THICKNESS ADJUSTING DEVICE FOR PARISON

摘要

PROBLEM TO BE SOLVED: To improve the responsiveness of thickness adjustment during the injection of a parison while the thickness thereof is being adjusted (adjustment is made to vary the thickness in a longitudinal direction). SOLUTION: A first core 12 is secured to a fixed part of a housing 22. A die 10 is provided so as to be radially spaced apart from the outer periphery of the core 12. The die 10 is supported by a die holder 24 so as to be vertically movable. A first resin passage 14 formed between the inner periphery of the die 10 and the outer periphery of the core 12 comprises an upper side straight cylindrical passage 14a and an approximately funnel-shaped passage 14b which continuously extends downward from the passage 14a with its diameter being made exceedingly smaller with distance from the passage 14a. An injection port 16 is formed on the lower end side of the die 10 and core 12.