The vacuum state is the environment that supports the operation of the vacuum coating machine, especially the equipment that requires a high degree of vacuum. Usually, we need to achieve a high degree of vacuum. The role of the vacuum system is indispensable, but in addition to air extraction, the operation of the vacuum coating equipment In the process, another point is the degassing of the workpiece.
Some workpieces have a lot of gas, moisture, etc. in themselves. These substances will be discharged into the vacuum chamber when the equipment is heated, reducing the vacuum degree. What's more, some gases have toxic components, which directly damage the vacuum chamber. The internal mechanical structure causes the equipment to not function properly.
In addition, during the coating process, due to the heating and expansion of the gas in the workpiece, it is easy to crack the coated film. Of course, the probability of this situation depends on the physical properties of the workpiece itself, such as plastics that are easy to expand, the probability is relatively high. For hard materials such as metal, the probability is relatively low, but it cannot be ignored, so the degassing of the workpiece is very necessary.
The commonly used workpiece degassing method is baking, and the gas and moisture in the workpiece are discharged by heating. Before coating, the workpiece is heated while the gas is pumped. When the moisture and gas in the workpiece are released due to heating, the gas in the vacuum chamber is pumped out together by the vacuum pump.
Different degassing measures are taken for different workpieces to effectively control the emission of gas and moisture inside the workpiece, and improve the stability and uniformity of the coating.