LASER TRANSMISSION WELDING OF SEMI-CRYSTALLINE PLASTICS

摘要

Laser transmission welding is an innovative process, which is very suitable for the joining of complex injection moulded parts. When the production demands a high quality of the weld line it is absolutely necessary to consider all the influences of the welding process. While welding semi-crystalline thermoplastics the morphology of the transparent joining partner has to be taken into consideration, because the laser beam characteristics and the amount of energy of the welding process depend extensively on the crystallisation characteristics. Many injection moulding process parameters (e.g. the melt and mould temperatures) affect the cooling conditions of the part, and thereby influence the crystalline structure. Therefore the injection moulding process should be integrated into quality assurance systems for laser transmission welding. In this paper the results of intensive experiments for PBT are documented.