How to avoid Burr in metal laser cutting?-Bunny
Many professionals who work with laser cutting will know why the burr comes out in the material when working with the cut. But … What is burr? If we rely on the definition of the dictionary of the Spanish language, it is a “Portion of excess material that stands out irregularly on the edges or on the surface of any object. Like the mortar that forms a highlight in the bricks when sitting on the construction site. ”
In our case, the burr is part of the material that remains adhered to the edge of the piece during laser cutting. And there are several ways to prevent it from coming out. But it is necessary to take into account some factors that directly relate to “the burr ”
Today, metal fiber laser cutting machines program to automatically control various laser parameters, such as power and beam profile. There are also other settings that can affect the quality of the cut and the technician. Or operator of the machine can configure manually:
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Alignment of the beam by means of the alignment system.
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Focal distance
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Centering of the nozzle.
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Nozzle distance
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Cutting speed
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Fréquence laser
Most of these parameters program automatically. There are three that must adjust to improve the quality of the cut and thus avoid burr: gas pressure, focal length and cutting speed.
As far as gas is concerned, whether it is Nitrogen or Oxygen what we are going to use, we must ensure that it is as pure as possible. The oxygen must have a minimum purity of 99.95% and the nitrogen of 99.999.
- Speed: Not necessarily going slower gives better results. Many times, by decreasing the cutting speed, the temperature induced to the groove is increased, causing vapors that disturb the flow of the gas, and does not allow the waste to be removed, which will remain attache to the piece.
- Gas pipe system: we must ensure that the cylinders are as close as possible to the machine, in this way we will not lose pressure.
- The environment: The gas reacts differently depending on the environmental conditions. Temperature, humidity, and especially changes can affect the quality of cut.
- The focal length: Depending on the material we are going to cut the focal length can be 0 (laser focus on the surface of the material). It can be negative (below the surface). Or positive (focus above the surface of the material).