Depending on the material of the cutting workpiece, the choice of the focus position of the laser cutting machine
will be different. The following is the specific relationship between the selection of the focus position of the laser cutting machine
and the material of the workpiece to be cut:
First, zero focal length, the focus is on the surface of the workpiece. Laser cutting machine
is used when cutting SPC, SPH, SS41 and other workpieces. Because the focus is on the upper surface of the workpiece, the cutting is smooth near the upper surface and not smooth near the lower surface.
Second, the positive focal length, the focus is inside the workpiece. Laser cutting machine used to
cut stainless steel, aluminum and other workpieces. The focus is in the center, so the smooth surface has a larger range, the cutting width is wider than that of zero focal length, the cutting gas flow is larger, and the perforation time is longer than that of zero focal length.
Third, the negative focal length, the focus is on the workpiece. Laser cutting machine for
cutting thick iron plates. When cutting a thick iron plate, the oxidizing effect of oxygen for cutting must be from top to bottom. The cutting width is wide due to the thickness of the board. This setting can get a wider cutting width. The cut surface is similar to the gas cut. It can be said that it is blown with oxygen, so the cut surface is rough.