最新消息NEWS

2017/07/21 Tips : How to Avoid Bad Cutting Quality

  1. Cutting Parameters:
Wrong cutting conditions may affect the cutting quality. The commonly-adjusted parameters are velocity, power, frequency, bandwidth, cutting focus point, nozzle height and gas pressure.
Any one of these parameters will affect the cutting quality. Please adjust them according to the cutting parameter table provided by the manufacturer. If the cutting quality is still bad, please check other factors.
 
  1. Protective Len:
Protective Lens may be contaminated. During the cutting, debris resulted from cutting or puncturing may get into the nozzle and contaminate the protective lens. If the lens is too much contamination, the laser energy passing through the lens may be decreased and the cutting quality is therefore affected. if this happens, the protective lens needs to be taken out of the machine for cleaning and wiping.
If the cutting quality is still bad after cleaning, it is highly possible that the lens has been badly damaged and need to be replaced.
 
  1. Cutting Gas:
Cutting pressure, especially nitrogen, may be consumed too much and therefore the remaining amount is inadequate to provide enough pressure. This will affect debris expelling, resulting in bad cutting quality.
If this happens, users can check if the pressure is enough for cutting from the human-machine interface. Do not adjust the cutting parameters without checking first.
The purity of the auxiliary gases for cutting needs to be over 99.997%. If the purity of oxygen is not high enough, the combustion-supporting may be affected. If the purity of nitrogen is not high enough, the cutting surface may be too yellowish or blackish.
 
  1. Nozzle Gap:
The distance between the nozzle and the sheet may affect the location of cutting focus. If the cutting quality is bad, height correction can be conducted first. After the nozzle or ceramic ring is replaced, height correction is also needed.
 
  1. Overheated Sheet:
If the sheets are arranged in a very dense way, they may be overheated. This generally happens on the carbon steel above 6mm in thickness. If the temperature is too high, cool the material first and then conduct the processing again.
  1. Nozzle Diameter:
The nozzle diameter may have a great effect on the cutting. If the nozzle diameter is too large, the turn may be melted. If the nozzle diameter is too small, the cutting may not be through.
If the nozzle diameter of nitrogen is too small, there may be barbs on the work. If the diameter is too large, the debris may be too large to make the cutting start unstable.
Therefore, if the cutting quality is bad, users may check if the nozzle diameter is wrong.
 
  1. Cooling Water:
Cooling water is for the heat dissipation of the laser oscillator and fiber caber. If the effect of heat dissipation is getting worse, it may cause the lens dilated to shift the cutting focus. This may cause the condition that the first half of the processing is good and the second half is bad.
 
  1. Cut In Lines:
The guidance cutting lines should be long enough. Generally, their length should be as same as the thickness of the material.
If the length of guidance cutting lines is too short, during the nitrogen cutting, the cutting may not be through after a turn and the debris may contaminate the surface of the material.
If this happens in the oxygen cutting, the cut lines after a turn may become tore.
  1. Serious Rusting of Material:
If the material is rusted, the rust may affect the absorption of laser energy.
If the material is rusted, users should put the side with less rust upward to absorb the energy and with the side with more rust downward. In this way, the cutting quality will be better.
If both sides are badly rusted, they need to be de-rusted first before cutting (sand wheels are prohibited. Steel brushes should be used.).
 
  1. Power Quality:
Because of the excellent power transformation rate, fiber laser needs good power quality to maintain stability. It is suggested to equip the machine with the voltage stabilizer to improve the voltage fluctuation or the laser power may become unstable because of the voltage fluctuation.