In the production process of many products, the presence of particulate pollution will have a serious impact on the yield of finished products, so the number of particulates will be strictly controlled through the use of clean room. But it seems that it is not enough to rely solely on clean rooms for the principle of particulate pollution, and some basic principles must be followed.
One of the principles is that workers do not bring particles into the clean room when they enter the clean room. In order to achieve this, before entering the clean room, workers should clean the machine and parts they bring in. At the same time, they should also wear dust-free clothes, caps, anti-static shoes, anti-static gloves and special conductive fibre materials which do not generate static electricity. Masks, etc.; the particles attached to the surface of clothes must be removed with high-speed clean air before entering the clean room.
The second principle is to control the dust emission of the manufacturing machine in the dust-free clean room. Because the friction and contact peeling of the articles are easy to cause dust emission when they move, and the articles will also have particles when they move, so try to reduce the action form of contact peeling dust emission as much as possible; use the materials with small abrasion dust emission and lubricating oil with small dust emission to achieve dust-free. Dust control in clean room.
The third principle is to quickly remove the particles that have occurred in the clean room. The particles that have occurred usually stay on the surface of the surrounding objects according to gravity and electrostatic adsorption force. Therefore, sudden vibration and unstable air flow will cause these accumulated particles to rise again in the air, increasing the risk of major particle pollution.
Therefore, as long as the control of air flow can prevent the accumulation of particles in the clean room, but for the charged surface, the accumulation of particles can not be prevented. In order to prevent the adhesion of particles caused by electrostatic adsorption, the conductive materials with the degree of charge below tens of volts are usually used in the clean room.
The fourth principle is to design a perfect exhaust system for the clean room. When the exhaust volume is compressed as much as possible, it is not only to exhaust outside the clean room, but also to return the air after particle removal to the clean room.