Various process monitoring approaches of transparent thermoplastics laser beam welding

Main focus of this contribution is an investigation on process monitoring methods for transparent thermoplastic film laser beam welding. Target is to find feasible approaches to monitor and control the welding process in common industrial applications. The welding process is supported by an IR-absorber between the join partners. The presented work is focused on three different wavelength ranges: Starting from the visible wavelength through near infrared to mid infrared wavelength. In these areas two kinds of sensors are used. The sensors are imaging and integrating systems. The detectors for visible and near infrared are integrated into the beam path.