Method of producing a hollow resin body and apparatus therefor
AssigneeToyoda Gosei Co., Ltd.
InventorsMitsuo Ogura, Hironao Tanaka
Life of this patent
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Abstract
After molten resin is injected into a mold cavity, an inert gas is sent from an inert gas supply device into the molten resin through a change-over valve and a gas nozzle device so that the molten resin is injection molded. At the same time, a tub is filled with part of the molten resin through a tub communication path. Thereafter, a burr portion of the injection-molded resin is bored using a boring punch so as to make a space within the hollow resin body communicate with the atmosphere. Next, the change-over valve is switched to send a cooling gas from a cooling gas supply device to the hollow space within the hollow resin body so as to cool the injection-molded resin.
Claims10
A method for manufacturing a hollow resinous body, comprising the steps of:
- providing a mold having a molding cavity and a resin tub which is in communication with the molding cavity through a tub communication path;
- closing off the tub communication path;
- supplying molten resin into the molding cavity;
- injecting a gas into the molten resin and opening the tub communication path so as to form a hollow space within the molten resin, thereby forming a hollow body;
- forming a through hole in the hollow body such that the hollow space is opened;
- supplying a mixture of an atomized liquid carried by a gas as a cooling medium into the hollow space to cool the hollow body;
- and
- discharging the cooling medium through the through hole.
Dependencies are inferred from the claim text.