MANUFACTURE OF POLYPROPYLENE BASED RESIN EXPANDED BODY

摘要

PROBLEM TO BE SOLVED: To provide a method to manufacture a polypropylene based resin expanded body wherein the appearance is favorable, and of which the expansion ratio is high, at a high productivity. SOLUTION: In this manufacturing method of a polypropylene based resin expanded body by using a continuous extruder having a feeding section and a vent section, a set temperature between the feeding section and the vent section is set at 120-150 deg.C, and an extrusion molding is performed by setting a die pressure at 5 MPa or lower. As a foaming agent, 0.5-5 pts.wt. of a thermally decomposing type foaming agent, particularly sodium hydrogen carbonate, is used based on 100 pts.wt. of the resin component. Also, as a foaming agent, an inorganic gas is used, and is injected at 0.5-2.5 MPa.