17 Nov 2006
A new German applications company has developed a better technique for cutting glass using disc lasers.
H2B Photonics, a new laser applications company, together with partner and part-owner Rofin, has developed a better technique for cutting glass using disc lasers. H2B was specifically launched earlier in 2006 to commercialize the patented technique called Multiple Laser Beam Absorption (MLBA).
The technology works by volume absorption of the laser radiation in the glass, rather than surface absorption as with conventional CO2 laser glass cutting. H2B's specially developed reflector system allows the laser beam to pass several times through the glass. In this way, laser energy is optimally used to cut glass with a thermally induced tension fissure in one single step.
The MLBA approach overcomes two common problems associated with laser glass cutting: partial cuts that require subsequent physical breaking and thermal stresses that are introduced into laser cut edge areas of the glass.
Michael Haase, managing director at H2B Photonics explained to optics.org the origins and advantages of the patented technique.
"MLBA was originally developed at Laser Zentrum Hanover by myself and some colleagues. This led to the founding of H2B, which has the exclusive right to license the technique. H2B's key partner and laser supplier is Rofin, part of Rofin Sinar," he said. The company is named after its three founders: Michael Haase, Oliver Haupt and Carsten Büsching.
"One of the key advantages that we offer in glass cutting is a full body cut in a single step. This is a real improvement on previous techniques. Our process does not cut using any cooling medium; that occurs only by convection in air. Our cutting process uses a near infrared wavelength so we can guide the beam precisely by fibre," says Haase.
MLBA technology cuts single glass plates between 0.2 mm and 24 mm thick, as well as multi-layer glasses (display or laminated glass) in a single operational step. The usual subsequent breaking process is not necessary so a user benefits from shorter production times cut up to 50%.
Other capabilities of MLBA, which uses multi-kilowatt lasers between 750 W and 3 kW, include: the selective separation of individual glass plates in a stack; and the cutting of contours in a single step, which opens up new possibilities in glass processing.
These features make the method suitable for processing sensitive glass products or deployment in sensitive production environments. The high edge quality, free of glass chips or micro cracks, enhances the stability of glass parts by a factor of two. Production losses by glass breakage or mechanical damage of high-quality glass parts are also reduced.
Tubocut: Cutting tubular glass
A related capability at H2B is the cutting of tubular glass. The so-called Tubocut method uses YAG lasers to cut tubular and hollow glass. The particular setting of laser beam and workpiece allows to exploit the energy efficiently and produces edges with the same high quality as with the MLBA process.
Considering other applications, disc lasers are most beneficial for the cutting of glass. Performance stability, scalability and excellent dynamic features of the Rofin DS series with a power range of 750 to 3000 W allow flexible and high-performance solutions for a range of applications. YAG laser beam may be carried by optical fibers, making the laser flexible, which may be integrated into almost any production environment.
By coupling several fibers to one laser, highly efficient and individual production solutions can be realized, putting the investment for laser sources in relation to the cutting system into new perspectives. Present developments of the MLBA technology together with the new generation of disc lasers by Rofin, broaden the range of applications even to borosilicate glasses.