Connecting SLS Parts to Injection Molded Components
„FAB-Weld“ Research Project to Investigate Welding Processes
There is a high demand for large SLS components. At the same time, the size of the compartment is restricted by the design of the plant, which continues to be a limiting factor. FAB-Weld is the name of a research project that has just started to investigate the topic of joining components produced by additive production. Joining will be done by welding in order to tailor serial components to the respective requirements. So as to optimize welding processes for plastics, the Institute of Polymer Technology at Friedrich Alexander University in Erlangen-Nürnberg (FAU) works together with several companies, e.g. FIT Additive Manufacturing Group and BMW. The project is funded by the Bavarian Research Foundation (Bayerische Forschungsstiftung).
Economic Production with SLS
A specialist for additive production, FIT Additive Manufacturing Group support the project with their know-how in the area of selective laser sintering. This expert knowledge is contributed by the company’s subsidiary Sintermask GmbH.
Applying the SLS (selective laser sintering) process, the user is able to produce complex components from thermoplastic materials by means of additive manufacturing. Other than with injection molding, no expensive tools are required. SLS is thus suitable for the economic production of small and micro series with a high degree of geometrical freedom, and for customized components.
No More Process-Related Limits to Size
The new „FAB-Weld“ research project is aimed at finding a way to eliminate the downsides involved in restrictions to size by applying specially optimized welding techniques. If customer-specific SLS components are to be connected to standard moldings to form assembly groups, this calls for high-strength and impermeable joints. However, also stable SLS-SLS links are essential for large-volume and modular components.
Vibration, as well as infrared welding, are feasible as techniques for joining in this project. FIT will provide the specimens, on the basis of which mechanical characteristic figures for the individual welding processes will be determined, and SLS components will be submitted to optical scanning (GOM) and CT scanning. The respective appliance is available at the company. The project is scheduled to run over a period of three years.
Christian Wiesner, in charge of the project at FIT, stresses the importance of the research target: “There is no information available at present, concerning the mechanical load that is applied during the high-strength welding of SLS parts. We will therefore look into the basic interrelations that exist during the process of joining as such. The result will mean a leap forward in the entire field of additive manufacturing with SLS.”