| 摘要 |
PURPOSE:To make it possible to form a hollow molding without using a core by injecting a resin which adheres firmly to a material resin for an inner hollow form and is molded at an adequately higher temperature than the material resin of the inner hollow form, into an injection molding space, and forming an outer peripheral surface layer which covers the outer peripheral surface of the inner hollow form integrally on the outer peripheral surface of the inner hollow form. CONSTITUTION:An inner hollow form 1 molded by assembling split parts is set in the cavity 2 of an injection molding die B for a finished product hollow molding. This cavity 2 has a shape and a size which are equivalent to the outer profile of a hollow molding as a finished product, and is one size large than the inner hollow form 1. Next, an injection-molding material for an outer peripheral layer which firmly adheres to the material resin of the inner hollow form 1 and is molded at an adequately higher resin temperature than that of the material resin of the inner hollow form 1, is injected into an injection molding space 22 formed between the inner hollow form 1 and the inner surface of the cavity 2. Thus a hollow molding can be obtained without using a core by forming the outer surface layer integrally at the outer side of the inner hollow form 1 in such a manner that the outer side is enveloped. |
