Electronic transformer varnishing process - partial introduction (Ningbo Chuangbiao Electronics)

Electronic transformer varnishing process

1. The purpose of electronic transformer impregnation insulating varnish

    1. Electrical insulation function of mobile electronic transformer

      The electronic transformer impregnated insulating varnish can improve the dielectric strength and insulation resistance of the transformer insulation system to improve its electrical insulation function and meet the electrical insulation function requirements of the transformer.

    2. Enhance the environmental adaptability of electronic transformers

      The electronic transformer impregnated insulating varnish can enhance the moisture resistance, mildew resistance, corrosion resistance, salt spray resistance, UV resistance and other harmful substances of the transformer insulation system, so as to enhance the adaptability of the electronic transformer to the environment.

    3. Enhance the mechanical strength of electronic transformers

      The electronic transformer impregnated with insulating varnish can increase the mechanical strength of the transformer and meet the requirements of vibration and impact generated during transportation and use. At the same time, it can also reduce the noise generated by the electromagnetic force during use.

    4. Improve the thermal conductivity of electronic transformers

       The electronic transformer is impregnated with insulating varnish, and the vacancies in the core and winding are filled with the varnish film, which can improve the overall thermal conductivity of the transformer and reduce the temperature rise of the transformer.

    5. Improve the appearance of electronic transformers

2. Requirements for insulating paint of electronic transformers    

    1. Excellent insulation performance;

    2. Good adhesion and high mechanical strength;

    3. Small shortening stress;

    4. Heat resistance should meet the different requirements of transformers;

    5. Special requirements for outdoor or special environments should be met, such as radiation protection, corrosion protection, UV protection, etc.;

    6. Excellent workmanship, such as good operability, short drying time, etc.

3. Classification of insulating paint

1. According to the presence or absence of solvent

      Insulating varnishes are classified into solvent-containing insulating varnishes and solvent-free insulating varnishes according to whether they contain solvents.

   (1) Solvent-containing insulating varnish Solvent-containing insulating varnish is generally composed of film-forming resin and organic solvent, and the solvent content is generally about 50% of the total amount of varnish. Assuming that the solvent content is less than 30%, this type of solvent-containing insulating varnish is generally called low-solvent insulating varnish or high-solid insulating varnish.

   (2) Solvent-free insulating varnish Solvent-free insulating varnish is generally composed of film-forming resin and reactive diluent, etc. The reactive diluent can undergo a curing reaction together with the film-forming resin. In the process of curing and film-forming of most solvent-free insulating varnishes, a lot of reactive diluent will still evaporate. There are very few solvent-free insulating varnishes that do not evaporate solvent.

   2. According to the curing method

      Insulating varnishes are classified according to the curing method into self-drying insulating varnishes, baking insulating varnishes and UV-curing insulating varnishes.

  (1) Self-drying insulating paint Self-drying insulating paint refers to insulating paint that can dry itself into a film after coating. The mechanism of self-drying is generally divided into three categories: one is evaporation drying, that is, high molecular weight solid resin is dissolved in an appropriate solvent, and the solvent evaporates after coating, leaving solid film-forming resin. This type of insulating paint is easy to use and dries quickly. However, it has poor solvent resistance and is easy to soften when heated. This type of insulating paint contains drying vegetable oil. The unsaturated double bonds in the molecular structure of the drying vegetable oil will self-oxidize and cross-link under the action of oxygen in the air, thereby achieving the purpose of drying. General oily, phenolic resin and drying oil alkyd resin insulating paints are all classified as oxidative drying insulating paints. Because this type of insulating paint has a high content of vegetable oil and low heat resistance, it is a Class A or Class E insulating material and takes a long time to dry, usually one day. The third type is room temperature curing drying. This type of insulating paint is cross-linked and cured at room temperature through chemical reactions. This type of paint is two-component or multi-component and is ready for use. This type of paint is commonly used such as polyamide resin cured epoxy resin paint and two-component polyurethane paint, etc. Because this type of paint is chemically cross-linked, it has better heat resistance, solvent resistance and chemical resistance.

   (2) Drying type insulating paint Drying type insulating paint refers to insulating paint that needs to be heated and baked to a certain temperature before it can react and solidify. Most insulating paints are drying type insulating paints, such as amino alkyd resin paint, epoxy ester paint, polyester resin paint and silicone resin paint. This type of paint is chemically cross-linked and is heated and baked, so it has good performance and diverse uses.

According to the baking temperature and curing speed, baking type insulating varnish can be divided into conventional baking varnish, quick-drying baking varnish, low-temperature baking varnish and low-temperature quick-drying baking varnish. The speed of curing is a relative concept, there is no clear standard, and the temperature also affects the speed of curing. Generally, the impregnation varnish with a drying time of less than 1 hour in the product target is called quick-drying varnish, and the product that can be dried within 100℃ is called low-temperature baking varnish.

  (3) UV-curing insulating varnish This is a type of insulating varnish that is cured by ultraviolet light. This type of varnish is formed by adding a photoinitiator to the components of unsaturated resin and reactive diluent. The curing mechanism is that the photoinitiator is decomposed to form free radicals by irradiation with ultraviolet light of appropriate wavelength, which then triggers the cross-linking and curing of the unsaturated resin and reactive diluent. This type of varnish has an extremely fast curing time, curing in a few minutes or even seconds, and is very suitable for assembly line production operations. This varnish is mostly used as a surface coating for products, and can also be used as an impregnation varnish to quickly cure and encapsulate the surface, and then heat and cure the inner layer to achieve the effect of reducing losses and increasing the amount of paint.

Ningbo Chuangbiao Electronic Technology is a professional manufacturer that produces and sells various electronic transformers. The company was established in 2010. The company has now formed a product line characterized by EI type transformers, and also produces various toroidal transformers, C type power transformers, medical transformers, audio transformers, high voltage transformers, industrial control transformers, anti-electric shock, reactors, high frequency transformers and other products. The company has a complete organizational structure and can provide the entire process from planning, procurement, manufacturing, quality assurance, logistics, sales and customer service.

  We select materials from approved high-quality suppliers in accordance with ISO9001 standards. Our employees are specially trained and use the most advanced technology including CNC machines and automatic inspection systems. Each transformer we produce undergoes a comprehensive quality inspection and test before leaving the factory. For more information about transformers, you can consult Ningbo Chuangbiao Electronic Technology. The company is located under the Hangzhou Bay Bridge in Ningbo, Zhejiang, with convenient transportation.