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Home , Coconut, Durian, Durio zibethinus, Wax

The First Thai-Biomass Utilization Symposium ______Effective Utilization of Forest Biomass for Regional People in

Particleboards from and

Sarocha Charoenvai*, Jongjit Hirunlabh*, and Joseph Khedari* Abstract

Manufacturing particleboards from tropical peel particle; durian ( ) peels and coconut coir ( Cocos nucifera ); with low thermal conductivity is the main purpose of this study. Two main parameters were investigated namely binder types, (UF 12%, PF 6% and IC 3%) and board density. In general, the effect of adhesive type on the properties of boards was not obvious whereas that of the density was more significant on most properties of boards. Experimental investigation indicated that the mechanical properties of all boards increased with increasing board density, but this decrease the dimension stability, expressed by the thickness swelling and the thermal conductivity as well.

Keywords: Synthetic Binder; Thermal Conductivity; Modulus of Rupture; Modulus of Elasticity; waste ______*Building Scientific Research Center, King Mongkut’s University of Technology Thonburi, Bangmod Rasburana, 91 Pracha U-thit Rd., Thungkru, Bangkok 10140, Thailand Email address: [email protected] www.kmutt.ac.th/organization/bsrc The First Thai-Biomass Utilization Symposium ______Effective Utilization of Forest Biomass for Regional People in Thailand Introduction

Nowadays, due to forest production and environment awareness the use of natural is steadily decreasing. Technology is used to manufacture materials from agricultural waste which is considered to substitute natural wood. The productivity of Thai fruit [1] is anticipated to increase in the future and the associated produced waste will lead to social and environmental problems, if we are unable to dispose them. After a series of preliminary tests on thermal conductivity and bulk density of peels of [2], it was found that durian (Durio zibethinus) and young coconut (Cocos nucifera) are the most suitable to be used due to their low thermal conductivity. The objective of this research work is to evaluate the suitability of durian peel and coconut coir as raw materials for particleboard to be used as construction panel with low thermal conductivity for energy conservation of building [3]. That obviously implies the study of some of the relevant parameters thought to be significant in relation to particleboard performance such as board density and adhesive type.

Particleboard Manufacturing In this study, three board densities were considered for each products (0.3, 0.6 and 0.9 g/cm 3 for durian and 0.3, 0.5 and 0.6 g/cm 3 for coconut coir) and three types of commercial adhesives were selected: formaldehyde (UF), phenol-formaldehyde (PF) and isocyanate (IC). The boards were made with three replicates at each combination, so there are 54 experiment boards. Raw Materials The properties of raw material have an effect in both the processing condition and the properties of end products. It is necessary to know the basic and chemical properties of fruit peel before preparing sample. The results of durian peel chemical analysis performed following TAPPI standard [4] are shown in Table 1. Hemi-cellulose is the difference between holocellulose and α-cellulose. It can be seen that durian peels have a rich hemi-cellulose content. Consequently, can be added to composite boards. This would impact the resistance to absorption of liquid water by the final product (particleboard). On the contrary, durian peels contains low lignin ratio. For coconut coir which is the -hair fibre obtained form the outer shell (Endocarp) or of the coconut. Chemical composition are given in Table2. It contains high lignin ratio (45.84%) that makes stiffer and The First Thai-Biomass Utilization Symposium ______Effective Utilization of Forest Biomass for Regional People in Thailand tougher The stiff and tough fibers are difficult to beat, do not conform and collapse against each other so well. That would like impact manufacturing process and properties. Table 1 Chemical composition of durian peel. Chemical composition Result Standard (%) -Benzene 16.65 TAPPI-T204-cm-97 Ethanol-Solubility 2.68 TAPPI-T264-cm-97 Lignin 15.45 TAPPI-T222-om-98 Holocellulose 73.54 Acid Chlorite’s Browing α-cellulose 60.45 TAPPI-T203-cm-88 Hemi-cellulose 13.09 - Ash 4.35 TAPPI-T211-om-93

