Adhesion and bonding charecteristic of preservatives treated bamboo (gigantochloa scortechinii) laminates

This study were investigate the adhesion and bonding characteristics of bamboo (Gigantochloa scortechinii) strips and laminates treated with permethrin-based preservative (Light Organic Solvent-Based (LOSP) and Water-Based (WBP)) formulations, Tributyl Tin Oxide (TBTO) and borax. The bomboo culm were cut into strips and treated with those selected chemicals. The bamboo strips were then glued edge to edge to form a bamboo veneers before fabrication of the three ply perpendicular bamboo laminates. In this research the properties studied include wettability, buffering capacity, shear strength and wood failure. Untreated strips and bamboo strips which were boiled in water (100°C) were also tested for comparison purposes. Those strips treated with LOSP had higher contact angle (3°-9°) which reflects that the surface of the treated strips is less readily wetted. Whereas, borax-treated strips had the highest wetting rate where the value is 1°. In buffering capacity study shows that treated bamboo was more stable towards alkali. This is suggested that a buffering agent (Calcium carbonate) is required in the adhesive formulation to ensure sufficient curing of the resin. Preservative treatments on bamboo strips significantly affect shear strength and wood failure of the laminates. Shear and wood failure of the laminated bamboo were significantly reduced especially in the wet condition where, the range is 0 N mm-2 (WBP treated) to 0.65 N mm-2 (boiled-treated) when compared to untreated bamboo laminates (0.79 N mm-2). While, in dry condition test, the glue bond strength of were range from 0.64 N mm-2 (WBP-treated) to 2.04 N mm-2 (borax-treated). All chemicals and non-chemical treatment generally affects the glue strength of the bamboo laminates especially in wet condition test. In dry condition test there are slightly reductions in glue bond strength but the quality still meets the requirement in the British Standard Part 8: Specification for Bond Performance of Veneer Plywood

The behaviour of boron compounds in treated rattan when dehydrated at high temperatures

The behaviour of boron compounds per se and boron compounds in treated stem of rotan manau (Calamus manan A1iq.) dried at elevated temperatures was studied. When borax and boric acid are mixed, sodium 1:5 borate is formed. After drying at 100±30, 50±10, or <O°C, the measured and the calculated (in parentheses) percentage weight losses from the mixtures were 40.34 (40.10), 39.31 (36.39) and 29.43% (30.11 %), respectively. The experimentally measured values were used to estimate the amount of solute retained in the rattan samples which had been treated with such a boric acid-borax mixture and then dried. The further weight losses of the mixture in treated rattan dried at higher temperatures are presumably attributable to: 1. the volatilization of low molecular weight rattan components; 2. the volatilization of boric acid in water vapour during drying and 3. the mechanical loss of permeating liquid during the early stage of drying. Treatments of rattan or other cellulosic material which involve boric acid in aqueous solution should avoid high temperature drying in order to ensure optimum retention of boric acid equivalent (BAE)

Nonwood-based composites

Nonwood fibers are derived mostly from fastgrowing plants. For the past few decades, nonwood plant fibers have received much attention, especially for composite material applications, because of their low cost, low density, high specific strength, good mechanical properties, nonabrasiveness, eco-friendliness, and biodegradability. This article reviews the performance of nonwood fibers found mostly in Asia, as well as issues regarding their bonding. Because various classifications of nonwood exist, this article sorts nonwood fibers based on previous classifications with some modifications, accounting for the availability of these fibers in Asia. The mechanical and physical properties of nonwood-based composites such as fiberboard, particleboard, and veneer-based laminated products also are reviewed and discussed. All fibers demonstrate certain advantages over conventional composites, with some having better mechanical and physical properties. This article also highlights the issues and challenges regarding the use of nonwood fibers as composite materials

