Patent ID: 8870441
Filing Date: 2014-10-28
Classification: B29C

Abstract:
1. A plastic extrusion method comprising: preparing a cylinder comprising a transport section cylinder, a kneading section cylinder and a releasing section cylinder, wherein a screw is installed in the cylinder and comprises a transport section screw, a kneading section screw and a releasing section screw; supplying a plastic raw material into the cylinder from a hopper of a raw material supplying portion at an upstream side of the transport section cylinder; plasticizing and kneading the plastic raw material; and extruding the plasticized and kneaded material from the releasing section cylinder, wherein the transport section cylinder comprises an upper polygonal groove and a transition portion, the upper polygonal groove beginning at a downstream end of the hopper, the transition portion being arranged at the downstream side of the upper polygonal groove and being configured as a shape in which the upper polygonal groove tapers downward so as to gradually disappear before reaching the kneading section cylinder, and wherein in the supplying the plastic raw material, the plastic extrusion method comprises releasing at least inert gas components and volatile components toward the hopper when the plastic raw material passes through the upper polygonal groove.