METHOD FOR MANUFACTURING POLYOLEFIN RESIN PRELIMINARILY EXPANDED PARTICLE

摘要

PROBLEM TO BE SOLVED: To provide a polyolefin resin preliminarily expanded particle low in the variation in magnification. SOLUTION: In this method for preparing the polyolefin resin preliminarily expanded particle, a polyolefin resin particle is dispersed in an aqueous dispersion medium in a pressure-tight vessel, and after the resin particle is heated to not lower than the softening point of the polyolefin resin and pressurized, it is discharged into a vessel with a pressure lower than the pressure of the pressure-tight vessel. At this time, all the preliminarily expanded particle is collided with a collision board or the wall of the vessel which is installed at a distance of L (5 mm