Foaming polymer granules - using gas led into plasticizing chamber

摘要

Process comprises introducing a gas pref. N2 into a mass of polymer granules in a cylindrical chamber prior to plasticising and moulding. The chamber has a drive mechanism for propelling the granules through the plasticiser, passage ways for introducing the gas around the granules, pressure flow regulators for the gas and a seal linked with the piston to prevent gas escaping from the chamber.