Abstract: Electrically insulated wire with an inner layer of non-crosslinked and non-crosslinkable polymeric material and a skin layer of irradiation crosslinked material compatible with the inner layer. The inner layer provides desirable flexibility and electrical insulating properties suitable for telecommunications cable and appliance wiring. The skin layer gives abrasion resistance suitable for the above purpose and heat resistance and fire retardance properties suitable for building wiring. The polymeric material of both layers is preferably of a polyvinylchloride composition.

Abstract: Electrically insulated wire with an inner layer of non-crosslinked and non-crosslinkable polymeric material and a skin layer of irradiation crosslinked material compatible with the inner layer. The inner layer provides desirable flexibility and electrical insulating properties suitable for telecommunications cable and appliance wiring. The skin layer gives abrasion resistance suitable for the above purpose and heat resistance and fire retardance properties suitable for building wiring. The polymeric material of both layers is preferably of a polyvinylchloride composition.

Abstract: An inside cable having a core of conductors with conductor insulation formed from polyvinylchloride and in which interstices between conductors contains a fire resistant powder to resist burning of the core. The core is surrounded by a fire resistant jacket and the cable is devoid of a tubular metal shield or sheath surrounding the core.

Abstract: Low voltage electrical wire with only two layers of insulation. An inner layer of polyolefin is covered by an outer layer of irradiation crosslinked material of a PVC based composition. The outer layer has abrasion and heat resistance but its material has an extensibility at break comparable with the conductor. To increase its capability to protect the conductor, the inner layer is capable of absorbing stresses and strains imposed axially upon the conductor so that while the inner surface of the inner layer extends with the conductor, relative movement of the molecules is possible throughout the depth of the inner layer. Thus, the outer layer restrains the outer surface of the inner layer from extending. The net result is that the outer layer extends less than the conductor and is capable of continued unbroken protection after the conductor has severed.

Abstract: Cross-linked polyethylene is continuously produced by injecting dicumyl peroxide (Dicup) into the polyethylene in the mixing barrel of the extruder. The Dicup injection nozzle extends into the flight of the screw of the extruder and the flight is interrupted, or notched, at this position. This enables the Dicup to be injected at a position about half way between the extruder barrel wall and the core of the screw and also avoids pulsed back-pressure on the feed pump for the Dicup. A closely controlled and constant ratio of cross-linking agent to raw polyethylene is obtained.