Table 2 Chemical composition of coconut coir [4]. Chemical composition Unit (%) Water solubles 5.25 Pectin and related compounds 3.00 Hemi-cellulose 0.25 Lignin 45.84 Cellulose 43.44 Ash 2.22

Particle Preparation Based on general methods [5] of particle processing with a serie of preliminary tests, particle preparation was made as follows: the first step was to reduce the raw materials to approximately pulp-chip size (1 × 2 cm 2). The chip-size pieces were oven-dried at 80 °C for 8 hours. Dried durian chips were hammermilled. Coconut coir fibres were cut to about one centimeter. Next fibers were screened to remove excess fines by Sieve Machine over a 60 mesh The First Thai-Biomass Utilization Symposium ______Effective Utilization of Forest Biomass for Regional People in Thailand screen. The particle furnishes were returned to dry before used in making particleboards. Board Preparation The solid content of adhesives of particle furnish based on oven- dry weight were: UF 12%, PF 6% and IC 3% [6]. For all types, a of 1% solid wax based on oven-dry weight of particle furnish should be added. The adhesive was sprayed on particles in a rotating drum blending machine with air-atomization nozzles. The moisture contents of particlemat were controlled at 12%. The blended particles were felted by hand into the final with a forming box (300 × 300 mm). All boards made using phenolic resin were pressed to 10 mm stops using a platen temperature of 180 °C. Boards made with urea resin and IC were pressed to 10 mm thickness using a platen temperature of 150 °C. Applying a three step-down method of pressing (25, 15 and 10 kgf /cm 2) was applied for the boards. The total pressing time was 9 minutes. Specimen Preparation and Testing After the hot pressing, [7] all boards were stacked in order to be completely cured for 24 hours and then trimmed and cut into various test specimens. The specimens were conditioned in a conditioning room until they reached equilibrium for at least two weeks at room temperature. After conditioning to equilibrium weight. Standard specimen size and test procedures as outlined in JIS A 5908 (Japanese Standard Association 1994) were used throughout, except for the thermal conductivity. The thermal conductivity of the particleboards were measured by using a guarded heat flux method in accordance with BS 874 Part 2 (British Standard).

The First Thai-Biomass Utilization Symposium ______Effective Utilization of Forest Biomass for Regional People in Thailand Results and Discussion Tables 3 summarizes all test results. The manufacture durian boards and coconut coir boards are shown in Figs. 1 and 2.

Fig.1 Durian borards Top: PF bonded board, Right bottom: UF bonded boardand Left bottom: IC bonded board.

Fig.2 Coconut coir boards Top: PF bonded board, Right bottom: UF bonded board and Left bottom: IC bonded board The First Thai-Biomass Utilization Symposium ______Effective Utilization of Forest Biomass for Regional People in Thailand Table 3. Physical and mechanical properties of particleboards form durian peels (D) and coconut coir fibres (C).

Boards Binder MC TS WA MOR MOE IB Density Type (%) (%) (%) (kgf/cm 2) (kgf/cm 2) (kgf/cm 2) (g/cm 3) 0.336 11.20 21.980 151.900 - - - UF 0.590 10.43 29.418 106.770 49.878 6993 2.562 (D) 0.860 8.92 30.648 49.853 251.772 37761 18.938 0.360 11.68 14.957 157.139 - - - PF 0.610 10.19 39.928 88.550 81.546 11844 2.793 (D) 0.850 8.04 41.225 57.803 215.572 34116 18.729 0.332 13.39 31.148 189.235 - - - IC 0.570 10.30 87.653 146.175 28.146 4848 2.199 (D) 0.920 9.04 104.273 58.118 124.938 76194 17.901 0.360 6.805 23.995 156.322 - - - UF 0.588 7.313 35.283 131.895 173.874 21337 2.12 (C) 0.648 7.505 53.353 78.800 260.513 29156 12.645 0.380 7.915 17.973 185.598 - - - PF 0.518 7.465 26.438 133.853 160.615 13317 3.723 (C) 0.611 7.395 32.635 77.453 419.592 30094 13.07 0.320 7.398 28.508 62.540 - - - IC 0.545 7.198 26.438 57.283 188.407 16629 1.994 (C) 0.613 7.690 32.303 56.283 202.588 18420 10.669

