To improve the strength of the mouth part of a bottle by a method wherein the mouth part is re-heated for crystallization under the condition that a guide pin is closely inserted in the mouth part after the mouth part of a perform or the mouth part of the bottle after blow molding is heated with a heating body.
A support 61, which pressingly holds the bottom part of a forming body against the freely rotatable holder 43 at the tip part of a rotary shaft part 42, is equipped with the bottom part of a perform 32 or a recessed part 63 corresponding to the outer shape of the bottom part of a bottle after forming in a block body 62 mounted to a shaft part 64 drivingly rotated by a motor. The recessed part 63 is equipped with an air-sucking hole 62a for suckingly fixing so as to suck air through an air passage 64a in the shaft part 64 in order to suckingly hold the bottom part of the perform 32 or the bottom part of the bottle after forming. Under the condition that a guide pin 44 is tightly insertingly held in a mouth part 32c, the shaft part 64 and the block body 62 are drivingly rotated so as to uniformly heat the mouth part 32c with a heating body 51. The stable uniform crystallization of the bottle mouth part 32c can be realized, resulting in allowing to improve the strength of the mouth part.
IWASAKI AKITAKA
SAITO TAKASHI
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