Continuous prodn. of expanded polyolefin particles for use in e.g. cars

摘要

A continuous process for the prodn. of expanded polyolefin particles (I) comprises suspending the polymer particles in a dispersion medium, impregnating with a volatile blowing agent under elevated pressure and then discharging the impregnated particles into a low-pressure space. The impregnation stage is carried out in a screw machine. Pref. the polyolefin is a copolymer of propylene (P) with 0.5-15 wt.% ethylene (E) and/or 4-8C alpha -olefin, or a copolymer of ethylene with 3-18 wt.% 4-10C alpha -olefin. The blowing agent is propane, butane, pentane, hexane, CO2 or a mixt. thereof.