Why do burrs occur when using laser cutter?

Burrs are still occurred while the parameters are set up well during using the laser cutting machine. So what caused such a problem? Let's take a look at the causes.

Figure 1  The comparision of cutting workpiece

Firstlyl, geometric errors exist in the plates itself. For example, if the processing product is uneven or with small particle residue on the surface, the default cutting process is to set the flat plate cutting data. If the product surface is uneven, different areas may be heated unevenly during cutting, and the thin plate surface will be overheat melting, thus the thick plate surface may not be able to be melted. As the surface is not smooth, the focus of laser will change randomly with the position and set position of the surface which the object being processed.

Figure 2  plates

Secondly, the actual thickness of the material exceeds the cutting range. For example, equipment with 1500W power can cut carbon steel plate at most 12mm thick. If it is forced to cut carbon steel plate at 14mm thick, even if the machine can cut through the plate, there will definitely be errors or slag hanging at the bottom. Therefore, it is necessary to determine the thickness of the plate and the actual thickness of the equipment before cutting. Otherwise, the quality and accuracy would not be promised if beyond the cutting range.

Figure 3  Cutting Parameters

Thirdly, the error of the focus position will also cause burrs in the cutting process. Many factors can change the position of the focus relative to the surface of the product, which will also affect the accuracy of the machined product. For example, the clamping method of fixture, the level of the placement of the machine tool itself, the bed rack wear degree, etc. In order to reduce such errors, please recheck before cutting.

Figure 4  Focus Position

What’s more, if the purity of the gas is not high enough, it will also cause burrs as well. When workpiece surface is vaporized, the gas blows off the slag on the surface of the workpiece. If the gas is not used, the slag will form burrs attached to the cutting surface after cooling.

Figure 5  Cutting principle