Process for preparing a foamed perfluorocarbon dielectric coaxial cable

摘要: An improved foamable dielectric composition comprising a melt extrudable perfluorocarbon resin containing therein (i) polytetrafluoroethylene (PTFE) nucleating agent and (ii) volatile blowing agent, preferably lower fluorocarbon having only one or two carbon atoms; process for forming such composition; and, products produced therewith. More specifically, foamed fluorinated ethylene-propylene (FEP) polymer PTFE blown to structure by means of fluid--e.g., as fluoromethane or, preferably, fluoroethane, compostion; therewith jacketed electrical conductors and/or coaxial cables wherein at least conductor is bonded resin. The characterized its thermal stability, fire resistance, small closed cell structure, low density, insulating loss characteristics. In preferred embodiment, the comprises cellular with cells ranging from 10 40 mils., density 1.0 g./cc., an insulation less than 1.8 db/100 ft. 1000 MHz.