The manufacture of wires and cables is totally different from that of most mechanical and electrical products. Mechanical and electrical products are usually assembled into parts by other parts, and then assembled into a single product by multiple parts. The products are measured by the number of units or pieces. Wires and cables are based on length. All wires and cables start from the conductor processing, adding insulation, shielding, cabling and protective layer on the outer layer of the conductor to make wires and cables products. The more complex the product structure, the more layers it will stack. The main process of wire and cable wire and cable are made by three processes: drawing, stranding and covering. The more complex the model and specification, the higher the repeatability.
1. Drawing in metal pressure processing. Under the action of external force, the metal is forced to pass through the mold (pressing wheel), and the cross-sectional area of the metal is compressed, and the required cross-sectional area shape and size of the technical processing method is called metal drawing. Drawing process: single wire drawing and stranding drawing.
2. Stranding in order to improve the flexibility and integrity of wires and cables, it is called stranding that more than two single wires are interwoven in the specified direction. Stranding process includes conductor stranding, cabling, knitting, steel wire armor and winding.
3. According to different performance requirements for wires and cables, special equipment shall be used to cover different materials outside the conductor.
Coating process: A. extrusion: rubber, plastic, lead, aluminum and other materials. B. longitudinal package: rubber, corrugated aluminum strip material. C. wrapping: Ribbon paper tape, mica tape, alkali free glass fiber tape, non-woven fabric, plastic tape, and thread like cotton yarn, silk and other fiber materials. D. dip coating: basic process flow of manufacturing plastic wires and cables such as insulating paint and asphalt
1. The common copper and aluminum rod materials used for drawing wires and cables with single copper and aluminum wire are reduced in cross section, increased in length and increased in strength by using wire drawing machine to pass through one or several die holes of drawing die at room temperature. Wire drawing is the first process of wire and cable companies. The main process parameter of wire drawing is die matching technology. 2. The annealed copper and aluminum single wires are heated to a certain temperature and recrystallized to improve the tenacity and reduce the strength of the single wire, so as to meet the requirements of wire and cable for conductor core. The key of annealing process is to stop the oxidation of copper wire
. 3. In order to improve the flexibility of wires and cables and facilitate the laying and installation, the conductor core is made of multiple single wires. From the form of conductor core stranding, it can be divided into regular stranding and irregular stranding. Irregular stranding can be divided into bundle stranding, concentric compound stranding, special stranding, etc. In order to reduce the occupied area of the conductor and the geometric size of the cable, the compact form is adopted while the conductor is twisted, so that the ordinary circle is changed into semicircle, fan-shaped, tile shaped and compact circle. This kind of conductor is mainly used in power cable.
4. The extruded solid insulation layer is mainly used for the insulated extruded plastic wires and cables. The main technical requirements of the extruded plastic insulation are as follows: 4.1. Eccentricity: the deviation value of the extruded insulation thickness is an important mark reflecting the extrusion process level. Most product structure dimensions and deviation values are clearly specified in the standard. 4.2. Smoothness: the surface of the extruded insulating layer shall be smooth, and ther