables studied, while the significance of difference was calculated using Scheffe’s test.


Color Difference in Bamboo Treated with Copper Nitrate-Methanol Solution

Kauayan tinik with and without pre-treatment. The ANOVA on color difference of kauayan tinik without pre-treatment showed that the L*, a* and b* values were not significantly affected by solution temperature and treatment duration. This means that the green color surface of the kauayan tinik did not vary regardless of whether the 1.5% Cu(NO3)2-methanol solution used was heated to 40˚C and 60°C or not, and whether the treatment was done in 1 or 2 hr.

The cutin layer and the presence of extractives on the bamboo epidermis could be the reason behind this. Liese (1992) reported that the bamboo culm is covered at its inner and outer side by an impermeable skin which makes it hard for the chemicals to penetrate it. A special treatment is necessary to improve its appearance. Likewise, findings of Kawamura and Katani (1990) showed that the application of lacs and dyes on bamboo is hindered by the chemical composition of the culm epidermis. On the other hand, the ANOVA on kauayan tinik pre-treated with DOT shows that treatment duration affected the three color parameters. Based on Scheffe’s grouping (Table 1), the a* value (-10.10) obtained at 2 hr was higher than the -6.03 of those treated for 1 hr. This means that as treatment time increased, the green color tones on the surface of kauayan tinik increased.

Pre-treatment with DOT reduced the waxy coating of the bamboo epidermis, making the adhesion of Cu(NO3)2-methanol solution into the bamboo surface much easier. Thus,



the longer the pre-treated kauayan tinik is soaked in the solution, the more green color solution adhered to the surface, increasing the samples’ green color tones.

However, the L* value decreased from 62.14 to 38.02. This means that the green color in the 1-hr treatment was brighter than those treated for 2 hr. The lightening of the color might have been due to a slight degradation of chlorophyll, the attractive green color in the bamboo epidermis. Li (2004) observed the degradation of chlorophyll in the epidermis when extracted with alcohol-toluene as evidenced by the extraction solution which turned to dark green. The said color change of the solution was likewise observed in the present experiment.

Several studies cited by Li revealed that chlorophyll in the epidermis is very easily degraded, thus treatment with organic salts has been used to conserve the green color of bamboo surfaces (Chang et al. 1998, 2001, Wu 2002). Furthermore, the heat of the water bath may boost the reaction between the substrate and the solution, leading to chlorophyll degradation.

According to Lewis (2011), heat at a range of temperatures can cause the structure of an object or substance to change. Thus, in the hot-water extraction of bamboo, part of the extraneous components such as inorganic compounds, tannins, gums, sugar, starches and coloring matter present in bamboo are removed (Wenying et al. 2003). As such, it is possible that the application of heat could have caused some changes such as the lightening of the green color on bamboo’s surface. Overall, however, the color difference (DE) showed no significant variation between the untreated and treated samples without cutin.

Kauayan kiling with and without pre-treatment. The ANOVA for kauayan kiling without pre-treatment shows that only the L* value among the three parameters assessed was significantly affected by solution temperature and treatment duration. Scheffe’s test (Table 2) shows that lightness did not vary among treatment combinations (solution temperature/treatment duration) of 25/1, 25/2, 40/1, 40/2 and 60/1.

Treatment Duration (hr) CIE Lab Values

1

2

L* a* b*

62.14 a

38.02 b

-6.03 b

-10.10 a

21.20 b

1.96 a

Table 1 Effect of treatment duration on lightness and color of kauayan tinik bamboo (without cutin) treated with 1.5% copper nitrate

Solution Temperature (°C) Treatment Duration (hr) Mean Value of L*

402540602560

211122

57.39 a56.82 a56.10 a56.10 a54.79 a50.05 b

Table 2 Effect of solution temperature and treatment duration on lightness in kauayan kiling (with cutin) treated with 1.5% copper nitrate

65

Only the samples subjected to 60°C for 2 hr gave a significantly lower L*value (50.05). The others had L* values ranging from 54.79 to 57.39. The resulting green color was not as bright as the other samples subjected to Cu(NO3)2-methanol solution at elevated temperature (60°) for 2 hr. As mentioned earlier, this could be attributed to the slight degradation of chlorophyll in the bamboo epidermis at longer treatment period.

