The air compressor for laser cutting machine is generally 13~16bar or 20~30bar. The laser beam hits the workpiece surface. So it bring the workpiece to the melting or boiling point. At the same time, compressed air blows the molten metal away. As the beam moves relative to the workpiece, there forms a slit in the material. Finally achieve the purpose of cutting.
13 bar laser cutting application air compressor for thinner sheets. It’s energy efficient. The 16 bar laser cutter air compressor is suitable for thicker plates. Because it has higher cutting efficiency. In addition, the 20~30 bar air compressor is more applicable for high precision fiber laser cutting machine.
1.Working principle of laser cutting machine
The laser cutting machine needs a pressurized air source as power when working. Commonly used auxiliary gases are as follows: oxygen, nitrogen and compressed air. Sometimes, it also use Argon. According to the air pressure, it can include high pressure air and low pressure air.
Firstly, the laser device emits the horizontal laser beam. Then it becomes a vertically downward laser beam through a 45° total reflection mirror. Afterwards, they are focused by a lens. A very small spot of light gathers at the focal point. When the light spot shines on the material, the material is quickly heated to the vaporization temperature. Thus, evaporation forms pores. With the movement of the beam to the material, compressed air blows away the molten slag. Finally complete the cutting of the material.
The demands on the thickness and efficiency of cutting sheets are constantly changing. Therefore, the compressed air pressure also develops from the previous 1.25MPa to 1.3MPa to a higher pressure. It even reaches 2.0MPa to 3.0MPa. At present, the 1.6MPa compressed air is mainly used in the market. For example, we usually use the 4 in 1 air compressor for laser cutting machine. It’s screw compressor with dryer and filters.
2.The effect of oil in compressed air
The quality of compressed air has a very direct impact on the quality of laser cutting. It contains water mist and oil. If it is not cleaned, high pressure is sprayed on the lens surface of the laser cutter head. It will seriously affect the transmission of the laser beam. Then scatter focus. Eventually, it will affect the cutting of the products.
Especially it’s for the super power laser cutting machine. As long as there is a slight oil film or water mist on the protective mirror, it may also cause the high-energy laser emission to burn out the laser head. We know the laser head is very expensive. And most air compressor can not handle the oil and moisture very well. With the use of equipment, the effect of oil and air separation becomes worse. The oil content in the compressed air also increases. Bring uncertainty to use. Therefore, it is necessary to remove water and oil from the compressed air. That is, we need to install the purification equipment to air compressor for laser cutting machine.
3. How to get the oil free compressed air?
In compressed air, it is relatively easy to remove water. Only need to install the matching refrigerant air dryer and filters. However, it is much more difficult to keep the compressed air free of oil. If you choose an oil-free air compressor, it will undoubtedly increase the user’s acquisition cost. In addition, oil-free machines are also difficult to generate such high pressure.
Use the conventional lubricated air compressor to get oilless compressed air. Then add the oil-removal equipment. So as to obtain oil-free compressed air. Its use process is shown in below picture.
This system removes the moisture and dust particles in the compressed air. More importantly, it also purify the gaseous oil. Thus, it avoids the pollution of the lens. The compressed air purifier mainly composes of the following parts. That is, high-efficiency heat exchangers, reactors, electric heaters, electric control systems, etc.
4.The use effect of screw air compressor and purification device for laser cutting machine
Firstly, the compressor produces compressed air. It enters the filter after passing through the air receiver tank and the pipeline. The filter effectively separates the liquid water. At the same time protect the reaction system. Afterwards, the compressed air enters a high-efficiency heat exchanger. Here the low temperature air from the precision filter is fully heat exchanged with the high temperature air from the reactor. So compressed air heats up. Then enter the reactor. The oil impurities in it come into contact with the cold catalyst. At the temperature of 180～220℃, the catalytic oxidation reaction occurs: CnHm+(n+m/4)O2→nCO2+m/2H2O.
All the oil is converted into carbon dioxide and water. At the same time, the high temperature can kill the biological bacteria in the compressed air. Finally we get highly clean compressed air. Moreover, the high-efficiency heat exchanger will also recovers the heat of the purified high temperature air. Then it is sent to the user’s air-usage unit. The entire process is automatically regulated by a high-precision temperature control system. So it’s safe and stable.
This combination method has a good application in oil-free conditions. For example, the effect is obvious in the electronics, food and photovoltaic industries. We use it to match the air compressor for laser cutting machine. The effect of use also meets the expectations of customers.