Project title: Increasing the strength for a resource-efficient hot gas welding process through a new type of hot gas nozzle and through a new type of joining movement.

In a previous research project between GMB Kunststoffteile GmbH and the Department of Plastics Technology (LKT) - Faculty of Machines and Systems at Esslingen University of Applied Sciences (funding reference: ZF4166303FH8), a new kind of nozzle for hot gas welding of plastics was developed [DE 20 2021 101 884 U1 - utility model specification: Device for welding plastic parts]. One advantage of the non-contact welding process (hot gas welding) is, among other things, that no particles are produced which could lead to system damage during subsequent operation of the components. This new type of top nozzle has a number of advantages over the round nozzles currently in use. For example, the joining zone can be heated much faster and more evenly.
In the new research project, the top nozzle system is to be further developed so that it is possible to heat three-dimensional welding seams more evenly. The influence of the new top nozzle on the welded joint is to be researched, as well as the targeted, uniform heating of the plastic component in the area of the joining zone. Another point in the research project is the further development of the joining movement. In order to significantly improve the economic efficiency of hot gas welding and to open up new fields of application, the aim is to increase the strength of the joined components at the weld seam. Here, a joining movement during the welding process is to be integrated into the process by means of a robot-based approach in order to improve the weld seam strength. In addition, the further development of the top nozzle should make it possible to weld strength-inhibiting geometries such as edges or radii much better and, through targeted gas guidance, three-dimensional seam courses should also become weldable. This will make it possible to further improve the seam strength. Due to a higher weld seam strength, the component can be designed with thinner walls. Overall, there are significantly more options available in the component design due to a lower strength drop in the joint. Therefore, the need for a new hot gas nozzle concept and a new type of joining movement is high.

Duration: September 2021 until August 2023
Project partner: GMB Kunststoffteile GmbH, robomotion GmbH, TU Chemnitz - Department of Lightweight Structures and Polymer Technology
Funding sign: KK5052604WO0
Project Management Agency: AiF Projekt GmbH, ZIM-Cooperation Projects
Contact persons: Prof. Dr.-Ing. Matthias Deckert, Johannes Schmid, M.Sc.

Selection of publications within the framework of the project:

•  Analyse von zwei verschiedenen Düsensystemen zum Hei?gasschwei?en mittels CFD-Simulationen und Messergebnissen