| 摘要 |
PURPOSE:To obtain a hollow molded article uniform in wall thickness, free of chaps and excellent in appearance by premolding a parsion in a high temperature mold and finish-molding an obtained semi-product in a low temperature mold. CONSTITUTION:A cylindrical parison 2 is injected from a parison die 1 between 1st molding dies 3, 4 kept at high temperature as much as 240-300 deg.C, the molding dies 3, 4 are closed, air is blasted from an air blast tube 9 into the parison 2, the parison 2 is expanded and premolded into a semiproduct state. Thus, since the 1st molding dies 3, 4 are kept at high tempeatures, the parison 2 is not attached and slides well even if it comes in contact with the surfaces of the molding dies and a semiproduct of uniform thickness is obtained. Then, the molding dies 3, 4 are opened, the semiproduct is stored in the 2nd molding dies 6, 7 kept at low temperatures, air is blasted again into the parison 2 and finish-molded to obtain a desired hollow molded article. |
