From the Sector

The DITF is leading the joint project "DACCUS-Pre*". The basic idea of the project is to develop a new building material that stores carbon in the long term and removes more CO₂ from the atmosphere than is emitted during its production.       

In collaboration with the company TechnoCarbon Technologies, the project is now well advanced - a first demonstrator in the form of a house wall element has been realized. It consists of three materials: Natural stone, carbon fibers and biochar. Each component contributes in a different way to the negative CO₂ balance of the material:

Two slabs of natural stone form the exposed walls of the wall element. The mechanical processing of the material, i.e. sawing in stone cutting machines, produces significant quantities of stone dust. This is very reactive due to its large specific surface area. Silicate weathering of the rock dust permanently binds a large amount of CO₂ from the atmosphere.

Carbon fibers in the form of technical fabrics reinforce the side walls of the wall elements. They absorb tensile forces and are intended to stabilize the building material in the same way as reinforcing steel in concrete. The carbon fibers used are bio-based, produced from biomass. Lignin-based carbon fibers, which have long been technically optimized at DITF Denkendorf, are particularly suitable for this application: They are inexpensive due to low raw material costs and have a high carbon yield. In addition, unlike reinforcing steel, they are not susceptible to oxidation and therefore last much longer. Although carbon fibers are more energy-intensive to produce than steel, as used in reinforced concrete, only a small amount is needed for use in building materials. As a result, the energy and CO₂ balance is much better than for reinforced concrete. By using solar heat and biomass to produce the carbon fibers and the weathering of the stone dust, the CO₂ balance of the new building material is actually negative, making it possible to construct CO₂-negative buildings.

The third component of the new building material is biochar. This is used as a filler between the two rock slabs. The char acts as an effective insulating material. It is also a permanent source of CO₂ storage, which plays a significant role in the CO₂ balance of the entire wall element.

From a technical point of view, the already realized demonstrator, a wall element for structural engineering, is well developed. The natural stone used is a gabbro from India, which has a high-quality appearance and is suitable for high loads. This has been proven in load tests.  Bio-based carbon fibers serve as the top layer of the stone slabs. The biochar from Convoris GmbH is characterized by particularly good thermal insulation values.

The CO₂ balance of a house wall made of the new material has been calculated and compared with that of conventional reinforced concrete. This results in a difference in the CO₂ balance of 157 CO₂ equivalents per square meter of house wall. A significant saving!

* (Methods for removing atmospheric carbon dioxide (Carbon Dioxide Removal) by Direct Air Carbon Capture, Utilization and Sustainable Storage after Use (DACCUS).

Since inventing the first fleece crafted from recycled plastic water bottles more than three decades ago, Polartec®, a Milliken & Company brand, and the creator of innovative and more sustainable textile solutions, has upheld its pledge to protect the environment.

With its new Beyond Begins Today initiative, Polartec aims to raise awareness around the important global themes of sustainability, diversity and positive change.

Polartec is engaged to make the goal of zero waste a reality – from using 100% recycled and plant-based materials, to delivering certified waste reductions and innovative technologies that reduce the impact of its activities.

Beyond Begins Today is a multifaceted campaign featuring static and multimedia content, including short films released throughout the year via multiple touchpoints and channels – the first of which will be released on Earth Day 2024 to underscore the underlying premise that the future is what we make it. Polartec’s commitment to sustainable solutions go beyond the integration of increasingly advanced manufacturing methods or the ongoing exploration of novel fibers, and continued investments in sustainable materials development.

Polartec’s promises that every product launches in 2024 will either reduce the impact on the planet, endure the test of time, or contribute to circularity processes. Beyond Begins Today looks at how Polartec fabrics are made to last, and made to be used and enjoyed from one generation to the next and beyond. It explores the innovative monomaterials, repurposed plastic and plant-based nylon membranes and fabrics that Polartec uses to set new standards for high performance materials and the ambitious climate-related objectives across the entire value chain that exceed existing mandates. This holistic strategy shall allow Polartec to stay at the forefront of its industry by producing top-notch textiles that champion environmental stewardship and pave the way for a more sustainable tomorrow.

The 17th World-Pultrusion-Conference (WPC) took place in Hamburg from 29 February to 1 March. Pultrusion, also known as the extrusion process, is a highly efficient method for producing fibre-reinforced plastic profiles for various applications in the construction/infrastructure and transport sectors.

A record number of almost 150 participants from all over the world attended the event. An international audience of experts from Europe and the USA, as well as China, India and Japan was represented.

The lecture programme with a total of 25 specialist lectures was strongly characterised by the topic of sustainability. The process development of thermoplastic pultrusion and applications in wind energy, solar panels, bridge construction and the automotive industry were also discussed at length. Despite the difficult market environment, many opportunities and possibilities for the pultrusion industry were presented.

The conference takes place every two years in a European country of importance to the pultrusion industry and is organised by AVK for the European Pultrusion Technology Association (EPTA), in cooperation with the American Composites Manufacturers Association (ACMA).

The German Institutes of Textile and Fiber Research Denkendorf (DITF) have modernized and expanded their melt spinning pilot plant with support from the State of Baden-Württemberg. The new facility enables research into new spinning processes, fiber functionalization and sustainable fibers made from biodegradable and bio-based polymers.