Effect of board density on moisture content (MC). The moisture content is inversely proportional with the density in the case of durian peel boards. The lower density yields higher porosity, spaces and voids. Consequently the moisture content increases when the porosity increases as durian fibres and parenchyma can absorb more moisture. It was also observed that the effect of density of coconut coir boards is not regular on moisture content as noticed in Table 3. For instance, in case of UF coconut coir boards made with high resin content (12%), high density boards have high weight and resin content as well. After blending, the amount of moisture and its distribution through the high density boards is higher than that of low density boards. Consequently, high density UF boards get more moisture content than final low density boards. This observation is not true for the boards manufactured with the other as (PF and IC). Therefore, further investigations have to be made in order to understand this relationship.

The First Thai-Biomass Utilization Symposium ______Effective Utilization of Forest Biomass for Regional People in Thailand Effect of board density on water absorption (WA) The water absorption is inversely proportional with board density as the space in the low density boards is larger than that of high density board of the same thickness. Consequently the water absorption decreases when the density increases as indicated in Table 3. Effect of board density on thickness swelling (TS) It was observed that thickness swelling increases with increasing board density. At room temperature the thickness swelling of the two kind of particleboards are rather high in comparison to the standard specification requirements for particleboards. Hence, it is necessary to research suitable condition to improve this property. Factor which may contribute to these high swelling values is hemi-cellulose of the durian peel and coconut coir fibre. In fact, hemi-cellulose plays an important role in fibre bonding process. Therefore, the tendency of swelling and shrinkage tend to occur during the drying process where dense sheets are formed. It is then reasonable to conclude that the protective influence of the wax is essentially lost. Effect of board density on MOR (Modulus of Rapture) and MOE (Modulus of Elastic) The value MOR and MOE for all boards increased linearly with increasing boards density. Also, higher density boards are stronger and stiffer, regardless the type of resin binder used. This is due to the low lignin content of the durian peel. Therefore, the average MOR of all these data is rather low in comparison to the average MOR of coconut coir boards. For the same density range, the average MOE of durian boards is smaller than that MOE of coconut coir boards. Effect of board density on internal bond. Board density is a significant parameter. That affects the internal bond. The increase of board density results in more intimate contact between the particle in the mat being compressed into the final board. Consequently, for high density board adhesive transfer of from one particle layer to another results in the increase of cross link between the particle in the board. It was also observed internal bond of durian boards is high in comparison with coconut coir boards. In fact, as durian boards have more void than coconut coir boards, resin is lost in interparticle voids in durian boards. The First Thai-Biomass Utilization Symposium ______Effective Utilization of Forest Biomass for Regional People in Thailand Effect of board density on thermal conductivity. Thermal conductivity versus board density for all boards is plotted in Figures 3 and 4. As expected, a consistent dependence of conductivity on density was observed. The thermal conductivity of the duiran boards is less than the conductivity of boards made from the coconut coir fibre. This is probably due to the insulating effect of the voids in the durian peel as a hygroscopic, porous material.

0.2 y = 0.242x - 0.0177 0.15 0.1 0.05 0

Thermal conductivity(W/m.K) Thermal 0 0.2 0.4 0.6 0.8 Board density (g/cm 3)

Fig. 3 Thermal conductivity of durian peel board VS board density

0.2 y = 0.1882x - 0.0176

0.15

0.1

0.05 0 Thermal conductivity(W/m.K) Thermal 0 0.2 0.4 0.6 0.8 1

Board density (g/cm 3)

Fig. 4 Thermal conductivity of coconut coir boards VS. board density The First Thai-Biomass Utilization Symposium ______Effective Utilization of Forest Biomass for Regional People in Thailand Comparison between particleboard and medium density fiberboard A comparison of properties of durian particleboards and rubber wood medium density fiberboards (MDF) [8] is shown in Table 4. This table reveals that 1. The MOR of durian particleboard is not different from rubber wood MDF. 2. The MOE and internal bond of rubber wood MDF is lower than durian particleboard by 22 and 61 percentage, respectively. Hence, -based particleboards could be used for ceiling roof housing. 3. The thickness swelling of durian particleboard is more than rubber wood MDF because of the high hemicellulose content in durian peel. Although no rubber wood MDF’s thermal conductivity is compared to durian partilcleboard, it is expected that the thermal conductivity of particleboard is expected to be lower than fiberboard. Table 4 Comparison between durian particleboards and rubber wood medium density fiberboards.

