Product Code: ICAL05_805

A 2-D Thermal Model for Laser Transmission Welding of Thermoplastics
Authors:
Gene Zak, Queen's University; Kingston ON Canada
Layla Mayboudi, Queen's University; Kingston ON Canada
Presented at ICALEO 2005

Recent years have seen wider application of laser transmission welding (LTW) as a means for joining plastic components. Advantages of LTW arise from it being a contact-free method for delivering precisely controlled energy to the weld interface. LTW involves a laser beam passing through a laser-transparent component and subsequently being absorbed by the laser-absorbent component near the weld interface. Heat generated at the interface melts a thin layer of plastic in both components and thus forms a joint through molecular interdiffusion.
To form a strong bond, it is important that the weld interface is exposed to sufficient heat to melt the polymer without degrading it. Delivery of the thermal energy by the laser beam is affected by process parameters, such as laser power, scan speed, beam spot size, and material properties, such as absorptivity, presence of reinforcements and other additives.
This paper presents a 2D transient thermal finite element model of LTW that was developed for a modified T-joint geometry. The molten zone predicted by the model was compared to those observed in laser welded Nylon 6.6 specimens.