The composition of the cable

Wire and cable are generally composed of four parts: wire core, insulation layer, shielding layer and protective layer (divided into inner sheath and outer sheath). Cables are more complex than wires.
List of basic structure of wire and cable:
(1) Wire core
It is mainly used to conduct current or signal, and is divided into solid core and stranded. Materials include copper, aluminum, silver, copper-clad steel, aluminum-clad steel, etc., mainly using copper and aluminum, copper's conductivity is much better than aluminum.
(2) Refractory layer:
Only fire-resistant cables have this structure. The materials used today are mainly mica tapes that are resistant to high temperatures and have an insulating effect. Its function is that when a fire occurs, it can protect the conductor from running for a certain period of time and give people more time to escape.
(3) Insulation:
Coated outside the conductor, its function is to isolate the conductor, to ensure the transmission of electric energy, insulation materials are diverse, such as polyvinyl chloride (PVC), polyethylene (PE), cross-linked polyethylene (XLPE), rubber (butadiene rubber, nitrobutylene rubber, styrene-butadiene rubber, ethylene propylene rubber, etc.), fluoroplastic, nylon, insulation paper, etc.
(4) Shielding layer:
It is located between the insulation and outer sheath and acts to limit electric fields and electromagnetic interference. For different types of cables, the shielding materials are also different, mainly copper wire braid, aluminum wire (aluminum magnesium alloy wire) braid, steel wire, copper strip, steel strip, etc.
(5) Filling layer:
The role of filling is mainly to make the cable round and stable structure, and the filling of some cables also plays the role of water barrier and flame retardant. The main materials are polypropylene rope, glass fiber rope, asbestos rope, rubber, etc., there are many types, but there is a major performance requirement is non-hygroscopic materials, of course, can not conduct electricity.
(6) Inner cladding:
The function of the inner sheath is to protect the insulated core from being damaged by the armor layer or shielding layer. The inner sheath is squeezed
There are several forms such as wrapping, wrapping and longitudinal packing.
(7) Armor layer:
The function of the armor layer is to protect the cable from external damage. The most common are steel belt armor and steel wire armor, as well as aluminum belt armor, stainless steel belt armor, etc. The main function of steel belt armoring is to resist compression, and steel wire armor is mainly for tensile use.
(8) Outer cladding:
The part that protects the outermost layer of the cable. There are three main types: plastics, rubber and metals.
Among them, the most commonly used plastics are polyvinyl chloride plastics, polyethylene plastics, and flame retardant type, low-smoke low-halogen type, low-smoke halogen-free type, etc. according to the characteristics of cable two and two.