PRE-EXPANDED PARTICLES OF NON-CROSSLINKED LINEAR LOW DENSITY POLYETHYLENE AND PROCESS FOR PRODUCING CELLULAR MATERIALS THEREFROM

摘要

A pre-expanded particle of a non-crosslinked linear low density polyethylene having an average cell diameter as large as 120 to 1,200 mu m which can be molded, without further imparting an expandability prior to molding or without aging under pressure, by heating in a closed mold permeable to a fluid heating medium such as steam to form a well bonded unitary cellular molded article having a good appearance, a high expansion ratio and improved heat resistance and mechanical property with a slight volumetric shrinkage.