In the core manufacturing process of electrical equipment such as motors, transformers, and electromagnetic coils, insulation treatment is the "lifeline" that determines their performance and lifespan. Due to its inherent limitations, the traditional atmospheric pressure impregnation method is no longer able to meet the current strict requirements for high reliability and high efficiency. Vacuum impregnation technology, as an advanced process in modern industry, is becoming the industry standard for high-end manufacturing with its incomparable advantages.
What is vacuum impregnation?
Vacuum impregnation is an advanced process of impregnating insulating varnish on components such as motor stators, rotors or transformer windings in a vacuum environment. The core steps are as follows: First, place the workpiece in a sealed impregnation tank and evacuate it to a high vacuum to remove the deep gas and moisture inside the winding. Then, under vacuum or pressure conditions, fully penetrate the solvent-free insulating varnish into every tiny gap; Finally, the paint is dripped and cured. This process may seem simple, but it contains tremendous energy for enhancing product quality.
The five core advantages of vacuum impregnation:
Advantage One: Ultimate penetration, no blind spots in filling
Pain point of traditional process: When impregnating under normal pressure, the gas inside the winding cannot be completely discharged, forming an "air cushion" effect, which causes the insulating varnish to fail to penetrate deep and dead corners, leaving weak points in insulation.
Vacuum impregnation solution: In a high vacuum environment, the air and moisture in the internal pores and capillaries of the windings are thoroughly extracted, creating an excellent condition for the inflow of insulating varnish. Insulating varnish can quickly and completely fill every gap, interlayer and inter-turn of the winding under the action of pressure difference, achieving 100% perfect penetration.
Advantage 2: Significantly enhance heat conduction and dissipation performance
Pain point of traditional craftsmanship: Air is a poor conductor of heat. The presence of air in the unfilled pores will seriously affect the heat conduction inside the windings, causing local overheating (temperature rise) during equipment operation and accelerating insulation aging.
Vacuum impregnation solution: The thermal conductivity of insulating varnish is much higher than that of air. When the insulating varnish completely fills the gaps, an efficient "heat conduction network" is formed inside the winding, which can quickly conduct the heat generated during operation to the core and casing, significantly reducing the temperature rise (usually by 10-20℃). This not only enhances efficiency but also greatly extends the service life of the equipment.
Advantage 3: Outstanding electrical strength and environmental tolerance
Pain points of traditional craftsmanship: Residual moisture and partial discharge are the main causes of insulation system failure. In harsh environments such as dampness, dust, and corrosive gases, traditional impregnation equipment is prone to damage.
Vacuum impregnation solution: The vacuum environment completely eliminates moisture and, together with insulating varnish, forms a dense and robust integral structure. This can effectively prevent corona discharge and partial discharge, and significantly enhance dielectric strength and withstand voltage level. Meanwhile, this structure can effectively prevent the intrusion of moisture, chemical pollutants and dust, enabling the equipment to operate stably even under harsh working conditions.
Advantage Four: Enhance mechanical strength and stability
Pain points of traditional craftsmanship: When motors and transformers are in operation, they generate electromagnetic force and mechanical vibration. Long-term vibration can easily lead to loose windings, wear (inter-turn short circuit), and even damage.
Vacuum impregnation solution: The cured insulating varnish acts like a powerful "glue", firmly bonding loose wires, cores and insulating materials into a solid whole. This greatly enhances the mechanical strength and rigidity of the winding, effectively resisting vibration and shock, reducing operating noise, and ensuring the structural stability of the equipment during long-term high-speed operation.
Advantage Five: Integrated molding, extending the overall lifespan
Comprehensive benefits: The accumulation of all the above advantages ultimately converges into one point - greatly extending the overall service life and operational reliability of the equipment. A device that has undergone vacuum impregnation treatment means a lower failure rate, less maintenance costs and a longer service life, bringing you long-term economic benefits and brand reputation.