TRUMPF: Laser cutting with the right beam source - The application dictates which laser technology to use

CO2 or solid-state laser? Many users ask this question when they consider doing cutting work with the laser. "The application decides which beam source is best to use," explained Dr. Arnd Szelagowski of TRUMPF Laser- und Systemtechnik, Ditzingen/Germany. He recently spoke at the congress of the German Welding Society (DVS) on September 26, 2010, in Nuremberg/Germany. In his presentation "Laser Beam Cutting Today and Tomorrow – Current Developments and Trends in Laser Cutting Technology," Szelagowski said depending on material and sheet thickness, the CO2 laser is a better choice for one application, while the solid-state laser a better choice for another."

CO2 laser is the universal cutting laser

If users want a flexible way to cut across all sheet thicknesses and obtain very good cutting quality, the CO2 laser is the beam source of choice – despite its lower efficiency compared to the solid-state laser. If the user's focus is on thin sheet cutting, the solid-state laser has real advantages.
Szelagowski explained the reason for this by describing the absorption ranges of both laser beam technologies for iron. With a wavelength of 1µm, the solid-state laser produces a very broad, almost constant absorption level across an angle of incidence varying from 0 to 60 degrees. In the range of about 78 degrees, a distinct level with a subsequently steep drop is noticeable. With a wavelength of 10 µm, on the other hand, the CO2 laser shows a significant increase in the absorption level with an increasingly steeper angle of incidence (greater than 80 degrees), and thereby an improved coupling of the laser output into the material. These effects directly impact the laser beam fusion cutting – but not the flame cutting. "In this case, the laser plays only a subordinate role. That is why the cutting quality and speed in flame cutting for mild steel do not vary between CO2 and solid-state lasers," he added.

Solid-state lasers with high feed rate for thin sheet range

The situation is different for thin sheet metal, which is processed at a generally higher feed rate and develops a flat cutting front. This favors the solid-state laser and therefore leads to improved coupling conditions with the wavelength of
1 µm. "But with increasing sheet thickness, the maximum achievable cutting speed drops, resulting in a steeper cutting front," explained Szelagowski. Conversely, this cutting front feature, in conjunction with the high melting temperature, produces a constant high absorption rate in the CO2 laser beam in thick sheet metal. The molten material is homogenously low-viscosity across the sheet to the bottom edge and ─ despite its high volume ─ it can be driven out of the groove, improving the cutting quality.
This explains the different areas of application for these two laser technologies. "Solid-state lasers show considerable advantages for stainless steel sheet thicknesses up to 4 mm. Compared to the CO2 laser, they cut faster and are therefore more efficient and productive with the same high cutting quality," concluded Szelagowski. With the CO2 laser, in contrast, a broad material and sheet thickness range can be processed with very high quality cutting results.

Machine dynamics must be in line with the productivity of the solid-state laser

In order to obtain optimum benefit from the high productivity of the solid-state laser, the machine dynamics have to be in line with the laser's performance capacity. "On top of that, users should be aware that a 700 hp engine does not turn a compact car into a Formula 1 race car," said Szelagowski.

TRUMPF offers a broad range of systems with fiber-guided solid-state lasers for 2D and 3D laser cutting ranging from combination punching and laser cutting machines to welding cells with robot technology. The laser beam in the solid-state laser is directed to the machine through a laser light cable and can be used for multiple machines. This laser network makes it possible to make the best use of the laser source and thereby keep investment costs down.
This year, TRUMPF has introduced two new machines with solid-state laser technology. The new flatbed cutting machine, the TruLaser 5030 fiber, utilizes the advantages of the fiber-guided solid-state laser, and thanks to its high dynamics, reaches very high cutting speeds in the thin sheet range. For fusion cutting, the machine achieves a feed speed up to three times faster than the CO2 model, depending on the material thickness to be processed.
The new TruLaser Cell 7040 fiber provides a system for 3D sheet processing with a TruDisk disk laser. The TruLaser Cell 7040 fiber with a working range of 4 x 1.5 m is the largest model in the TruLaser Cell Series 7000.

About TRUMPF
With sales totaling US $ 1.86 billion (€ 1.34 billion) and 7,800 employees (preliminary figures for the 2009/10 fiscal year), the TRUMPF Group ranks among the leading manufacturing companies worldwide. The three following business divisions are combined under the umbrella of a holding company: Machine Tools/Power Tools, Laser Technology/Electronics and Medical Technology. Its core business is machine tools for flexible sheet metal processing for punching and forming, laser processing and bending. In the field of industrial lasers and laser systems, the company is the technological leader in the world market. With about 60 subsidiaries and branch offices, the Group is represented in almost every European country, in North and South America as well as in Asia. Production locations can be found in Germany, Austria, China, Czech Republic, France, Great Britain, Japan, Mexico, Poland, Switzerland and the USA.

For further information about the company, please visit www.trumpf.com.

TRUMPF Group
Business Field Laser Technology
Press/Public Relations
TRUMPF GmbH + Co. KG
Johann-Maus-Straße 2
71254 Ditzingen
Germany

Holger Kapp
+49 7156 303-31559
holger.kapp@de.trumpf.com

This release was published on openPR.