A process for producing coated, expanded polyolefin beads

A process for producing coated, expanded polyolefin having a bulk density of 40 to 150 g / l, characterized in that a) impregnating a polyolefin pellets in suspension under pressure at at least 100 ° C with a blowing agent and thereafter, abruptly relieves the suspension at at least 100 ° C, wherein the foam impregnated polyolefin particles to the expanded polyolefin, and b) applying a Antiverklebungsmittelbeschichtung on the expanded polyolefin, containing hydrophilic or hydrophobic silica or a metal salt, an ester or an amide of a long chain carboxylic acid or mixtures thereof.