With regards to kauayan kiling with pre-treatment, ANOVA shows that the a* value was significantly affected by treatment duration. The a* value was high for samples treated for 2 hr (Table 3). This means that the surface color of kauayan kiling without cutin was greener when subjected to longer heating over a water bath than those treated for 1 hr.

The same trend was observed in kauayan tinik. When pre-treatment was applied, the waxy layer at the bamboo surface was reduced, triggering the penetration of

Cu(NO3)2 into the surface. Thus, the longer the soaking time in the heated solution, the more solution was absorbed and the greener the bamboo surface became.

Comparison of L*, a* and b* of fresh and treated kauayan tinik and kauayan kiling. Table 4 shows the comparison of treatment means between fresh samples of kauayan tinik and kauayan kiling against kauayan tinik without pre-treatment (KtN), kauayan tinik with pre-treatment (KtP), kauayan kiling without pre-treatment (KkN) and kauayan kiling with pre-treatment (KkP). For KtN, the L*, a* and b* values were 58.66, -8.16 and 22.79, respectively.

Only the L* value was significantly different from the fresh samples, which means that the treated samples were lighter in color than the fresh ones. Again, this might be due to the slight degradation of chlorophyll in the treated bamboo. The same trend was observed for KtP where no significant variations were observed among L*, a* and

Treatment Duration (min) Mean Value of a*

21

-10.377 a-7.830 b

Table 3 Effect of treatment duration on the green color (a*) value of kauayan kiling (without cutin) treated with 1.5% copper nitrate

Bamboo Species/Condition

CIE Lab Values

L* a* b*

Fresh Kt

KtNKtP

Fresh Kk

KkNKkP

61.98

58.66s60.08ns

58.67

55.20s 57.19ns

-7.82

-8.16ns-8.06ns

-5.34

-8.35s-8.62s

21.84

22.79ns22.58ns

23.63

21.57s22.30s

Table 4 Comparison of treatment means between kauayan tinik with no pre-treatment (KtN), kauayan tinik with pre-treatment (KtP), kauayan kiling with no pre-treatment (KkN), kauayan kiling with pre treatment (KkP) and fresh kauayan tinik and kauayan kiling

significantly different from the standard speciesns - not significantly different from the standard species



b* values. The lightness and color of kauayan tinik subjected to treatment was not far from those of the fresh ones. This shows that the solution used protected the color of the bamboo although it was not as bright in the fresh bamboo.

For KkN, L*, a* and b* values significantly differed from those of fresh kauayan kiling. This indicates that the treated kauayan kiling (without pre-treatment) was greener, but not as bright as the fresh samples. For KkP, only a* and b* values significantly differed from the fresh specimens, i.e., kauayan kiling with pre-treatment was greener than the fresh bamboo sample. The reduction of the culm’s waxy layer could have contributed to better adhesion of the chemical solution on the kauayan kiling surface.

Wettability Test. Wettability of a liquid is defined as the contact angle between a droplet of the liquid in thermal equilibrium on a horizontal surface. On the other hand, contact angle is a quantitative measure of the wetting of a solid by a liquid.

In this study, wettability of the treated bamboo was determined to assess if the alcohol-borne reagent used did not reduce the self-defense layer of bamboo or if it will provide better penetration for subsequent treatments.

ANOVA on contact angles for kauayan tinik with and without pre-treatment showed that it was not affected by solution temperature and treatment duration. This means that wettability was relatively the same even if the

solution temperature and treatment duration varied, and whether kauayan tinik was pre-treated or not. The values of the contact angle for kauayan tinik were >90, indicating non-wetting.

