There are many types of PC insulation materials, which can be divided into three categories: gas, liquid, and solid. Commonly used gas PC insulation sheet materials include air, nitrogen, sulfur hexafluoride PC insulation sheet PC film, etc. Liquid PC insulation sheet materials mainly include mineral PC insulation sheet oil and synthetic PC insulation sheet oil (silicone oil, dodecylbenzene, polyisobutylene, isopropylbiphenyl, diarylethane, etc.). Solid PC insulation sheet materials can be divided into two categories: organic and inorganic. Organic solid PC insulation sheet materials include PC insulation sheet paint, PC insulation sheet adhesive, PC insulation sheet paper, PC insulation sheet fiber products, plastics, rubber, lacquer cloth paint pipes and PC insulation sheet impregnated fiber products, electrical films, composite products and tapes, electrical laminated products, etc. Inorganic solid PC insulation sheet materials mainly include mica, glass, ceramics and their products. In contrast, there are various types of solid PC insulation materials, which are also the most important.

Different electrical equipment has different requirements for the performance of PC insulation materials. The PC insulation material used in high-voltage electrical equipment such as high-voltage motors and cables requires high breakdown strength and low dielectric loss. Low voltage electrical appliances mainly require mechanical strength, elongation at break, and heat resistance level.

The macroscopic properties of PC insulation materials, such as electrical properties, thermal properties, mechanical properties, chemical resistance, climate change resistance, corrosion resistance, etc., are closely related to their chemical composition, molecular structure, etc. Inorganic solid PC insulation sheet materials are mainly composed of silicon, boron, and various metal oxides, with an ionic structure as the main feature. The main characteristics are high heat resistance, working temperature generally greater than 180 ℃, good stability, good resistance to atmospheric aging, chemical resistance, and long-term aging performance under electric field action; But it has high brittleness, low impact strength, high pressure resistance, and low tensile strength; Poor craftsmanship. Organic materials are generally polymers with an average molecular weight between 104 and 106, and their heat resistance is usually lower than inorganic materials. Materials containing aromatic rings, heterocycles, silicon, titanium, fluorine, and other elements have higher heat resistance than general linear polymer materials.

The important factors affecting the dielectric properties of PC insulation sheet materials are the strength of molecular polarity and the content of polar components. The dielectric constant and dielectric loss of polar materials are higher than those of non-polar materials, and they are prone to adsorbing impurity ions to increase conductivity and reduce their dielectric performance. Therefore, in the manufacturing process of PC insulation sheet materials, attention should be paid to cleanliness to prevent pollution. The dielectric used in capacitors requires a high dielectric constant to improve their specific characteristics.