Plastics based on renewable raw materials are more and more used to manufacture complex and more durable products. This becomes possible through intensive research and development work, which is focused on the optimisation of the processing and usage properties of those materials. For this reason, new developments of injection moulded parts made of bioplastics have repeatedly been found in fields such as the automotive, electrical, sports or stationery industries. The economical production as well as the realisation of new products requires the choice of suitable joining technologies. In order to meet the increasing requirements of the modular component design, the knowledge of joining processes for the reliable joining of components made of biobased plastics is gaining in importance. The well-established series welding processes, e.g. the ultrasonic welding, offer the only economical and demand-oriented solution for many applications.