Process for producing expandable polyolefin particles by impregnation at low temperatures

摘要

A method for producing expandable polyolefin particles (I) involves (a) mixing polyolefin with a nucleating agent in an extruder and then cooling to solidify the polymer, (b) tempering at 100-200[deg]C and cooling again to below 100[deg]C and then (c) impregnating with a blowing agent at below 100[deg]C; the polymer is granulated at the end of stage (a) or (b). Independent claims are also included for (1) expandable polyolefin particles (I) obtained by this method (2) expanded polyolefin particles or foam obtained from (I) .