Bondability of tropical fast-growing tree species I: Indonesian wood species

To estimate the potential bonding performance of bonded wood products from tropical fast-growing tree species, a study on the bondability of Paraserianthes falcataria L. Nielsen, Pinus merkusii Jungh et. De. Vriese, and Acacia mangium Willd from Indonesia was conducted. Two-ply laminations were produced using polyvinyl acetate emulsion (PVAc), urea formaldehyde (UF), resorcinol formaldehyde (RF), and water-based polymer isocyanate (API) adhesives. In order to determine the bonding performance, the block-shear test was applied according to the Japanese Agricultural Standard for structural glued laminated timber under normal conditions and after accelerated-aging treatments. To support this study, the wettability of each wood species was also investigated through contact-angle measurement. The results showed that the bonding performance of low-density P. falcataria was better than that of medium-density P. merkusii and medium-density A. mangium, while the bonding performance of medium-density P. merkusii was better than that of medium-density A. mangium. Furthermore, compared with A. mangium, the small contact angle and good wettability in P. falcataria and P. merkusii result in better adhesion and more intimate contact between the wood surfaces and adhesive.