In the process of laser cutting, the main factors affecting the cutting quality and performance include laser beam quality, laser power, cutting speed, workpiece thickness, material type, etc. In addition, the design of cutting head nozzle is also an important factor. Today, we will learn more about the relationship between the nozzle and the cutting quality of the laser cutting machine.

The nozzle is usually installed at the front end of the laser cutting head, which first helps to control the auxiliary gas and protect the focusing lens.

1. When the center of the nozzle is different from the center of the laser, the impact on the cutting quality:

It affects the cutting part. When spraying cutting gas, the gas volume is not uniform, so the cutting part is more likely to have a molten side, while the other side does not. In particular, when the thickness of the metal plate is more than 3mm, the effect is more serious, and sometimes it cannot be cut.

Affects the quality of sharp corners. Local over melting may occur when cutting workpieces with sharp or small angles. When cutting thick plates, it may not be possible to cut.

Affects perforation. Especially for thick plates, the perforation process is unstable, and the time is not easy to control. The penetration of thick plates may cause over melting.

Influence of nozzle on cutting quality of laser cutting machine

2. Impact on cutting quality when nozzle diameters are different:

Nozzles have different diameters, e.g φ 1.0mm， φ 1.5mm， φ 2.0mm， φ 2.5mm， φ 3.0mm。 Currently, nozzle holes are often used in two sizes: φ 1.5mm and φ 2mm。

φ 1.5mm is more suitable for plates less than 3mm, and the cutting surface is thinner; If using φ 2mm, the cutting surface will become thicker and the corner will be easy to melt.

For thick plates above 3mm, the cutting time is relatively increased due to the strong cutting ability and longer heat dissipation time. φ When 1.5mm, the gas diffusion area is small and unstable, but it can be used basically. φ At 2mm, the gas diffusion area is large and the gas flow rate is slow, so the cutting is stable.

φ 2.5 mm diameter can only be used for cutting thick plates above 10 mm. In a word, the size of nozzle hole has a serious impact on cutting quality and piercing quality. Currently, laser cutting uses nozzles with diameters of 1.5mm and 2mm

Influence of nozzle on cutting quality of laser cutting machine

During the cutting process, the workpiece shall keep a stable distance from the nozzle to prevent the splash from rebounding during the cutting process. The diameter of the nozzle determines the shape of the air flow entering the slit, the gas diffusion area and the gas flow rate, thus affecting the stability of melt removal and cutting. The gas flow into the slit is large and fast, the position of the workpiece in the air flow is appropriate, and the ability to spray the melt is stronger. Therefore, the larger the nozzle aperture is, the worse the protection of the focusing mirror will be. Because the molten sparks are splashed during cutting, there is a great chance of bombs, so the life of the lens will be shortened.

Note: When the nozzle is deformed or melted, its impact on the cutting quality is the same as above. Therefore, the nozzle shall be placed carefully and shall not be damaged to avoid deformation; Melt stains on the nozzle shall be removed in time. The quality of the nozzle is very accurate at the time of manufacture and requires the correct installation method. If the conditions are changed due to poor nozzle quality during cutting, the nozzle shall be replaced in time.