Popularization of wire and cable products
The structural elements of wire and cable products can generally be divided into four main structural components: wire, insulation layer, shielding, and protective layer, as well as filling elements and tensile elements. According to the use requirements and application occasions of the product, some product structures are elementary.
2. Cable material
In a sense, the wire and cable manufacturing industry is a material finishing and assembly industry. First, the amount of materials used is enormous. The cost of materials in cable products accounts for 80-90% of the total manufacturing cost; the second is that the types and varieties of materials used are vast. The performance requirements are exceptionally high. For example, copper is required for copper purity. Above 99.95%, some products use oxygen-free high-purity copper; third, the selection of materials will have a decisive impact on the manufacturing process, product performance, and service life.
Simultaneously, the benefits of wire and cable manufacturing enterprises are also closely related to whether materials can be scientifically saved in the selection, processing, and production management of materials. Therefore, the design of wire and cable products must be carried out simultaneously as the selection of materials. Generally, several materials are selected and determined after the process and performance screening tests.
The materials for cable products can be divided into conductive materials, insulating materials, filling materials, shielding materials, and protective layer materials according to their use parts and functions. But some of the materials are common to several structural elements. Especially thermoplastic materials, such as polyvinyl chloride, polyethylene, etc., can be used on insulation or sheaths as long as part of the formulation is changed.
3. The name and material of the product structure
(1) Wire: The most basic and essential component for the product to carry out electric current or electromagnetic wave information transmission function.
Primary material:?Conductor is the abbreviation of conductive core, made of copper, aluminum, copper-clad steel, copper-clad aluminum, and other non-ferrous metals with excellent conductivity; optical fiber is used as the conductor.
There are bare copper wire, tinned wire, single branch wire, stranded wire, tinned wire after twisting.
(2) Insulation layer: It is a component that is wrapped around the periphery of the wire and plays an electrical insulation role. That is to say, and it can ensure that the transmitted current, electromagnetic waves, and light waves only travel along the wires and do not flow to the outside. The potential on the conductor (i.e., the potential difference formed to the surrounding objects, that is, the voltage) can be isolated; that is, it is necessary to ensure the standard transmission of the wire Function to ensure the safety of external objects and people. Wire and insulation are the two essential components that must be equipped to form cable products (except bare wires).
Primary materials: PVC, PE, XLPE, polypropylene PP, fluorine plastic F, rubber, paper, mica tape
(3) Filling structure: Many wire and cable products are multi-core. After these insulated cores or pairs are cabled (or grouped into multiple cables), the shape is not round, and the other is that there is a gap between the insulated cores. There is a large gap, so a filling structure must be added when the cable is formed. The filling structure is to make the line's outer diameter relatively round to facilitate the tape and squeeze sheath.
Primary material: PP rope
(4) Shield: It is a component that isolates the electromagnetic field in the cable product from the external electromagnetic field; some cable products also need to be separated between different wire pairs (or wire groups) inside. It can be said that the shielding layer is a kind of 'electromagnetic isolation screen'. The conductor shielding and insulation shielding of high-voltage cables are used to homogenize the electric field distribution.
Primary materials: bare copper wire, copper-clad steel wire, tinned copper wire
(5) Protective layer: When wire and cable products are installed and operated in various environments, they must have a component that protects the entire product, especially the insulating layer, which is the protective layer.
Because insulating materials are required to have excellent various electrical insulation properties, they must need highly high purity and minimal impurity content; often, they cannot take into account their ability to protect the outside world. Therefore, for the outside world (that is, installation, use occasions, and in-use ), The endurance or resistance of various mechanical forces, resistance to atmospheric environment, resistance to chemicals or oils, prevention of biological damage, and reduction of fire hazards must be borne by multiple protective layer structures.
Primary materials: PVC, PE, rubber, aluminum, steel belt
(6) Tensile components: The typical structure is steel core aluminum stranded wire, fiber optic cable, etc. In a word, in the developed unique small, flexible products that require multiple bends and twists simultaneously, the tensile elements play a significant role.
Primary material: steel wire