Research projects

The aim of the research project is to reliably identify and separate natural fibre-reinforced plastics from conventional plastics, and to develop a gentle cleaning process for natural fibre-reinforced plastics (NFK) that prevents any deterioration in properties caused by damage to the material.

Due to increased demand for natural fibre-reinforced plastics (NFK), this research project focuses on the development of a circular system. Plastics from end-of-life products are to be processed in such a way that up to 100 per cent can be reused.

The recycling cycle begins immediately after the plastic products are disposed of in the yellow bin or yellow bag. At the waste sorting plant, natural fibre-reinforced plastics must be reliably separated from conventional plastics such as PE, PP, PS or PET. Methods for the unambiguous identification of plastics must be analysed and compared so that plastic types can be separated from compounds. The separation of different fibre types is essential here, as only pure NFK can be reused to manufacture products with equivalent properties.

Following the separation and sorting process, the natural fibre-reinforced plastics undergo gentle cleaning and processing to produce single-type regranulates or recyclates, which are reused by plastics processing companies. The extent to which the regranulates can be used, either in full or in part, for new products is to be clarified as part of the project.

The aim of the project is to produce bioplastics with high antibacterial properties from natural raw materials. Polyphenols derived from pine wood kernels are already used as an agent against harmful bacteria and are safe for humans. The incorporation of pine heartwood into plastics is to be investigated and reliably implemented in comparison with existing solutions. In addition to standard plastics, bioplastics in particular are to be used. Combining bioplastics with pine heartwood saves up to 100 per cent of fossil-based raw materials.

The research project aims to process biopolymers in such a gentle manner that their properties are not adversely affected by the processing, but rather that the greatest possible extent of the biopolymers’ positive potential properties is retained or can be controlled during the processing. Gentle processing aims to minimise thermal and shear stress on the material during the processing stage.

This project examines energy consumption as a cost factor.

As part of the project, a fastening element for modern façade systems is being developed.

The fastener is designed to secure heavy, large-area components to the building envelope and is intended to minimise the heat flow through the wall in order to reduce thermal losses from buildings. Due to their low thermal conductivity, plastics are particularly well-suited to this application.

Various design solutions are being developed to meet the high requirements regarding long-term mechanical stresses, a wide temperature range, fire safety, a design suitable for manufacturing, and cost-effectiveness. The mechanical and thermal characteristics are simulated and analysed using software-aided finite element calculations. This enables a design-optimised construction. To ensure the component’s future use, a production process suitable for series manufacture is designed and a prototype is produced, the properties of which are tested and verified in real-world trials. The aim of the project is to obtain case-by-case approval from the DIBt for the mass-produced component.

As part of the collaborative project, the Group for Plastics Engineering at Ilmenau University of Technology is initially investigating the possibility of targeted shear-induced liquefaction of plastic melts. This process is used to impregnate reinforcing fibres, thereby transforming them into fibre-reinforced plastics. To this end, laboratory tests are being carried out to clarify the necessary boundary conditions for this novel technology. Based on the results of these tests, an initial test setup for fibre impregnation and subsequently for the production of sandwich composites is being developed. The newly developed process will also be used to produce, for the first time, fully bio-based sandwich composites using natural fibres and bioplastics.

FaSanDirEx follows on from a project previously carried out by the Group and builds on its results. The existing direct extrusion line will be upgraded with the shear-liquefaction unit to be developed, thereby further increasing energy efficiency and processing the material even more gently. This enables the use of bioplastics that are particularly susceptible to degradation. The addition of a production line for sandwich structures allows the entire process chain to be mapped out.

The aim of this research project is to develop the fundamental engineering principles that will make it possible – to a greater extent than has been feasible to date – to determine the strength and properties of components made from fibre-reinforced plastics prior to manufacture, thereby enabling the design of the component concept to be assessed and optimised, and the limits of its application to be identified.

In this way, it will be possible to assess both feasibility and the technical and economic implications at an early stage, thereby avoiding time-consuming ‘trial and error’ methods. This is of particular importance if fibre-reinforced plastics are to be utilised on a significantly larger scale for components in mechanical and plant engineering, where the design and complexity of the geometry differ from the large-area structures commonly encountered to date, which typically have low dimensional accuracy requirements.

