What material is cable shielding? In which industries is it generally applied？

 

1.Metal wire braided shielding

This shielding material is mainly woven from copper wire or tin plated copper wire. Copper has good conductivity and can effectively shield electromagnetic interference. For example, in some computer network cables (such as Category 5 and Category 6 cables), copper wire braided shielding can be used to reduce the impact of external electromagnetic signals on data transmission. Weaving density is a key parameter, usually represented by coverage, and the higher the coverage, the better the shielding effect. The general coverage rate is between 60% and 95%, and for some demanding industrial control cables, the weaving coverage rate may reach over 90%.

2.Metal foil shielding

Common ones include aluminum foil. Aluminum foil has good electromagnetic shielding performance and is lightweight. It is made by evaporating a layer of aluminum on insulating materials such as plastic film. In cables, aluminum foil is usually wrapped around the conductor or insulation layer. For example, in some cable TV coaxial cables, aluminum foil shielding can prevent external signal interference and reduce signal leakage inside the cable, ensuring high-quality signal transmission.

3.Composite shielding

Composite shielding is a combination of metal wire weaving and metal foil. This can comprehensively utilize their advantages and achieve better shielding effect. For example, in some communication cables and medical equipment cables that require extremely high electromagnetic compatibility, using composite shielding can effectively shield electromagnetic interference over a wide frequency range. The structure usually involves wrapping a layer of metal foil around the cable core, and then weaving a layer of metal wire around the metal foil.

 

 

1.Communication industry

Cable shielding plays a crucial role in the communication industry. For example, in auxiliary cables for fiber optic communication, shielded cables are used to transmit power and control signals, preventing external electromagnetic interference from affecting the normal operation of communication equipment. Using shielded cables, such as feeder cables in mobile base stations, can reduce signal transmission losses and improve communication quality. Meanwhile, the connection cables between servers and between servers and network devices within the data center also require good shielding performance to ensure the accuracy and stability of high-speed data transmission.

2.Power industry

For high-voltage power cables, shielding can act as a uniform electric field to prevent partial discharge. For example, in cross-linked polyethylene insulated power cables of 110kV and above, the shielding layer of the cable can effectively confine the electric field inside the insulation layer, improving the insulation performance and service life of the cable. The shielding layer of control cables in substations can prevent electromagnetic interference from affecting relay protection devices and automation equipment, ensuring the safe and reliable operation of the power system.

3.Industrial automation industry

In factory automation production lines, signal transmission cables between various sensors, controllers, and actuators require good shielding. For example, in automated welding equipment, if the welding current signal cable is disturbed by external factors, it may lead to a decrease in welding quality. The use of shielded cables can effectively transmit welding current signals and shield external electromagnetic interference, such as interference generated by nearby motors, transformers, and other equipment. In CNC machine tools, shielding the motor drive signal cable and position feedback signal cable can improve the machining accuracy and stability of the machine tool.

4.Medical equipment industry

Medical equipment has extremely high requirements for electromagnetic compatibility. For example, in magnetic resonance imaging (MRI) equipment, shielded cables are required for both signal transmission cables and power cables inside. Because MRI equipment itself generates strong magnetic fields and radio frequency signals, if the cables are not shielded, these signals may interfere with the normal operation of the equipment, or the cables themselves may be affected by interference and affect signal acquisition and transmission, thereby reducing image quality. In devices such as electrocardiography (ECG) and electroencephalography (EEG), shielded cables can reduce the impact of external electromagnetic interference on weak physiological signal acquisition, ensuring diagnostic accuracy.