Compatibilizer system for extruded polyethylene foam and film

This paper discusses the processing/product benefits by adding additives on extruded polyethylene (PE) foam and film. Low density polyethylene foam (over 30 times expansion) requires an adequate cooling to stabilize the melt/gas system for optimal foaming efficiency. Presence of small portion of high melting polyethylenes (i.e. LLDPE, KDPE) causes flow instability after cooling to make surface defects in finished products. We found that an addition of metal oxide and fatty acid ester improved processing latitude and foam product quality. This formula was also tested in film process on various ratios of LD/LLD/HD with promising results. It appears that this formula can allow us to accommodate post consumer resin (PCR) and to take advantage over PE price variation.