LESS IS MORE

Many industrial processes rely on water as a resource – both as a raw material for production and as a means of transport, a solvent or a separating agent. In order to use water as resource-efficiently and sustainably as possible and to conserve drinking water reserves, new solutions are needed for more efficient water use and recycling.

Reuse the resource water several times!

In the KMU-akut project “Efficient water treatment” – abbreviated EWA for “Effiziente Wasseraufbereitung” – a number of Fraunhofer Institutes under the leadership of Fraunhofer ISC and IFAM are pooling their expertise in electrochemical process technology, particle technology, and materials analysis. Together with industrial partners, they are working in four subject areas on the efficient treatment and multiple use of water, an important resource.

For many small and medium-sized companies, conventional commercial process water treatment is either oversized, too specific, too expensive, or simply unsuitable. The EWA project aims at closing this gap and developing solutions that meet the needs of small and medium-sized enterprises through their flexibility, scalability and comparatively low cost. Together with the three other Fraunhofer Institutes IKTS, ISE and IGB as well as five industrial partners, they carried out exemplary feasibility studies and validation projects in the fields of battery recycling, lithium extraction, alginite in sewage treatment processes and seawater desalination for the lead markets energy industry, chemical industry, health industry as well as plant and mechanical engineering.

A good overview of the working methods of the EWA project partners is provided, for example, by the subproject on the efficient and sustainable treatment of process water from lithium-ion battery recycling plants. The increasing number of electric vehicles produces more used traction batteries. The ISC‘s goal in the EWA project is to recover valuable battery materials as efficiently as possible and to purify process water such that it can be recirculated.

Ideally, the materials should then be sorted by type so that they can be directly reprocessed into new batteries. The starting point for the project work was the electrohydraulic shredding process (referred to as EHZ, elektrohydraulische Zerkleinerung) – a development of the project partner Impulstec – with which the batteries can be broken down into individual material fractions. The water-based process produces coarse and fine material fractions as well as substances that go into solution.

Project partner MAB Recycling is a user of the EHZ and was looking for a suitable treatment method to remove valuable battery materials as completely and separately as possible and to free the process water from disturbing impurities.

The recycling specialist supplied the process water as a raw material and in return received analysis results and important know-how to advance its own water treatment. Another industrial partner in the project was CEPA, a manufacturer of industrial centrifuges. The company has been working for some time with Fraunhofer ISC on the further development of centrifuge technology.

In the EWA project, the three companies worked together with Fraunhofer ISC on specific issues to reduce the volume of process water, to recycle it as far as possible, and to promote the separation of materials by type as far as possible. As a result, processes are improved, water is saved, and further ideas for joint projects beyond EWA are generated.

Selective adsorption of metal ions and environmental pollutants

In this process, magnetic adsorbent particles are used to selectively and efficiently remove (heavy) metal ions and pollutants such as drug residues from process and sewage waters. Terra Natural Resources GmbH is also on board as an industrial partner. Magnetic and silicate particles are combined with a particularly efficient and selective adsorbent for  environmental pollutants: alginite. It is a special, naturally occurring, recyclable mineral that, unlike the activated carbon currently used, is cost-effective and has high environmental compatibility and very good separation performance for both hydrophilic and hydrophobic substances.

The clever modification of alginite with magnetic particles ensures a consistently efficient adsorption performance and also guarantees residue-free separation of the absorbent particles from the treated sewage waters. The cost-effective and sustainable process has great potential and will be a valid alternative for use in sewage water treatment plants in the future.

Website "ewa"

• More on research into battery recycling analysis and separation technologies (German)
  
• More on resource-saving lithium extraction (German)
  
• More on alginite in wastewater treatment processes (German)
• More on the novel process for seawater desalination (German)
  

Future manufacturing processes will be digitally controlled and automated. In addition, they should be resource-conserving and energy-efficient and create products that are as fully recyclable or biodegradable as possible. In combination with the right material concepts, additive manufacturing can be a good solution and therefore has great potential in certain areas of application. Another advantage of additive processes is that individual components and entire systems can be customized easily and cost-effectively – keyword “batch size 1”. This applies in particular to energy-intensive manufacturing processes such as in special ceramics or novel material composites in the field of high-temperature lightweight construction, but also to the use of biological materials and their system integration, especially in the field of medical engineering and medical product development. For  example, this technology is interesting for biofunctionalized carrier materials or individualized implants. And the manufacture of specific (micro-)electronic and (micro-)optical components also benefits from the variability of additive manufacturing processes.

