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Abstract
This study investigated some of the important properties of single-layer particleboard panels made from bamboo (Dendrocalamus asper), rice straw, eucalyptus (Eucalyptus camaldulensis), or combinations of them. A total of 40 experimental panels were manufactured from each material type. Panels were also made using a 50:50 ratio of eucalyptus and bamboo, eucalyptus and rice straw, and bamboo and rice straw; a 50:25:25 ratio of eucalyptus, rice straw, and bamboo; and a 70:15:15 ratio of eucalyptus, rice straw, and bamboo, respectively. Average target density of the panels ranged from 0.75 to 0.78 g/cm^sup 3^. Modulus of rupture, modulus of elasticity, internal bond strength, thickness swelling, water absorption, density profiles, and surface roughness of the specimens were determined. Panels with 50:50 bamboo and eucalyptus particles resulted in the highest mechanical properties followed by panels made from 100 percent bamboo. Boards manufactured with 100 percent rice straw produced the lowest properties. The amount of rice straw in the panels significantly reduced both physical and mechanical properties of the samples. The overall panel properties improved as lower percentage of rice straw were added to the mats. Based on initial results of this study, three under-utilized species can be used to manufacture value-added particleboard panels. It also appears that an addition of rice straw into the mats should be less than 15 percent to achieve better panel properties.
Similar to many other countries in Asia, the forest resources of Thailand were over harvested in the past. Deforestation has created more erratic rainfall patterns, increased flooding, and a decline in the availability of lumber products. This has significantly influenced the wood products industry including composite panels manufactured in the country (Suksawadi 1996).
Wood composites panels, such as particleboard and fiberboard, are manufactured in Thailand from under-utilized hardwood species from forest plantations, such as rubberwood (Hevea brasiliensis). Currently, there are six composite panel (fiberboard and particleboard) manufacturers in Thailand and the majority of them use rubberwood as a raw material. The annual consumption of rubberwood was 240,000 m^sup 3^ during the early 1990s and it has continued to increase. Unfortunately, rubberwood has suffered from a low recovery rate of around 15 to 35 percent due to the use of poor technology and lack of technical knowledge in Thailand (Laemsak 2002). The...