vacuum coating machine is the most widely used vacuum equipment for manufacturing vacuum conditions. It is usually composed of vacuum chamber, vacuum unit and electrical control cabinet. The exhaust system is composed of "dispersion pump+mechanical pump+roots pump+cryogenic cold trap+polycold". vacuum coating machine is widely used in various industries, such as digital electronic products, decoration, communication, home furnishing, hardware, etc. The application industries, models, and coating methods are different, but the coating principles are similar. The following is a brief summary of the components and principles of the vacuum coating machine:

1、 Vacuum main body - The vacuum chamber varies according to the requirements of the processed product, and the size of the true cavity also varies. Currently, the most commonly used ones include diameters of 1.3M, 0.9M, 1.5M, 1.8M, etc. The chamber is made of stainless steel material, and it is required not to rust or be solid. The various parts of the vacuum chamber have connecting valves to connect various extraction pumps.
2、 Auxiliary pumping system: The exhaust system is an important part of the vacuum system of the coating machine, mainly composed of three parts: mechanical pump, booster pump (mainly introducing Roots pump), and oil dispersion pump. This exhaust system is composed of "dispersed pump+mechanical pump+Roots pump+low-temperature cold trap+polycold".
The exhaust process is as follows: the mechanical pump first draws the vacuum chamber to a low vacuum condition of less than 2.0 * 10-2PA, providing conditions for the subsequent vacuum pumping of the dispersion pump. Later, when the dispersion pump draws the true cavity, the mechanical pump forms a series connection with the oil dispersion pump to complete the pumping operation in this way.
Mechanical pump: also known as a front stage pump, mechanical pump is the most widely used low vacuum pump. It uses oil to maintain a sealing effect and relies on mechanical methods to continuously change the volume of the suction cavity inside the pump, causing the volume of gas in the pumped container to continuously expand and obtain a vacuum.
1. Classification of mechanical pumps for vacuum coating machine: There are many types of mechanical pumps, including slide valve type (mainly used for large equipment), piston reciprocating type, fixed plate type and rotary plate type (most widely used now, this article mainly introduces).
2. The mechanical pump of vacuum coating machine starts from the atmosphere, and its primary parameters include the limit vacuum and the pumping rate, which is an important basis for planning and selecting the mechanical pump. A single stage pump can pump the container from the atmosphere to an extreme vacuum of 1.0 * 10-1PA, while a double stage mechanical pump can pump the container from the atmosphere to 6.7 * 10-2 Pa or even higher.