Abstract: Disclosed is a coaxial cable having greatly improved mechanical and electrical properties derived from a foamed dielectric having a dielectric constant in the range of 1.32 to 1.1, such cable being provided by a novel method of coating a center conductor of the cable with a dielectric with an extruded cellular polyolefin base composition which has been rendered cellular by the direct injection of a blowing agent in a liquid form into the polymer during an extrusion process. Also disclosed is an apparatus and a method of continuous wire electropolishing and pre-coating.

Abstract: Disclosed is a coaxial cable having greatly improved mechanical and electrical properties derived from a foamed dielectric having a dielectric constant in the range of 1.32 to 1.1, a density between 0.1 and 0.29 grams per cubic centimeter, said foamed dielectric having dispersed throughout it undecomposed particles of a nucleating agent such cable being provided by a novel method of coating a center conductor of the cable with a dielectric with an extruded cellular polyolefin base composition which has been rendered cellular by the direct injection of a blowing agent in a liquid form into the polymer during an extrusion process.