Foaming method

摘要

PCT No. PCT/GB95/01315 Sec. 371 Date May 8, 1997 Sec. 102(e) Date May 8, 1997 PCT Filed Jun. 7, 1995 PCT Pub. No. WO96/00257 PCT Pub. Date Jan. 4, 1996A 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.