For kauayan kiling, the interaction between solution temperature and treatment duration was significant. Scheffe’s grouping showed that the contact angle did not significantly differ for samples subjected to solution temperature and treatment duration of 40/1, 25/2, 25/1 and 60/1 (Table 5). Similarly, 60/1 did not differ significantly from 60/2 and 60/2 from 40/2. However, 60/2 and 40/2 were significantly different from the rest. Although higher solution temperature and longer treatment duration gave lower contact angles, all the values obtained were >90°, which indicates non-wetting of the treated samples.

The contact angles in kauayan tinik and kauayan kiling were not significantly different from the fresh bamboo samples whose contact angle ranged from 112.92 to 130.58˚. This means that the alcohol-borne reagents as claimed by Wu et al. (2005) did not only reduce the protective layer but also provided better wettability.

This non-wetting property of the samples could be taken both positively and negatively. Positive because the treated sample will repel the water that will touch its surface, meaning the chemical will not leach if the samples are wetted. However, adhesion of finishes may be impaired.

Solution Temperature (°C) Treatment Duration (hr) Mean Value of Contact Angle

402525606040

121122

129.45 a128.21 a125.87 a124.49 ab118.30 bc115. 81 c

Table 5 Effect of solution temperature and treatment duration on the contact angle of kauayan kiling without cutin

67

The variation on the effect of treatment variables (solution temperature and treatment duration) on wettability between kauayan tinik and kauayan kiling could be attributed to the chemical composition of the epidermis. According to Vick (1999), extractives on the wood surface are the principal physical and chemical contributors to poor wettability. This may also be true in bamboo because its epidermis is reported to contain the highest extractives compared to wood (Li 2004).

Espiloy’s (1996) study on the properties and utilization of bamboos stated that kauayan tinik contains higher extractives than kauayan kiling. This could be the reason behind the variation on wettability between the two species.

CONCLUSIONS

• Green color preservation in locally-grown kauayan tinik and kauayan kiling can be achieved by soaking fresh green bamboo in 1.5% methanol-Cu(NO3)2 solution and heating it over a water bath at 60°C for 2 hr.

• Treatment duration and solution temperature have no significant effect on the preservation of green color in kauayan tinik without pre-treatment but for those with pre-treatment, longer treatment gives greener color tones to the bamboo samples.

• For kauayan kiling without pre-treatment, both the solution temperature and treatment duration have an effect on lightness. Samples with solution heated at 60˚C and subjected to water bath for 2 hr are lighter and significantly different from the rest of the treatment combinations. On the other hand, pre-treatment of kauayan kiling shows that treatment duration has an effect on the color. Greener color tones are obtained from bamboo samples treated for 2 hr.

• The color of the treated kauayan tinik with and without pre-treatment is comparable with the fresh ones. For kauayan kiling, the opposite is true, although treated samples are greener than the fresh ones.

• Contact angle of treated samples is >90° which indicates non-wetting. This is not significantly different from the contact angle of the fresh bamboo. Non-wetting of a sample can be an advantage and a disadvantage. The chemical applied will not be prone to leaching, however, adhesion of finishes may be low.

• A follow-up study should be conducted to determine the depth of chemical penetration, chemical reaction that takes place between the substrate and the solution, as well as the weathering and the finishing properties of the treated samples. Preservation of the natural color of decorative bamboo species (yellow, striated, black, etc.) should likewise be explored.



LITERATURE CITED

CHANG ST and LEE HL. 1996. Protection of the green color of moso bamboo (Phyllostachys pubescens Mazel) culms and its colorfastness after treatment. Mokuzai Gakkaishi 42: 392-396.

CHANG ST 1997. Comparison of the green color fastness of the bamboo (Dendrocalamus spp.) culms treated with inorganic salts. Mokuzai Gakkaishi 43: 487-492.

CHANG ST and WU JH. 2000. Green color conservation of ma bamboo (Dendrocalamus latiflorus) treated with chromium-based reagents. J. Wood Sci. 46: 40-44.

CHANG ST and YEH TF. 2001. Protection and fastness of green colour of moso bamboo (Phyllostachys pubescens Mazel) treated with chromium-based reagents. J. Wood Sci 47:228-232.

