EFFECTS OF WOOD PARTICLE SIZE AND TEST SPECIMEN SIZE ON MECHANICAL AND WATER RESISTANCE PROPERTIES OF INJECTED WOOD–HIGH DENSITY POLYETHYLENE COMPOSITE

The objective of this study was to evaluate mechanical (tensile modulus and strength and flexural modulus and strength) and physical (water absorption and thickness swelling) properties of wood–plastic composites made from industrial wood particles used for manufacturing three-layer particleboards and highdensity polyethylene. The effects of wood particle (WP) size (0.25-0.5, 0.5-1, and 1-2 mm) and test specimen cross section (4 10, 6 15, and 8 20 mm2) were investigated. Mechanical properties increased with increasing WP size because of the higher aspect ratio of larger WPs. Composites with larger WPs had lower water resistance. The values of both mechanical and water absorption properties derived from specimens with a larger cross-sectional area were lower than those derived from specimens with a smaller cross-sectional area