RU168871U1 - COMMUNICATION CABLE LOW FREQUENCY WITH FILM-PORO-FILM POLYETHYLENE INSULATION - Google Patents

Abstract

The claimed technical solution relates to cable technology, namely, to the design of low-frequency communication cables with film-porous-film-film polyethylene insulation, intended for cabling telephone and telegraph nodes, for cable entry devices and deliveries to overhead lines, including those containing CM circuits, sealed in the spectrum up to 150 kHz, for PBX trunk line devices, as well as between the PBX and the MTS. The cable contains copper conductive cores insulated with a three-layer film-porous-film polyethylene insulation second, twisted around in the four star Cordele aggregate of polymer filaments, which, in turn, are twisted into a cable core. A core insulation of polymer tape and cable tape is applied along the core. An aluminum sheath is applied over the waist insulation. On the aluminum sheath - a layer of bitumen and a polymer sheath. Three-layer film-porous-film insulation: inner layer - film insulation of high pressure polyethylene; the middle layer (main) is porous, obtained by the method of physical foaming with nitrogen using a blowing agent; the outer layer is a protective film coating of high pressure polyethylene, which gives mechanical strength to the insulation. This insulation has high dielectric uniformity, stability of geometric dimensions and electrical characteristics.

Description

The utility model relates to cable technology, namely, to the construction of low-frequency communication cables with film-porous-film polyethylene insulation, intended for cabling telephone and telegraph nodes, for cable input devices and deliveries to overhead lines, including those containing CM circuits, sealed in spectrum up to 150 kHz, for devices of PBX trunk lines, as well as between PBX and MTS.

Known low-frequency communication cables with porous polyethylene insulation, having conductive cores insulated with porous polyethylene, belt insulation of synthetic tapes and paper tapes, an aluminum sheath and a sheath of polymeric material.

The closest known to the proposed utility model is a low-frequency communication cable with porous insulation of the TZPASH brand (Low-frequency communication cables with porous polyethylene insulation TU 16.505.715-75).

The cable contains copper conductive conductors twisted into a star four, insulated by porous polyethylene, which are twisted into a core by concentric layers. A core insulation of polymer tape and cable tape is applied along the core. An aluminum sheath is applied over the waist insulation. A layer of bitumen and a polyethylene shell are superimposed on the aluminum shell.

Significant disadvantages of such a cable are:

- insulation from porous polyethylene made by chemical foaming of the composition of polyethylene and the OVAS blowing agent does not provide a stable diameter and linear capacity along the length of the product, porous insulation does not have high mechanical properties.

The objective of the proposed technical solution is to remedy these shortcomings and develop a design of a low-frequency communication cable with a three-layer film-porous-film polyethylene insulation.

The task is achieved as follows: in a low-frequency communication cable, copper conductive cores insulated with a three-layer film-porous-film insulation are twisted into star quadruples around a cord made of polymer filament, which in turn are twisted into the cable core, a belt insulation of polymer tape is applied along the core and cable paper tapes. An aluminum sheath is applied over the waist insulation. A bitumen layer and a polymer shell are applied over the aluminum shell.

The inventive utility model is illustrated in the drawing, FIG. one.

In FIG. 1 is a cross-sectional view of a cable containing copper conductive conductors 1, each of which has a three-layer film-porous-film polyethylene insulation 2. The insulated conductors are twisted into a star quartet 3 around a filler core 4 of polymer thread, the four are wrapped with fastening thread 5, which twisted into the core of the cable 6. Over the core sequentially applied belt insulation of polymer tape and cable tape 7, an aluminum sheath 8, a bitumen layer 9 and a sheath of polymer 10.

The technological process of manufacturing a cable is as follows.

The combined process of drawing, annealing of copper wire for conductive conductors 1 and the application of a three-layer film-porous-film-polyethylene insulation 2 is carried out on automatic lines. Insulated cores are twisted around the filler core 4 into the star four 3 and fastened with threads 5 on the star four twisting machines. Fours are twisted into core 6 and belt insulation 7 is applied on lantern-type twisting machines. The aluminum sheath 8 is superimposed on a welding mill or aluminum press. The application of the bitumen layer 9 and the polymer shell 10 is carried out on an extrusion line.

Claims (1)

A low-frequency communication cable with a film-porous-film polyethylene insulation containing copper conductive wires, each of which has a film-porous-film polyethylene insulation made of three layers: the inner layer is film insulation of high pressure polyethylene, the middle layer is porous, obtained by the method of physical foaming with nitrogen using a blowing agent, the outer layer is a protective film coating of high pressure polyethylene, so the cores so insulated are twisted into a star the fourth four around the filler core made of polymer thread, the fours are wrapped with a fastening thread, these fours are twisted into the core of the cable, belt insulation from polymer tape and cable tape, aluminum shell, bitumen layer and polymer shell are sequentially applied over the core.

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