- SPECIAL REPORTS
During his presentation on Laser Types Used in Manufacturing, Tom Kugler, fiber systems manager for Laser Mech, noted that CO2 lasers are regularly used to mark denim blue jeans. Laser engraving can produce a dramatic contrast depending on the color of the denim. He says that some clothing manufacturers use lasers to create "stone-washed" and "whisker" effects on denim jeans.
Following this presentation, I walked onto the trade show floor and into the booth of Coherent Inc., one of the largest producers of CO2 lasers in the world. In the center of the booth was a glass case, and within the case were samples of materials that could be laser-marked.
The marked denim example caught my eye and that of other show attendees, who were just as interested as I about the process of engraving jeans. Pete Peterson, staff market development manager, explained that a sealed CO2 laser was used to create the graphic on the denim.
Peterson says that the laser was directed into a scanner-based marking system that burned dye from the denim at a speed of several meters per second. He also says laser marking provides superior reproducibility and maintains material quality better than conventional marking methods such as bleaching and stone-washing.
Gus Anibarro, LIA’s education director, says LME is unique because it’s just about the latest in lasers-unlike the association’s annual CALIO event for laser research and its biennial laser safety conference. Anibarro says next year’s LME will take place Oct. 23-24 and feature live equipment demonstrations.
Anibarro noted some trends in laser technology, including femtosecond lasers. This type of laser produces an extremely fine beam, one that is much smaller than a nanosecond laser. The beam does not put heat into any plastic or metal object it cuts or marks. For this reason, the femtosecond laser is growing in popularity among medical device manufacturers.
Jimmie Bates, salesman for Altos Photonics, says that femtosecond lasers are often used to cut cardiovascular and other polymer stents because nanosecond lasers can melt the stents. He also says femtosecond lasers perform surface oblation better than nanosecond lasers.
Dr. Mark Richmond, product manager for JK Lasers, says stents and other small tubes cut with a femtosecond laser have very smooth edging. As a result, they require little or no post-processing, lowering production costs.
Another topic of interest to me was 3D laser cutting, which I learned about from Dr. Daniel Wildmann, chief customer officer for Precitec KG. This German company showcased its SolidCutter system, which allows robots to perform variable-speed cutting of complex molded components.
The system is being used by automotive manufacturers, supply companies and job shops. Applications include hole cutting in finished vehicle bodies and underbodies, as well as in hot-formed steel and hydro-formed profiles.
The system features fast-reacting distance sensors, an integrated linear Z drive in a closed control loop and a double chamber. Recently developed, the double chamber provides a hermetically sealed optical path without external purging air. This feature produces long service life for optical components, even in environmentally harsh conditions.
“DMLM is a powder bed process wherein a 20-micron layer of metal powder is spread across a platen and a laser is scanned across the layer to selectively fuse the two-dimensional cross-section to itself and to any underlying structure,” says Rockstroch. “Thousands of layers thus produce the finished part. The primary engineering challenge is providing repairable access ports to remove the entrapped powder upon completion.”
Rockstroch says the selected design will be used in production core engine testing in 2012, Federal Aviation Certification in 2013 and full-scale production in 2014 on the GEA commercial Leap engine.