Possibility of extrusion of wood powders

Extrusion tests of mixed wood powders of cryptomeria with the Japanese cypress are carried out at various temperatures in order to confirm the possibility of near net shape forming of wood powders. Effects of extrusion temperature, extrusion ratio, moisture content and particle size of the mixed wood powders on the flow characteristics, bending strength, hardness and bulk density of extruded products are discussed. The experimental results show that the fluidity of the mixed powders and the bending strength and bulk density of extruded products increase with increasing temperature and moisture content of powders. However, when the extrusion temperature is too high, the bending strength and bulk density of extruded products tend to decrease due to bubbles generated in the extruded product.