In addition to the advantages in customization, resource efficiency is also playing an increasingly important role in the use of additive processes. Near-net-shape manufacturing by 3D printing without material losses is also attractive for the series production of complex components and structures, especially where highly qualified materials are used. The Fraunhofer Institute for Silicate Research ISC uses a range of processes in combination with customized material concepts for a wide variety of applications and continues to develop additive techniques. Common 3D printing processes build up workpieces layer by layer. Depending on the material, chemical (2C) or physical (temperature, light) initiation is used. Typically, 3D printing processes are used as stand-alone systems. For industry-related processes, however, concepts for the automation of process chains with integrated 3D printing are required. In terms of products, different 3D printing processes can even be combined to achieve optimally adapted material combinations and functions. Fraunhofer ISC is working on the system integration of different 3D printing technologies in one device and is developing in-process measuring and monitoring systems. In this context, the focus is on issues such as automated material supply, post-processing (3D polishing), or the standardization of interfaces in order to facilitate implementation in existing processes.

Special ceramics / metals / metal-ceramic composites

The Fraunhofer Center for High Temperature Materials and Design HTL uses two-stage additive manufacturing processes for the production of metals, ceramics and multi-material composites. To create what is called a green component, the low-energy additive manufacturing process is separated from the subsequent furnace treatment that usually demands a great deal of time and energy and is needed for debinding and sintering or infiltration. This has the advantage of avoiding thermal stresses and warpage that occur in other 3D printing processes. In addition, the simultaneous firing of many components makes these processes very attractive in respect of economic efficiency. In addition to feedstocks and printing parameters, HTL is developing analysis methods for quality assurance of green-state components. This enables efficient optimization along the first half of the process chain. For the design of the subsequent thermal processes, HTL determines the material properties that are crucial for the process kinetics. For this purpose, HTL uses, among other things, conventional thermal analysis as well as in-situ analysis in the in-house developed thermo-optical measuring systems (TOM). The measurement data are then used in a coupled FEM-based simulation that takes thermal, mechanical, chemical and geometric aspects into account for optimization. This allows the material, component design, furnace chamber and thermal processes to be simulated in interaction. This forms the basis for the a priori prediction of potential sources of defects, shrinkage and warpage with regard to specific components and materials and for designing the entire process chain for reliable, economical and yet flexible series production.

Sensors / actuators / optical components

Miniaturized sensor and actuator elements are also to be integrated into the manufacturing process via 3D printing. Fraunhofer ISC is developing the associated new material combinations, which can be operated in a piezoelectric, thermal, electrostatic, optical, chemical or mechanically responsive manner. The production of optical components requires particularly homogeneous, transparent and light-resistant 3D molds that are free from internal interfaces and have a very high surface quality. Aspheres and gradient-index (GRIN) lenses are difficult to manufacture using conventional methods. 3D printing offers optical designers the chance to design and rapidly test new components as free-form surfaces far from the usual spherical and rotationally symmetric geometries.

Biomedicine / medical devices

In addition to its use for dental products and custom earmolds, the use of additive manufacturing processes is also of interest for biomedical applications. For example, new biodegradable and/or 3D-printable materials offer solutions, e.g., for the production of support structures (scaffolds) or functional elements that are only needed temporarily and are subsequently degraded by their physiological environment. The growth process and behavior of cells and microorganisms can be specifically influenced with biocompatible and bioactive materials (stimulation, release of nutrients, support of wound healing). The combination of 3D printing processes with living cells (bioprinting) can offer completely new possibilities for biomedical and pharmacological issues. For this purpose, gentle printing technologies are being further developed together with cooperation partners.

Resource-saving recycling / secondary raw materials

The 3D printing process requires highly specialized primary materials with precisely defined properties, because resourceconserving use of recyclates or secondary raw materials has not been possible to date. Fraunhofer ISC aims at harnessing this valuable reservoir of materials with its chemical synthesis expertise. Production waste or recycled materials are to be modified such that they are available as secondary raw materials with the specifications required for 3D printing processes.

Further Information

• More on the topic of “Additive Manufacturing“
  
• More on the topic “Additive manufacturing with functional materials“
• Flyer-PDF on the topic of “Additive manufacturing of metal-ceramic composites“ [ PDF  0,4 MB ]

The first thing that literally catches the eye in most products is their surface. That is why its texture is enormously important. Innovative coatings not only give surfaces a fine appearance, they above all create new functionalities and added value with little material input and can help replace critical materials or process steps in production.

