In most people's impression, the metal laser cutting machine works with a red light, and then the material is cut. How can smoke and dust be generated? Since the materials, sizes and thicknesses of the products processed by the laser cutting machine are different, the types of laser cutting equipment selected are naturally different. How is the dust generated during the cutting process?

The working principle of metal laser cutting machine is believed to be very clear to everyone. It irradiates the work-piece with high power density laser beam to make the irradiated material melt and vaporize quickly, and at the same time, the high-speed air flow coaxial with the beam blows away the molten material, so as to cut the work-piece. This is also the process of dust and smoke generation.

Causes of cutting dust

1. Laser oxidation cutting: under the irradiation of laser beam, the surface of metal material can be quickly heated to the ignition point temperature, and then combust with oxygen to release a large amount of heat, so that small holes are formed in the material. The holes are surrounded by molten metal walls. These vapors and molten substances are taken away by the auxiliary air flow, and then float in the factory workshop, forming dust and smoke.

2. Laser vaporization cutting: under the heating of high power density laser, about 50% of the materials vaporize into steam and disappear. The remaining materials are blown away from the bottom of the cutting seam as ejected matter by the auxiliary gas and combined with the fine particles in the air to form dust.

3. Laser melting cutting: when the power density of the incident laser beam exceeds a certain value, the material at the irradiation point begins to evaporate, forming holes, and the material around the laser speed is melted. Then, the auxiliary air flow coaxial with the speed of light carries away the surrounding molten material to form soot.

Bad consequences caused by cutting dust

The harm of smoke and dust is easy to be ignored by the operators. The high temperature generated by the laser acts on the processing materials, producing a large amount of steam and smoke. Most of the smoke contains a large amount of chemical components, which will cause certain harm to the human body. In addition, some gases (such as carbon dioxide) produced by laser cutting are easy to harm the respiratory system.

Solutions

Laser cutting machines usually use dry processing or wet processing to remove dust from the dust generated during the processing.

Dry processing method (dry cutting)

It is to add a set of soot capture device for the cutting platform to directly transport the collected soot to the dust filtration and purification equipment, and then discharge it after the treatment meets the standard. For the collection of dust generated by laser cutting, the capture and collection cover is generally used. If the effect is required to be good, then the closed collection cover can be selected, which can collect a large amount of dust and dust. The smoke generated by plasma cutting is basically formed under the workpiece cut, so the suction negative pressure cutting platform has become the most common smoke trapping device at present. In order to save the equipment investment and improve the exhaust efficiency, i.e. to achieve a larger amount of soot collection and a smaller suction volume - only the area in the cutting process is evacuated, so the cutting platform will be along the main guide rail of the cutting machine. It is divided into (evenly) closed small areas with air outlets on the side. The working mode of the suction port is divided into the side suction moving suction port of the vacuum chamber and the side wall valve suction port. Among them, the former is widely used because of its simple structure, reliable operation and good dust removal effect.

Wet processing method (wet cutting)

The so-called wet machining method is to make a water bed cutting platform, place the work-piece on the water or water surface, and then complete the cutting operation under or near the water surface, and use water to capture the smoke generated in the cutting process, so as to achieve the purpose of purifying the environment.

About HGTECH: HGTECH is the pioneer and leader of laser industrial application in China, and the authoritative provider of global laser processing solutions. We have comprehensively arranged laser intelligent equipment, measurement and automation production lines, and smart factory construction to provide overall solutions for intelligent manufacturing.