CHANG ST, WU JH and YEH TF. 2002. Effects of chromated-phosphate treatment process on the green color protection of ma bamboo (Dendrocalamus latiflorus). J. Wood Sci 48: 227-231.

ESPILOY ZB 1996. Properties and utilization of Philippine bamboos. In: Ang Kawayan, Proceedings of the First National Conference on Bamboo. Iloilo City, Philippines.

http://www.attension.com/wettability and http://spec2000.net/09-wettability.htm. Retrieved April 18, 2013.

http://dba.med.sc.edu/price/inf/Adobe_tg/models/cielab.html. Retrieved January 11, 2011.

KAWAMURA N and KATANI K. 1990. The modification of culm epidermis. Proc. 40th Japan Timber Science Conference. 4.1 (as cited by Liese 1992, http://www.archisocial.com/forum/materiali/1992_bamboo.htm). Retrieved February 14, 2014.

LEWIS P 2011. The Effect of heat transfer on color change. Heat transfer www.asmedl.org/thermal_science.

LI XIAOBO 2004. Physical, chemical and mechanical properties of bamboo and its utilization potential for fiberboard manufacturing. M.S. Thesis. Louisiana State University, U.S.A. pp. 5-16.

LIESE WL. 1992. The structure of bamboo in relation to its properties and utilization. Bamboo and Its Use. International Symposium on Industrial Use of Bamboo. Beijing, China. 07-11 December 1992. pp. 1-6 (http://www.archisocial.com/forum/materiali/1992_bamboo.htm). Retrieved February 14, 2014.

VICK CB 1999. Adhesive bonding of wood materials. In: Wood Handbook - wood as an engineering material. Washington DC: Forest Products Society. US Department of Agriculture, Forest Service. pp. 9-3.

69

VIRTUCIO FD 2008. Assessment of bamboo resources in the Philippines. Paper presented during the National Bamboo Forum held at Philippine Trade Training Center, Pasay City. October 22-24, 2008.

WENYING F, WANG Z and GUO W. 2003. Sympodial Bamboo - chemical composition and fiber characteristics. INBAR Report. pp.1-9. (http://www.inbar.int/publications/?did=25)

WU JH, WU SY, HSIEH TY and CHANG ST. 2002. Effects of copper-phosphorous salt treatment on green colour protection and fastness of ma bamboo ( Dendrocalamus latiflorus). Polym Degrad Stab 78: 379-384.

WU JH, CHUNG MJ and CHANG ST. 2004. Evaluation of the effectiveness of alcohol-borne reagents on the green colour protection of makino bamboo (Phyllostachys makinoi). Polym Degrad Stab 83: 473-479.

WU JH, CHUNG MJ and CHANG ST. 2005. Green color protection of bamboo culms using one-step alkali pretreatment-free process. J Wood Sci 51: 622-627.a



CHEMISTRY AND ANTI-FUNGAL PROPERTIES OF THE ESSENTIAL OIL

FROM CAMBODIAN-GROWN DIPTEROCARPUS ALATUS

Mariluz Sp. Dionglay, Rowena E. Ramos,Rebecca B. Lapuz, Audel V. Mosteiro1and Mildred M. Fidel2

1Senior Science Research Specialist, Science Research Specialist I, Senior Science Research Specialist & Research Assistant, respectively, Material Science Division

& 2Chief Science Research Specialist, Technical Services Division,FPRDI-DOST, College, Laguna 4031 Philippines

ABSTRACT

Essential oil was extracted from the raw resin of Dipterocarpus alatus by hydrodistillation and analyzed by gas chromatography (GC) and GC/mass spectroscopy (MS) to determine the oil’s components. Seventy-eight components were identified, constituting 97.63% of the oil.

The major chemical components identified were α-gurjunene (54.84%), γ-gurjunene (5.65%), allo-aromadendrene (4.84%) and spathulenol isomere (3.32%). The minor ones were calarene (1.57%), cascarilladiene (2.05%), alaskene isomer (2.41%) and germacrone (1.56%). Spectral analysis indicated that the oil was a typical hydrocarbon compound.

