Patent ID: 8621829
Filing Date: 2014-01-07
Classification: B29B,B29C,B29K,B65D,Y10T

Abstract:
1. A method for producing a thermoplastic resin container for distinguishing before and after retort processing comprising: performing stretch blow molding on a preform made of a thermoplastic resin, thereby obtaining an intermediate body; heating the intermediate body to cause heat shrinkage; performing secondary stretch blow molding on the intermediate body wherein a part of the intermediate body is not stretched or insufficiently stretched and is rapidly cooled by a stretching rod, the bottom surface of the stretching rod being preliminarily cooled in cooling blocks, thermal effect of the cooling blocks being reduced by heat insulators; packing and sealing a content in the container; and then, heating the content and the container in a retort processing thereby whitening the transparent or translucent part not stretched or insufficiently stretched, wherein the secondary stretch blow molding is a biaxial stretch blow molding wherein the part that is not stretched or insufficiently stretched is at a bottom of the intermediate body, wherein the secondary stretch blow molding of the intermediate body is performed by longitudinally stretching the intermediate body with a stretching rod whose bottom surface of the tip end is cooled so that the part that is not stretched or insufficiently stretched and rapidly cooled is formed at a center part of a bottom part of the container.