Application of Insulating Materials

The function of insulating material is to isolate the charged parts with different potential in electrical equipment. Therefore, insulating materials should first have high insulation resistance and voltage strength, and can avoid leakage, breakdown and other accidents. Secondly, it has good heat resistance and avoids aging and deterioration due to long-term overheating. In addition, it should have good thermal conductivity, moisture and lightning resistance, high mechanical strength and convenient processing. According to the above requirements, the performance indicators of common insulating materials are insulation strength, tensile strength, specific gravity, expansion coefficient and so on.

Insulation voltage withstanding strength: The higher the voltage applied at both ends of the insulator, the greater the electric field force on the charge in the material, and the more likely the ionization collision will occur, resulting in the breakdown of the insulator. The lowest voltage that breaks down an insulator is called the breakdown voltage of the insulator. When insulating materials with thickness of 1 mm are broken down, the voltage kilovolts needed to be added are called insulating voltage strength of insulating materials, which is referred to as insulating strength for short. Because insulating materials have certain insulation strength, various electrical equipment, various safety appliances (electrical pliers, electroscope, insulating gloves, insulating rods, etc.), all kinds of electrical materials, manufacturers have stipulated a certain allowable use voltage, called rated voltage. When used, the voltage must not exceed its rated value, so as to avoid accidents.