Galvanized plastics, for example, are manufactured and used in the automotive industry and in many other sectors. The galvanized surfaces give plastic components, which are inexpensive and easy to manufacture, a high-quality metallic appearance and pleasant feel. However, electroplating requires very complex procedures and processes using rare metals of the platinum group as well as highly toxic and/or harmful substances (e.g., acids such as hydrofluoric acid or chromosulfuric acid). It is therefore economically and ecologically necessary to make existing electroplating processes for plastic parts more environmentally compatible, to simplify the process and also to greatly reduce the amount of rare metals in the process. In order to refine polymers, but also other electrically non-conductive materials, with a metal layer in an electroplating process, a thin, electrically conductive coating must first be applied through “chemical metallization”. Thin copper or nickel layers are usually used to do this.

Less is more - the new electroplating process not only saves critical substances, but also process steps.
© Fraunhofer ISC

The “chemical metallization“ process requires a catalyst on which copper or nickel is deposited. This catalyst is palladium (Pd), an element of the platinum noble metal group. In the processes commonly used today, all materials to be chemically metallized are first given a palladium layer by dip coating. Before the palladium coating is applied, the plastic surface is “roughened” by etching with chromosulfuric acid. This step is particularly
critical because hexavalent chromium is still used here.

Fraunhofer ISC is working with two well-known industrial partners from the plastics and electroplating sectors to develop a more environmentally friendly and faster process. It eliminates the need for palladium as a conductive metallization material, avoids the use of environmentally harmful chemicals and significantly reduces the number of process steps previously required. This is made possible by specially designed multifunctional hybrid polymers. Thanks to their chemism and special structure, they provide good adhesion between the plastic surface and the electroplated metal layer, and doping provides the conductivity required for the electroplating process. The raw materials required for their manufacture are inexpensive and commercially readily available, and they are applied in a single, simple painting process. The sometimes toxic chemicals for etching steps and activation, as well as the critical palladium, are thus completely replaced.

In the ongoing joint project, the material and process are being optimized to ensure that the surface quality of the electroplated product meets the highest demands. At the same time, the material synthesis for the conductive hybrid polymer is being scaled up in order to already have capacities for sampling and testing under pilot conditions at the end of the project. Fraunhofer ISC‘s material innovation could make electroplating much more environmentally friendly and simpler by eliminating critical process chemicals.

For the industrial companies involved, not only the environmental aspects but also the simplification and acceleration of the process are very attractive from an economic point of view.

• Technical article: "Green ways of finishing plastics - Simplified, environmentally friendly process for electroplating plastic components" (German) 
  
• More about "Structuring processes and coatings for surfaces"
  

As part of the EU “OASIS” project, 12 pilot lines for innovative lightweight composites – including nanoparticle production at Fraunhofer ISC – have been set up and expanded so far. These pilot lines have already proved their worth in the OASIS showcase projects. Fraunhofer ISC was involved in the Acciona Construccion SA construction group’s showcase for the development of a new CO₂-saving production technique for reinforced lightweight concrete components. To this end, the ISC’s particle technology contributed inductively heatable nanoparticles that were used to uniformly cure the resin matrix of glass fiber reinforcement (GFRP) during extrusion. The advantage of the new process is the rapid inductive heating. This allows the entire cross-section to be cured uniformly and reliably. Defects and incompletely cured areas are avoided. The new lightweight reinforcements can thus save energy and weight, a step forward in reducing CO₂ emissions in building and construction. The magnetic particles were used to preheat the resin in the production process via an induction coil, thus achieving a 100% increase in production speed in practice. The final concrete components reinforced with GFRP bars have achieved good results in terms of mechanical properties and fire behavior. At present, durability tests in a real marine environment are being conducted, the results of which will provide further interesting information.  

However, “OASIS” actually aims at a steady use of the pilot lines beyond the showcases carried out in the project and, above all, at making this infrastructure available to small, medium and large companies. For this reason, there have already been two open calls to companies to apply with project ideas. Interesting projects for the ISC pilot line emerged from both the first and second calls. With a well-known Polish manufacturer of railroad seats, the nonhalogen flame-retardant particles of the ISC pilot line, in combination with nano-based products of other ”OASIS” pilot lines, will be used for a new product that is lightweight, customizable according to customer requirements and environmentally friendly. For the manufacturer, the new development may mean a significant competitive edge in the rail sector.

