Insulating varnish commonly used by electricians can be divided into inorganic insulating paint, organic insulating varnish and mixed insulating varnish according to their chemical properties. Commonly used inorganic insulating paints are: mica, asbestos, marble, porcelain, glass, sulfur, etc., which are mainly used for winding insulation of motors and electrical appliances, base plates and insulators of switches. Organic insulating varnishes include shellac, resin, rubber, cotton yarn, paper, hemp, rayon, etc. Most of them are used to make insulating varnishes and coating insulation for winding wires. Mixed insulating varnish is a variety of molded insulating varnishes processed from the above two materials and used as the base and casing of electrical appliances. The function of insulating paint is to isolate the live parts with different electric potentials in electrical equipment
The greater the resistivity of the insulating varnish, the better the insulation performance. Insulating varnish is an indispensable material in electrical products, and it accounts for a large proportion of electrical equipment. In general, motors and electrical equipment are composed of conductive materials, magnetic materials, insulating paint and structural materials. Except for insulating varnish, the others are all metal materials. During the operation of motors and electrical appliances, they are inevitably subjected to various factors such as temperature, electricity, mechanical stress and vibration, harmful gases, chemicals, humidity, dust, and irradiation. These factors have a more significant effect on insulating varnish than other materials. It can be said that insulating varnish is more sensitive to these factors, and is prone to deterioration and damage to electrical equipment. Therefore, insulating varnish is a key material that determines the reliability of motors and electrical appliances.
Motor insulation has always been an important link in motor production. From the beginning of winding the coil, until the finished product is assembled, insulation problems are involved. If the insulation structure is properly selected, there are generally fewer failures; if the insulation system is not properly designed or the insulation is not properly selected or the quality of the insulation is unstable during the insulation treatment, or the insulation treatment process is not strictly operated, the problems generally occur
Impregnating varnishImpregnating varnish is divided into two categories: solvent varnish and solvent-free varnish. It is mainly used to impregnate the coils of motors and electrical appliances to fill the gaps and micropores. After curing, it can form a continuous and smooth paint film on the surface of the impregnated object. Make it bond into a hard whole.
The basic requirements for impregnating paint are:
● Low viscosity, good fluidity, high solid content, easy to penetrate and fill the impregnated material.
● Fast curing, good drying performance, strong bonding force, thermal elasticity, after curing, it can withstand the centrifugal force when the motor rotates.
● It has excellent electrical properties and chemical stability, moisture resistance, heat resistance and oil resistance.
● Good compatibility with conductors and other materials
Cover varnish Cover varnish is used to coat coils and insulating parts that have been immersed, and form an insulating protective layer with a uniform thickness on the surface to prevent equipment insulation from mechanical damage, atmospheric and chemical erosion, and improve surface insulation strength. Therefore, the covering varnish is required to have the characteristics of fast drying, strong adhesion, hard paint film, high mechanical strength, moisture resistance, oil resistance, and corrosion resistance.
Cover varnish is divided into alkyd paint, epoxy paint and silicone paint according to the type of resin. Epoxy paint has better moisture resistance, mildew resistance, internal dryness and adhesion than alkyd paint, and has high paint film hardness. It is widely used for surface coating of electrical and electronic equipment parts in hot flash areas. Silicone paint has high heat resistance and can be used as a covering paint for H-class electrical appliances.
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YAAN specializes in manufacturing electrical insulation varnish for almost 34 years.
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