Laser Transmission Welding of Thermoplastics With Dual Clamping Devices

Beside well chosen process parameters a geometrical joining partner design suitable for laser transmission welding and adequate clamping pressure appliance is necessary to form high quality welds. Amongst other clamping techniques Dual Clamping Devices (DCD) are a promising approach to fulfill the process needs and to get to a robust and also fail safe clamping. When using DCD the laser beam has to pass thin non transmitting bars while a weld seam is formed. So the laser beam is partial refracted, reflected and absorbed. Here the influences of the bars onto the laser beam intensity distribution behind the bars rather in the interaction zone of the laser beam and the two joining partners are investigated. Welding experiments with DCD are carried out and discussed. Based on the experimental results thermal process simulations are performed, to get a deeper knowledge about the effect of the bars onto the spatially and temporally changing temperature field within the joining partners.