Abstract: An insulation system for electrical conductors is provided. The insulation system has a layer of polymer selected from ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer and ethylene-tetrafluoroethylene terpolymer surrounding the conductor. This layer of polymer is irradiation crosslinked with from 3 to 20 megarads of high energy ionizing irradiation. Bonded to the surface of the irradiation crosslinked layer of polymer is a polyimide coating. The insulation is a high temperature, flame resistant system having a combination of properties useful in the aircraft industry as airframe and hookup wire.

Abstract: A radiation resistant cable is made by wrapping a barrier film over a conductor and covering it with a silicone saturated asbestos covering. The asbestos is passed through one or more dies to compact the asbestos covering and accurately size it. One or more layers of polyimide tape is wrapped about the asbestos. The polyimide tape is covered by a heat-sealable tape over which a fiberglass cover is braided. The cable is then heated to seal the heat-sealable tape to itself as well as to the adjacent layers. The cable is then passed through a coating bath to impregnate and saturate the fiberglass braid, following which the cable is heated to extract the solvent in the coating solution.