| 摘要 |
PROBLEM TO BE SOLVED: To provide an extrusion molding machine capable of extrusion-molding pipe moldings of excellent appearance and high quality without the generation of a flight mark on the external wall face of the pipe moldings in an extrusion molding process for molding the pipe, and an extrusion molding method. SOLUTION: This extrusion molding machine is equipped with a screw arranged in a freely rotating manner and also in the axial direction inside the cylinder body of the extrusion molding machine so that a raw material resin powder supplied into the cylinder body of the extrusion molding machine is melted and kneaded and a die part having an annular opening arranged at the downstream side of the screw in order to mold the molten resin melted and kneaded by the screw into the shape of a pipe. Further, the screw is formed in such a tapered shape that the protruding height of a screw flight formed on the outer periphery of a screw shaft gradually decreases. |
