Different electrical equipment requirements for the performance of insulating materials are focused. High-voltage electrical equipment such as high-voltage motors, high-voltage cables and other insulation materials require high breakdown strength and low dielectric loss. Low-voltage electrical appliances, such as mechanical strength, elongation at break, heat-resistant grade as the main requirements.
    The macroscopic properties of insulation cable paper such as electrical properties, thermal properties, mechanical properties, chemical resistance, weather resistance, corrosion resistance and other properties are closely related to its chemical composition and molecular structure. Inorganic solid insulation material is mainly composed of silicon, boron and a variety of metal oxides, mainly to the ionic structure, the main features of high heat resistance, the working temperature is generally greater than 180 ℃, good stability, resistance to atmospheric aging, Chemical properties and long-term under the action of the electric field aging performance; but high brittleness, low impact strength, high pressure and low tensile strength; poor process. Organic materials are generally polymers with an average molecular weight between 104 and 106, and their heat resistance is usually lower than that of inorganic materials. Contains aromatic rings, heterocycles and silicon, titanium, fluorine and other elements of the laminated mica sheet heat resistance is higher than the general line of chain polymer materials.
    An important factor affecting the dielectric properties of insulating materials is the strength of the polar and the content of polar components. The dielectric constant and dielectric loss of the polar materials are higher than those of the non-polar materials, and the impurity ions are easily adsorbed to increase the conductivity and reduce the dielectric properties. Therefore, in the insulation material manufacturing process should pay attention to clean, to prevent pollution. Capacitor dielectrics require high dielectric constants to increase their specificity.