a system and a method for the production of thermoformable plastic foam material from a mix of plastic foam selvage and a foamable virgin plastic resin . accordingly , the present invention provides for a selvage formed during the production of thermoformed foam material articles from a plastic foam sheet stock is recycled and admixed with the virgin foamable plastic resin , in that the material components are admixed in a feed hopper and then conducted from the feed hopper into a twin - screw compressor which will impart a positive forward feed to the compressible plastic materials conveyed therethrough .