Hand-held laser welders: precision and efficiency put to the test

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Hand-held laser welding machines are a real alternative to TIG/MIG/MAG processing. They enable maximum precision, speed and efficiency, all with minimal distortion and simple operation. Kolless has tried it out.

In recent years, a number of suppliers of small hand-held laser welding devices have introduced themselves to the German market—the manufacturers are predominantly from China with sometimes significant differences in price and quality in the 600 to 2,000 watt laser output power range, mostly fiber-doped and in the 1,060 to 1,080 micrometer wavelength range, primarily as a workshop device for substituting TIG or MIG/MAG welding tasks.

German importers take care of the necessary CE testing and labeling and have sales partners from conventional welding technology for the mostly regionally oriented sales, including service and support.

With around 15 employees, Kolless GmbH in Bremen specializes in sheet metal processing up to 3 millimetres (approx. 0.5 inches) and apparatus engineering. The company, which has welding approval in accordance with DIN2303 Q1BK3, was able to carry out initial product tests at the beginning of 2024 thanks to its many years of experience in laser technology and invested in a 1,500-watt air-cooled manual welding laser system at the end of 2024. The company supplies the maritime, food, medical technology and defense technology sectors, among others.

Kolles has created the organizational and occupational safety framework conditions for safe in-house applications in close coordination with the relevant employers' liability insurance association. In contrast to conventional TIG/MIG/MAG welding, additive safety criteria must be ensured in day-to-day workshop operations due to the short-wave laser radiation with a resulting hazard potential for the workers. First of all, a safe laser cabin, personal protective equipment (PPE) for the worker including laser safety visor and BG-compliant signage as well as instruction by the operator or the occupational safety specialist Si Fa up to the laser safety officer must be set up.

The successive substitution in the component application was carried out after customer consultation, partly by adapting the geometry of the previous joining zone through to the redesign of sheet metal components in order to achieve better accessibility with increased process stability and maximum quality. The manual welding head can be designed as a pen or as a handpiece/gun, whereby the experienced welder tends to use the familiar gun because it is easier to position and handle. The handpiece has an adapted wire feed as well as an axial shielding gas feed, whereby the correct welding angle is around 45 degrees—all common materials such as stainless steel, steel or aluminum can be welded.

The hose package with fiber optic cable, power supply and control line, gas hose and integrated pilot laser is very similar to the conventional variants in terms of handling—the employee has to practice a little and uses a few protective lenses and focusing lenses at the beginning. The resulting seam quality, the almost negligible thermal component load, i.e. distortion-free connections and ultimately the significantly reduced post-processing by grinding, leads to process optimization and quality improvement.

The total investment from the laser welding machine plus consumables and wear materials, the necessary spatial conversion measures and the expenditure for additional PPE including training, instruction and bureaucracy, is significantly higher than for conventional welding—the benefit of manual laser welding primarily from a qualitative point of view, but relativizes the amortization.

Increased precision is necessary in fixture construction, as the tolerable gap dimension is one power lower than in conventional manual welding, where more generous filler wire can be added during the process. The laser can achieve a welding speed that is 3 to 6 times faster, with less distortion and up to 50 percent less rework. Overall, important key figures in the production process are positive, particularly in terms of efficiency and quality.