Eyewear manufacturer Silhouette International achieves better results with laser welding.
Call
Austrian premium eyewear manufacturer Silhouette International maintains a competitive edge by producing eyewear that provides superior comfort and functionality as well as stylish looks. Their "Titan Minimal Art" (TMA) frames, which weigh just 1.8 grams, were the first screwless and threadless titanium glasses, and the success of this product has motivated Silhouette International to expand the threadless approach to many other designs. However, this design presents several manufacturing challenges, including the need to combine different materials such as titanium and other specialized alloys. And these joints must be aesthetically pleasing, meaning they are not visually recognizable and also do not create a change in texture that is easily felt. Finally, the joints must be strong and very flexible, and have the ability to be cycled and opened many, many times without any change in shape or deterioration in mechanical strength. Traditional resistance welding has problems in all of these areas.
Solutions
Laser welding is a proven method that overcomes the limitations of resistance welding. However, the introduction of laser welding for this type of precision application in mass production, in a cost-effective manner, has required some technical innovations. One improvement that has proved crucial for Silhouette International is the use of 'beam oscillation', the rapid movement of the beam both along and perpendicular to the weld joint. Coherent has developed an advanced implementation of beam motion called SmartWeld, which allows more flexible and precise control of the heat distribution produced by the laser. It incorporates complex beam patterns, including circles, ellipses or even zigzag shapes. SmartWeld technology improves weld quality and process consistency and can also bridge larger gap widths in welded parts. This reduces tolerances and lapping requirements, speeding up production and reducing costs.
"The switch from resistance to laser welding has been a huge success, resulting in overall cost savings of approximately 80%. In addition, the improved accuracy and repeatability has enabled us to successfully introduce cutting-edge lens frame designs into production."
- David Illitz
Process Manager Raw Parts Production Silhouette International Schmied AG
Result
Silhouette International installed a Coherent MPS Rotary automated welding, cutting and drilling system that includes a 200 W fiber laser source and an optical scanner. Overall, it reduced tooling and production costs by allowing multiple process steps to be performed on a single machine, resulting in increased energy savings and productivity. In addition, the use of SmartWeld has improved weld quality, specifically producing joints with higher strength (due to lower heat input to the part) as well as better flexibility. The MPS Rotary system also supports the company's need to reduce time-to-market for new designs, as well as limited batch sizes (typically 150-300 pieces).
Source: Coherent.com
