Laser power and material type

Watching the fiber laser cutting process is an amazing experience, as cutters often work at such high speeds that they resemble printers more than metal cutting machines. This has become possible because modern technological solutions used in feed systems enable cutters to move at speeds often exceeding 250 m/min.

However, the feed speed itself does not directly translate into device efficiency. The latter depends on other factors - for example, the laser power. If it is too low, the cutting speed will simply be small. On the other hand, low cutter dynamics will prevent fast project implementation even with high laser power, and manual sheet replacement will mean that a powerful and fast cutter will be idle waiting for the next cutting processes.

Laser Power

The highest power of currently available fiber lasers reaches 15 kW, while just a few years ago it was 6 kW. Power levels are very high and would seem to be reaching limit values. However, from a purely technological point of view, such a limit does not exist - the power of modern fiber laser welding systems can exceed 100 kW [1]. So it's not just about power. The problem currently is the laser beam delivery system. Fiber optic cutting heads with power from 1 to 6 kW do not cope well with the energy density of ultra-high power lasers, and many manufacturers have major problems with head durability at powers exceeding 6 kW.

On the other hand, devices operating with power of 8, 10, 12, or 15 kW and guaranteeing the reliability and operating time necessary for working in production plants can only be offered by those fiber laser manufacturers who have invested considerable amounts in development and research, optimized fiber optic beam delivery systems, and also ensured the absence of optical contamination. However, their machines are, for obvious reasons, much more expensive than cutters operating at lower powers.

For this reason, most systems available on the market offer powers ranging from 1 to 6 kW.

Laser Power and Material Type

When choosing a fiber laser, its power should be matched to the specific application, i.e., determine what type of work it will perform and the type of material to be processed. Laser cutters can be used for cutting, die-cutting, and engraving a wide range of materials, such as: metals, aluminum, glass, wood, plastic, acrylic, and many others.

Another parameter to consider is - apart from the size of the metal sheet or part, which simply must fit in the cutter - the thickness and type of material being cut. The general rule applies here that the thicker and denser the material, the greater the laser power needed to cut through it.

Material thickness is actually the only limitation for laser technology - fiber lasers are unrivaled when it comes to cutting thin materials. Unfortunately, for materials with a thickness above 25 mm, one should consider another technology or buy a machine with a power greater than 6 kW.

As a rough guide, it can be assumed that a laser cutter with a power of:

Allows cutting materials with a thickness of:

Of course, this data may differ for specific solutions, and for this reason, it is best to contact the manufacturer of the selected laser cutter before purchasing it.

Let's also remember that laser power affects not only the thickness of the material being cut and the speed of the cutting process. High-power laser cutters also offer better quality and repeatability of the cutting process, and allow ignoring small deviations in the material structure.

Finally, choosing a fiber laser with specific power is associated with another basic, if not the most important, aspect of the enterprise, which is the profitability of production.

Production Costs

By choosing a high-power laser, we get not only higher efficiency but also a significant increase in production costs associated with the high price of the device itself and the higher cost of its operation - doubling the power increases the cost of operating the laser by 20 to 30 percent.

However, these costs may not be so significant if the additional power allows for a significant reduction in the cutting process and increased efficiency, as they still represent a fraction of the fixed costs, which include, among others: operator salaries, programming costs, infrastructure costs, taxes, equipment depreciation (leasing installments), shipping, general and administrative costs, and of course raw material costs.

In most production plants, these expenses far exceed the cost of laser operation, because, while the costs of purchasing a laser cutter are high, the situation changes radically when the machine starts working. The costs of laser cutting are relatively low.

When choosing a laser cutter, one should opt for a device that will meet production needs not only at present but also in the near future. And because laser cutting technology has been developing very rapidly in recent years, it is necessary not only to research the market offer and learn about the latest solutions but also to discuss any doubts with specialists. Such an approach will allow choosing the best device, avoiding unnecessary costs, and more importantly, increasing the company's competitive advantage.

Taking into account laser power and machine dynamics, it is worth remembering that higher power allows for faster cutting, especially of thicker materials, and greater machine dynamics allows for greater work efficiency, especially in the case of thinner materials. Regarding material loading and unloading, production cannot be carried out during these operations. So the faster they are, the better.

Therefore, when choosing a fiber cutter, one should focus on the three most important factors affecting the efficiency of a fiber laser - laser power, machine dynamics, and the speed of material loading/unloading operations. And the laser power should be appropriately matched to the applications and processed materials.

[1] https://www.osapublishing.org/ol/abstract.cfm?uri=ol-43-19-4667