High vacuum coating machine is currently the most widely used equipment for making vacuum. The components are as follows: Mechanical pump、 booster pump、oil diffusion pump、condensate pump、 vacuum measurement system.

         The following is a detailed introduction to the composition and working principle of each part

1.Vacuum body-vacuum chamber

         The size of the vacuum chamber varies according to the requirements of the processed products. At present, the most widely used diameters are 1.3M, 0.9M, 1.5M, 1.8M, etc. The cavity is made of stainless steel, which is not rusty, solid, etc. Each part of the vacuum chamber is provided with a connection valve for connecting each pump.

2. Auxiliary air extraction system

         This exhaust system is composed of "diffusion pump + mechanical pump + roots pump + cryogenic cold trap + polycold".

         The Exhaust process : the mechanical pump first pumps the vacuum chamber to a low vacuum state less than 2.0*10-2PA, which provides a prerequisite for the subsequent vacuuming of the diffusion pump, and then when the diffusion pump pumps the vacuum chamber, the mechanical pump cooperates with oil Diffusion pumps are connected in series to complete the pumping action in this way.

         The exhaust system is an important part of the vacuum system of the coating machine, which is mainly composed of three parts: mechanical pump, booster pump (mainly introduces Roots pump), and oil diffusion pump.

         Mechanical pump: Also called backing pump, mechanical pump is one of the most widely used low vacuum pumps. It uses oil to maintain the sealing effect and relies on mechanical methods to continuously change the volume of the suction cavity in the pump to make the gas in the pumped container The volume expands continuously to obtain a vacuum.

         There are many types of mechanical pumps. Commonly used are slide valve type (this is mainly used in large equipment), piston reciprocating type, fixed vane type and rotary vane type (this is currently the most widely used, this article mainly introduces) four types.         

         vacuum coating machine Mechanical pumps are often used to pump out dry air, but cannot pump out gases with high oxygen content, explosive and corrosive gases. Mechanical pumps are generally used to pump out permanent gases, but they are not good for moisture. Effect, so it cannot remove moisture. The main parts of the rotary vane pump are the stator, rotor, shrapnel, etc. The rotor is inside the stator but has a different axis from the stator, like two inscribed circles. There are two shrapnels in the rotor slot, and a spring is installed between the two shrapnels. Ensure that the shrapnel is tightly attached to the inner wall of the stator.