Interreg

Efficient small batch production on an industrial scale
In the “Smart Production” project, new technologies in the field of 3D printing and deep drawing were brought to a new technological level on an industrial scale.
“We succeeded in realising 3D printers with a print volume larger than 1 m³ and individual production in deep-drawing processes with a variable mould, as well as fully automated non-destructive quality assurance,” says project manager Martin Gründkemeyer on the successful completion of the project.
The production and quality assurance of small series (number of pieces from 1 to 1000) is becoming increasingly important in various fields – for example, in medical technology, automotive and mechanical engineering as well as aerospace. At present, however, this is usually expensive and cumbersome, as only the production of larger batches is worthwhile. The EU-INTERREG project “Smart Production”, which ends in June 2021, set itself the goal of simplifying the production of small batches. The project was initiated in 2016 by the Netzwerk Oberfläche NRW e.V. (Surface Network NRW). (www.oberflaeche-nrw.de) based in Münster and brings together a total of 15 German and Dutch project partners from industry and research.

The production of parts in small batches poses a particular challenge in established production processes, especially from an economic perspective. This is largely due to the fixed costs incurred, for example, for the development and creation of deep-drawing moulds. In view of the steadily increasing demand for individual solutions and products as well as the growing need for prototypes due to ever shorter innovation cycles, there has also been a strong trend towards flexible production systems for some years now. Against this background, the multilateral project “Smart Production” focused on the optimisation of 3D printing techniques with the use of flexible plastics (“thermoplastic elastomers”, TPE), the development of a large-scale 3D printer prototype and on the development of a flexibly programmable thermoforming tool that can be used for the production of individualised small series. The third pillar of the project was the production and optimisation of a non-destructive measurement system on non-metallic surfaces using THz technology for quality assurance.

“Additive manufacturing” – 3D printing in new dimensions
In the first sub-project, “additive manufacturing”, a compact 3D printer was developed which can theoretically produce endlessly long parts in one piece on a conveyor belt. For example, long seals made of flexible TPE in Shore 90 could be produced. In addition, the development of an extruder with variable contact pressure control significantly increased the process reliability of the FFF/FDM method. Another measure of the sub-project consisted in the development of techniques for the efficient realisation of large-scale 3D printers with print volumes of one to several cubic metres. For this purpose, a size-scalable automation platform was developed, which enables a sufficiently high stability and reproducibility of the position of the 3D print head for the required large distances. For a detailed characterisation and verification of the positioning during the commissioning of large-volume printers, a camera-based method was successfully tested. The findings from the sub-project have enabled the realisation of a 3D printer with a printing area of approximately 2 m2 for research applications. Such large-volume printers will considerably simplify the production of larger components in small series in the future.
“Fleximould” – Variable tool for thermoplastic deep-drawing processes
For the “Fleximould” sub-project, research was conducted into a new thermoplastic forming process that enables the time-, cost- and resource-efficient production of individual parts and small series (https://www.youtube.com/watch?v=XAl2sAq4Wn0). Fleximould makes it possible to deep-draw suitable materials on an area of 1600 mm x 600 mm and 300 mm high. Starting from the 3D CAD model of the component, the desired shape is created directly with the aid of an automated setting mechanism based on the principle of pinart or nail play. Thermoforming will make it possible to produce large-area parts with relatively thin and uniform wall thicknesses quickly and cost-effectively in the future. 3D-printed inlets are used in the mould to represent sharp-edged structures.

The project also enabled the production of seat shells individually adapted to the body, e.g. for wheelchairs of people with multiple physical limitations. Without such aids, pressure points arise that lead to further illnesses, muscle tension or other problems. Within the scope of the cooperation, it was demonstrated with this technology that a corresponding shell can be produced for testing within two days. This significantly shortened the production time for the definitive fitting, so that affected persons do not have to wait several weeks for the adapted aid. For the future, it is planned to further investigate the applicability of this technology and to introduce it to the market.

Non-contact quality control on non-metallic surfaces
In the third sub-area, “Monitoring”, analytical methods were developed for the non-destructive layer thickness measurement of protective coatings on plastics and fibre composites. The project partners analysed and specified measurement methods based on terahertz radiation that can also be used on non-metallic substrates and, compared to classical methods, offer a wider range of information when examining multi-layer coatings. Applications can be found, for example, for non-destructive multilayer coating thickness measurement for quality control of coating systems. In this context, algorithms for the analysis of the number of layers as well as the dielectric material properties of coating materials were researched. Special evaluation algorithms for dynamic applications allow local defects in dielectric materials to be localised and displayed as an image. For this purpose, THz technology was combined with a robot-assisted positioning system based on a cobot, so that in future it will be possible to carry out measurements interactively through human-robot collaboration as well as to measure larger areas automatically. A “proof of concept” demonstrator system was developed for this purpose as part of this sub-project.

“After the development of the systems was completed, there were already numerous collaborations during the project to establish the new technologies in the existing production processes,” reports Gründkemeyer and offers to make the systems available to other interested companies for testing.

In addition, the project represents another important step for cross-border cooperation between actors from Germany and the Netherlands and could be successfully completed not least because of the broad, subject-specific expertise of the scientists and entrepreneurs involved.
The Smart Production project is co-financed within the framework of the INTERREG programme Germany-Netherlands with funds from the European Regional Development Fund (ERDF), the Ministry of Economic Affairs, Energy, Industry, SMEs and Crafts of the State of North Rhine-Westphalia (MWEIMH NRW), the Ministerie van Economische Zaken en Klimaat, as well as the provinces of Fryslân, Gelderland and Overijssel.

Questions or interest in the technologies can be directed to Martin Gründkemeyer: mg@oberflaeche-nrw.de.

Lead partner: Network Surface NRW e.V.
Project partners: Aeolus Coatings B.V., Bond High Performance 3D Technology B.V., Cato Composite Innovations B.V., Demcon Advanced Mechatronics Enschede B.V., DNL-mobiel GmbH, Grunewald GmbH & Co. KG, HS Düsseldorf, ITA Industrie-Technik Ahlen GmbH, Parthian Technology B.V., Saxion Hogeschool, Systec Elektronik und Software GmbH, Urbanmaker UG, Stichting Polymer Science Park