| 摘要 |
PURPOSE:To obtain the stiffness of a mouth part of a wide mouthed jar and the stability of its dimension accuracy by a method wherein the biaxially oriented blowing is carried out after the mouth part of a molding product is crystallized by the heat treating. CONSTITUTION:A molding product 1 which is injection molded using thermal plasticity synthetic resin such as polyethylene terephthalate resin etc. is layed on a jig 9 and a mouth part 3 is heated from above and outside directions (arrow marks), and furthermore is gradually cooled and crystallized. The jig 9 is made in the cylinder shape, the upper end surface of the jig is abutted against a step part 8 in order to prevent a main body from being heated and crystallized. The stiffness will be ensured as well as the stability of the dimension is maintained by carrying out the blowing of the wide mouthed jar body after the mouth part of the molding product is crystallized in this manner. |
