FOAMING METHOD

摘要

A process for forming a foamed article having a closed cell structure without the need to use a halogenated blowing agent. In the process, a polymer blend comprising at least 50 % by weight of a styrenic polymer and up to 50 % by weight of an acrylic polymer which has an average molecular weight which is less than 90 % of that of the styrenic polymer and a hydrocarbon blowing agent are supplied to a heated extruder where the blend is formed and the blowing agent incorporated to form a molten mixture from which the foamed article is formed on release from the extruder.