There are two types of laser cutting techniques: the first is pulse laser for metallic materials, and the second is continuous laser for non-metallic materials. The latter is an important application field of laser cutting technology.

Several key technologies of laser cutting machines are integrated technologies of light, machinery, and electricity. The parameters of the laser beam, the performance and accuracy of the machine and CNC system in the laser cutting machine directly affect the efficiency and quality of laser cutting. Especially for parts with high cutting accuracy or large thickness, it is necessary to master and solve the following key technologies: focus position control technology

One of the advantages of laser cutting is the high energy density of the beam, usually 10W/cm2. Due to the inverse ratio between energy density and area, the diameter of the focal spot should be kept as small as possible to produce a narrow slit; At the same time, the diameter of the focal spot is also proportional to the focal depth of the lens. The smaller the focal depth of the focusing lens, the smaller the diameter of the focal spot. However, there is splashing during cutting, and the lens can be easily damaged if it is too close to the workpiece. Therefore, high-power CO2 laser cutting machines are widely used in industrial applications with a focal length of 5 "~7.5" (127~190mm). The actual focal spot diameter is between 0.1 and 0.4mm. For high-quality cutting, the effective depth of focus is also related to the lens diameter and the material being cut. For example, when cutting carbon steel with a 5 "lens, the focal depth is within the+2% range of the focal length, which is about 5mm. Therefore, it is important to control the position of the focal point relative to the surface of the material being cut. Considering factors such as cutting quality and cutting speed, in principle, for 6mm metal materials, the focal point is on the surface; for 6mm carbon steel, the focal point is above the surface; and for 6mm stainless steel, the focal point is below the surface. The specific size is determined by experiments.