High-speed laser welding of plastic films

Laser welding of plastic materials has a large field of applications in the packaging industry provided that it can compete, in quality and productivi ty, with currently used industrial methods. Welding of white and transparen t thin films of polypropylene and polyethylene of low and high density at h igh speeds of 20 m s(-1) using a CO2 laser has been studied experimentally. The weld process has been characterised by the specific energy required fo r each thickness, kind of plastic and the resistance of the weld seam. The influence of the dimensions of the laser beam spot on weld strength has als o been analysed. (C) 2001 Elsevier Science Ltd. All rights reserved.