Abstract: An electrical conductor is advanced along a path and is preheated to within a controlled temperature range. A reaction mixture is extruded about the conductor, the preheat of which causes the reaction mixture to release a reaction product that etches the surface of the conductor. This results in an insulated conductor unexpectedly having desired adhesion values of the insulation to the conductor without degrading the overall physical and mechanical properties of the insulation. In one usage, the reaction mixture is plasticized polyvinyl chloride with hydrochloric acid being released to perform the etching.

Abstract: A line cord of a telephone handset having individually insulated conductors is jacketed with an extrudable flexible clear flame retardant composition which includes a polyvinyl chloride resin (PVC), 10 to 55 parts by weight per 100 parts by weight of the PVC of a phthalate plasticizer, 3 to 50 parts by weight per 100 parts by weight of the PVC of a phosphate plasticizer, 2 to 5 parts by weight per 100 parts by weight of the PVC of a metallic stabilizer, 0.25 to 1.0 part by weight per 100 parts by weight of the PVC of a lubricant, 0.25 to 1.0 part by weight per 100 parts by weight of the PVC of an ultraviolet absorber, 1 to 4 parts by weight per 100 parts by weight of the PVC of an epoxy resin, and 1 to 8 parts by weight per 100 parts by weight of the PVC of an epoxy plasticizer.

Abstract: A telephone service cable which runs from a distribution cable to a subscriber's premises or to a pay station is another link in a buried communications system having a water-resisting capability. A spirally quaded core comprised of individually insulated conductors is advanced through a bath of a flame-retardant, water-resistant composition prior to enclosing the core with a jacket. The interstices in the core and between the core and an inner jacket are caused to be filled with the composition which comprises a liquid system and a solid system. The liquid system includes a chlorinated paraffin while the solid system includes a polyvinyl chloride resin and a chlorinated polyethylene. An epoxy stabilizer and a phosphite stabilizer may be added to prevent thermal degradation of the filling composition.

Abstract: A priorly used three layer insulation covering for conductors forming a drop wire for connecting aerial distribution cables to a subscriber's premises is replaced with a single layer insulation of a plasticized polyvinyl chloride composition.It has been found that the temperature of preheat of the conductors must fall with a critical range to control the adhesion of the composition to the conductors to be within a desired range of values. The adhesion of the composition to the conductors is important from the standpoint of the manner of installation and of strippability. The adhesion must be sufficient to facilitate support of the drop wire by a clamp customarily attached to the subscriber's premises. However, the adhesion must not be excessively high in that the forces required to strip the insulation from the conductors may damage the surfaces of the conductor.