Title:
METHOD AND DEVICE FOR INJECTION MOLDING SYNTHETIC RESIN MOLDED ARTICLE
Document Type and Number:
Japanese Patent JP3469647
Kind Code:
B2
Abstract:
PURPOSE: To obtain an injection molding method for a synthetic resin molding, capable of preventing a defect caused by residue of air in a cavity and eliminating the sinkmark, warpage, and distortion of the molding.
CONSTITUTION: After a melt resin is charged in a cavity 8 with the suction of air in the cavity 8 of molds 4, 5, compressed fluid is injected to the rear surface of a molding 90 in the cavity 8 before the melt resin is completely cooled and set. The suction of air eliminates residual air in the cavity 8 and prevents a defect caused by the residual air. The molding 90 is cooled and set with the top surface pressed against an inner surface of the cavity 8 by the injection of the compressed fluid. In this manner, the molding 90 has no sinkmark on the top surface thereof even when having a rib 91.
Inventors:
Takayoshi Tanaka
Application Number:
JP20962494A
Publication Date:
November 25, 2003
Filing Date:
September 02, 1994
Export Citation:
Assignee:
Idemitsu Petrochemical Co., Ltd.
International Classes:
B29C31/04; B29C45/17; B29C45/34; B29C45/57; (IPC1-7): B29C45/57
Domestic Patent References:
| JP61192531A | ||||
| JP51130468A | ||||
| JP6112314A | ||||
| JP608029A | ||||
| JP454815U | ||||
| JP5975020U | ||||
| JP59384B2 |
Other References:
【文献】欧州特許出願公開593308(EP,A1)
Attorney, Agent or Firm:
Minoru Kinoshita (2 outside)
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