METHOD FOR PRODUCING FOAMED SHEET OF POLYOLEFIN RESIN

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a foamed polypropylene sheet excellent in surface smoothness and the foamed sheet. SOLUTION: In the method for producing the foamed sheet of a polypropylene resin, when a polypropylene resin is melted by an extruder, after the obtained molten resin and a foaming agent are kneaded at a high temperature under a high pressure, and the mixture is extruded to a low pressure area through a circular die and mandrel-molded to produce the foamed sheet, an outer mandrel is contacted with the surface of the foamed sheet of an optional part the temperature of the surface of the foamed sheet of which is 70-160 deg.C.