Biological, physical and mechanical properties of particleboard manufactured from waste tea leaves

Environmental questions have arisen from the use of chemicals in wood or bio-based composite to stop biodeterioration. As a consequence, various environmentally friendly treatments or naturally durable plant species are now being evaluated. We believed the high phenolic extractive content of tea leaves, and their abundance as residual waste at tea producing factories warranted studies on the utilization of these wastes in particleboard manufacture. Waste tea leaves particleboard (WTLB) is expected to be more resistant against biological agents owing to high phenolic extractive content. Mass loss of WTLB, the edges of which had been sealed with an epoxy, was 3.5-8.6% and 6.0-12.1% for paraffin-added and non-added specimens, following degradation by Tyromyces palustris and Coriolus versicolor, respectively. The addition of paraffin to binder UF resin during the manufacturing of the board and sealing the edges of specimens before decay testing kept degradation to a minimum. In reference materials reported previously, WTLB proved resistant to decay-type fungi. Mass loss of WTLB after exposure to Formosan subterranean termite Coptotermes formosanus was around 16%. However, termite mortality levels and trends over the three weeks of termite attack suggest that phenolic extractives of tea leaf act as natural toxicants that gradually but steadily increase mortality particularly from the third week of exposure. Tested physical and mechanical properties of WTLB indicated that it performs as well as the general purpose boards designated in BS 5669. (C) 1998 Elsevier Science Ltd. All rights reserved.