Preparation of Wood Plastic Composite Sheets by Lateral Extrusion of Solid Woods Using their Fluidity

Abstract

Abstract During the course of our studies, we have learned that solid wood has significant deformability characteristics under specific conditions, resulting from slippage occurring among wood cells when wood treated with small-molecular resins is compressed under heat. Furthermore, the deformed shapes obtained are maintained when the resin introduced into the wood cells is cured. In this study, the lateral extrusion of thin discs of wood treated with thermosetting phenol resin is performed to apply this flowlike deformation behavior of wood to wood-forming techniques. Resin-treated thin discs of wood placed in a heating container were compressed by a punch, and under constant pressure the wood flowed into the cavity of a mold. Successful molding conditions were achieved by varying the pressure, temperature and wood fiber direction for the extrusion ratio of 42. The mechanical properties of the wood plastic composite (WPC) sheets obtained by this extrusion process are affected by the fiber direction of the wood in the extrudate, which is almost equivalent to the longitudinal direction of the cellulose crystals of wood. The maximum bending strength of the WPC sheets obtained was about 180 MPa, which is suitable for engineering plastics.