Rumblings in the laser industry?
I am here in Sindelfingen, Germany, at the massive Mercedes Benz complex, with a group of journalists who have been invited by Daimler, hosts for a Messe Stuttgart review of the upcoming LASYS show. We are standing in front of a twin-laser robot system that produces a smooth laser-brazed seam along the trunk lid underlip of the new Mercedes C Class W204 sedan.
I marvel at the synchronicity of several robots that make up this component assembly station. Daimler uses 31 laser systems, here and in Bremen, Germany, and East London, South Africa, to join components of the W204 sedan. Of these, 23 units are RobScan remote welders powered by trumpf 4kW disk lasers.
We are told about Daimler’s drive to improve quality in the auto body, especially in visible joint applications such as the braze joint, which undergoes a post-braze process joint inspection to ensure any pores are completely closed. Not only are visible weld joints checked, but Daimler uses a UV light device to inspect every weld seam produced in another station where RobScan units, powered by disk lasers, assemble components of the body side ring.
Five days a week, three shifts a day, approximately 900,000 laser-welded joints are made, replacing about 15% of the spot welds on the new C class. This includes front and rear doors, rear-end center assembly, inner side walls, and the tail-gate assembly.
We are told by Berthold Hopf, Production Planning, that Daimler invented the RobScan process five years ago at the Ulm R&D facility and worked out all the bugs so that the Sindelfingen installation went smoothly and the process was up and running with little difficulty. In reality, it is these two assembly operations that we are shown that serve to gain the attention of my fellow journalists who are not “laser aware.”
Laser aficionados like me and colleagues Antonio Vendramini and Franz Gruber were interested to see the first large-scale employment of high-power disk lasers-a technology that has been in the seemingly endless German controversy of fiber versus disk lasers. In fact, my soon-to-be colleague, Franz Gruber, in a recent issue of the trumpf magazine Laser Community (www.trumpf-laser.com/laser-community), wrote, “Why do the seers of the industry feel obliged to see the future in only one technology?”
Hopf, when questioned about the fiber versus disk laser situation, said, “What we showed you (the tour) was a process developed five years ago when disk lasers held a technology edge over fiber.” Would Daimler change today, he was asked. It is likely, he said, as he further hinted that fiber already has a role in subsequent joining operations at Daimler.
In April, Gruber will assume editor-in-chief duties for the new Industrial Laser Europe, a spin-off from ILS. In his Laser Community Market View on the disk versus fiber laser he writes about what he sees as a developing situation between solid-state lasers (fiber) and CO2 in the “megamarket” of 2-D laser sheet-metal cutting, which he defines as a declaration of war. At ILS, we look forward to more of these cogent remarks from our about-to-be associate.
David A. Belforte
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