| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and a device for injection molding capable of maintaining or shortening a cycle time for molding while preventing the performance of a molded article from deteriorating by residual gas. SOLUTION: In the method for injection molding, a molten resin is injected into a molding space CV of a molding mold 40 to fill the molding space CV in such a state that the inside of the molding space CV is made to be comparatively low vacuum degree P2 by a lessening step (S14) for lowering the inside of the molding space CV than the vacuum degree P1 attained by a decompression step (S13). The molding space CV can be quickly depressurized thereby, and gas melted in a molten resin by the higher vacuum degree than necessary can be prevented from being separated from the molten resin. The cycle time for injection molding can be shortened by quickly depressurizing the molding space CV like this. Furthermore, a flow mark or the like can be prevented from being formed on the surface of a lens LE of the molded article by preventing gas from separating from the molten resin. COPYRIGHT: (C)2010,JPO&INPIT
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