This article introduces the types and characteristics of common insulating coatings
As a key material to ensure the safe and stable operation of electrical equipment, insulating coatings play an indispensable role in modern industry and daily life. Different types of insulating coatings are widely used in various fields because of their unique properties and characteristics. Below, let's take a closer look at the common insulating coatings.
Enamelled wire insulating paint: mainly used to coat various wire diameters of copper wire, alloy wire and glass wire covered outer layer. For example, the common acetal paint, the main component is polyvinyl formaldehyde, often used in the production of oil transformer enamelled wire; Polyurethane paint, composed of polyamino-methyl grease, is widely used in the production of enamelled wire for winding of electronic equipment such as electronic transformers and electronic coils. It requires good coating property, can be uniformly covered on the wire surface, and the paint film adhesion is strong, smooth, soft and ductile, but also has a certain wear resistance, elasticity and good electrical properties.
Impregnated insulating paint: divided into solvent paint and solvent-free paint two categories, mainly used for impregnating motor, electrical coil. It needs to have a low viscosity and good fluidity in order to be able to fully penetrate and fill the gaps and microholes in the coil. After curing, it should be able to form a continuous flat paint film on the surface of the impregnated material, bond the coil into a hard whole, and have excellent electrical properties, chemical stability, moisture resistance, heat resistance and oil resistance.
Coating insulating paint: Used to coat impregnated coils and insulated parts to form an insulating protective layer on their surface. According to the type of resin can be divided into alkyd paint, epoxy paint and silicone paint. Epoxy paint has good moisture resistance, mold resistance, internal drying and adhesion, high film hardness, and is often used for the surface coating of electrical equipment parts in hot flusher areas. Silicone paint has high heat resistance and can be used as a covering paint for H class motor appliances. The coating paint can prevent the equipment insulation from mechanical damage and the erosion of the atmosphere and chemicals, and improve the surface insulation strength.
Silicon steel sheet insulating paint: coated on the surface of silicon steel sheet, can reduce the eddy current loss of the core, enhance its corrosion resistance. The silicon steel sheet coating usually needs to be dried at high temperature for a short time after coating, which is characterized by thin layers.
Special fire retardant anti-corrosion insulating paint: The insulating coating of this kind of insulating paint can withstand the high temperature of 600 ° C, and can play the role of leakage protection in high temperature environment, with high temperature resistance, large insulation volume resistance, waterproof anti-corrosion characteristics. For example, the high temperature and heat resistant insulating paint jointly developed by the Aeronautical Materials Research Institute and Beijing Zhisheng Weihua Chemical Co., Ltd. has excellent performance and plays an important role in the high temperature insulation of high-temperature structural materials for supersonic spacecraft.
Ceramic ultra-high temperature insulating paint: can withstand the high temperature of 1800℃, such as ZS-1091 high temperature ceramic insulating paint, can work at 1800℃ for a long time, volume resistivity greater than 1016Ωm, dielectric strength greater than 104KV/m. It can form a coating with high volume resistivity on the surface of the coated object, can withstand strong electric field without being broken down, and has good chemical stability, aging resistance, corrosion resistance and oxidation resistance.
Different insulating coatings play a key role in their respective application fields, and with the continuous progress of science and technology, insulating coatings are also developing in the direction of higher performance and more environmentally friendly to meet the growing demand for electrical equipment.