How to choose and use laser cutting nozzles

During the laser cutting process, the laser head nozzle collects capacitance signals and transmits them to the signal processor through the ceramic ring, thereby keeping the laser cutting machine tracking the distance of the laser head to the workpiece during the cutting process, and guiding the gas to pass smoothly through the workpiece to be cut. And high pressure is formed near the nozzle outlet to speed up the cutting speed, take away the slag, and protect the internal lens of the laser head.
The coaxiality between the nozzle exit hole and the laser beam is one of the important factors affecting the quality of cutting, especially when the workpiece being cut is thicker, its impact is greater. Therefore, the concentricity of the nozzle center and the laser must be adjusted to obtain a better cutting section.

Effect on cutting quality when the center of the nozzle is not coaxial with the center of the laser beam
1. The cutting gas is ejected from the center of the nozzle and acts on the cutting plate. The laser spot can be divided into four areas according to the positive and negative directions of the , some surface stripes are thick, even slag hanging or cut continuously.
2. For the bright surface effect of 10,000-watt cutting of carbon steel, small nozzles combined with high-focus technology are currently used. The laser is not in the center of the nozzle. It can easily cause the nozzle to heat up, affect the follow-up, cannot stabilize the processing, and directly burn the nozzle in serious cases.

Nozzle type
Generally, laser cutting nozzles are divided into single and double layers. Single-layer nozzles are used for melt cutting, that is, nitrogen is used as auxiliary gas. They are usually used for cutting stainless steel, aluminum alloy, brass, etc.; double-layer nozzles are generally used for oxidation cutting. That is, oxygen is used as an auxiliary gas, usually used for cutting carbon steel.


Nozzle size selection
The diameter of the nozzle determines the shape of the airflow entering the incision, the gas diffusion area, and the gas flow rate, thereby affecting the removal of molten material and the stability of cutting. The greater the air flow entering the incision, the faster the speed, and the proper position of the workpiece in the air flow, the stronger the ability of the jet to remove molten material.
The user selects the nozzle size based on the power of the laser used and the thickness of the metal sheet being cut. Theoretically, the thicker the plate, the larger the nozzle should be used, the greater the proportional valve setting pressure, the greater the flow rate. Only by ensuring the pressure can the normal cross-section effect be achieved.

Different power nozzle options
Laser power ≤ 6000W
For cutting carbon steel, the nozzle specification diameter is generally double-layer S1.0~5.0E;
For cutting stainless steel, use single-layer nozzles of ordinary specifications;

6000W cutting effect

Laser power ≥6000W
For cutting carbon steel, 10~25mm carbon steel bright surface cutting, the diameter of the cutting nozzle selected is generally double-layer high-speed E-type S1.2~1.8E; the diameter of single-layer fan type is generally D1.2~1.8;
For cutting stainless steel, use single-layer nozzles of ordinary specifications;

15000W cutting effect