One of the cutting processes of laser cutting machines is cutting perforation technology, and there are currently two processing methods for this technology: blast perforation and pulse perforation. The effects of different cutting and perforating methods are also different. Therefore, before operating the cutting machine for perforation processing, it is necessary to fully understand these two perforation techniques. So the following small series will give you a detailed introduction to these two perforation techniques.
Laser cutting perforation technology: Any kind of thermal cutting technology, except for a few cases, which can start from the edge of the board, generally requires a small hole in the board. Earlier, on the laser stamping compound machine, a punch was used to punch a hole, and then a laser was used to start cutting from the small hole. There are two basic methods of piercing for laser cutting machines without punching devices:
(1) Blasting perforation
After the material is irradiated by a continuous laser, a pit is formed in the center, and then the molten material is quickly removed by an oxygen flow coaxial with the laser beam to form a hole. Generally, the size of the hole is related to the thickness of the plate. The average diameter of the blasting perforation is half of the thickness of the plate. Therefore, the diameter of the blasting perforation for thicker plates is larger and not round, so it should not be used on parts with higher requirements (such as oil screen slit pipes). ), can only be used on scrap. In addition, since the oxygen pressure used for perforation is the same as that for cutting, the splash is larger.
(2) Pulse perforation
A pulsed laser with high peak power is used to melt or vaporize a small amount of material. Air or nitrogen is often used as an auxiliary gas to reduce the expansion of the hole due to exothermic oxidation. The gas pressure is lower than the oxygen pressure during cutting. Each pulsed laser produces only a small jet of particles, progressively deeper, so the perforation time for thick plates takes a few seconds. Once the laser cutting machine perforation is completed, immediately change the assist gas to oxygen for cutting. In this way, the diameter of the perforation is smaller, and the perforation quality is better than that of blasting perforation. For this purpose, the laser used should not only have high output power; more importantly, the time and space characteristics of the beam, so the general cross-flow CO2 laser can not meet the requirements of laser cutting.
As mentioned by the editor above, the laser cutting machine uses different cutting and perforating methods, so the quality and effect of the cutting process are also different. Therefore, before everyone controls the equipment for processing, it must be combined with customer needs and actual use. It is necessary to choose a more suitable cutting and perforating technology according to the situation, so that the cutting quality will be better.
