PRODUCTION OF POLYPROPYLENE RESIN FOAM COMPOSITE MOLDING

摘要

PROBLEM TO BE SOLVED: To weld a molten resin to a polypropylene resin foam to be integrated without generating deformation and surface roughening by an injection molding method. SOLUTION: After a polypropylene resin foam having a gel content of at least 50% is put into an injection molding mold and the mold was clamped, when a molten resin is injected into the mold, the injection pressure of the resin is increased at least in two steps in which the pressure is controlled to be 100 kg/cm2 or below in the first step and 500 kg/cm2 or below in the succeeding steps so that the molten resin is made to flow along the surface of the resin foam while compressing the surface. After the completion of the flow, the pressure of the molten resin is maintained to be 500 kg/cm2 or below for a given time, and the molten resin is cooled to be solidified.