What parameters should be noted in laser engraving

Laser engraving is currently widely used in various fields such as molds, signs, hardware accessories, advertising decorations, and automotive parts. Compared to traditional corrosion techniques, laser engraving has extremely high accuracy, achieving a positive or negative 0.1mm or even lower accuracy, and can easily handle difficult to handle right angles. Meanwhile, laser engraving produces almost no pollution and does not have a significant impact on the physical health of operators. Therefore, in recent years, laser engraving has been increasingly sought after by more and more industries.

Laser engraving related parameters and their meanings

1. Laser power
The laser power required for laser engraving mainly depends on the engraving material, material thickness, and engraving speed requirements. Laser power has a significant impact on engraving thickness, engraving speed, and incision width. Generally, as the laser power increases, the thickness of the material that can be carved also increases, the carving speed accelerates, and the cutting width also increases.

2. Focus position
The focus position has a significant impact on the width of the incision. The distance between the focus and the workpiece is also known as defocus. When the focus is above the workpiece, it is called positive defocus; When the focus is on the surface of the workpiece, it is called zero defocus; When the focus is located inside the workpiece, it is called negative defocus. When processing metal materials, the focus is located about one-third below the material surface, with the maximum carving depth and the minimum mouth width.

3. Focal moment
When carving thicker steel plates, a beam with a longer focal moment should be used to obtain a well perpendicular carving surface. The depth of focus is greater, the diameter of the spot also increases, and the power density decreases, resulting in a decrease in carving speed. To maintain a certain carving speed, it is necessary to increase the laser power. It is advisable to use a beam with a smaller focal length for carving thin plates, which has a smaller spot diameter, higher power density, and faster carving speed.

4. Auxiliary gas
The carving of low-carbon steel often uses oxygen as the carving gas to promote the carving process by utilizing the reaction heat of iron oxygen combustion. Moreover, the carving speed is fast, the quality of the cut is good, and a slag free cut can be obtained. The pressure increases, the kinetic energy increases, and the slag discharge capacity enhances; The size of the engraving pressure is determined based on factors such as material, plate thickness, engraving speed, and surface quality of the engraving.

5. Nozzle structure
The structural shape of the nozzle and the size of the light outlet also affect the quality and efficiency of laser engraving. Different engraving requirements require the use of different nozzles. The commonly used nozzle shapes include cylindrical, conical, and square shapes. Laser engraving generally adopts a coaxial (air flow and optical axis are concentric) blowing method. If the air flow and optical axis are different, it is easy to produce a large amount of splashing during engraving. To ensure the stability of the carving process, it is usually necessary to control the distance between the nozzle end face and the workpiece surface, which is generally 0.5-2.0mm, in order to facilitate smooth carving.