Application of Insulating Materials
The role of insulating material is to isolate the charged parts of different electric potential in the electrical equipment. Therefore, the insulation material should first have high insulation resistance and pressure strength, and can avoid accidents such as leakage, breakdown and so on. Secondly, the heat resistance is better, avoiding aging and deterioration due to long-term overheating. Besides, it should also have good thermal conductivity, moisture resistance and lightning protection, high mechanical strength and convenient processing.
According to the above requirements, insulation strength, tensile strength, specific gravity, expansion coefficient and so on are commonly used for insulation materials.
According to their chemical properties, the insulating materials used by electricians can be divided into inorganic insulating materials, organic insulating materials and mixed insulating materials. The commonly used inorganic insulation materials: Mica, asbestos, marble, porcelain, glass, sulfur, mainly used for winding motor, electrical insulation, switch plate and insulator etc.. Organic insulating materials: shellac, resin, rubber, paper, cotton, linen, rayon, mostly used in the manufacture of insulating paint, winding insulation coating etc.. The mixed insulating material is made of all kinds of insulating materials made by the two kinds of materials. It is used as the base and shell of the electric appliance.