Stuttgart, Germany - The processing of composite materials, in particular carbon fiber-reinforced plastics(CRP) presents a special challenge. It is often one of the biggest hurdles when substituting metallic materials in large-scale production. Laser can help solve these problems and can be seen in action at LASYS, the international trade fair for lasermaterial processing, which is taking place in Stuttgart from 12 to 14 June 2012.
Composite materials are, unlike metals, physically inhomogeneous. But it is precisely these different properties which are brought together in a new material and used advantageously. This, however, makes processing difficult, as Prof. Dr. Thomas Graf, Director of the IFSW Institut für Strahlwerkzeuge at the University of Stuttgart, explains: "On the one hand, this inhomogeneity influences the distribution of the laser beam; on the other hand, the heat conduction is very anisotropic and the parameters that are decisive for the ablation of the materials are very different. The result: In the event of incorrect process control the high heat conductivity of the carbon fibres in carbon fibre-reinforced materials and the very different properties of carbon and plasticmay cause serious damage to the plastic matrix. They present a big challenge for the development of suitable laser systems focus position control are some of the challenges presented."
"The challenge for laser processing is to achieve the highest possible surface effectiveness at a homogeneous energy input, for example for large components from the aerospace industry or pipes in the offshore and onshore area", adds Michael Nagel, Technical Sales Manager at Laserline GmbH in Mülheim-Kärlich. He goes on to say that the main advantage of laser is the efficient processing of thermoplastic fibrer einforced composites whilst protecting the materials. The processing is generally in the form of a tape, performed in one single process step and without any additives. In contrast, thermosetting plastics require special epoxy resins, which are pressed into special hot air autoclaves and hardened at approx. 400° C and 20 bar. Laserline primarily focuses on very efficient diode lasers when processing composite materials which are currently manufactured up to 15,000 W, and corresponding optics. "They are also sufficient for large focus dimensions for wide tapes and make available energy for the welding process, also homogeneously."
Michael Nagel sees huge potential primarily in the aerospace industry. Because particularly for large aircraft areas and structures it comes down to high rigidity developed parallel to this such as pressure-resistant pipelines with an almost infinite length for pipeline construction, or the reinforcement of pressure tanks and structural applications are still in the research and development stage, confesses Nagel, who is confident, however, that "laser material processing will continue to play a key role in this technology area, also requiring high process efficiency in comparison to alternative energy types such as infrared or hot air".
Approximately 200 exhibitors are expected at LASYS 2012 , which is taking place from 12 and 14 June in Stuttgart. http://www.messe-stuttgart.de