Analysis of the impregnation process of Induction Heating And Melting Capacitors

1. The core principle of impregnation treatment

Induction Heating And Melting Capacitors adopt a composite structure combining solid medium and liquid medium. The solid medium is usually a roughened polypropylene film, while the liquid medium is mostly diarylethane. The impregnation treatment is to place the wound capacitor components in an impregnation tank filled with diarylethane, and allow diarylethane to fully penetrate into the tiny pores of the polypropylene film under a vacuum environment to fill the original air gap. ​
From a physical point of view, the dielectric constant of air is low, and its presence will limit the electrical performance of the capacitor. When the air gap is filled with diarylethane, the situation changes dramatically. Diarylethane has a high dielectric constant, which can enhance the electric field strength of the capacitor, allowing the capacitor to store more charge at the same physical size, thereby greatly increasing the capacitance. At the same time, this filling can also effectively reduce dielectric loss, reduce energy loss during the storage and release of electrical energy, and improve energy conversion efficiency. In addition, the good electrical insulation properties of diarylethane further enhance the electrical strength of the capacitor, enabling it to work stably at higher voltages and reducing the risk of breakdown and other failures. ​
II. Fine operation process of impregnation treatment​
(I) Component preparation and tank placement​
Before the impregnation treatment, the wound capacitor components have been carefully made, and their roughened polypropylene film and high-purity aluminum foil are tightly wound to form components with preliminary electrical properties. At this time, these components are carefully placed in the impregnation tank that has been strictly cleaned and dried. The cleanliness of the impregnation tank is crucial. Any impurities may affect the impregnation effect of diarylethane and may even damage the capacitor components. Therefore, it is necessary to ensure that the inside of the impregnation tank is spotless before use. ​
(II) Creation of vacuum environment​
After placing the capacitor components in the impregnation tank, quickly seal the impregnation tank and start the vacuum system. The creation of a vacuum environment is a key step in the impregnation treatment. By vacuuming, the air in the impregnation tank is exhausted as much as possible. When a certain vacuum degree is reached in the tank, the air originally existing in the pores of the polypropylene film is extracted to form a negative pressure space. This creates favorable conditions for the penetration of diarylethane, allowing diarylethane to enter the film pores more quickly and fully under the action of pressure difference. ​
(III) Liquid medium injection and penetration​
After reaching the predetermined vacuum degree, the pre-prepared diarylethane is injected into the impregnation tank. After entering the tank, diarylethane will quickly diffuse and penetrate into the polypropylene film pores of the capacitor element due to the vacuum state in the tank. During the penetration process, it is necessary to pay close attention to the penetration situation to ensure that every pore is fully filled. This process is not completed instantly, and it takes a certain amount of time to ensure that diarylethane can evenly and comprehensively fill the film pores to achieve the best impregnation effect. ​
(IV) Temperature and time control​
Impregnation time and temperature are important factors affecting the impregnation effect and must be strictly controlled. The optimal impregnation time and temperature are different for capacitors with different specifications and design requirements. Generally speaking, properly increasing the temperature can speed up the molecular movement of diarylethane and make it penetrate into the film pores faster, but too high a temperature may have adverse effects on the performance of polypropylene film and aluminum foil, such as causing film deformation and aluminum foil oxidation. Therefore, it is necessary to accurately set the impregnation temperature according to the characteristics of the capacitor element and the physical and chemical properties of diarylethane. ​
The impregnation time also needs to be accurately controlled. If the time is too short, diarylethane cannot fully penetrate, and some pores may not be filled, affecting the performance of the capacitor; if the time is too long, it may increase production costs and may even cause unnecessary damage to the capacitor element. In actual production, the optimal impregnation time and temperature parameters are usually determined through a large number of experiments and production experience accumulation, and these parameters are strictly followed during the production process to ensure that each capacitor element can achieve the ideal impregnation effect. ​
III. The profound impact of impregnation treatment on capacitor performance ​
(I) Improvement of electrical performance ​
After impregnation treatment, the electrical performance of the capacitor has been significantly improved. The increase in capacitance enables the capacitor to meet the higher energy storage requirements of induction heating equipment. In industrial applications, it provides more powerful electrical support for the equipment, ensures that the equipment can heat up quickly, and improves production efficiency. At the same time, the reduction in dielectric loss and the enhancement of electrical strength make the capacitor more stable and reliable during operation. Low dielectric loss reduces energy waste and reduces the operating cost of the equipment; high electrical strength ensures that the capacitor can work normally in a complex electrical environment and is not easily damaged by factors such as overvoltage, thereby improving the reliability and stability of the entire induction heating system. ​
(II) Improvement of heat dissipation and lifespan​
The good heat dissipation performance of diarylethane also plays an important role after impregnation. During the operation of the induction heating equipment, the capacitor will generate heat due to the passage of current. If the heat cannot be dissipated in time, the internal temperature of the capacitor will rise, affecting its performance and lifespan. After the capacitor is impregnated, diarylethane can quickly conduct the generated heat away, effectively reduce the operating temperature of the capacitor, and maintain the stability of its internal temperature. This not only helps to maintain the stable performance of the capacitor, but also greatly extends the service life of the capacitor, reduces the frequency of equipment maintenance and replacement, and reduces the production cost of the enterprise.​
(III) Enhanced environmental adaptability​
Due to the excellent chemical stability and high flash point of diarylethane, the environmental adaptability of capacitors after impregnation treatment has also been enhanced. In harsh industrial environments such as humidity, dust, and corrosive gases, diarylethane can provide good protection for capacitor components and prevent external environmental factors from damaging capacitor performance. The high flash point ensures the safety of capacitors in high-temperature working environments, reduces the risk of safety accidents such as fire, and enables capacitors to be reliably used in a wider range of industrial fields. ​