Biological performance of wood- and bamboo-polypropylene composites: Effects of particle content, particle size and Zn borate
S N Kartal, S Aysal, E Terzi, T Yoshimura, K Tsunoda
Particle content and size of wood material in wood plastic composites (WPCs) can affect efficacy of WPCs against fungi and termites. This study evaluated fungal and termite resistance of WPCs manufactured by using two different levels of particle content (50 and 70%) and three different particle sizes (30, 60, and 100 mesh). In fungal resistance tests, Tyromyces palustris, a standardized test fungus, Schizophyllum commune and Pycnoporus coccineus observed previously on commercial WPC products in field tests by various researchers were employed. Termite resistance tests were performed in laboratory conditions using the subterranean termites, Coptotermes formosanus. Mold growth on the WPCs was evaluated in a test period of 4 weeks. In general, WPC specimens containing higher particle content and smaller particle size resulted in increased mass losses in decay resistance tests. As particle content increased, mass losses in the specimens in termite resistance tests increased; however, decreased particle size caused slightly decreased mass losses. The composite specimens along with Zn borate treated specimens were completely colonized by the fungi in a short period of 4 weeks.