Martorell, Spain–SEAT, a Spanish company that is part of the Volkswagen group, installed three high–power Nd:YAG laser welding stations, which provide advantages in the production of the new Ibiza, a vehicle built on VW's AO4 (Polo) platform. The essential laser advantage is increasing product quality by joining chassis and other complex shaped parts with a near seamless finish.
Three Haas (Schaumburg, Ger many) 4kW, CW Nd:YAG lasers power 14 welding heads, via fiber delivery and a switching system provided by HighYAG (Stahnsdorf, Germany). The systems, one of which is shown in the photo, produce 1300 chassis per day. Each laser produces, on demand, the correct power for a specific weld joint and configuration. A seven–meter seam is welded in two minutes.
Access to difficult–to–reach areas is accomplished with ease and precision because of the reduced size of the welding robots. The smooth finish on the long welded seam has made it possible to eliminate the roof gutters. This new Ibiza also uses laser–welded tailored blanks produced at the Tailor Metal facility in Pedrola (see the March issue of ILS).
Laser–welding the roof of the new Ibiza.
VW has, as usual, been quite close–mouthed about this welding application on the AO4 platform. However, ILS has learned that a paper presented at the 3rd European Automotive Laser Application (Bad Nauheim, Germany), gives some clues to this laser welding on the AO4 platform. In addition, we have indications that as many as 40 Nd:YAG lasers are used worldwide for this application. –DAB
Cutting large–diameter non–metal parts
Mukilteo, WA–A frequently asked question concerns the ability of lasers to cut through larger–diameter cylinders, leaving a flat square edge. The expected wedge and, in the case of certain organic materials, residual ash, usually make this application somewhat problematical. However, process developers at Synrad Inc., taking advantage of a phenomenon called "waveguiding," have produced some fine–looking specimens.
The photo shows a 2.5–inch–thick urethane bushing, which was cut in nine seconds using 250 watts of CO2 laser power. By rotating the part 21 times under a fixed focus beam and using a 7.5–inch focal length lens with a 0.012–inch diameter spot with nitrogen assist gas, a slightly discolored but usable part is produced.
According to industry experts, the waveguide phenomenon is well known in the cutting of thick section wood, such as slots for steel rule dies. Dr. Bill Steen, one of the world's preeminent laser process developers, explains that, contrary to expectations in processing thick urethane material, the laser beam appears to be reflecting at glancing angles from the walls of the cut in the kerf.
John Powell, author of a widely used book on CO2 laser cutting, says the kerf acts as an optical element to keep the beam narrow as it reflects off the cut walls, thus the waveguide concept.
Steen suggests that some further study of these phenomena in non–metals might be useful in confirming the waveguide thesis. We find this square edged cut to be very interesting because our experience with other materials has not been as successful.
For further details of this application contact John Law, applications engineer for Synrad, at firstname.lastname@example.org. –DAB
Laser improves duct manufacturing and performance
Thomasville, NC–Nordfab Systems Inc., a leading supplier of clamp–together ducting, thinks so much of its laser welding operation that it calls the welded product Laser Quick–Fit. Further, the company promotes the laser weld in its literature and at trade shows. We can vouch for the latter because the ILS exhibit at last November's Fabtech was directly across the aisle from Nordfab, and we delighted in directing our visitors to step across to hear this laser success story.
Last year Nordfab installed a $1–million laser tube–welding system, built by Weil, in its facility. In April the company began shipping new product, dubbed Laser Quick–Fit. By eliminating a conventional lock–form seam, the laser weld produces a long list of benefits that merited it being part of the new product name.
Laser–welded ducts are virtually seamless because of the 100 percent weld penetration. There is no air loss through the laser–welded seams and a smooth inner and exterior finish are produced at no extra cost. Further, the duct is round after welding, making it easier to clamp with a better seal between sections. Eliminating the need to caulk leaky seams for oil mist applications is an added benefit.
Laser–welded seams are available on 4–in.– to 22–in.–diameter pipe, adapters, nipples and collars. The company says that these products are especially attractive to the food and beverage, chemical, pharmaceutical and woodworking industries. The patented Quick–Fit clamping process has become more attractive, thanks to laser welding.
Contact Nordfab at Tel. (336) 889–7873 or visit www.nordfab.com. –DAB
Warren, MI–On February 14th, DCT Inc., a designer and builder of automotive assembly line welding equipment was forced into Chapter 7 bankruptcy by four vendors. Thus ends the saga of a technology–savvy company that made significant contributions to industrial laser technology. Slow business in the auto industry and other factors brought this once booming company, which a few years ago had invested millions in new equipment, facilities and employees, to it's knees.
In 1986, DCT established a laser activity under the name Utilase. This was the company's entry into the laser processing business. Started by several young welding engineers known as the "Ohio State Mafia" (named after their alma mater), the company lead the development of laser/robot welding systems and laser hydroform tubing cutting systems. The company was also a prime driver behind the growth of laser tailored blank welding, through a thriving contract processing business, which eventually was sold to Noble Industries.
ILS had a warm relationship with DCT/Utilase personnel who were always ready to contribute to the industry knowledge base. DCT technical and management people stepped forward to offer assistance in growing laser technology in the auto industry, by their strong support of the annual Automotive Laser Applications Workshop meetings. As they scatter to new opportunities, ILS looks forward to renewing relationships with these industry pioneers. –DAB
Laser contributes to video quality
Vienna, Austria–Philips, the market leader in convenient, integrated combination laser/video sets, recently introduced a larger–screen TV–Combi set that features the company's award–winning Philips Real Flat tube design. This design is leading the trend toward flatter and thinner displays, while providing a compact product with excellent performance.
The video recording and playback section of the TV–Combi utilizes laser–cut heads to maintain the same high performance throughout their long lifetime. This is facilitated by a laser cutting technique that Philips has employed for more than ten years at its factories in Vienna.
The beam from a frequency–doubled (green) Nd: YAG laser cuts the ferrite cores of the magnetic heads with high dimensional precision so that the magnetic field is concentrated at the interface between the magnetic heads and the tape. –DAB