Product Code: PIC06_107

Transmission Laser Welding of Polymers using Laser Additives
Authors:
Peter Roberts, BASF; Melbourne Australia
Simon Doe, CSIRO; Adelaide Australia
Presented at PICALO 2006

Many polymers need to be joined allowing complex shapes to be processed, and welding is one process that may be employed. Transmission laser welding of thermoplastic polymers is a well established process, and is often used. To ensure that the weld occurs between the layers of plastic it is necessary for one of the plastics to be transmissive to laser light and the other to absorb the laser energy, to ensure that the beam focuses on the joint region. The traditional method has been to load the lower component with carbon black, however new laser additives have been developed which allow transparent or coloured parts to be transmission laser welded. Transmission laser welding is capable of welding thick parts, and since the heat affected zone is confined to the joint region no marking of the outer surfaces occurs. This paper describes the transmission laser welding process and its traditional limitations, and details laser additives that have been developed allowing coloured materials to be processed.