The RadiciGroup High Performance Polymers Business Area is adding significantly to its global production capacity with new construction and installations in North America, Europe and China.

Compound

Kunststoff Werkstoffe

Thermoplaste

Compoundeure

Dienstleistungen

Handel

Kunststoff

Bauwesen

Baustoffe

Radici Increases Production Worldwide

Transparent polyethylene films can now be produced with antimicrobial and electrically conductive properties as well. This can be achieved by combining several films with the relevant property profiles. The surface conductivity of the films can also be increased by using a suitable new coating technique. The article describes the newly developed special compounds required for this and demonstrates their industrial feasibility. 

Folien

Special Compounds: Transparent, Conductive, and Antimicrobial 

There is still a need to catch up in terms of ion leaching and hydrolysis resistance of the materials used to date for fuel cells. Specially developed PPS represent one possibility for this.

Material Improvements Make Fuel Cells More Reliable

Automotive

Elektronik

Brennstoffzelle

Stromversorgung

Brennstoffzellen

Mobilität

Technische Kunststoffe

Fahrzeugbau

Hochleistungskunststoffe

Getting Fuel Cell Vehicles Fit for Use

Even if the European market is currently only showing modest growth, PVC has continued its global growth unbroken. The plastic is becoming ever more environmentally compatible and is benefiting from global trends. The restructuring of the industry has made progress; the consolidation pressure on Western European PVC raw materials manufacturers has eased for the time being. 

PVC Is Showing a Positive Growth Trend, however, It Has Still Not Entirely Regained its Former Strength 

Polyvinylchlorid

Polyvinyl Chloride (PVC) 

Energy efficient, inexpensive LEDs are inspiring designers and engineers to develop new esthetic and functional applications of light. Since this cannot be done without plastics, Albis Plastic invited interested appliers in the supplier and automotive industry to an exchange of ideas regarding new compounds and advanced applications. 

Lighting Design for Automobile Interiors at the First Albis Automotive Lounge 

Lichtvorhänge

Oberflächentechnik

Recht allgemein / sonst.

Illuminated Feel-Good Ambience 

Ter Plastics Polymer Group recently held its 5th Polymer Forum, which is increasingly evolving into an industry gathering. For the first time, the forum featured parallel sessions on high-performance polymers in the context of current and challenging applications. The focus was on new developments and trends in polyphthalamide (PPA), polyphenylene sulfide (PPS) and polyamide (PA) 66. 

Advanced Structural and Thermal Applications at the Heart of the Polymer Forum 

Polyamide

Polymer Molecules Get Smart 

Nowadays, wearing comfort and minimum weight coupled with high strength, toughness, and durability are some of the most important requirements for sports and leisure articles – regardless of whether winter sports or racing bicycle, smart watches or drones. Novel polyamide formulations permit the design of lightweight and efficient sports and leisure equipment. 

Low Density and Outstanding Mechanical Properties but without Fiber Reinforcement 

High Performance without High Weight 

Plastic compounds are becoming increasingly specialized and have to offer more and more functions simultaneously. Not only are the requirements regarding to technical characteristics getting stricter. Sustainability is steadily coming into focus as well, with bio-based or recycled material versions. 

Pushing Material Properties to the Limit, Combining Materials, and  Finding Alternative Raw Materials 

Additive

Verbände, Institutionen, Messen

Down to the Smallest Detail 

Sophisticated property profiles and additives that are tricky to handle make it difficult for raw-material producers to perform compounding themselves. A possible way around this is offered by partner companies for toll, contract, or licensed manufacturing. The provider, PolyComp, shows what raw material producers need to consider and what they should be prepared for. 

Different Contract Compounding Models and Services 

Compoundieren

Lohnfertigung

Produce In-House or Buy in? 

UV- and weathering-resistant components with a high-quality surface straight from the machine without post-finishing are in demand for automotive exterior applications. This combination of properties is only possible with targeted compound developments, as the example of a radiator grill demonstrates. 

Polypropylene Replaces Acrylonitrile-Styrene-Acrylic Ester and UV-Resistant Paint for Exterior Applications 

Polypropylen

Like Modern Ship Figureheads 

Transparent plastics are used in medical technology for disposable articles such as catheter accessories, blood/plasma separators, thorax drainage sets, and medical filter and device housings. Since they are being exposed to increasingly aggressive solvents, disinfectants and drugs (for example new cancer drugs), these plastic articles have to be comprehensively tested for their chemical resistance. 

