Insulation Materials Main Feature
The edge material is a material for isolating the conductive portions of different potentials. Its conductivity is about 10-10 West / m below. The insulating material described in this regulation is an electrical insulating material. According to the national standard GB2900.5 provides the definition of insulating material is: "used to make the device in the electrical insulation of the material." That is, to prevent the current through the material. Its resistivity is very high, usually in the range of 10 ^ 9 ~ 10 ^ 22Ω · m. As in the motor, the insulating material around the conductor isolates the turns and isolates it from the grounded stator core to ensure safe operation of the motor.
Classification and performance
Many types of insulating materials, can be divided into gas, liquid, solid three categories. Commonly used gas insulation materials are air, nitrogen, sulfur hexafluoride and so on. Liquid insulation materials are mainly mineral insulating oil, synthetic insulating oil (silicone oil, dodecyl benzene, polyisobutylene, isopropyl biphenyl, diaryl ethane, etc.) two categories. Solid insulation materials can be divided into organic, inorganic two categories. Organic solid insulation materials include insulating varnishes, insulating glue, insulating paper, insulating fiber products, plastic, rubber, lacquered lacquers and insulating impregnated fiber products, electrical thin films, composite products and adhesive tape, electrical laminates. Inorganic solid insulation materials are mainly mica, glass, ceramics and their products. In contrast, the variety of solid insulation materials, but also the most important.
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 insulating materials 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 material 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 polarity 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.
Insulation board: plastic plate is made of plastic sheet, plastic for the synthesis of polymer compounds, can be free to change the body style. Plastic is the use of monomer raw materials to synthesis or condensation reaction polymerization of materials, synthetic resin and filler, plasticizers, stabilizers, lubricants, colorants and other additives, and its main component is synthetic resin.