Equilibrium moisture content and volumetric changes of Gigantochloa scortechinii

Equilibrium moisture content and volumetric changes of Gigantochloa scortechinii. Relative humidity (RH) is known to affect the moisture content (MC) of bamboo but to date, only the maximum shrinkages at the tangential and radial directions were commonly determined. For bamboo to be glue-laminated and used as building components, the hygroscopicity of bamboo split and strip, and its effects on the shrinkage/swelling behaviour in relative humidities between 12 and 93% were studied. The equilibrium moisture content (EMC) and dimensional changes of Gigantochloa scortechinii (buluh semantan) were determined with the fibre saturation point (FSP) obtained by extrapolation. Experimental EMC values obtained at various levels of RH showed little variation between bamboo split and strip. However the degree of volumetric shrinkage and swelling changes varied between the variables studied. In transverse section, the bamboo strip is relatively stable in shrinkage at lower relative humidity, although during adsorption the volumetric swelling is high. The mean FSP for G. scortechinii was 24.28%. This study showed that the readiness of bamboo to dimensional changes below FSP was of prime concern. By understanding the hygroscopic characteristics and behaviour of G. scortechinii, users would be able to understand the limitations of the material and find alternatives to prevent these changes before it could be used as building components

Characterization of plant nanofiber-reinforced epoxy composites

In the present study, oil palm empty fruit bunch (OPEFB) fibers were taken from a 25-year-old oil palm tree. The cellulosic nanofiber (CNF) was isolated from the OPEFB using a chemo-mechanical process and utilized as reinforcement in an epoxy matrix. Various CNF loading percentages (0 to 0.75%) were applied in the epoxy matrix to explore the potential of using OPEFB-CNF as reinforcement. The morphological, mechanical, physical, and thermal characteristics of the OPEFB nanofiber-reinforced epoxy composites were evaluated. Results showed that the 0.25% and 0.5% CNF loadings were homogenously distributed and well-dispersed in the composite matrix. Conversely, agglomeration was detected in the matrix with 0.75% CNF loading. Determination of the water absorption behavior of CNF-reinforced epoxy composites at various loadings revealed that the physical properties of the composites increased with reinforcement loading. Furthermore, the analyses of the mechanical and thermal properties of the CNF-reinforced composites revealed that the incorporation of OPEFB-CNF enhanced the mechanical performance and thermal stability up to 0.5% loading

Effects of chemicals treatments on durability properties of Gigantochloa scortichinii strips and ply-bamboo

The aim of this study is to investigate the effect of some preservative treatment on the durability properties of bamboo (Gigantochloa scortechinii) strips and bamboo laminated product. The durability properties are examined by exposed the of bamboo samples to termite (Coptotermes curvignathus) for 4 weeks and white rot fungal (Pycnophorous sanguineus Wulfex Fries) for 12 weeks. The efficacy of treatments on bamboo strips and laminates against white rot and termite attacks were evaluated based on their weight loss after exposure to those biodeteriorating agents. All preservative-treated materials had resulted lower weight loss values compared to untreated and water-boiled bamboo treatment. The Water-Borne Preservatives (WBP) (5.80% weight loss) gave the best protection against termite whereas borax acid-treated (39.3%) materials had the least efficacy on protecting the strips. For the bamboo laminates, TBTO gave the best protection against termite attacks with only 8.9% of weight loss. The durability test against white rot fungal show that all preservative increased the resistance of bamboo strips and laminates. TBTO was found to be the best preservative to protect both bamboos strips (10. 7% weight loss) and laminates (9.71% weight loss). Boiling in water for 30 minutes had decreased the resistance of the strips against white rot with the weight loss value for this strip was 21.8 while 22.4% for the laminates