Design rules for component design are to be established and compared with theoretical models using FEM calculations. The fundamental investigations into material behaviour carried out as part of the overall project will be incorporated into these calculations. To this end, material behaviour will be investigated on real moulded samples in our own research, compared with FEM calculations, adjusted where necessary, and incorporated into the design rules.

In addition to the mechanical properties, the process parameters of various processing methods (hand lay-up, vacuum infusion, RTM, VARTM and RIM) will be investigated; various resin and fibre combinations will be examined. A process model is to be developed. Process conditions to be adhered to can be defined and specific processing recommendations drawn up, with a view to incorporating these into the initial step of correlating manufacturing with material properties. The process models will be developed on the basis of experiments in combination with the material models. In doing so, the related process technologies within the overall project must be taken into account in the design rules, and the insights gained from them must be incorporated. An outlook on the process conditions for series production is planned in collaboration with the project partners.

The Lightweight Construction Research Group at the Thuringian Innovation Centre for Mobility (ThIMo) focuses on reducing vehicle weight by utilising the specific properties of plastics. The Plastics Engineering Group is responsible for four of the seven thematic areas covered.

In Research Area 1, the resin transfer moulding (RTM) process for the manufacture of thermosetting fibre-reinforced composites is being investigated in greater detail. The aim is to characterise the factors determining quality and cycle time more precisely in order to enable the rapid production of defect-free products.

Research area 2 involves an economic analysis of various value chains for the manufacture of fibre-reinforced composites. The aim is to analyse and reorder time-critical process steps in order to accelerate the process. The focus of this work is on the manufacture of thermoplastic fibre-reinforced composite components using organic sheets.

The research group’s fourth area involves investigations into the manufacture of plastic-coated aluminium foams. The first step is to characterise the production of the foams and the mechanical properties that can be achieved in greater detail. The second step involves overmoulding with thermoplastics.

As part of the project, composites made from aluminium foam and fibre-reinforced thermoplastics are to be produced and their suitability as automotive crash elements investigated.

The aim of the project is to determine the fundamental relationships between material composition, processing parameters and the properties of 3D moulded parts made from wood shavings.

Against the backdrop of lightweight construction, the project aims to establish the fundamentals for the use of a combination of FRP and post-cured plastic foam in hybrid sandwich construction for components subject to vibrational loads in mechanical and plant engineering. The material behaviour will be investigated and used to create FEM calculation models. Model components will be manufactured and tested using various production processes. The findings will be incorporated into the design and simulation of a demonstrator component, as well as into the establishment of technical and economic design rules.

The project serves as a basis for the development and manufacture of FRP-plastic foam hybrid structures, as well as for defining their property profiles, incorporating connection elements for dynamically loaded machine components.

The need to conserve resources is making energy consumption in the operation of machinery and plant an increasingly important consideration in the industrial processing sector. At the same time, the aim is to improve the properties of machine components (damping behaviour, acceleration values) and to achieve even higher performance parameters for the machines (reduced cycle times).

Detailed information can be found on the project website:

https://www.proki-ilmenau.de

The project aims to increase productivity and quality in the manufacture of injection-moulded thermoplastic components and semi-finished products. The innovation behind the project lies in the use of rheofluidisation, which enables the melt viscosity of plastics to be reduced without damaging the material. Lower viscosity allows moulded parts to be demoulded more easily and extruded products to be manufactured with greater dimensional accuracy, both within a more stable process window. This can open up entirely new avenues for innovation, significantly simplifying existing production processes and increasing output whilst maintaining high quality standards.

These improvements enable a general increase in productivity in injection moulding and extrusion processes. New degrees of freedom are provided in mould and tool design, which can stabilise or enable manufacturing processes. Furthermore, new material combinations become possible in multi-component processes, particularly in extrusion.

Fibre composites are characterised by their high stiffness and strength combined with low density. Resin transfer moulding (RTM) is frequently used as the manufacturing process, as it is suitable for medium to large production runs. The use of two mould halves results in moulded parts with a high surface finish that require only minimal reworking.

The process begins with the insertion of a preform made from continuous fibres. The mould is closed and resin is injected according to predefined parameters.

To date, the processes taking place within the mould have not been monitored. The aim of the project is to use suitable sensors to monitor the injection process and automatically compensate for variations in the material and environmental conditions. The flow behaviour of the resin is analysed and the injection parameters adjusted accordingly without the need for user intervention. This enables consistently high product quality to be achieved whilst maintaining short cycle times. The cost-effectiveness of the process is enhanced by the avoidance of defects and scrap parts.