Key technology for recycling composite materials –
simplified bonding/debonding with inductively heatable particles

The second call involves a project by another well-known German supplier working on a concept for improved recycling of composite materials in novel lightweight structures for the mobility sector. Here, the purpose of the inductively heatable particles from the ISC pilot line is to enable simple bonding/debonding and break adhesive bonds by inductive heating. In both cases, the particulate additives from the expanded co-pilot plant at Fraunhofer ISC, with their quality-assured particle production on a kg scale, make a significant contribution to the success of new, more environmentally friendly and resourceconserving industrial products, and do so with a comparatively low material input – less is (often) more.
The “OASIS” concept, an open access single-entry point for companies wishing to use an infrastructure for innovative lightweight materials that is based on research but is also capable of pilot production, is obviously proving its worth.

Thus, in the two open “OASIS” calls, eleven so-called democases for new product ideas have already been carried out or at least started, with industrial customers from different sectors. In addition to the construction and mobility branches, OASIS customers also come from the medical engineering and sporting goods sectors. For this reason, work is currently underway to establish a corresponding facility that will continue to offer the services developed to date even after the end of the EU “OASIS” project – a project result that is also positive for the ISC pilot line.    

Website “oasis“

• Website EU-Project "OASIS“
• More about “inductive heatable particles“

The “ImAi” project, funded by the German Federal Ministry of Education and Research, aims at creating an animal-free replacement for the Draize test on rabbits used worldwide to evaluate the eye irritation potential of chemicals. The new test is based on tissue models of the cornea cultivated in the laboratory in conjunction with impedance spectroscopy.

Every chemical substance that is put into circulation must undergo various tests to define its hazard potential and declare it accordingly. One of these mandatory tests examines the potential hazard for eye irritation and classifies the substances accordingly into categories “1” for irreversible damage, “2” for reversible damage, or “3” not requiring labeling if the substance is not irritating. To classify the harmfulness of substances to the eye, a stressful toxicological test is performed worldwide on live rabbits, the so-called “Draize test” (according to OECD test guideline TG 405), in which the substances are dripped into the eye of living rabbits. This test has been in effect since 1944.

In order to replace this painful procedure, several attempts have been made to cultivate tissue models of the human cornea in the test tube (in vitro) and to use them as test systems. However, since previous tissue models do not allow to differentiate between irreversible and reversible damage, only a reduction, not a replacement of animal experiments has been achieved so far.
The Translational Center for Regenerative Therapies TLC-RT of the Fraunhofer ISC, the Federal Institute for Risk Assessment and the Goethe University Frankfurt are working together with the companies Clariant Produkte GmbH and Courage Khazaka Elektronik GmbH on a powerful test system in the “ImAi” project. The new method is not only intended to completely replace the “Draize Test”, but also to allow more reliable predictions, since the tissue model will be based on human cells.
The core of the test system will be the modified, long-lived cornea model of the TLC-RT. In order to distinguish between the different categories of ocular damage, a non-invasive measurement methodology will also be developed, which will allow repeated examination of the artificial cornea without additional disturbance. In this way, a potential damage to the eye can be reliably predicted.

The first milestones – test setup and adaptation of impedance spectroscopy to the cornea models, i.e., how can the damage and modes of action on the cornea be easily measured, distinguished and evaluated by impedance spectroscopy – have already been passed. The prototype of the handy and easy-to-use mobile spectrometer is also already being used to measure the test substances. In the coming months, the device software, the parameterization of the test procedure, the standardized test procedure and the measurement protocols will be optimized to enable the most comprehensive statements possible about the modes of action of the test substances and a reliable and rapid prediction about the irritant potential of chemicals. Subsequently, the new test procedure will be validated in a multi-laboratory validation study.

3R principle saves animal lives and resources

In the medium term, if validation is successful, the results obtained in the project will allow implementation as a stand-alone method in an OECD test guideline. Then, after about 80 years, the end of the “Draize Test” might finally be in sight – and not only the rabbits will not shed a
tear. This is because the new procedure not only spares the test animals, but also saves personnel resources and time, and ultimately reduces the costs of a test. In the future, it is conceivable that the measurement method can be transferred to other in vitro models (skin, blood-brain barrier) and serve as a platform technology. There is already great interest in the method from industry.

Website In vitro Models

• Press release on the "ImAi" project
• Website “In vitro Test Systems“
  
• Publication on the topic of "Replacing Draize Eye Test“