Core competence »polymer engineering and composite materials«

Since 1994 Fraunhofer ICT has been researching technical plastics for practical use within its core competence of “polymer engineering and composite materials”. Our work ranges from polymer synthesis, materials technology, plastics processing, component development and production through to recycling.

Colored PET bottles are shredded, depolymerized and purified to produce clean, white PET pre-products, then re-polymerized and reprocessed into PET preforms
© Fraunhofer ICT | Mona Rothweiler
Colored PET bottles are shredded, depolymerized and purified to produce clean, white PET pre-products, then re-polymerized and reprocessed into PET preforms
Biobased PLA semi-finished sheets made from two types of polylactide with different melting points
© Fraunhofer ICT | Mona Rothweiler
Biobased PLA semi-finished sheets made from two types of polylactide with different melting points
Glycolysis product with recycled polyol (upper phase)
© Fraunhofer ICT
Glycolysis product with recycled polyol (upper phase)
Application example: Seat shell made from polylactide
© Fraunhofer ICT
Application example: Seat shell made from polylactide

We see polymer synthesis as a basis for the further development of so-called classic polymers such as polyurethanes, polyesters and polyamides, in order to improve their functionalities (e.g. heat resistance), thus opening new application fields. Sustainability developments, such as plastics made of biobased raw materials or the fully comprehensive recycling of used plastics, are another core research topic. Further development topics are the synthesis of additives, such as flame retardants or compatibilizers for new plastic compounds. In modern flame retardant systems no halogen-containing components are used. The latest developments aim to combine thermoplastic and thermosetting functionalities in next-generation functional polymers.

The research group for material development and compounding technologies develops new compounding processes and material recipes. Particularly important topics include extractive compounding processes to reduce emissions, the removal of impurities during recycling and innovative reactive extrusion for polymer synthesis or polymer modification in twin-screw extruders. Innovative materials are produced on modern plant technology, for example in the field of biobased or nano-functionalized polymer compounds for high-quality injection molding materials and for generative manufacturing processes.

The thematic field of foam technologies is concerned with particle foam technology and the manufacture of foamed semifinished products in the direct foam process. In addition to the optimization of conventional materials, we are concerned with the foaming of biobased polymers and technical raw materials, most of which are resistant to increased temperatures. The combination of plastic foams with phase change materials enables the manufacturing of hybrid lightweight construction materials with high insulation values and additional room temperature control options. New technologies, such as radio frequency technology for particle foam processing, open up completely new areas of application for particle foams.

The research group for injection and compression molding focuses on standard and specialized processes in the injection molding and flow compression molding of thermoplastic and thermoset (fiber composite) materials. The integration of local, load-path-compatible wound or tape-laid fiber composite structures into injection molded components significantly improves the mechanical properties between load application points.

Key elements of research in the field of structural composites include the further development and industrialization of process chains for the production of highly durable, continuous-fiberreinforced lightweight structures with thermoset and thermoplastic matrices. The core technologies are resin transfer molding (RTM) and wet compression molding (WCM) as well as thermoplastic tape laying (ATL). The placement of textile and pre-impregnated semi-finished products to produce preforms, and their handling, combination with polymer foams and metallic structures and subsequent resin infusion or stamp forming are important process steps within the processing chains.

In the research group for microwave and plasma technology we develop testing units and measurement technology. Applications include the microwave-based heating of polymers, the accelerated curing of adhesives and resin systems, and coating or modification of surfaces in the plasma-enhanced chemical vapor deposition process. A particular focus is on corrosionresistant layers and nanoporous adhesive layers.

In our testing laboratory, we carry out comprehensive examinations of polymer materials along the entire processing chain, from the raw material through to the component. In the event of damage or failure, we offer systematic analysis of the causes of the damage and the influences leading to failure, using analytical and technological measurement methods. In addition to the standardized testing of standard materials, we also offer the testing of fiber composites and polymer rigid foams, and can characterize polymer compounds with regard to their acoustic damping behavior.

In the field of online process monitoring, spectral and microwave- based measurement methods are developed for plantintegrated process and material monitoring and for process control. Projects in the context of Industry 4.0 build on our significant experience in the field of probe technology, the process integration of sensors and process-specific know-how in the evaluation of the raw data obtained. The application and integration of big data and KI algorithms enable “learning/ immature processes”.

