Product Code: ICA10_1605

New Perspectives for the Absorber Free Laser Welding of Thermoplastics
Authors:
Andrei Boglea, Fraunhofer Institute for Laser Technology; Aachen Germany
Andreas Röesner, Fraunhofer Institute for Laser Technology; Aachen Germany
Alexander Olowinsky, Fraunhofer Institute for Laser Technology; Aachen Germany
Presented at ICALEO 2010

Polymeric products play an important role in almost every facet of our lives and constitute a wide variety of products starting from everyday products up to high tech products in the automotive, electronics, aerospace, medical and other sectors. The possibility to fabricate complex shapes in various sizes provides design flexibility and high performance at lower costs and allowed designers to face today's complex demands. Starting as an unconventional joining technology for the manufacturing of polymeric products the laser beam welding earned through an extensive research effort within the last decade a respectable place among the other available joining methods.
Currently one of the main process limitations is related to the requirement of having a laser transparent and a laser absorbing joining component. A possibility to overcome this limitation is to adapt the wavelength of the laser source to the absorption characteristic of the material and to select a suitable irradiation strategy. Following this approach this paper presents the latest results and the future perspectives for the laser absorber free welding using adapted laser wavelengths and irradiation strategies. The welding results for Polymethylmethacrylat (PMMA) transparent components with feed rates up to 100 mm/s and different laser wavelengths such as 1550 nm, 1700 nm or 1900 nm are presented and discussed.