Why does the laser cutting machine protect the lens with water mist
When the laser cutting machine is cutting, it needs to use auxiliary gas. The common auxiliary gas is divided into three types: nitrogen, oxygen and air.
Let us first understand the performance of different gases during laser cutting and the materials suitable for cutting:
Mainly used for laser cutting machine to cut carbon steel. While the oxygen reaction heat is used to increase the cutting efficiency in a large format, the oxide film produced will increase the beam spectrum absorption factor of the reflective material. The cut end is black or dark yellow. Mainly suitable for rolled steel, rolled steel for welding structure, carbon steel for machine structure, high tension plate, tool plate, stainless steel, electroplated steel plate, copper, copper alloy, etc.
Some metals use oxygen to form an oxide film on the cutting surface when cutting, and nitrogen can be used to prevent oxidation film from appearing in non-oxidation cutting. The non-oxidized cutting surface has the characteristics of direct welding and painting, and strong corrosion resistance. The cut end is whitish. The main applicable plates are stainless steel, electroplated steel plate, brass, aluminum, aluminum alloy, etc.
Air can be provided directly by an air compressor, so the price is very cheap compared with other gases. Although the air contains about 20% oxygen, the cutting efficiency is far less than that of oxygen, and the cutting ability is similar to that of nitrogen. A small amount of oxide film will appear on the cut surface, but it can be used as a measure to prevent the coating layer from falling off. The end face of the incision is yellow. The main applicable materials are aluminum, aluminum alloy, stainless copper, brass, electroplated steel plate, non-metal and so on.
When many customers use air cutting, the situation of protecting the lens water mist is more concentrated, and the main source of air is air compressor. The air provides cooling and cleaning effects for the laser lens and cutting lens, preventing pollutants from reflecting in from the air nozzle.
However, the air contains a lot of moisture and impurities. If it is not purified, it will cause great harm to optical components, especially moisture. The air pipe used to blow air is very close to the protective lens. If there is water, it is easy to spray on the protective lens when spraying through the air outlet. There is a temperature on the protective lens when it is working, and it will condense and appear astigmatism when it meets with water, resulting in insufficient laser focusing intensity and accuracy, which will seriously affect the cutting quality. After a long time, the focusing lens or the protective lens will easily break. Therefore, it is necessary to configure a desiccant to cooperate with an air compressor to filter drainage, but not all dryers can guarantee the use of laser gas.
Therefore, the dryer is the culprit of water mist during laser cutting.
So how do we choose the dryer matching the laser cutting machine?
The common dryers on the market are mainly refrigerated and adsorbed:
1. Refrigerated dryer: Due to technical limitations, refrigerated dryers are generally used for compressed air that is not demanding. Because the pressure dew point of the cold dryer can only reach 3℃, it cannot meet the air dryness requirements of the laser cutting machine.
2. Adsorption dryer: If there is no liquid water at the air outlet, you can only choose an adsorption dryer. The pressure dew point of the core adsorption dryer can continuously and stably reach -40℃, and the highest can reach -80℃, which can fully meet the needs of laser cutting processing.
The purpose of using air is to save costs, but while saving costs, you must not choose too bad air compressors and dryers, otherwise the instability of cutting will lead to waste of materials and cause greater losses.