The antifungal activity of the oil was evaluated against Aspergillus niger and Trametes versicolor by zone inhibition method using filter paper and wood blocks assay. The essential oil showed bioactivity against the test fungi.

Keywords: chemical composition, anti-fungal properties, essential oil, Cambodian- grown, Dipterocarpus alatus

INTRODUCTION

Non-timber forest products (NTFPs) are a source of livelihood for many people in developing countries. For instance, in Cambodia, the tapping of resin exudates from the trees of the Dipterocarpus species contributes to improving the income of numerous families. According to Hong-Troung & Pinto (2007), 34 - 86% of the population from two provinces in

northeastern Cambodia are resin tappers, with each family owning 35 to 260 trees.

Dipterocarpus alatus is native to both evergreen and dry deciduous forests from east India and the Andaman Islands to Cambodia, Laos and Vietnam, south to the border of Thailand and Peninsular Malaysia and in Luzon, the Philippines where it is known as D. philippinensis (Ankarfjard & Kegl 1998). This species is also an important source of timber.


71

D. alatus resin is commonly used by indigenous people for illumination and caulking of boats. A study by Richardson et al. (1989) showed that several products can be developed from it such as bactericide and insecticide. Knowledge of the chemical composition of the resin’s essential oil will help establish scientific basis for the assessment of its bioactivity. From here, value-added products may be developed thus creating sources of livelihood in the communities where the resin is tapped.

This study aimed to extract essential oil from D. alatus resin from Cambodia by hydrodistillation; determine the components of the essential oil by GC and GC-MS; conduct spectral analysis of the oil; and determine its antifungal properties against Aspergillus niger and Trametes versicolor.

MATERIALS AND METHODS Raw Material

The D. alatus resin - a viscous, brownish liquid- was provided by the Non-Timber Forest Products Exchange Programme for South and Southeast Asia(NTFP-EP), Cambodia. Essential Oil Extraction

The resin was water distilled using a Clavenger apparatus to extract the essential oil. About 1L of the oleoresin was hydrodistilled. The extraction was stopped when no more oil was collected from the receiver. GC-MS Analysis The oil was submitted for GC analysis to the Sarl Pyrenessences Analyses in France. The analysis was carried out using an Agilent CPG 5890 Chromatograph equipped with a flame ionization detector (FID) with a polar HP INNOWAX column measuring 60 m x 0.25

mm x 0.5 µm. Helium was used as carrier gas. Oven temperature was held isothermal at 60oC for 6 min and then programmed to increase to 250oC at 2oC/min and finally isothermal at 250oC for 20 min.

The oil was further analyzed using CPG 5890 chromatograph coupled to a mass spectrometer MS 5970. The capillary column and temperature program were the same as in the GC analysis. One µl diluted with 5% hexane was introduced by direct injection. The helium carrier gas had column pressure of 30 psi/FID and 23 psi MS.

A data processing system and library search software were used to identify the components.

Spectral Analysis

A Shimadzu IR Prestige-21 Fourier Transformed Infra-red Spectrophotometer was used to determine the functional groups present in the extracted essential oil.

Oil Bioassay The antifungal activity against A. niger and T. versicolor was evaluated by filter paper and wood blocks method described by Giron and Garcia (1980). Distilled water was used as control.

The appearance of a zone of inhibition in the potato dextrose agar (PDA) plates indicated the oil’s bioactivity . All plates were incubated for five days at 29+2oC.


The essential oil extracted from D. alatus resin by hydro distillation was clear yellow and had a citrus scent. The yield ranged from 79 to 83% oil. The specific gravity of the oil as measured by pycnometer method was 0.959 + 0.002.

Mariluz Sp. Dionglay, et al. .


GC/MS Analysis

Table 1 presents the composition of the essential oil extracted from D. alatus resin. Seventy-eight components were identified and constituted 97.63% of the oil. The major component was α-gurjunene (54.84%) (Fig. 1). This is also one of the major chemical components of the oil from Drimys brasiliensis Miers, a tree from Southern Brazil with medicinal properties.

