Abstract: A wire includes a conductor. A foam insulation surrounds an outer surface of the conductor. A jacket surrounds the foam insulation and presents a plurality of projections on an inner surface thereof, which extend toward the conductor, yet do not purposefully contact the conductor. With the foam insulation having a lower dielectric constant than the jacket material, the electrical performance of the wire is improved, while maintaining a good crush resistance.

Abstract: There is disclosed a communications cable having a cable jacket and a first pair of twisted wires disposed within the jacket, each wire thereof having a conductor surrounded by a first insulating material. A second twisted pair of wires is disposed within the jacket and has a twist lay length different from that of the first twisted pair. Each wire of the second twisted pair has a conductor surrounded by an insulating material. The insulating material of the first twisted pair differs in a physical property from the insulating material of the second twisted pair, the physical property of the insulating material of the second pair being correlated with the physical property of the insulating material of the first twisted pair and with differences in twist lay length of the first and second twisted pairs so that the phase delay of the twisted pairs is matched. There is also provided a communications cable having more than two twisted pairs.

Abstract: There is disclosed an insulating composition comprising a mixture of a polyolefin, such as polyethylene or polypropylene, and a partially fluorinated copolymer such as ethylene-chlorotrifluoroethylene (ECTFE) or ethylene-trifluoroethylene (ETFE) in an amount from about 3.0% to about 50% by weight polyolefin. Such mixture may be used as either a solid or foamed insulation over a metallic conductor in a plenum-type communications cable. Such an insulation has been found to have improved mechanical and electrical properties over insulations consisting of 100% ECTFE or ETFE. Specifically, the insulation exhibits improved elongation performance and lower dielectric constant and dissipation factor values. These insulated wires may be used in the transmission of electronic signals, such as voice, data or video, and possess unique properties in electrical, fire safety and cost performance.

Abstract: A fire-resistant plenum-type electrical cable is provided that is insulated with an inner layer of a fluorocarbon containing polymer in contact with a surrounding electrical conductor, and an outer layer of abrasion-resistant polyvinyl chloride surrounding the inner fluorocarbon containing polymer layer. The inner layer of fluorocarbon containing polymer may be foamed.