Who invented it?
In the 2D laser machines made by TRUMPF, the solid-state lasers ensure rapid and efficient cutting — and they’ve done that for more than 15 years now.
That opening question brings us to a surprising answer. The use of the solid-state laser to machine sheet metal was invented by TRUMPF. In practical use since 1995, it was just as amazing then as it is today, especially when handling thin sheet metal. The story began in 1972. A laser beam powered by a new source proved to be the door to a new field of business for the Carl Haas Coil Spring Factory in the town of Schramberg. Carl Haas was looking for an efficient way to weld coil springs and found the solidstate laser to be a suitable tool. As opposed to the CO₂laser, the crystals in the rod-type lasers were excited with the light produced by arc lamps. Thin-gauge sheet metal readily absorbs the short wavelength of about one micron. The laser beam makes its way through a bundle of flexible fibers — the optical waveguide — to the cutting head. This can be done over extended distances and without reflecting mirrors. While initially used only to weld spiral springs, the laser
later cut sheet metal too.
In 1995, the solid-state laser developed by the Schramberg-based company, which has since become a member of the TRUMPF family, was installed for the first time in a machine tool. What at that time was the Sächsische Werkzeug und Sondermaschinen GmbH in Neukirch, Saxony, today also a part of the TRUMPF Group, integrated a rod laser into an existing machine tool. The work table in the TRUMATIC LY 2500 measured 2,500 by 1,250 millimeters. The HL 803 D solid-state laser delivered eight hundred watts — seven hundred of which could be employed at the cutting head. The flexible waveguide was just 0.3 millimeters in diameter. “Eight hundred watts of laser output was not enough to perform miracles,” recalls Stefan Grahle, Technical Sales Consulting Manager at TRUMPF Saxony. “In addition to the advantages found when working thin-gauge material, the machine offered consistently good edge quality during oxygen cutting — comparable with a CO₂ laser machine.” Programming right at the controls did away with the need for an additional programmer and lent considerable flexibility. That is why job shops favored this kind of machine to execute smaller orders.
That changed when the successor model came out. The TRUMATIC HSL 2502 was introduced to the market in 1997. The workingdimensions remained the same, but wear-free linear drives that achieve tremendous acceleration made the new flatbed laser machine extremely productive. Its dual cutting heads helped increase output. “They more than doubled the machine’s productivity in one fell swoop,” according to Grahle. Initially, the eight hundred watt laser found in the forerunner model was used. But by the time the unit was introduced to the market, that laser had been replaced by two lasers with each delivering 1.2 kilowatts of power. Mild steel up to ten millimeters thick and stainless steel up to three millimeters could be worked on both machines. The very first dual-head machine, the TRUMATIC HSL 2502, was deemed to be a specialist for thin sheet metal. However it is now used primarily for longer production runs. “The two cutting heads and linear drive technology made the machine far more dynamic. It took the high advancing speeds when working thin sheet metal and translated them into shorter part processing times,” says Grahle. Direct measurement systems made the machine extremely exact, as well.