Many different types of insulating material, the separable gas, liquid, solid three categories. Commonly used in gas-insulated materials are air, nitrogen, sulfur hexafluoride insulating PC film. Liquid insulating materials are mainly mineral insulating oil, synthetic insulating oil (silicone oil, dodecylbenzene, polyisobutylene, isopropyl biphenyl, diaryl ethane, etc.) categories. The solid insulating materials can be divided into organic and inorganic two categories. Organic solid insulating materials including insulating paint, plastic insulation, insulating paper, insulating fiber products, plastics, rubber, linoleum paint tube and impregnated fiber products, electrical film, composite products and adhesive tapes, electrical laminate. Inorganic solid insulation material mica, glass, ceramics and their products. In contrast, a variety of solid insulating materials, but also the most important. Each focusing on a different electrical equipment performance requirements of the insulating material. High breakdown strength and low dielectric loss of high-voltage electrical devices such as high-voltage motors, high voltage cable insulation material requirements. The low-voltage electrical appliances are based on mechanical strength, elongation at break, heat-resistant grade, etc., as the main requirement. The macroscopic properties of the insulating material, such as electrical properties, thermal properties, mechanical properties, chemical resistance, resistance to climate change, and corrosion-resistant properties and its chemical composition, molecular structure closely related to. Inorganic solid insulating material is mainly composed of silicon, boron, and a variety of metal oxides, mainly ion-type structure, the main characteristic of the high heat resistance, the working temperature is generally greater than 180 ° C, good stability, resistance to atmospheric aging. good chemical resistance and long-term aging properties of the electric field;, high brittleness, low impact strength, high pressure and low tensile strength; process is poor. The organic materials are generally polymer, with an average molecular weight of between 104 to 106, its heat resistance is usually less than the inorganic material. Materials containing aromatic ring, heterocyclic and silicon, titanium, fluorine and other elements of its heat resistance is higher than the general line of chain-shaped polymer materials. The important factors affecting the dielectric properties of insulating materials is the molecular polarity of the strength and content of polar components. The polar material permittivity, dielectric loss higher than that of non-polar material, and easily adsorbed impurity ions to increase the conductivity and reduce its dielectric properties. Therefore, in the insulating material in the manufacturing process should pay attention to clean, to prevent pollution. The capacitor dielectric requires a high dielectric constant to increase its ratio characteristics.