D. brasiliensis oil was tested for toxicity against cattle tick (Rhipicephalus (boophilus) microplus) and brown dog tick (Rhipicephalus sangguineus). It was found lethal, killing 100% of the larvae of both ticks (Ribeiro et al. 2008).

Alpha-gurjunene Gamma-gurjunene

Fig. 1 Chemical structures of alpha-gurjunene and gamma-gurjunene

Other main components of D. alatus oil were: γ-gurjunene (5.65%), allo-aromadendrene (4.84%) and spathulenol isomer (3.32%). Minor components were calarene (1.57%), cascarilladiene (2.05%), alaskene isomer (2.41%) and germacrone (1.56%).

Compound % Composition

1 Limonene2 α-Cubebene3 α-Copaene 4 α-Gurjunene5 Gurjunene Isomere6 α,cis-Bergamotene7 α-Santalene8 Isoledane9 α,trans-Bergamotene10 β-Elemene11 Calarene12 β-Caryophyllene13 β-Copaene14 Aromadendrene15 β-Gurjunene16 Allo-aromadendrene17 γ-Gurjunene18 Cascarilladiene19 Alaskene Isomer20 Sesquiterpene21 Muuroladiene Isomere22 cis-4,5-Muuroladiene23 Sesquiterpene Mw=20424 Cypera-2,4-diene25 Eremophilene + Geramcrene D

0.560.120.18

54.840.170.030.040.040.040.651.570.220.160.150.144.845.652.052.410.040.250.710.180.880.20

Table 1 Essential oil composition of D. alatus oleoresins by GC/MS

73

Compound % Composition

26 Gurjunene Isomere27 Bicyclogermacrene28 Sesquiterpene Mw=20229 δ-Cadinene30 γ-Cadinene31 Sesquiterpene Mw=20232 Sesquiterpene Mw=20233 Sesquiterpene Mw=20234 Calamenene35 Compose Mw=21836 Vetivenene Isomere Mw=21837 Dihydrokaranone Mw=21838 Palustrol39 Compose Mw=22040 Epoxyde Sesquiterpenique41 -Calacorene42 Oxyde d’Isocaryophyllene43 Oxyde de caryophyllene44 Sesquiterpenol45 Sesquiterpenol Mw=22246 6,7-Epoxy humulene47 Gleenol48 Epi-cubenol49 Cubenol + Sesquiterpenol50 Sesquiterpenol51 Viridiflorol52 Eudesmol Isomere53 Rosifoliol54 Spathulenol55 Spathulenol Isomere56 Sesquiterpenol57 Spathulenol Isomere58 Sesquiterpenone Mw=21859 Sesquiterpenone Mw=21860 Sesquiterpenone Mw=21861 Sesquiterpenol62 Sesquiterpenol Mw=22063 Sesquiterpenol Mw=22264 Sesquiterpenone Mw=21865 Sesquiterpenol Mw=22066 Sesquiterpenone Mw=21867 Acetate Sesquiterpenique 68 Germacrone Mw=21869 Compose Mw=23270 Compose Sesquiterpenique Oxygene Mw=23671 Germacrone Isomere72 Cyperone Isomere Mw=21873 Compose Sesquiterpenique Oxygene Mw=23674 Compose Sesquiterpenique Oxygene Mw=23675 COMPOSÉ POLYOXYGÉNÉ AZOTÉ76 COMPOSÉ POLYOXYGÉNÉ Mw=21677 DITERPENOL Mw=28678 COMPOSÉ LACTONIQUE Mw=216

TOTAL

0.140.030.050.110.130.670.260.090.070.030.200.100.090.700.350.280.140.720.110.070.360.050.120.070.090.020.070.380.290.810.133.320.120.220.150.061.751.760.200.550.260.231.560.071.610.360.080.120.340.980.180.070.18

97.63

Table 1 continued

Compounds are arranged as per order of elution in HP INNOWAX Column. Highlighted are major and minor components.



