Method for producing polystyrene resin foam.

摘要

A method for producing a polystyrene resin foam (9) expanded to a predetermined dimension comprises extruding a melt of a polystyrene resin containing a blowing agent through a shaping device (5) located exteriorly of an extruder (1) and secured to the discharge end of the extruder (1) while expanding and solidifying the molten mass so that it fills the shaping device (5), at least a part of that area of the inside surface of the shaping device (5) with which the expanded resin makes contact being formed of a plate (6) of a fluorocarbon resin, said plate (6) being secured to the inside surface of the shaping device (5) by fitting portions (7), said fitting portions (7) having a sufficient space for absorbing an increase in the volume of the fluorocarbon resin plate (6) at the temperature of extrusion molding, and the blowing agent being a mixture of 5 to 10 parts by weight of dichlorodifluoromethane and 2 to 4 parts by weight of methyl chloride and/or 2 to 4 parts by weight of ethyl chloride and being used in said amounts per 100 parts by weight of the polystyrene resin.