| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a resin tube and its apparatus capable of forming a resin tube with a uniform thickness over the circumferential direction, even if molten resin is extruded horizontally from an extrusion mold. SOLUTION: The resin tube 1 can be formed with the uniform thickness over the circumferential direction, by extruding the molten resin 2 from the extrusion mold 20 with a central axis of an inner periphery of an outer mold 23 displaced upward in relation to a central axis of an outer periphery of an inner mold 22, and by extruding the molten resin 2 to make the upper thickness thick and the lower thickness thin in advance to move the resin from the upper side toward the lower side by self-weight. Thus, the productivity can be improved, dispensing with the labor for canceling unevenness of the thickness of the resin tube 1 by adjusting or exchanging the mold, as required in the past. COPYRIGHT: (C)2009,JPO&INPIT |
