EXTRUSION MOLDING METHOD AND DEVICE FOR MULTI-LAYER PARISON

摘要

PURPOSE:To decorate the surface of a hollow container with a stripe pattern or the like by molding a sub-material layer on a desired site of the circumference in the meandering partially cylindrical shape and extrusion molding a multi-layer parison in which the sub-material layer is not molded partially. CONSTITUTION:Main material resin extruded out of a main material extruder 52 is passed through a resin base 10c and a main material resin passage 36 and stored in a main material accumulator 50. Also, sub-material resin extruded out of a sub-material extruder 54 is sotred in a sub-material accumulator 56. Respective pistons of both accumulators 50 and 56 are moved downward, and a tapering component 26 is rotated through a worm shaft and a worm in a manner of rotation by the given cycle. The main material resin is extruded in the cylindrical shape toward a die slit 20a of the main material resin passage by said arrangement, and the sub-material resin passed through a piping 42, a resin passage 10b and a sub-material resin passage 38 and extruded in the meadnering semi-cyrindrical shape toward the die slit 20a.