Three Approaches in Utilizing High Power Diode Laser to Join Thermoplastics

As we enter the micro age, the new challenge in the plastics industry is to manufacture and assemble smaller and smaller parts. Standard joining methods, such as adhesives, fasteners, ultrasonic or vibration welding may no longer suffice. Conventional lasers, such as the CO2 and Nd:YAG, have developed into important tools for the metals industry but their use to the plastics industry is limited to the cutting and scribing of plastics. Diode lasers have a shorter wavelength and have now reached output powers that allow them to be used to produce a controlled melt, or welding, of thermoplastics. Weld lines as narrow 0.1 mm (0.004 in.) have been achieved using diode laser welding systems. This paper reviews the capabilities of the diode laser welding process, and expands on three methods of delivering the diode laser energy to the work piece