MOLDING OF DOUBLE-LAYERED MOLDED OBJECT

摘要

PURPOSE:To control the shape of a hollow part and to improve the 'sink' or deformation of a double-layered molded object to ensure excellent appearance. CONSTITUTION:A skin layer 3 is arranged in the cavity between movable and fixed molds 1, 2 held to an imperfectly closed state and a molten resin 4 is injected into the cavity and, thereafter, both molds are stepwise closed. Low pressure gas is injected into the molten resin 7 in such a state that the mold cavity is imperfectly closed to form a preparatory hollow part 7 and high pressure gas is injected into the preparatory hollow part 7 in such a state that the mold cavity is perfectly closed to form a hollow part 8.