The pvd coating machine with bellows is usually divided into two types: forming bellows and welding bellows. The bellows used in ultra-high vacuum systems is generally made of SUS316 stainless steel.

      To make a formed bellows with a slightly larger diameter, first roll the stainless steel sheet into a cylindrical shape and weld the joints. The cylinder is inserted into the bellows mold, and the forming of the bellows is completed by hydraulic pressure.
      In the ultra-high vacuum system, the bellows connecting the molecular pump and the mechanical pump are mostly formed bellows with NW flanges at both ends.
      The advantages of forming bellows are simple production and low cost. The disadvantage is the lack of stretch and flexibility. What makes up for the lack of formed bellows is welded bellows.
      Welded bellows are thin-walled corrugated hoses formed by alternately welding circular stainless steel sheets with inner and outer diameters (Figure 2). The welding method is plasma welding. This bellows has great flexibility and is an indispensable part for the connection of ultra-high vacuum systems and various motion introducers. Reasonable selection of the natural length of the bellows, the service life can reach more than hundreds of thousands of times.
      Dongguan Huicheng Vacuum has been specializing in the manufacture of various pvd coating machine for many years, constantly introducing foreign advanced technology, and has been committed to the research and development and production of pvd coating machines for many years. Customized process solutions and machines.