Lightweight Flat Pressed Wood Plastic Composites: Possibility of Manufacture and Properties

Usually the conventional wood plastic composites (WPC) are produced with the densities of approximately 800-1000 kg/m3. The possibility of manufacture and properties of the lightweight fl at pressed WPC using expanded polystyrene was described in this study. The shredded recycled low density polyethylene (rLDPE), wood particles (WP) and expanded polystyrene (EPS) were used for making one-layer lightweight WPC boards (non-laminated and laminated). Bending strength (MOR), modulus of elasticity (MOE), tensile strength perpendicular to the plane of the board (IB) and thickness swelling after immersions in water for 2 hours (TS/2h) and 24 hours (TS/24h) of the lightweight WPC boards were evaluated. It was established that the EPS content and boards’ density as well as the lamination process have a significant impact on the properties of lightweight WPC boards. Thus, it was found that the use of expanded polystyrene enables the production of lightweight WPC within a density range of 500-700 kg/m3, which is almost twofold less than the density of the conventional WPC. The results of research have shown that the bending strength, modulus of elasticity and internal bond strength of non-laminated lightweight WPC boards meet the requirements (for lightweight particleboards) of EN 16368 (type LP1) and ANSI A208.1 (types LD-1 and LD-2) standards. The bending strength and modulus of elasticity of laminated lightweight WPC boards meet the requirements of ISO 13894-2.