| 摘要 |
PURPOSE:To inject a sublimable substance for forming a hollow part in a simple, low-cost, and safe manner by a method wherein after a melt resin is charged into a mold, a sublimable substance sublimating by the heat of the melt resin is injected in a required position of the melt resin through an injection path of the mold. CONSTITUTION:When a hollow molding is to be conducted, firstly a mold l is closed to a core mold 6, and a melt resin is charged into a cavity 3 formed between the cores through a sprue 22. Next, before the melt resin is cooled and set, a sublimable substance is supplied to a first path 21 a from a sublimable substance supply device 4, and a plunger 51 is advanced toward the cavity 3 by a piston 5 to inject the sublimable substance of a required amount in a required position of the melt resin charged in the cavity 3. Then, the sublimable substance rapidly sublimates to a gas by the heat of the melt resin, thereby being expanded in volume to press the melt resin outward and form a hollow part in the required position. In this manner, the molded piece has the hollow part in a thick-wall part. |
