SCREW PLUNGER TYPE BLOW MOLDING MACHINE

摘要

PROBLEM TO BE SOLVED: To improve conveying characteristics of a plastic material in a blow head. SOLUTION: An annular groove 13 is formed in an upper inside wall 2a of a blow head 2 in such a width as to cross three or more pitches P of a helical protrusion 9 of a rotary screw 7 at the uppermost portion thereof, and a feed port 11a of a hopper 11 for feeding plastic materials 10 into the groove 13 is connected to the groove 13 to use the groove 13 as a plastic feed port in the head 2. Thus the materials 10 fed from the hopper 11 can be surely fed into between the protrusions 9 so as to be distributed along the whole inner circumferential wall of the head 2, and hence the plastic materials 10 can be properly conveyed by the protrusions 9 regardless of the feed amount of the materials 10.