Telephone Cables with Polyethylene Insulation and Water-Blocking for Reliable Communication

1 Conducting cores - single-wire from copper soft wire. 2 Insulation - film-porous-film (three-layer, consisting of solid, porous and solid layers of polyethylene); 3 Pairs - twisted from insulated cores of different colours. Pairs together with strands of water-blocking materials are twisted into five or ten-pair elementary bundles.

4 Core - twisted from elementary bundles of different colours. 5 Belt insulation - made of polyamide, polyethylene, polyethylene terephthalate, polypropylene tapes and tapes of water blocking material. 6 Shield: aluminopolyethylene tape laid lengthwise.

A tinned copper wire is laid longitudinally under the screen. 7 Sheath: halogen-free polymer composition.