E.i. Dupont De Nemours and Company

Alphagary Corporation

John L Netta

Sundar Kilnagar Venkataraman

Robert Thomas Young

Mark A Jozokos

George Martin Pruce

Yevgeniy I Globus

Gary Thuot

Robert Kenny

A process of twinning a pair of polymer-insulated conductors to form a twisted pair, where the polymer-insulated conductors are formed by extruding a uniformly thick coating of polymer onto the conductors. More than one twisted pair is encased in a polymer jacket forming a cable. The twisted pair obtains a desirable average impedance performance using a reduced amount by weight of polymer forming said polymer-insulated conductors by: (i) extruding to form longitudinally running peaks and valleys in the exterior surface of each of the polymer-insulated conductors of the pair of polymer-insulated conductors and (ii) twinning resultant polymer-insulated conductors to nest at least one of the peaks in the exterior surface of one of the polymer-insulated conductors in at least one of said valleys in the exterior surface of the other of the polymer-insulated conductors of the pair of polymer-insulated conductors.

Crush resistant conductor insulation

The present invention relates to the extrusion of a composition comprising tetrafluoroethylene/hexafluoropropylene copolymer, 10-60 wt % inorganic particulate filler, and hydrocarbon polymer for dispersing the filler in the copolymer, preferably 0.1 to 5 wt % hydrocarbon polymer, at low temperatures, e.g. up to 650&#xb0; F. (343&#xb0; C.).

Extrusion process

The present invention relates to jacketed cable especially useful for plenum enclosures of buildings, the jacket of the cable comprising perfluoropolymer, such as tetrafluoroethylene/hexafluoropropylene copolymer, and inorganic char-forming agent, and preferably an additional ingredient, hydrocarbon polymer, the cable passing the NFPA-255 burn test.

Plenum cable

FEP compositions are provided that provide foam insulation in coaxial cable that surpasses the return loss obtained when PFA is used to make the foamed insulation, one composition comprising a blend of tetrafluoroethylene/hexafluoropropylene copolymers, one of said copolymers exhibiting a strip force of at least about 3 lbf (13.3 N) and another of said copolymers exhibiting a strip force no greater than about 2.5 lbf (11.1 N), said blend exhibiting a strip force of at least about 3 lbf (13.3 N), each said strip force being the force necessary to break adhesion between conductor and said one of said copolymers, said another of said copolymers, and said blend, respectively, and another composition comprising tetrafluoroethylene/hexafluoropropylene copolymer having an MFR of no greater than about 16 g/10 min and containing &#x2014;CFend groups and an effective amount of wire affinity end groups to exhibit a strip force of at least about 3 lbf (13.3 N), said strip force being the force necessary to break adhesion between conductor and said copolymer, the coaxial cable exhibiting an average return loss of no greater than about &#x2212;26 dB at 800 MHz to 3 GHz and having a void content of about 20 to 65% and (b) forming an outer conductor over said foamed insulation.

Fluoropolymer wire insulation

Communication cable is provided comprising a twisted pair of polymer insulated conductors, the twisting to form the twisted pair forcing the surface of polymer insulation of each polymer-insulated conductor of said polymer-insulated conductors into contact with one another, the polymer insulation of each polymer-insulated conductor including (i) a foamed portion being crushable by the forcing together of the contacting surfaces of the polymer insulation of each of the polymer-insulated conductors and (ii) a crush-resistant portion extending radially within said insulation into the foamed portion and being present where the surface of the polymer-insulated conductors are into said contact with one another, thereby protecting the foamed portion from crushing by the forcing together of the contacting surfaces.

Crust resistant twisted pair communications cable

The present invention relates to plenum cables jacketed with a composition comprising perfluoropolymer, inorganic char-forming agent, and hydrocarbon polymer, which passes the NFPA-255 burn test.

Growing community of inventors

Newark, DE, United States of America

John L Netta