The magnetic fluid seal of the pvd coating machine is limited by the following conditions during operation:

Limit condition 1 for magnetic fluid sealing: evaporation. The magnetic fluid consists of three parts: magnetic particles, surfactants, and carrier liquid. The evaporation of the carrier liquid is the main factor determining the maximum rotation frequency and service life of the seal. Because sealing works with limited magnetic fluid. To ensure efficient sealing, a carrier liquid with low steam pressure should be selected to minimize evaporation loss.

Limit condition 2 for magnetic fluid sealing: Temperature rise, which can cause demagnetization of the magnet and evaporation of the magnetic fluid. Because the temperature increases, the viscosity decreases, and the power consumption also decreases, which is a beneficial aspect. However, as the temperature increases, the magnetic saturation strength decreases, which may also cause a slight decrease in the sealing pressure resistance. Therefore, the temperature of the magnetic fluid should generally not exceed 105 ℃, otherwise cooling measures should be taken.
Limit condition three for magnetic fluid sealing: ultimate vacuum degree. The ultimate vacuum degree of magnetic fluid sealing depends on the volatility of the carrier liquid, and the carrier liquid made of a grease lubricant can meet 1.333 × Requirements for 10-7 Pa ultra-high vacuum technology.
Limit condition four for magnetic fluid sealing: circumferential speed. Generally, magnetic fluid sealing is suitable for operation with high circumferential speed of 30m/s or above, without limit signs. But considering the temperature and heat dissipation of the magnetic fluid seal, the circumferential speed should be limited to 60-80m/s, and at this time, the ultimate pressure resistance should also be considered.
Guangdong Huicheng Vacuum has been specializing in the manufacturing of various vacuum coating application equipment for many years, and has been committed to the research and development and production of vacuum coating machines. With the latest technology, we continuously manufacture pvd coating machine that meet market needs, providing customers with customized process solutions and machines.