The World of Laser Cutting

In the early 60s, laser cutting technology advanced so fast, it took some time to figure out how it could be put to work. It was only a matter of time before it caught the attention of the world at large, and industry in particular. Laser cutting brings speed, precision, efficiency, economy, and adaptability, all with a remarkably small kerf. Even in the present day, there hasn’t been much of a challenge to the laser. Laser cutting gives a higher quality cut compared to punch, plasma, abrasive waterjet, ultrasonic, oxyflame, sawing and milling.

Types of laser cutting machines

Laser cutting is used widely in the automotive and aviation industries, metallurgy, marine, and construction. It accounts for the biggest segment of the metal cutting market, according to 2016 figures. In fact, you’ll see laser cutting on our own products: the canopy panels on Atlas Copco compressors are laser cut.

The two main categories of lasers used in industrial applications are gas lasers and solid-state lasers. CO2 lasers are an example of gas lasers. Fiber lasers are an example of solid-state lasers (actually they are a variant). Gas lasers such as CO2 or excimer lasers are referred to as such because they use a gas mix to generate the laser beam. So, for example, in CO2 lasers (the most popular type of gas laser in manufacturing), CO2 is the active laser medium. Solid-state lasers on the other hand use a solid medium to generate the laser beam. This solid medium could be glass, crystal, or fiber (a variation of the solid-state laser).

How it works

The major difference between CO2 and fiber lasers lie in the way the beam is generated and guided. But when it comes to the cutting head, the operation is the same. Here with the help of lenses, the laser beam is focused on a specific area of the surface which melts as a result of the rapid increase in temperature.

At the very same time the area is blasted with assist gas that is supplied through a gas connection. The quality of the cut is affected by many factors including:

  • Material (type, surface, thickness, shape)
  • Available power
  • Cutting speed
  • Focal distance of the lens
  • Focal point of the lens

The assist gas being used also plays a significant role in cut quality. The gas being used can influence the required cutting power, fogging of lenses/mirrors from fumes, area affected by heat, cut zone, and effectiveness in removing molten material. Of course, the benefits are only secured when the assist gas is used at the right flow rate, pressure, purity, and quantity.

Nitrogen, oxygen, and air are the most common assist gases used in laser cutting of metal. While the choice of one or the other depends on the purpose, nitrogen is by far the most popular gas for cutting metal when a high-quality cutting edge is required. Oxygen on the other hand is highly reactive, so the cutting edge created with it is not as fine, however because it boosts the power of the laser beam, it cuts fast and deep and is preferred for cutting through thicker metals. Similarly, air too does not create a fine cutting edge but it is less costly and is preferred for cutting where the metal will be undergoing further processing.

We explore the role of assist gas in depth in this post

If you are looking to set up your laser-cutting enterprise or to step up you existing operations, explore Pneumatch’s range of nitrogen generators. Or get in touch with us right away. Call at +49 (0)2841 788 480 or email to support-eu@pneumatech.com.