Laboratory-made particleboards were tested for their resistance to subterranean termite, Coptotermes curvignathus Holmgren (Order Isoptera, Family Termitidae) by Indonesian standard SNI 01.7207–2006, during four weeks and at the end of the test their mass loss percentage and feeding rate were determined. Particleboards consisted of: jabon (Anthocephalus cadamba, Family Rubiacea) with a density of 0.41 g/cm3; sungkai (Peronema canescens, Family Verbenaceae) with a density of 0.46 g/cm3; mangium (Acacia mangium, Family Rhamnaceae) with a density of 0.60 g/cm3 separately and the three species mixture at a rate of 1:1:1. Densities of the boards were targetted at 0.60 g/cm3 and 0.80 g/cm3 by using 12% urea formaldehyde as binder with 2% paraffin as additive based on oven dry wood particle weight. The hand-formed mats and hot-pressing at 130 °C and 2.45 MPa for 10 min were applied. The results showed that particleboards density did not affect mass loss and feeding rate, but the particleboards made from higher density wood resulted in higher resistance to subterranean termite attack. The most resistant particleboards were made of magium, followed by sungkai, mixed species, and jabon.

No abstract

Wood has long been recognized by the community, as the multi-purpose materials. In this regard, wood materials can be utilized for either construction, decoration, source of ~nergy, weapons, or other uses. Wood, as multi-purpose materials and considering its ~ssential existence, in its development has underwent a lot of modification. This fact is also spurred by some accompanying inconvenient situations, e.g. more difficulty in procuring wood, the· ever-increasing price of solid wood products, and less available timber with adequate strength and high durability; and even by the demand of creating appropriate technology applicable to a more efficient wood utilization (Hadjib and Abdurachman, 1999).Since then, certain people or related parties have made a great stride in adopting proper technologies to convert wood such that its properties can be suited with the needs of the people/ parties referred to. Among them is the technology of manufacturing wood polymer composite (WPC) so-called more famously as wood plastic. Wood plastic has some benefits, among which are its rigidity and high strength, thereby rendering it suitable for its heavy-duty uses under harsh circumstances. Besides, this plastic technology can also transform wood of rather soft/weak texture as well as low durability into a hard, rigid, durable, dimensionally more stable, and stronger material (Had jib and Sumarni, 2000). I. INTRODUCTIONThe disadvantage of fast-growing species is that they have inferior physical and mechanical properties. Polystyrene impregnation can be applied to improve physical and mechanical properties. Wood samples, which were dried until 10% moisture content were put into impregnating tank and vacuum pressured at 20-mm Hg for two hours. During the gradual release of vacuum, styrene monomers, vinyl acetate monomers and terbutyl-peroxide catalyst was streamed into the tank. Afterwards, the pressure inside the tank was allowed to decrease to 500 mm Hg and kept for 60 minutes. Wood samples which had been impregnated were subsequently immersed in water, then wrapped in aluminum foils and put in the oven for 24 hours at 60°C. The samples were then tested for the polymer loading and their physical and mechanical properties. The results showed that the polymer loadings in wood plastics with the species of origin (i.e. consecutively sengon, pine and rubber wood) were 118%, 72% and 44%, respectively. Impregnation with polystyrene (copolymer of styrene and vinyl acetate monomers) could improve the physical and mechanical properties of wood plastics, i.e. specific gravity, moisture content, water absorption, shrinkage/ swelling, compression parallel to the wood grain, MOR and MOE. Greater use of vinyl acetate decreased physical and mechanical properties.Keywords: wood species, vinyl acetate, styrene monomers, polystyrene copolymer, wood plastic ABSTRACT Nurwati Hadjib1

This paper studies the physical and mechanical characteristics of the glued-laminated (glulam) beams

No abstract

Combination of bamboo and wood composite beam is ABSTRAKBalok komposit yang terbuat dari kombinasi bambu dan kayu adalah sebuah produk yang memungkinkan untuk dikembangkan. Pada umumnya, produk komposit dari kayu solid memenuhi persyaratan untuk kostruksi u , namun sifat balok komposit kombinasi bamb dan kayu belum dipelajari secara intensif mempelajari kombinasi . Tulisan ini sifat-sifat balok komposit dari tiga jenis bambu: andong, petung dan ori dengan kayu jabon menggunakan perekat isosianat dan ekstrak kayu merbau. Untuk meningkatkan keawetan balok komposit bambu dan kayu jabon diawetkan menggunakan larutan asam borik dan borak pada konsentrasi 7%. Hasil penelitian menunjukkan bahwa sifat fisik dan mekanik balok komposit bambu dan kayu jabon yang direkat dengan perekat isosianat lebih baik dari balok komposit tanpa kayu jabon. Kerapatan balok komposit terbaik ialah 0,64 g/cm pada kadar air 9,7%.

Betung bamboo (Dendrocalamus asper) samples were obtained from Bogor area, Indonesia. The samples were air dried, and then immersed into methyl metacrylate-urea solution for 24 hours prior to irradiation. Urea was added into methyl metacrylate (MMA) with concentration of 1%, 3%, and 5%, and without urea as control. The samples were vacuumed at 35 mmHg for five minutes prior to immersion, and without vacuum were done as well as control. The samples were wrapped up with aluminum foil and then with polyvinyl sheet, and irradiated with 60 Co gamma ray with 40 kGy. After opening the wraps, the samples were dried in the oven at 70 C for 24 hours. For comparison, the samples of control or original bamboo were also prepared. The all samples were tested for physical and mechanical properties. Factorial randomized complete design 2 Â 4 was used for analytical purpose the factors were vacuum treatment and urea concentration. The results showed that polymer loading of MMA-bamboo reached 10.7-12.8%, and the physical and mechanical properties were better than the origin. Vacuum treatment enhanced hardness only, and urea enhanced polymer loading and physical properties but reduced mechanical properties, and the addition of urea at 1% could be satisfied.

The objectives of this study were to investigate basic and drying properties of three wood species from Indonesia, i.e. kuda (Lannea coromandelica Merr.), waru (Hibiscus tiliaceus L. and mindi besar (Melia dubia Cav.). The basic properties include density, shrinkages, modulus of rupture (MOR), compression parallel to grain (C//), wood strength and anatomical structures. Meanwhile, the drying properties included drying time and drying defects. The initial-final temperature and humidity for each species was based on defects that resulted from high temperature drying trial.The results showed that the drying properties were significantly affected by wood anatomical structure. The initial-final drybulb temperature and wetbulb depression for kuda wood are 50 -70ºC and 3-30ºC respectively, while the corresponding figures for waru wood are 65-80ºC and 6-30ºC, and for mindi besar wood are 55-80ºC and 4-30ºC. These drying schedules, however, still need further trial prior to their implementation in the factory-scale operation. All wood species studied have density and considerable strength recommended in their use for light medium construction purposes. Mindi besar wood has decorative appearance so it is suitable for furniture.