Teflon™  FFR 770 is a fluoroplastic resin compounded with  a foam nucleating package. This resin is supplied as white  pellets and is used in a nitrogen gas-injected foam extrusion  process to produce uniform foam cells in the dielectric  insulation. Foaming the fluoroplastic reduces its dielectric  constant, providing opportunities for miniaturization and  weight savings. Foamed insulation of Teflon™  FFR 770  produces cables for high frequency signal transmission with  minimal distortion. 

Teflon™  FFR 770 is ideal for producing foamed primary  dielectric insulation for twisted pair cables and miniature  coaxial cables. A typical cable core would have conductor  sizes of 32 AWG or greater, wall thickness of 0.004 in or  greater, with void content from 20% to 65%. 

These voids are closed cell in nature and range from  0.0007 in (0.018 mm) to 0.0013 in (0.033 mm) in diameter.  Achievable void content will vary based on wall thickness and  processing conditions.