Spectral Analysis

Figure 2 shows the FTIR Spectrum of the hydrodistilled oil. The spectrum is a typical hydrocarbon compound with –C-H stretching and bending vibrations in the regions near 3000 cm-1 and 1460 cm-1, respectively. Absorptions near 3100 cm-1 and 900 cm-1 are due to stretching and bending vibrations of the –C=C-H. This indicates that the essential oil of D. alatus is prone to oxidation which can lead to its darkening.

Oil Bioassay

The growth of A. niger in PDA was inhibited using the filter paper and wood blocks method. The filter paper discs and wood blocks treated with D. alatus oil inhibited the fungus growth. On the other hand, the filter paper discs and wood blocks dipped in distilled water were invaded by the fungus (Figs. 3 & 4).

Likewise, growth of T. versicolor was also inhibited in both filter paper discs and wood blocks (Figs. 5 & 6) after five days of incubation, respectively. The results showed that the oil had inhibited the growth of both fungi.

Dipterocarp timbers are known to resist biological attack from microbes. Richardson et.al.’s study revealed that (1989) termites

fed with Shorea species suffered 86-99% mortality while termites that ate non-dipterocarp Dyera costulata showed a lower mortality of only 13%. Essential oil from Valeria indica, a Sri Lankan dipterocap, also inhibited bacterial growth.

Fig. 2 Infra-red spectra of D. alatus hydrodistilled oil.

Fig. 3 Growth inhibition in A. niger in PDA plates using filter paper discs after 5 days incubation

at 29+2oC.

Fig. 4 Growth inhibition in A. niger in PDA plates using filter paper discs after 5 days incubation

at 29+2oC.

Fig. 5 Growth inhibition in T. versicolor in PDA plates using filter paper method after 5 days incubation

at 29 + 2 oC.

75

Fig. 6 Growth inhibition in T. versicolor in agar plates using wood blocks after 5 days incubation at 29+2oC.

CONCLUSIONS

• D. alatus resin is a viscous liquid, light brown and with a distinct odor. It contains 79-83% essential oil. As revealed by GC and GC/MS analyses, the essential oil

has 78 components, comprising 97.63% of the oil.

• The major components are α-gurjunene (54.84%), γ-gurjunene (5.65%), allo-aromadendrene (4.84%) and spathulenol isomere (3.32%). The minor components include calarene (1.57%), cascarilladiene (2.05%), alaskene isomer (2.41%) and germacrone (1.56%).

• FT-IR spectrum indicated that the oil is a typical hydrocarbon compound. The spectral analysis of the hydrodistilled oil shows the presence of stretching and bending vibrations of the –C=C-H band near the regions 3100 cm-1 and 900 cm-1, respectively, which accounts for the oil’s darkening during storage.

• D. alatus resin has fungicidal activity against A. niger and T. versicolor.

LITERATURE CITED

ANKARFJARD R and KEGL M. 1998. Tapping oleoresin from Dipterocarpus alatus (Dipterocarpaceae) in a Lao Village. Econ. Bot. 52(1). New York Botanical Gardens. Bronx, N.Y., USA.

GIRON MY and GARCIA CM. 1980. Effectiveness of basiment 300 against wood staining fungi under laboratory conditions. Terminal Report. FPRDI Library. College, Laguna, Philippines.

HONG-TRUONG L and PINTO F. 2007. Dipterocarp oleoresin in Vietnam and Cambodia: harvesting techniques, resource management and livelihood issues: A Report from an Exchange Visit to Cambodia. CBD and NTFP Exchange Programme for South & Southeast Asia.

RIBEIRO VLS, ROLIM V, BORDIGNON S, HENRIQUES A, DORNELES G, LUMBERGER R and VON POSER G. 2008. Chemical composition and larvicidal properties of the essential oils from Drimys brasiliensis Miers (Winteraceae) on the cattle tick Rhipicephalus (Boophilus) microplus and the brown dog tick Rhipicephalus sanguineus. Parasitology Res. 102 (3).

.RICHARDSON DP, MESSER AC, GREENBERG S, HAGEDORN HH and MEINWALD J.

1989. Defensive sesquiterpenoid from a dipterocarp (Dipterocarpuskerrii). J. of Chem. Ecol. 15 (2).


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