General Cable Corporation

Paul F Thompson

George Bahder

Petrolatum-based filling compounds are known to migrate into the insulation and jacket of telephone cables and to extract the stabilizers, and as a consequence, to affect the physical and/or electrical characteristics of those cable components. It does not seem possible to avoid these characteristics of petrolatum in commercial compounding operations. The filling compound of this specification is for use in telephone cables and is based on better resistance to dripping at elevated temperatures, compatibility with high density polyethylene insulation and low density and medium density polyethylene jacket compounds. It has processability at moderate elevated temperatures, resistance to cracking at room temperature and low temperatures, adhesiveness and desirable electric properties.

Filled communication cable employing a paraffinic oil-base filling

This telephone service wire has metal conductors insulated with polyethylene plastic insulation or equivalent, assembled in a core having a flame-retardant polyvinyl chloride jacket. Space between the individual insulated conductors is filled with an improved filling compound for preventing access of water into the core of the service wire. The filler compound is an ester-based compound that avoids the disadvantages of the usual petrolatum-based filler compound which extracts not only antioxidants and copper-inhibitors from a polyethylene component but plasticizers from a polyvinyl chloride compound. Depletion of these essential compounding materials can seriously affect the physical characteristics of either the insulation or jacket of such filled telephone service wires.

Telephone service wire with ester-based filling compound

This invention is an improved filling compound for preventing moisture penetration along the interior of high voltage electric power cables. Amorphous polypropylene, mixed with carbon where it must be semiconductive, is an extremely good filling compound because of its electrical characteristics and also because of its good flow characteristics when extruding. When the cable is to be used under conditions where it must withstand temperatures so low that the polypropylene becomes brittle, it can be blended with polyisobutylene rubber to withstand lower temperatures, but the blend must be kept within limits to prevent loss of the good flow characteristics of the amorphous polypropylene.

Semiconductive filling compound for power cable with improved properties

Filling compounds for high voltage, electric power transmission cables have been deficient in one characteristic or another, such as incompletely filling voids during manufacture, forming voids when cables are in service, lack of permanent adhesion to cable components to prevent passage of water lengthwise of the cable, and low drip point when cables are at elevated temperatures. This invention is a cable filled with a compound of isobutylene rubber that obtains all of the desirable filler characteristics for a high voltage power transmission cable.

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Millington, NJ, United States of America

Paul F Thompson