| 摘要 |
PURPOSE:To easily obtain an internal pressure resisting container, by a method wherein a closed end part of a parison is locally cooled, a bottom central part of a container is molded by blow molding without stretching the closed end part, and a bent- back part is formed between the bottom central part and a bottom peripheral part. CONSTITUTION:A cylinder part 3 of a closed-end parison molded from a synthetic resin by injection molding is heated to be stretchable, and the closed end part 2 of the parison 1 is cooled to a temperature at which the part 2 can not be stretched. The parison 1 is transferred into a cavity of a metallic mold 11 for blow molding which consists of left and right molds 6a, 6b and a bottom insert mold 7 projected to the inside of the metallic mold, and the mold 11 is closed. Then, primary blow molding is conducted by blowing primary pressurized air 12 into inside of the parison 1. Further, the closed end part 2 of the parison 1 is moved toward a top part 8 of the insert mold 7 by the tip 5a of a rod 5, the part 2 is clamped between the tip 5a of the rod 5 and the top part of the insert mold 8, and the cylinder part 3 is molded into a container shape by secondary pressurized air 13, thereby phi obtaining a container 15 with a bottom centeral part constituting a bent-back part 14. |
