Speaking of power cable, I believe everyone is familiar with it. We can often see and use it in our daily life. If we can observe carefully, we will find that these power cables are wrapped with an insulating layer. So, how much do you know about wire and cable insulation? What role does insulation play in wires and cables? What kinds of insulating materials are there for wires and cables? Next, ocean cable Co., Ltd. will tell you about the types of wire and cable insulation layers and insulating materials.
The insulating layer, like the protective layer, shielding layer, sheath layer and conductor core, is a necessary basic component of wires and cables. It ensures that the current or electromagnetic wave and light wave transmitted by the conductor core only propagates along the conductor and does not flow to the outside world. At the same time, it ensures the safety of external objects and personnel.
Wire and cable insulation materials can be generally divided into plastic insulation materials and rubber insulation materials. The characteristics of these two insulating materials are as follows:
1. Plastic insulated power cable
Power cables with extruded plastic insulation. Commonly used plastics include polyvinyl chloride (PVC), polyethylene and cross-linked polyethylene (XLPE). Among them, PVC is still widely used in low-voltage cables because of its convenient process, good comprehensive electromechanical performance, good flame retardant performance and low cost. Polyethylene is widely used in cable insulation and outdoor cable sheath because of its excellent electrical properties, moisture resistance, cold resistance and medium mechanical properties, while cross-linked polyethylene is widely used in the insulation of medium and high voltage cables because of its excellent electrical and mechanical properties. Polypropylene is often used in the insulation of communication cables and oil well cables because of its superior electrical properties, good high temperature and oil resistance. It is also the preferred insulating material for telephone and computer flexible ropes.
Plastic cable has the advantages of simple structure, convenient manufacturing and processing, light weight and convenient laying and installation. It is not limited by the difference of laying. Therefore, it is widely used as medium and low-voltage cable and has the trend of replacing viscous impregnated oil paper cable. Its biggest disadvantage is that there is branch breakdown, which limits its use under high voltage.
2. Rubber insulated power cable
Its insulating layer is made of rubber and various compounding agents. After full mixing, the insulating layer is extruded on the conductive wire core and heated for vulcanization. The insulating layer is soft and elastic, suitable for frequent movement and small bending radius. The rubber materials commonly used for insulation are natural rubber styrene styrene rubber mixture, ethylene propylene rubber, butyl rubber, etc.
The long-term allowable working temperature of ethylene propylene rubber is 90 degrees and the allowable temperature of short-circuit thermal stability is 250 degrees. It is suitable for large temperature perimeter, cold resistance and high temperature resistance. It has strong environmental adaptability, weather resistance, light resistance, oxygen resistance, ozone resistance and moisture resistance. It has been widely used in Europe and the United States.
Well, the above is our common wire and cable insulation materials. I hope you can understand and correctly apply these insulated power cables for our use.