In the area of recycling and waste management, processes and technologies for the material recycling of polymers are developed, aiming for a complete reintroduction into high-quality applications. The focus is on technologies for the recycling of composites and composite materials (GRP, CFRP) after the fibers have been extracted (e.g. by solvolysis or microwave-assisted pyrolysis processes), and the separation of PET multilayer composites in the packaging sector. Some consumer thermoplastics have to be subjected to an extraction process before they can be reused, for example to remove flame retardants or colorants. This involves the use of conventional solvents as well as supercritical fluids such as carbon dioxide. Starting with materials from old aircraft seats, a process of depolymerization, purification and new synthesis gives rise to materials which could be used in demonstrators of new aircraft seats. An accompanying life cycle assessment calculation shows that these seats are not only lighter but also more sustainable.

Fraunhofer Innovation Platforms (FPCs), Karlsruhe Research Factory and Alliances

The partnership between the FPC@WESTERN in London, Ontario, Canada and Western University optimally combines the competences of Fraunhofer ICT in the field of fiber composites with the know-how in material and surface research of the Canadian university. The large-scale plant technology enables commissioned research to be carried out on an industrial scale. The research focus of the FPC@UNIST in Ulsan, South Korea, is on manufacturing processes for fiber composites, new material solutions and the transfer of lightweight construction into mass production.

The "Karlsruher Forschungsfabrik®" is an initiative of the Fraunhofer-Gesellschaft with its institutes ICT and IOSB as well as the Karlsruhe Institute of Technology (KIT-wbk) on the East Campus of the Karlsruhe Institute of Technology (KIT). Together with industrial partners, the aim is to quickly bring new, still immature production processes to series production scale. The project will make an important contribution to the “Artificial Intelligence Strategy" of the German Federal Government. In 2019, the foundation stone was officially laid by representatives of the state, KIT, and the Fraunhofer-Gesellschaft. The factory is currently under construction, scheduled for completion in early 2021.

The close thematic networking with other Fraunhofer institutes within the Fraunhofer Alliances "Building Innovation” and "Lightweight Construction” enables us to offer system solutions from a single source.

 

Facilities and equipment

  • Twin screw extruders with 18 to 32 mm screw diameter
  • Dosing systems for liquid and highly viscous media and gravimetric dosing systems for pellets, powder, fibers, etc.
  • Laboratory for reactive extrusion, equipped with safety devices for working with hazardous substances
  • Parallel-running hydraulic compression molding machines for the processing of plastics with 6,300 and 36,000 kN clamping force
  • Direct LFT unit
  • Injection molding units with clamping forces between 350 and 7,000 kN
  • Advanced processing technologies for injection molding, injection embossing, multicomponent injection molding, thermoplastic foam injection molding, expansion foaming, thermoset injection molding
  • Injection molding compounder with 40 mm twin-screw extruder and 7,000 kN clamping force
  • Automated thermoplastic tape-laying process for nonwovens with a diameter of 2 m
  • Plant technology for radiation-induced vacuum consolidation for thermoplastic nonwovens up to 0.94 x 1.74 m²
  • Automated winding technology to produce complex loop structures
  • 3D printing technologies for processing functionalized polymers - filament-based and AKF technology
  • Particle foam technology with twin-screw extruder, underwater pelletizing, prefoamer, and a (radio frequency) molding machine
  • Tandem foam extrusion plant for foamed semi-finished products
  • SMC production line and BMC kneader
  • Polyurethane processing PU-RIM and PU fiber spraying technology
  • Thermoplastic RIM/RTM processing
  • RIM/RTM technologies for processing thermoset and thermoplastic materials in high-pressure injection and highpressure compression RTM processes
  • Microwave generators with an output of 60 kW at 915 MHz, 12 kW to 60 kW at 2.45 GHz, 0.8 kW at 5.8 GHz and 0.8 kW at variable frequency from 5.8 GHz to 7.0 GHz
  • Microwave-based sensor technology for process monitoring
  • Low pressure area plasma with 500 x 1,000 mm application area and 8 x 2 kW power output
  • Low pressure plasma unit with 8 gas channels, ECR plasma and 1000 mm plasma length
  • Universal testing machines with fixtures for bending, tensile, peel and compression tests
  • Impact pendulum and falling dart test
  • HDT/Vicat device
  • Dynamic mechanical analysis (DMA)
  • High-pressure capillary viscometer with pVT measurement technology and Rheotens® device for extensional viscosity measurement, and plate-plate viscometer
  • Contact angle measurement device
  • Differential scanning calorimetry (DSC)
  • TG-MS, pyrolysis GC-MS
  • Gel permeation chromatography (GPC)
  • Light microscopy (incident light and transmitted light), polarization
  • Scanning electron microscope with element analysis (SEM-EDX)
  • FTIR, UV-VIS, and NIR spectroscopy
  • Flame retardant test stands
  • Thermal conductivity measurement device
  • Hydrostatic compression testing facility for the characterization of polymer foams