EREP – Successful remanufacturing through data-based decision-making and intelligent process planning
The circular economy has been a suitable means of making product life cycles more resource-efficient for decades. In general, a distinction is made between the three cycles of reuse, remanufacturing and recycling.
Project details
The circular economy supports industrial production on the path to economic and ecological sustainability and promotes the resilience of German companies to upheavals in global trade. Remanufacturing in particular is a promising variant of recycling, since both energy and raw material efficiency are increased and products of the latest generation leave the remanufacturing production chains. However, the remanufacturing processes established in the industry are currently limited to replacing defective components with spare parts.
Within the scope of the project, the area of application of remanufacturing is to be expanded by also enabling the redesign of components through intelligent and variable process planning. The basis for this expansion of the application area of remanufacturing is a hybrid process chain consisting of additive and subtractive processes. In particular, a combination of directed energy deposition processes (e.g. wire arc additive manufacturing and direct metal deposition) and subsequent milling will be investigated. Two applications are considered in the project: cast housings (product), which in the commercial vehicle sector experience comparatively few design changes due to the long product cycles, and deep-drawing dies (equipment), which are used in vehicle construction for a common manufacturing process for generating geometrically complex sheet metal geometries.
Procedure
When implementing the hybrid manufacturing chain of additive and subtractive processes for the remanufacturing of machined components, there are three main challenges:
Decision-making: It is important to assess whether a component is suitable for redesign into a current generation of workpieces. Here, both a conversion into the direct successor generations as well as the redesign into other components must be considered.
Process planning: If the conversion into a current generation of components is possible, the manufacturing processes required must be planned. In particular, the tool paths and the process parameters of additive and subtractive manufacturing have to be developed and defined with a suitable CAM environment.
Process documentation and validation: In remanufacturing, the additive manufacturing process is often conducted on three-dimensionally curved free-form surfaces. This poses additional challenges for process management. Furthermore, shape errors due to deformations and unfavorably selected process parameters are to be expected. The subsequent machining must be able to take these contour deviations into account. In order to document the component quality and to continuously improve the process planning of the additive and subtractive manufacturing processes, it is necessary to monitor and document the manufacturing process on the basis of machine data and external sensors.
Acknowledgements
This research and development project is/was funded by the German Federal Ministry of Education and Research (BMBF) within the “The Future of Value Creation – Research on Production, Services and Work” program (funding number 02J21E112) and managed by the Project Management Agency Karlsruhe (PTKA). We would like to thank the BMBF for the funding and the PTKA for the support and for the good and trusting cooperation. The author is responsible for the content of this publication.