For years the laser has been applied for processing polymer materials, for example for cutting and marking. The comparatively novel technique laser plastics welding offers a particular growth potential. The Bavarian Laser Centre has been investigating this technology for some years already and today it is the main research focus in the area polymer processing.

 

The most common variant of laser plastics welding, transmission welding, makes use of the fact that most thermoplastic polymers possess a high level of transparency in the wavelength range of typical diode and solid state lasers. One laser transparent and one laser absorbing polymer component are contacted in lap joint. The laser beam is focused through the transparent joining partner onto the surface of the absorbing component. The polymer melt that forms at the contact area moistens the transparent joining partner and the two components are welded together.

 

Current research and development activities in the field of laser plastics welding deals with possibilities for extending the process boundaries, miniaturisation tendecies, the design of adapted clamping devices as well as simulation and thermography. Other research topics besides welding are laser sintering of polymers and the generation of functional structures by means of laser technology for different applications.