Chemical and Environmental Stress-Crack Resistance of PMMA-Based Compounds in the Medical Environment 

Polyacrylate

Medizintechnik

Maintaining Clarity Long-Term 

The non fossil fuel-based portfolio offers same high quality and performance for applications in all industries.

Gehäuse aus Kunststoff

Elektromechanik

Kühlkörper

Polyethylen

Polystyrol

Kunststoff-Aufbereitung

Kunststoffverarbeitung: Verfahren

Standardkunststoffe

Kunststoff-Regenerate

Kunststofffasern

Verstärkungsstoffe

Kunststoff-Recycling

Borealis Launches Portfolio of Circular Polyolefins

The Danish company Plastix recycles old fishing nets and ropes. The granules produced are used by JSP International, among others, to manufacture expanded polypropylene (EPP).

Expanded Polypropylene from Maritime Plastic Waste

Schaumstoffe und Vorprodukte

Schaumstoffe

Recycling

Umweltmanagement

Polypropylen-Compound

Kunststoff-Rezyklat

From Fishing Net to Particle Foam

The central issue in all polyurethane applications is the conversion from the past linear economy into a circular economy, and the use of sustainable raw materials in manufacturing. To do so, manufacturers are taking measures such as using bio-based raw materials, chemical recycling, and CO2 as a synthesis component. Digitalization, electromobility, autonomous driving and the construction industry are also driving PU development.

Polyurethane (PU)

Bauchemie

Polyurethan-Schaumstoffe (PUR)

Halbzeuge und Zwischenprodukte

Kunststoff-Halbzeuge

Baubetrieb / Bauwirtschaft

Polyurethan

Windkraft

Energieerzeugung

Erneuerbare Energie

Sustainable Growth

Due to its high-performing properties polyetheretherketone thermoplastic polymer is being used more and more frequently in many products.

Polyetheretherketone (PEEK)

Elektronik-Fertigung

Polyetherketon

Mikroelektronik

Medizinprodukte

Delivering Efficiency Even in  Harsh Environments

Modified Conductive Compounds Make It Possible to Manufacture Bipolar Plates from a Bipolar Film Coil

Bipolar plates are one of the key components of fuel cells and redox flow batteries. They consist of plastics compounds highly filled with electrically conductive materials. To save space, cut costs, and reduce weight, there is increasing demand for the production of thinner plates without compromising robustness and service life. This can be achieved using modified polymers. With a new technology, bipolar plate films based on these modified polymers can be processed as coils.

Sustainable energy sources are of vital importance for society’s future power supply. Since wind and solar power are subject to fluctuation due to changing weather conditions, the generated energy must be held in medium or long-term buffer storage. The ideal solution for this task is provided by so-called redox flow batteries. These generally take the form of 40-ft containers which, as electrochemical converters, can store and deliver large amounts of energy. Another possibility is fuel cells that convert fuels such as hydrogen into electrical energy. This technology is becoming increasingly popular for mobile and portable applications and is already being used for trucks, cars, trains, boats, domestic energy supply (cogeneration), and independent power supply units, e. g. for data centers.

For these technologies to become established in the market, further development of bipolar plates, as the central functional elements of fuel cells and redox flow batteries is necessary. Bipolar plates are a key component of fuel cells and redox flow batteries. Conventional carbon-containing bipolar plates usually consist of thermoplastic or thermoset matrix materials with a high content of conductive fillers such as graphite, carbon black or carbon nanotubes. Although made from plastics, bipolar plates must have very good electrical and thermal conductivity. To achieve suitably high conductivity, the plastic must be filled with up to 80 or 90 wt. % conductive material. Here, the binding polymer plays a crucial role in preventing the compound from becoming brittle and ensuring optimum processability, although it only makes up 10 to 20 wt. % of the compound. For long and economical use of bipolar plates, high electrical conductivity, resistance to degradation, and mechanical stability under load are required.

Polypropylene (PP) and polyolefins in general are frequently used as the polymers for bipolar plates. But for special requirements, other materials such as polyphenylene sulphide (PPS), polyvinylidene fluoride (PVDF), and phenolic resins are also used. Although highly filled graphite bipolar plates based on PP, polyethylene (PE), PVDF, and PPS offer high durability and can be manufactured economically, users are also increasingly demanding thinner, weight-optimized components to save space, reduce weight, and cut material costs. Low thickness and high durability are very conflicting requirements for such high conductive-filler loadings and make the achievement of this goal even more challenging.

