| 摘要 |
PURPOSE:To attempt dissolving of irregularity in color, warpage, shrinkage, etc., by increasing a kneading effect by a method wherein a gap between an outer peripheral surface of a main flight and an inner wall surface of a cylinder barrel is made invariable in an injecting direction of resin, and an outer diameter of a sub flight is gradually decreased in the injecting direction of the resin. CONSTITUTION:A sub flight 6 which is separated into a resin material supply side screw groove 7 and a fusion plasticized resin discharge side screw groove 8 within a partial range of a screw 1 in a cylinder barrel 4, is provided between main flights 2. Herein, a gap (alpha) between the cylinder barrel 4 of a compression part CZ and the main flight 2 is constant toward an injecting direction of resin. Further, a gap between the cylinder barrel 4 and the sub flight 6 has a gap (beta1) between an outer peripheral surface of the sub flight 6 at a border part between a feed zone FZ and the compression zone CZ and an inner wall surface of the cylinder barrel 4, and a gap (beta3) between the outer peripheral surface of the sub flight 6 at the border part between the compression zone CZ and the metering zone MZ and the inner wall surface of the cylinder barrel 4, and a gap interval is made to be gradually increased like beta1<beta3. |
