It’s obvious that people want to earn money with their laser cutters. Many think that increasing laser power will increase their earnings—sometimes this is true, but sometimes not. If we consider how increasing the power will affect earnings, we should discuss this in detail. When the power range is quite low, any power increase is directly visible in the overall efficiency. As the power increases, the cutting speed increases proportionally, but when the parts are small, the sections over which the laser moves do not allow the cutting speed possible for a given laser power to be used in full.
Increasing the power on small parts is no longer effective, so increasing the power with thin sheets and small details does not make any sense. All these considerations apply to cutting in nitrogen; after a certain thickness, a transition to cutting with oxygen is necessary. However, when cutting with oxygen, the feed rate is much lower and does not increase with increasing power. This means that increasing the power makes sense only for plates of medium thickness. For example, with power of 6 kW, the maximum thickness of cutting in nitrogen is 6 mm—after exceeding this value, cutting in oxygen should begin, which is done at a much lower speed and therefore reduces the overall efficiency. When increasing the power to 8 kW, the maximum thickness of the cut in nitrogen is 8 mm, 10 kW is 10 mm, 12 kW is 12 mm, etc.
High laser powers only make sense for cutting medium thicknesses. For thin sheets, high power cannot be used because the dynamics of the machine is limiting, and for thick sheets, the oxygen cutting technology is limiting. Therefore, if the largest part of a job is a metal sheet that is 8 mm thick, laser with a power of at least 8 kW should be used and if it is, for example, 12 mm, a laser with a power of 12 kW should be used, and so on.
The above dependence shows that further increasing the power to, for example, 15 or 20 kW should almost completely eliminate the need to cut thick sheets in oxygen. Laboratory research confirms this, but is the industry ready for such high power?
The rapid development of fiber laser sources in recent years has resulted in the fact that power capacities of 20 kW or even 30 kW are already available on the market. However, it turns out that their implementation into cutting machines is not so simple. Offering extremely high power looks great in advertising, but can the huge purchase cost really pay off?