By modifying the plastics used in bipolar plates such as PP, PE, PVDF, and PPS, their mechanical properties can, at least within certain limits, be adapted to the required specification and, through impact strength improvement, for example, be made more flexible or ductile. This is essential for the manufacture of thin plates. By using special impact modifiers, Eisenhuth GmbH & Co. KG has been able to produce thin, highly filled, very conductive bipolar plate films as coils in a continuous process (Fig. 1). In this process, polyolefin block copolymers additionally containing ethylene-propylene-diene-monomer rubber (EPDM) were produced with varying graphite content.

The starting point was the production of highly filled compounds. Compounding was carried out on twin screw extruders from Collin, Leistritz, and Battenfeld. On these machines, various modified PP, PE, PVDF, and PPS compounds with a carbon content of about 80 wt. % were produced and pre-conditioned for the shaping process. The next important step comprised processing them into thin films on a suitable continuous production unit.

Modified Films Achieve the  Required Values

The average thickness of the films was well below 1mm and for the most part between 0.5 and 0.8 mm (Fig. 2).

During production, however, the film can be precisely adjusted to the specification so that the required thickness can be ensured to a tenth of a millimeter in serial production. The tensile strength of the plates produced was between 4 and 11 N/mm² (Fig. 3), which is lower than that of the reference material.

It should be remembered, however, that the measurements were not carried out on a standard test bar but on the film itself, which is only about 0.6 mm thick. Further trials to improve tensile strength are currently in progress. The electrical resistivity values of the different material types are higher than those of the reference material (Fig. 4). However, it should be borne in mind that thinner plates compensate for the somewhat poorer electrical conductivity.

The films also open up new processing options. Until now, suitable shaping methods for producing bipolar plates have been hot pressing and injection molding. In these processes, the preconditioned material is generally fed into a heated compression or injection mold. In the case of compounds with a thermoset matrix, a chemical curing reaction under heat must take place before the plate can be removed from the cavity.

With thermoplastic matrices, on the other hand, the compound must first be melted and then brought below the melting or glass transition temperature of the particular plastic before demolding. In hot pressing or injection molding, the technically challenging options consist in directly shaping the required structures or producing unstructured sheet blanks instead.

With the latest technology, graphite compound films can now be processed as coils (Title figure). In a similar way to stamping, the films are drawn down from a coil and processed by stamping/bending to produce the final structured plate (Fig. 5).

The new technology represents a further important step in automated manufacture of conductive compound films to achieve the economy of scale effect.

In this way, the overall costs of fuel cell or battery systems can be significantly reduced. The mechanical properties obtained are comparable with those of graphite-filled, pressed or injection molded bipolar plates. Electrical conductivity, too, lies within a range that is suitable for the application. In view of the current legal framework conditions specified in particular by the EU Commission, there is an ever more pressing need for action to make mobility emission-free. The films described can make an important contribution towards greater acceptance of fuel cell technology.

Eisenhuth GmbH & Co. KG  

https://www.eisenhuth.com

Ausgabenartikel

The modified polymers enable films to be processed  as coils

Fig. 1. By modifying the highly filled plastics, considerably thinner bipolar plate films can be produced than was previously the case 

Fig. 2. Film thickness of the processed compounds and comparison with reference materials (filling degrees in brackets): the thickness of the plates ranges between about 0.5 and 1 mm

Fig. 3. The tensile strength of the different films is lower than that of the reference materials. However, the reference materials are also considerably thicker (3 mm) 

Fig. 4. The electrical resistance of the compounds (filling degrees in brackets) is higher than that of the reference materials. However, this is compensated for by the lower thickness of the films

Fig. 5. Stamped graphite compound film: the bipolar plate is produced by the stamping/ bending process 

KU 6-21_Eisenhuth - Hauptartikel

 Dr. Thorsten Hickmann is CEO of Eisenhuth GmbH & Co. KG, Osterrode, Germany; <a href="mailto:t.hickmann@eisenhuth.de">t.hickmann@eisenhuth.de</a>

Dr. Thorsten Derieth works in marketing and application technology in the Fuel Cells and Batteries Department of Eisenhuth; <a href="mailto:t.derieth@eisenhuth.de">t.derieth@eisenhuth.de</a>

Read the German version of the  article in our magazine Kunststoffe or at  <a href="https://www.kunststoffe.de/a/fachartikel/duennere-bipolarplatten-fuer-brennstoffz-326015" target="_blank">www.kunststoffe.de</a>