Until now, composite materials of wood flour and plastic (wood plastic material, WPC) have been used in wood deck and park facilities as anti-septic woods, but they were manufactured in long bar-shape with same cross-sectional shape by the method called “extrusion molding”. On the other hand, there is a method suitable for mass-production called “injection molding”, that injects heat-melted resin into a metal mold as a method of making a form such as a bucket or a toy. But it has been considered remarkably difficult to injection mold with wood plastic composite, and there has been almost nothing produced commercially.

Usually, WPC’s melt viscosity is remarkably large, if you raise the molding temperature at 200? higher in order to reduce the melt viscosity, wood components will thermally decompose, resulting in bad odors and burns resulting in blackening. There are many difficulties to realize commercial production by injection molding. The manufacturing technology that we have established for WPC allows injection molding, which up to now has been regarded as impossible. “i-WPC” can be molded with general-purpose plastic injection molding machines and metal mold.