Patent ID: 6177036
Filing Date: 2001-01-23
Classification: B29C,C08J

Abstract:
A process for producing a plastic foam article comprising a thermoplastic synthetic foam which contains at least 10% by volume of open cells, said process comprising:melting a polymer mixture comprising at least one cycloolefin homopolymer and/or copolymer and a nucleating agent which is an endothermic and self-nucleating blowing agent in a carrier and optionally a foreign polymer in a first extrusion step at a temperature of up to 320.degree. C.;injecting a blowing agent into the polymer melt under a high pressure of up to 350 bar at the end of the first extrusion step and mixing it homogeneously with the polymer melt;cooling the polymer melt in a second extrusion step to a composition temperature which is determined, based on the composition of the plastic foam, to provide an open-celled foam upon extrusion.