The aim of this sub-project is to carry out a technical and economic assessment of thermoplastic materials and their processing methods for the manufacture of dielectric elastomer actuators (DEA). These findings will be consolidated within the wider consortium to enable a comparison of the potential of different DEA manufacturing options and to focus on further courses of action within the smart³ consortium.

To date, DEAs have primarily been manufactured and characterised in research institutions. The manufacturing processes and materials used in these experiments were generally not selected or considered with mass production in mind. Scaling up the manufacturing conditions from these laboratory experiments is not straightforward.

The aim of this sub-project is to adapt known plastics processing methods, which demonstrate excellent scalability, for DEA production. The co-extrusion process offers the essential prerequisites for the manufacture of multi-layer actuators. Thermoplastic materials, whose creep behaviour is detrimental to the resulting actuators, are ideal for this process. Radiation cross-linking can be employed as a subsequent process step to achieve volumetric compensation. This transforms the thermoplastic into an elastomer. The main objective of this work is to investigate the applicability of this processing chain and to demonstrate it through pilot trials. A positive assessment of feasibility is provided by the use of a cost-effective manufacturing route for DEA, the plant technology for which is already established for other applications.

Thanks to developments in the direct impregnation of long-fibre-reinforced organic sheets, extensive expertise has already been built up at the Technical University of Ilmenau in recent years, which can be applied primarily in the automotive and supplier industries. To date, work in this area has mostly focused on fabric-reinforced semi-finished composite products. In future, thermoplastic tapes will play a very significant role in industry, as these oriented composite materials can be used to manufacture components reinforced to meet specific load requirements. For this reason, further developments in this field were prepared using the 2021 Innovation Voucher IVN 0108, and research collaborations with small and medium-sized industrial partners were initiated. To this end, targeted preparatory work was planned for the planning and preparation of further research projects – in particular within the Federal Government’s Technology Transfer Programme for Lightweight Construction – which will also serve to expand the core competence in plastics engineering and lightweight construction at the Technical University of Ilmenau.

The state of maintenance of an injection moulding machine has a significant impact on the stability of the manufacturing process and, consequently, on the quality of the moulded parts produced.

The aim of the project is to use sensor technology and the monitoring of machine functions and process variables to assess the wear status of injection moulding machines in such a way that preventive maintenance measures can be planned and scheduled.

The project forms part of the Leantec growth cluster. The aim of the project within the Group of Plastics Technology is to design, build, integrate and test an extruder fitted with a LEANTEC direct drive.

The LeanTec motor is intended to enable direct drive of the screw without a power transmission system (gearbox, belt drive or similar), whilst delivering high energy efficiency and power density, as well as constant operating parameters. The aim is to demonstrate that the direct drive enables higher efficiency, a simpler and more cost-effective connection of the plasticising screw to the drive system, and lower susceptibility to faults compared with conventional extruder drive systems; that this is technically feasible in a production environment; and that all required performance parameters can be achieved.

For various plastics and different machine configurations (screw/cylinder/moulds), the required process reliability is to be demonstrated for standard industrial operating points. In doing so, the characteristic values for start-up behaviour, torque/speed characteristic curve, power consumption, throughput and torque stability at different back pressures and back-pressure fluctuations, as well as temperature and melt homogeneity, will be used as reference parameters for the suitability of the LEANTEC drive system and compared with values from a standard industrial drive system.

The desert sledge serves as a means of transport and helps to enhance the range of leisure activities available in desert regions.

As part of the project, low-abrasion plastic surfaces with friction-optimised properties were developed and put to use on sand. To achieve this, we drew on the specific material and design advantages of plastics, enabling us to produce complex geometries as one-off items and mould them efficiently on a frequent basis.

Furthermore, the plastic allows for the incorporation of additives that further reduce both the coefficient of friction and abrasion. To further improve the surface structure, we drew on the principles of bionics and analysed the adaptations found in the flora and fauna of desert catchment areas. The aim of the project was to develop a prototype that fulfils all the desired properties and has been tested using measurement sensors from PCE Deutschland GmbH. We would like to extend our special thanks to the construction company Franz Hofmann Bau from Sonnefeld for helping to realise a 30-metre-long test track. The project’s objective – to develop a prototype that ensures low friction and abrasion values and can be extensively tested in the desert – has been achieved.