POLYLINE | Integrated line application of polymer-based AM technologies

Up to now, the vertical and horizontal integration of additive manufacturing processes in conventional lines has only been possible to a limited extent. On the one hand, this is due to AM-specific production steps (e.g. production time in the "batch process") and the generally low level of automation of the processing and transport processes. The result is isolated production steps and a great deal of manual effort. On the other hand, there is no continuous digital data chain at many interfaces along the horizontal process chain, which in turn leads to a lack of transparency, high error-proneness and limited monitoring along the processes. This makes effective production planning and control more difficult. The great potential of additive manufacturing processes can be severely inhibited by such restrictions.

The aim of POLYLINE is to further develop additive manufacturing with polymer-based laser-sintering (LS) into an automated and efficient production process. Additive manufacturing technology should thus be able to meet classical processes in high-throughput line production systems at eye level. This can promote a more flexible production with parts production in Germany, which will be demonstrated by the example of series parts from the automotive industry.

One focus of the Fraunhofer IGCV within the project is the development of a digital process chain for plastic components manufactured by additives. For the breakthrough of additive manufacturing in series production, continuous data availability is of fundamental importance. The aim of this sub-project is therefore to link the various software solutions used via standardized interfaces in order to improve the quality of decision-making.

Important sub-goals are the conception of a suitable system architecture for the software solutions and the design of the interfaces between the software systems. Furthermore, a procedure for the clear identification of the components is to be developed together with the project partners in order to be able to assign the process data to the digital twin. Based on this qualitatively and quantitatively better data basis, a novel approach to production planning and control can be developed, taking into account the unique properties of the additive manufacturing technologies, and tested for its suitability for series production using a simulation model.

In the area of component cleaning or finishing, the focus is on technical cleanliness. In addition to the increasing demand for additive manufacturing, the requirements for technical cleanliness with regard to finishing processes have risen sharply in recent years. Due to the advantage of additive manufacturing of being able to produce complex structures, there is also the disadvantage of process-related accumulation of impurities in fine and therefore difficult to access spaces or channels in the component. In addition, the increase in the variety of parts poses a challenge for component cleaning. The diverse spectrum of product groups, series and quality levels (e.g. degree of contamination) requires specific cleaning steps in each case, whereby the associated product variants result in many process variants for additive production.

Although component cleaning in particular represents a decisive process in additive manufacturing, this area has been mostly neglected up to now due to a lack of well-founded process knowledge in research and industry. For this reason, extensive innovation potentials (e.g. missing specifications, limits of applied cleaning technologies, non-established analytical methods) as well as saving potentials (e.g. time, costs, rejects) are not yet fully exploited today. Therefore, cleaning process chains have to be developed which close procedural gaps and thus enable continuous product engineering and efficiency-enhanced finishing processes of components for industrial applications. In addition, technical cleanliness must be improved, resources saved and the necessary occupational safety ensured.