Speaking of cables, we are all strangers, and we all know that wires and cables are mainly composed of three basic structural elements: conductive core, insulation layer and sheath layer. There is no strict boundary between wire and cable, but in a broad sense, the cable structure is more complex, and it has a complex sheath layer. The structure of the wire is relatively simple, some only have a conductor and an insulating layer, and some only have a braided waxed light sheath or a light soft sheath. The main function of the cable sheath is to protect the insulation layer, and its main performance is moisture-proof, oil-proof and anti-corrosion; Anti-solar aging, flame resistance, and mechanical protection (the role of the outer sheath is mainly to strengthen the mechanical protection of the cable), but also has the functions of anti-electricity, anti-magnetic dry reactance, etc.

From the perspective of wire and cable sheath, braiding is one of the many kinds of sheath or outer sheath of wire and cable. However, according to the material used in the wire and cable braid and the different parts of the braid in the wire and cable structure, the role of the braid is different. Next, we will introduce you to the role of different material braiding layers in wire and cable:

01

The role of the fiber braid

In the case of wires, the fiber braid is a form of its lightweight protective layer. Its main function is to protect the insulation from all kinds of light, heat, humidity, low temperature, acid and alkali gas erosion and external force damage, so as to ensure the stable operation of the cable, therefore, the fiber braid layer is usually added in the middle of the sheath to improve the tear resistance of the sheath, for example: the reinforced sheath is to add cotton yarn, hemp and other fiber braids in the middle of the rubber or plastic sheath to improve the strength of the sheath.

02

The role of metal braid layers

There are two main types of metal braid layer: copper wire braid and steel wire (iron wire) braid:

The main functions of steel wire braiding are: (1) mechanical protection, such as marine power cable CF31; (2) Withstand longitudinal tensile force, such as WCGC type and WCT type magnetic cables for marine geological exploration; (3) Magnetic field shielding.

The main functions of copper wire braiding are: (1) shielding electromagnetic interference, such as tinned copper wire braided American standard cables and copper wire braided control cables; (2) Eliminate the shielding effect of the surface potential of the power cable, such as the total shielding of the high-voltage cable; (3) Braided copper wire outside the main core insulation and have good contact with the ground core or used as ground wire, which can respond to leakage in time, such as shielded mining cables.

From the above, we can see that the role of the braided layer of fiber, copper wire and steel wire is significantly different. Therefore, we should choose the appropriate braid wire and cable according to the use requirements.