Detailed explanation of manufacturing process flow

Date:Mar 11st,2024

Wire and cable is the length of the basic unit of measurement,all wire and cable from the conductor processing,in the outer layer of the conductor layer by layer plus insulation,shielding,cable ,protective layer and so on to make wire and cable product.The more complex the product structure,the more layers are stacked.

Wire and cable production process

1 Copper,aluminum single wire drawing

Wire and cable commonly used copper and aluminum rods, at room temperature, the use of wire drawing machine through one or several drawing mold holes, so that its section is reduced, the length is increased, the strength is increased. Wire drawing is the first process of each wire and cable company, and the main process parameter of wire drawing is die matching technology.

2 Monofilament annealing

Copper and aluminum monofilaments are heated to a certain temperature and recrystallized to improve the toughness and reduce the strength of the monofilament to meet the requirements of conductive wire and cable cores. The key of the annealing process is to prevent the oxidation of the copper wire.

3 Stranding of conductors

In order to improve the softness of the wire and cable for easy installation, the conductive wire core is twisted by several single wires. According to the form of stranding of conductive wire core, it can be divided into regular stranding and irregular stranding. Irregular stranding is divided into bundle stranding, concentric double stranding, special stranding and so on.
In order to reduce the occupied area of the wire and reduce the geometric size of the cable, the compact form is adopted while the twisted conductor, so that the ordinary circle is changed into a semi-circle, a fan, a tile shape and a compact circle. This conductor is mainly used in power cables.

4 Insulation extrusion

Plastic wire and cable mainly use extruded solid insulation layer,plastic insulation extrusion of the main technical requirement;

4.1. Eccentricity: The deviation value of the extruded insulation thickness is an important sign of the level of the extrusion process, and most of the product structure size and its deviation value are clearly specified in the standard.
4.2. Smoothness: The surface of the extruded insulation layer should be smooth, and there should be no bad quality problems such as rough surface, burning and impurities.
4.3. Density: The cross section of the extruded insulation layer should be dense and strong, and no pinholes visible to the naked eye should be allowed to eliminate the existence of bubbles.

5 Cabling

For multi-core cables, in order to ensure the degree of molding and reduce the shape of the cable, it is generally necessary to twist it into a circular shape. The mechanism of stranding is similar to that of conductor stranding, because the stranding joint diameter is large, most of them adopt non-torsion mode.
The technical requirements of cable forming: first, to prevent the twisting and bending of the cable caused by the turning of the special-shaped insulated wire core; The second is to prevent the insulation layer from being scratched.
Most of the cables are accompanied by the completion of two other processes: one is filling to ensure the roundness and stability of the cable after the cable is formed; One is to tie, to ensure that the cable core is not loose.

6 Inner sheath

In order to protect the insulated wire core from being sheathed,the insulation layer needs to be properly protected,and the inner protective layer is divided into:extruded inner protective layer (isolation jacket) and wrapped inner protective layer (cushion). The wrapping pad is carried out simultaneously with the cabling process instead of the lashing tape.

7 armouring

Laying in the underground cable,the work may bear a certain positive pressure effect,can choose the inner steel tape armor structure.Cable laying in both positive pressure and tension function of the accasion(such as water,vertical shaft or large drop in the soil),should be selected with internal steel wire armor structure.

8 Outer sheath

The outer sheath is the structural part that protects the insulation layer of the wire and cable from environmental factors.The main function of the outer sheath is to improve the mechanical strength of the wire and cable,prevent chemiacl currosion,moisture-proof,waterproof immersion,and prevent cable burning.

According to the different requirements of the cable,the plastic sheath is directly extruded by the extruder.