Properties and Durian Rubber wood MDF standards particleboards Adhesive type Urea-formaldehyde Urea-formaldehyde 12% 13% % Solid resin 69.70 62.00 content Additive Wax 1 % Wax 1% Density (kg/cm 3) 850.000 806.469 MOR (MPa) 25.177 28.407 MOE (MPa) 3776.100 2947.234 Internal bond (MPa) 1.8936 1.177 Thickness swelling 30.648 21.721 Standards JIS A 5908 A 1994 JIS 5906 A 1983

Conclusion Experimental investigation indicated manufacturing particleboards from durian peels and coconut coir fibres with low thermal conductivity is feasible. Their thermal conductivity (durian and coconut coir fibre boards) is fairly low varying between 0.054 to 0.1854 W/m.K. Such low values would certainly help for promoting those boards as a component of construction material (ceiling, wall) for energy saving. However, the strength of boards is quite low due to the structure of agricultural waste which is different from The First Thai-Biomass Utilization Symposium ______Effective Utilization of Forest Biomass for Regional People in Thailand wood. The density of durian UF boards is in the range of 0.8-0.9 g/cm 3. The specimen properties are as follows: thermal conductivity of 0.1513 W/m.K, MOR of 251.772 kgf/cm 2 , MOE of 37761 kgf/cm 2, internal bond of 18.936 kgf/cm 2 and thickness swelling of 30.648 %. The properties of PF coconut coir boards are as following 0.51-0.54 g/cm 3: thermal conductivity of 0.1036 W/m.K, MOR of 160.615 kgf/cm 2 , MOE of 13317 kgf/cm 2, internal bond of 3.723 kgf/cm 2 and thickness swelling of 26.438 %.

Acknowledgement The authors would like to thank Thailand Research Fund (TRF) for partial financial support this research. The authors are also grateful to Dr. Nikhom Laemsak of the Kasetsart University for his kind advise and agreement to carry out the preparation and part of tests of particleboards at his laboratory.

References

[1] Ministry of Agriculture and Co-op, 2000, Statistic of Planting of Fruit , Data Processing Sub-Division, Department of Agriculture Extension, p.30. [2] Khedari, J., et al., 2000, “New lightweight composite construction materials with low thermal conductivity,” CECO Journal, No. 804 , pp.1-6. [3] Kamke, T.M., 1977, “Effects of Wood-Based Panel Characteristics on Thermal Conductivity,” Forest Products Journal, Vol.38, No.2, pp. 49- 50 [4] http://www.hayleysexport.com/whatis.htm [5] Maloney, T.M., 1997, Modern Particleboard and Dry Process Fiberboard Manufacture, USA, Miller Freeman Publication. [6] Laemsak, N. and Okuma, M., 1996. “Development of boards made from plam frond; manufacture and fundamental properties of oil plam frond particleboard,” Proceedings of the FORTROP’96, Kasetsart University, Bangkok, pp. 71-83. [7] , J.T., 1973, “Particleboard from “Silage” Sycamore Laboratory Production and Testing.” Forest Products Journal, Vol.23, No.2, pp.28- 34

The First Thai-Biomass Utilization Symposium ______Effective Utilization of Forest Biomass for Regional People in Thailand [8] Thongsumrit, V. and Viengsima, T., 1995, The Study of Solid Content of Urea-formaldehyde resin to Physical Properties and Mechanical Properties of Medium Density Fiberboards from Rubber wood (Hevea brasilliensis, Muell, Arg.), ” Bachelor of Civil Construction and wood- working Technology, King Mongkut’s Institute of Technology North Bangkok, 99p.