Multi-layer fluoropolymer foam structure

A process for the production of a multi-layer foamed fluoropolymer foam structure comprising the steps of

• A) coextruding:
• 1) a crystalline or semi-crystalline fluoropolymer foam wherein the fluoropolymer foam is manufactured comprising the steps of:
• (a) combining at least one fluoropolymer resin, optional blowing agent, optional nucleating agent and optional other additives;
• (b) processing the fluoropolymer resin, optional blowing agent, optional nucleating agent and optional other additives and introducing a gas into the combination of (a), wherein the gas is introduced either upon the heating of the blowing agent or by injection of a gas, to form a homogeneous fluoropolymer/gas mixture;
• (c) cooling the fluoropolymer/gas mixture in the end of the extruder, adapter and/or die;
• and
• (d) extruding the fluoropolymer/gas mixture from the extruder to form a fluoropolymer foam;
• and
• 2) at least one other thermoplastic fluoropolymer composition;
• and
• B) cooling the resulting structure to form a multi-layer structure comprising at least one foam layer and at least one other thermoplastic fluoropolymer layer;
• and optionally cutting the resulting cooled structure to a desired size, and
• wherein said fluoropolymer foam comprises a polyvinylidene fluoride homopolymer or copolymer.