The influence of focal length on the cutting quality of laser cutting machine!

There are many factors that affect the cutting quality of laser cutting machine, such as cutting speed, gas pressure, cooling water temperature, whether the lens is clean, etc., which will affect the cutting speed and cutting quality. SAN LASER will focus on the influence of the focal length and focal position of the focusing lens on the cutting quality.

Generally speaking, short-focus lenses should be selected for high-speed cutting of stainless steel below 3mm, and short-focus or long-focus lenses can be selected for 3-8mm stainless steel. It is recommended to use a long-focus lens for cutting stainless steel or carbon steel above 8mm. The short-focus lens has a small focusing spot size (the laser beam focusing spot size is proportional to the length of the lens), high power density at the focus, and fast cutting speed (the cutting speed of the material is proportional to the laser power density). It is very beneficial for material cutting, but its disadvantages are also obvious. First, the adjustment margin is small. For cutting thicker plates, the width of the cut after cutting on the top and the bottom will be different, thus affecting the cutting quality. At the same time, due to the concentrated cutting power density and finer cutting seams, slag will splash onto the lens surface when cutting the plate, affecting the service life of the lens, so short-focus lenses are generally used for high-speed thin plate cutting.

The power density of the focused spot of the telephoto lens is low, but its focal depth is large. As long as the total power of the laser is large enough, the advantage of cutting thick plates will be highlighted.