Laser cutting technology is making rapid progress. For many fields of application, the fiber laser has outstripped the CO2 laser. However, for thick sheet metal, in particular steel, CO2 laser technology still has its advantages. Article by Ralph Hofbauer, Bystronic.
At first, when Theodore Maiman developed the first functional laser in 1960, there were no practical applications for it. The US physicist described his invention as a ‘solution in search of a problem’. In the meantime, laser technology has found a wide range of applications—from medical technology to consumer electronics, right through to production engineering.
In the sheet metal processing industry, laser technology established itself during the eighties. At that time, the CO2 laser displaced conventional sheet metal processing methods, such as shears, die-cutting, and flame cutting. Nowadays, the fibre laser is considered state-of-the-art. The technology established itself astonishingly quickly. “Over the past five years, the fibre laser has experienced a greater development leap than the CO2 laser over a period of 20 years,” says Mario Duppenthaler, Laser Cutting Product Manager.
Ever-expanding Range of Applications
Bystronic launched its first cutting system based on fibre laser technology in 2010. Since then, the output power has grown fivefold: While the first model had an output of two kilowatts, Bystronic’s current top-of-the-line model, the ByStar Fiber, achieves ten kilowatts. This rapid progress has expanded the fibre laser’s range of applications. Initially, fibre laser technology was suitable only for thin sheet metal, but in the meantime fibre laser systems can cut sheet metal thicknesses up to 40 mm.
The success of fibre laser technology is based on a number of advantages. Compared to CO2 lasers, modern fibre lasers achieve up to five times the cutting speeds and are three times as energy efficient. This enables the costs per part to be decreased significantly. The operating and maintenance costs are lower, amongst other things because in contrast to CO2 laser system, fibre lasers do not have to be enriched with laser gas. In addition, fibre lasers can also cut non-ferrous metals, such as brass and copper.
For many sheet metal processing companies, the fibre laser has become the best choice. Nevertheless, there are still some production companies with special manufacturing needs that continue to rely on the benefits of the CO2 laser.
“In the thicker range of sheet steel, the cutting characteristics of CO2 lasers are more good-natured. Moreover, when cutting low-quality sheet metal, it achieves better results in terms of price per part,” Duppenthaler explains. Although the market share has decreased significantly over recent years, some ten percent of the cutting machines Bystronic sells still use CO2 laser technology.
More Power, Greater Flexibility
When investing in a fibre laser, one has to take both economic and ecological factors into account: When switching over to a fibre laser, companies that use the exhaust heat from their CO2 laser’s cooling system to heat their factory must be aware that the exhaust heat from a fibre laser is minimal. In addition, it is not easy to keep up with the ever-increasing cutting speeds: “Fibre lasers have considerably accelerated the cutting process stage. In some cases, to such an extent that the upstream and downstream processes are turning into bottlenecks,” Duppenthaler says.
In the thin and medium range of sheet thicknesses, the fibre laser generates a significantly higher output than CO2 laser technology. The reason for the higher cutting speeds lies in the lower wavelength: While the CO2 laser generates a wavelength of 10 µm, with the fibre laser it is only 1 µm, which results in a higher absorption of the laser beam in the material when cutting steel and aluminium. Due to the fast cutting speeds, the challenge with the current generation of fibre lasers is to load and unload the machine quickly enough. Hence, as a general rule, it makes sense to enhance fibre lasers with an automation system.
Many sheet metal processing companies on the market are pure job shops that do not produce any products of their own. These companies must be prepared to deal with a wide variety of order situations.
“Job shops are today more than ever dependent on flexibility,” Duppenthaler explains. “Thanks to their versatility, high-performance fibre lasers are the optimal solution for job order production.”
Fibre lasers with 8 or 10 kilowatts offer the required flexibility, because they cut thin sheet metal at fast speeds while simultaneously being able to cope with the thick sheet metal range. Moreover, in the medium range of sheet thicknesses between 5 and 10 mm, the costs per part are considerably lower than with CO2 lasers.
In order to remain competitive in a tough environment, being able to produce parts at the lowest possible cost and in the desired quality is a crucial factor for manufacturing companies. The different laser output levels and formats in Bystronic’s portfolio of fibre lasers and CO2 lasers make this possible for every order situation and range of applications.
How much output power is necessary?
For users who mainly operate in the thin sheet metal range up to 3 mm, a 3-kilowatt laser is usually quite sufficient. These include, for example, manufacturers of kitchen appliances or electrical control cabinets. However, companies that cut a wide range of thicknesses require more power. As a general rule, an 8-kilowatt or 10-kilowatt fibre laser is the optimal solution for job shops. These machines offer a higher level of flexibility with regard to the thickness and range of materials. In addition, the costs per part are significantly lower in the medium sheet thickness range.
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