An electric cable having a core made of insulated conductors disposed within a polymeric sheath. Voids within the core, between the conductors, are at least partially filled in the unused cable with a mixture comprising untreated calcium carbonate and a water-attracting polymer able to form a gel on contact with water without swelling. The cables are made waterproof by the presence of the mixture, which is cheaper than prior mixtures but as effective.
A technique is disclosed for coating or insulation grafting a metallic cationic wire wherein the wire is placed in water in the presence of salts of carboxylate or other appropriate polymers having anionic groups together with a cationic substance, such as lithium. A dc current is then introduced to establish the wire as an anode. By electrolysis action there is established a hydrophobic coating having a polymer-anionic-to-metal-cationic bond with the metal. The procedure of introducing salts of appropriate anionic polymers and cationic substances where there is an insulation break and short between the wires, providing moisture or standing water and a small dc current has been found useful in repairing such breaks by the formation of an electrochemical coating on the exposed anode wire.
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.
A procedure for drying cables having multiple pairs of insulated wires therein by using a compound comprising a mixture of polymer granules and granules of a lubricating and bond-breaking substance. The polymer granules are swellable and with respect to water and do not electrochemically heat in the presence of water. They encapsulate the water leaving the insulation material unaffected except for being dried. The principal polymer used is a salts of carboxylate. Further, a technique is disclosed for coating or insulation grafting a metallic cationic wire wherein the wire is placed in water in the presence of salts of carboxylate or other appropriate polymers having anionic groups together with a cationic substance, such as lithium. A dc current is then introduced to establish the wires as an anode. By electrolysis action there is established a hydrophobic coating having a polymer-anionic-to-metal-cationic bond with the metal. The procedure of introducing salts of appropriate anionic polymers and cationic substances where there is an insulation break and short between the wires, providing moisture or standing water and a small dc current has been found useful in repairing such breaks by the formation of an electrochemical coating on the exposed anode wire.
A method and apparatus for filling a jacketed signal conduit with a blocking material are provided. The blocking material is injected into the jacketed signal conduit such that the blocking material occupies space within the jacketed signal conduit not occupied by the signal conduit. The injected blocking material inhibits fluid intrusion and migration between the signal conduit jacket and the signal conduit.
The present invention provides a coaxial cable having increasing moisture absorbency to remove moisture present in the cable and to prevent corrosion of the conductors in the cable. The coaxial cable of the invention includes an inner conductive tube, a moisture-absorbent material within the inner conductive tube, a dielectric surrounding the inner conductive tube, and a tubular metallic outer sheath surrounding the dielectric. The present invention further includes a method of making a coaxial cable that is capable of absorbing moisture that is present in the cable.
