| 摘要 |
PROBLEM TO BE SOLVED: To provide an extrusion-molded article which materialized various patterns concerning coloring density on its outer surface by variously changing the thickness of the outer layer without spoiling the productivity of extrusion molding. SOLUTION: With the use of a die for multilayer coextrusion molding which has at least an inner layer resin passage for forming the inner layer and an outer layer resin passage for forming the thin outer layer, the feeding speed of the outer layer resin forming the outer layer is changed periodically, and the resin is extruded while being stretched by a hauling machine. By combining the average of the feeding speed, the variation cycle of the feeding speed, the slit clearance of the outer layer resin passage at a spot just before the junction, and the hauling speed, the thickness of the outer layer is changed variously to develop the pattern concerning the coloring density on the outside surface of the molding. COPYRIGHT: (C)2008,JPO&INPIT |
