PURPOSE: To eliminate a defective article from interposing dust in air and the circumference between a metallic mold and a formed film and to obtain a formed article whose accuracy is increased in accordance with a metallic mold, by executing a resin molding in the vacuum, and subsequently forming a thin film on the surface of its formed article without breaking the vacuum.
CONSTITUTION: Air in a metallic mold 12 and dust adhering to the inside surface are absorbed and removed by operating a vacuum pump in a state that the metallic mold 12 is placed in vacuum resin molding chamber 1, also air in the inside of a cylinder of an injection molding machine 2, and a hopper 5 and a raw material resin (a) particle space, and dust adhering to them are absorbed and removed, and thereafter, the metallic mold 12 is closed, for instance, under a vacuum of 10-5 Torr, the injection molding machine 2 is operated by a regular method, the resin (a) is pushed and fed in the cylinder, and a molten resin is injected into the metallic mold 12 by a piston 9. As for the molten resin, air is removed in advance, and also the outside circumference of a nozzle 6a of its cylinder 6 is in a vacuum state, therefore, its injected resin does not contain air, the resin itself adheres tightly to the inside surface of the metallic mold 12, and an injected formed article A the same as the metallic mold 12, for instance, a formed disk is formed.
OOTA YOSHIFUMI
AZUMI TSUTOMU
| JPS5949941A | 1984-03-22 |