| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing an injection-molded product not having an internal gap and having no sink on the outside thereof. SOLUTION: High temperature plastics is energized from a half of one mold by pressure gas to be separated and pressed to the other half to separate mold parts 14 and 16. The pressure gas is uniformly distributed behind the high temperature plastics and the pressure thereof is kept during cooling. The plastics fills a cavity 18, but does not fill the same perfectly. When the mold parts 14 and 16 are again closed, the locking surfaces of them are held to a contact state or a partially closed state. Since the gas in a mold cavity 18 is prevented from reaching the finish outer surface of a finished part during the shrinkage of the plastics, a gas seal is formed by the plastics. A large plastic volume region is provided to the root of the mold cavity corresponding to a part forming a rib in the molded product.
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