Title:
METHOD AND APPARATUS FOR INJECTION COMPRESSION MOLDING
Document Type and Number:
WIPO Patent Application WO/1989/011960
Kind Code:
A1
Abstract:
A desired quantity of a molten thermoplastic resin is injected into a mold cavity which has a greater capacity than a product volume and is set in advance to a higher temperature than the temperature at which the thermoplastic resin starts curing under a normal pressure. The thermoplastic resin thus injected is cooled inside the mold cavity and is pressed before it is cooled down to a temperature at which it starts curing under a normal pressure. Due to this pressing, the glass transition point of the thermoplastic resin is shifted to a higher temperature side and the thermoplastic resin cures during a small temperature drop. The thermoplastic resin is cooled in the pressed state until dynamic rigidity at normal temperature and normal pressure is obtained. The thermoplastic resin is further cooled to a withdrawing temperature and the pressure applied to the thermoplastic resin is controlled so that dynamic rigidity of the thermoplastic resin during this cooling process can be maintained at that at the normal temperature and normal pressure by offsetting the rise of dynamic rigidity of the thermoplastic resin to be caused by cooling.
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Inventors:
UEHARA TADAYOSHI (JP)
NAKAGAWA TATSUJI (JP)
OYAMADA YASUHIKO (JP)
NAKAGAWA TATSUJI (JP)
OYAMADA YASUHIKO (JP)
Application Number:
PCT/JP1988/000536
Publication Date:
December 14, 1989
Filing Date:
June 01, 1988
Export Citation:
Assignee:
AIDA ENG LTD (JP)
International Classes:
B29C45/04; B29C45/00; B29C45/56; B29C45/70; B29C45/73; B29C45/76; B29C45/77; B29C45/78; (IPC1-7): B29C45/56
Foreign References:
| JPH06260623A | 1994-09-16 | |||
| JPH06223723A | 1994-08-12 | |||
| JPH06212019A | 1994-08-02 |
Other References:
See also references of EP 0369009A4
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