EQUILIBRIUM MOISTURE CONTENT AND VOLUMETRIC CHANGES OF GIGANTOCHLOA SCORTECHINII

M. 2007. Equilibrium moisture content and volumetric changes of Gigantochloa scortechinii. Relative humidity (RH) is known to affect the moisture content (MC) of bamboo but to date, only the maximum shrinkages at the tangential and radial directions were commonly determined. For bamboo to be glue-laminated and used as building components, the hygroscopicity of bamboo split and strip, and its effects on the shrinkage/swelling behaviour in relative humidities between 12 and 93% were studied. The equilibrium moisture content (EMC) and dimensional changes of Gigantochloa scortechinii (buluh semantan) were determined with the fibre saturation point (FSP) obtained by extrapolation. Experimental EMC values obtained at various levels of RH showed little variation between bamboo split and strip. However the degree of volumetric shrinkage and swelling changes varied between the variables studied. In transverse section, the bamboo strip is relatively stable in shrinkage at lower relative humidity, although during adsorption the volumetric swelling is high. The mean FSP for G. scortechinii was 24.28%. This study showed that the readiness of bamboo to dimensional changes below FSP was of prime concern. By understanding the hygroscopic characteristics and behaviour of G. scortechinii, users would be able to understand the limitations of the material and find alternatives to prevent these changes before it could be used as building components. Keywords: Bamboo, fibre saturation point, volumetric shrinkage and swelling HAMDAN, H., HILL, C. A. S., ZAIDON, A., ANWAR, U. M. K. &amp; ABD. LATIF, M. 2007. Kandungan lembapan seimbang dan perubahan volumetrik Gigantochloa scortechinii. Kelembapan relatif (RH) mempengaruhi kandungan lembapan (MC) buluh tetapi sehingga kini hanya pengecutan maksimum pada arah tangen dan jejari sahaja banyak ditentukan. Bagi buluh untuk dilaminakan dan digunakan sebagai bahan binaan, kajian terhadap ciri higroskopik buluh belah dan buluh jalur serta kesannya terhadap kelakuan pengecutan/ pembengkakan pada kandungan lembapan antara 12% hingga 93% dikaji. Kandungan lembapan seimbang (EMC) dan perubahan dimensi Gigantochloa scortechinii (buluh semantan) ditentukan dan takat tepu gentian (FSP) diperoleh secara ekstrapolasi. Nilai EMC pada pelbagai tahap RH menunjukkan sedikit perbezaan antara buluh belah dengan buluh jalur. Namun darjah perubahan pengecutan dan pembengkakan isi padu berbeza antara pemboleh ubah yang dikaji. Pada keratan melintang, pengecutan buluh jalur secara relatifnya agak stabil pada RH rendah walaupun semasa jerapan air, kadar pembengkakan tinggi. Purata FSP untuk G. scortechinii ialah 24.28%. Kajian menunjukkan bahawa faktor FSP perlu dititikberatkan kerana mempengaruhi perubahan dimensi buluh. Dengan memahami ciri higroskopik dan kelakuan G. scortechinii, pengguna boleh memahami keupayaan bahan tersebut dan mencari pilihan bagi mengurangkan perubahan dimensi sebelum ia boleh digunakan sebagai bahan binaan

Adhesion and bonding properties of low molecular weight phenol formaldehyde-treated plybamboo

This study investigated the adhesion of bamboo (Gigantochloa scortechinii) strips after impregnation with phenolic resin and the effect of curing time on bonding properties of low molecular weight phenol formaldehyde (LMwPF)-treated plybamboo. The optimum pressing time to produce LMwPF-treated plybamboo was also determined. Properties studied included wettablity, buffering capacity, shear strength and wood failure. The study showed that phenolic-treated strips had higher contact angle and, thus, were more difficult to be penetrated by liquid compared with untreated strips. Buffering capacity showed that bamboo strip was stable towards acid. Shear bond strength of the plybamboo met the requirement of BS EN 314-1. The study concluded that the optimum pressing times were 22 and 33 min for three- and five-ply plybamboo respectively to produce good glue joints

Mechanical and physical properties of particleboard made from 4-year Old RRIM 2000 series clone rubberwood.

Rubber trees are normally felled after 25 years. With the drastic depletion of rubberwood supply, the Malaysian Rubber Board has identified new clones of rubberwood from RRIM 2000 series that are expected to be suitable for timber and latex production. In this study, particleboards were made from 4-year-old RRIM 2000 series rubberwood clones. The clones—RRIM 2002, RRIM 2020 and RRIM 2025 were compared with the currently available clone, PB 260, that is used by most rubberwood processing plants in Malaysia. The board was fabricated using E1 grade urea formaldehyde resin to a density of 700 kg m-3 and board performance was determined according to JIS A 5908-2003. The study revealed that it was technically feasible to use 4-year-old rubberwood from the RRIM 2000 series clones, especially RRIM 2002, for making particleboard which is comparable to that made from the mature (25-year-old) PB 260 clone