Injection molding method with compression for hard

专利名称：Injection molding method with compression

for hardening

发明人：Tadayoshi Uehara,Tatsuji

Nakagawa,Yasuhiko Oyamada

申请号：US07/445868申请日：19891112公开号：US05108689A公开日：19920428

摘要：A predetermined amount of melted thermoplastic resin of raw material isinjected into a molding space which is previously set to a temperature higher than that atwhich the resin beings to harden under atmospheric pressure and which has a capacitylarger than a volume of a product. The injected resin is cooled in the molding space andpressurized before the resin is cooled to the temperature at which the resin begins toharden under atmospheric pressure. When pressurized, the glass transition temperatureof the thermoplastic resin is shifted to a higher temperature so that the thermoplasticresin hardens in slight reduction of the temperature. The resin is cooled in the

pressurized state until the resin possesses the dynamic rigidity under room temperatureand atmospheric pressure. While the thermoplastic resin is further cooled to theextraction temperature, the pressure applied to the resin is controlled until a furtherincrease of the dynamic rigidity due to the cooling ceases and the dynamic rigidity of thethermoplastic resin in the cooling is maintained to that under room temperature andatmospheric pressure.

申请人：AIDA ENGINEERING LTD.

代理机构：Wenderoth, Lind & Ponack

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