Patent ID: 8227521

Claim:
A process for making a fluoropolymer foam comprising the steps of: 1a) mixing a fluoropolymer resin and a blowing agent to produce a compound, wherein the blowing agent is in non-gaseous form or a form in which gas is not liberated from the blowing agent 1b) forming or shaping an artifact from the compound 1c) heating the artifact under pressure to a temperature above the softening point of the resin and above an activation temperature of the blowing agent in order to convert the blowing agent to a gaseous form or to liberate gas from the blowing agent 1d) reducing the pressure while maintaining the temperature above the softening point of the resin in order to expand the artifact 1e) cooling the resultant fluoropolymer foam to ambient temperature wherein the compound is crosslinked by irradiating it with an electron beam or with gamma radiation after step (1b).