In the field of melt spinning, the DITF are working on several pioneering research areas, for example the development of various fibers for medical implants or fibers made from polylactide, a sustainable bio-based polyester. Other focal points include the development of flame-retardant polyamides and their processing into fibers for carpet and automotive applications as well as the development of carbon fibers from melt-spun precursors. The development of a bio-based alternative to petroleum-based polyethylene terephthalate (PET) fibers into polyethylene furanoate (PEF) fibers is also new. Bicomponent spinning technology, in which the fibers can be produced from two different components, plays a particularly important role, too.

Since polyamide (PA) and many other polymers were developed more than 85 years ago, various melt-spun fibers have revolutionized the textile world. In the field of technical textiles, they can have on a variety of functions: depending on their exact composition, they can for example be electrically conductive or luminescent. They can also show antimicrobial properties and be flame-retardant. They are suitable for lightweight construction, for medical applications or for insulating buildings.

In order to protect the environment and resources, the use of bio-based fibers will be increased in the future with a special focus on easy-to-recycle fibers. To this end, the DITF are conducting research into sustainable polyamides, polyesters and polyolefins as well as many other polymers. Many 'classic', that is, petroleum-based polymers cannot or only insufficiently be broken down into their components or recycled directly after use. An important goal of new research work is therefore to further establish systematic recycling methods to produce fibers of the highest possible quality.

For these forward-looking tasks, a bicomponent spinning plant from Oerlikon Neumag was set up and commissioned on an industrial scale at the DITF in January. The BCF process (bulk continuous filaments) allows special bundling, bulking and processing of the (multifilament) fibers. This process enables the large-scale synthesis of carpet yarns as well as staple fiber production, a unique feature in a public research institute. The system is supplemented by a so-called spinline rheometer. This allows a range of measurement-specific chemical and physical data to be recorded online and inline, which will contribute to a better understanding of fiber formation. In addition, a new compounder will be used for the development of functionalized polymers and for the energy-saving thermomechanical recycling of textile waste.

Kelheim Fibres is showcasing recent research findings at this year's Cellulose Fibres Conference (13rd-14th of March). The development, led by Dr. Ingo Bernt, Project Leader of Fibre & Application Development at Kelheim Fibres, and Dr. Thomas Harter from Graz University of Technology, provides insights into the correlation between the geometry of viscose fibres and the liquid absorption of tampons.

Kelheim Fibres has long been engaged in the functionalization of viscose fibres, including the specific adaptation of fibre cross-sections. The trilobal Galaxy® serves as an example. The current study underscores the properties of the fibre, primarily rooted in its geometry. This involves taking a closer look at the underlying mechanisms. It has been confirmed that, in contrast to the traditionally round viscose fibres and despite similar chemical compositions and mechanical properties, Galaxy® enables significantly better liquid absorption.

While the higher specific surface area of trilobal fibres already promotes improved liquid absorption, this is not the main factor accounting for the difference in absorption. Instead, the geometric shape of the fibres proves to be crucial. Trilobal fibres create and maintain a more voluminous, extensive network within the absorbent body, providing a larger volume for liquid absorption.

Dr. Ingo Bernt emphasizes, "The results of our study are not limited to tampons—any application requiring increased absorbency can benefit from the properties of our Galaxy® fibres."

The lecture "Geometry Matters: Unveiling Tampon Absorption Mechanisms" by Dr. Ingo Bernt und Dr. Thomas Harter takes place on the 14th of March at 2:50pm.

Freudenberg Performance Materials (Freudenberg) is unveiling a new 100 percent synthetic wetlaid nonwoven product line made in Germany. The new materials can be manufactured from various types of polymer-based fibers, including ultra-fine micro-fibers, and are designed for use in filtration applications as well as other industrial applications.

Customers in the filtration business can use Freudenberg’s new fully synthetic wetlaid nonwovens in both liquid and air filtration. Applications include reverse osmosis membrane support, support for nanofibers or PTFE membranes as well as oil filtration media. The new materials are suited to use in the building & construction industry or the composites industry.
For filtration applications, the new fully synthetic wetlaid nonwovens are marketed under the Filtura® brand.

Versatile and flexible manufacturing
Freudenberg’s fully synthetic wetlaid nonwovens can be made of polyester, polyolefin, polyamide and polyvinyl alcohol (PVA), using staple fibers of up to 12mm fiber length and microfibers as fine as 0.04dtex. In terms of weight, the product range spans weights of between 8g/m² and 250g/m². Freudenberg’s flexible wetlaid manufacturing line has the capability to combine various thermal and chemical bonding technologies. The materials have high precision in weight and thickness as well as a defined pore size and high porosity.

Wetlaid capabilities for various applications
In addition to its fully synthetic range, Freudenberg can also incorporate glass fibers, viscose and cellulose. General industry applications for Freudenberg wetlaid nonwovens are surfacing veils for glass-fiber reinforced plastics, compostable desiccant bags, battery separators, acoustics, heatshields, and apparel applications such as embroidery substrates.

At this year's JEC World 2024 from 5 to 7 March, KARL MAYER GROUP will be exhibiting with KARL MAYER Technical Textiles and its STOLL Business

One focus of the exhibition will be non-crimp fabrics and tapes made from bio-based yarn materials for the reinforcement of composites.

"While our business with multiaxial and spreading technology for processing conventional technical fibres such as carbon or glass continues to do well, we are seeing increasing interest in the processing of natural fibres into composites. That's why we have a new product in our trade fair luggage for the upcoming JEC World: an alpine ski in which, among other things, hemp fibre fabrics have been used," reveals Hagen Lotzmann, Vice President Sales KARL MAYER Technische Textilien.

The winter sports equipment is the result of a subsidised project. The hemp tapes for this were supplied by FUSE GmbH and processed into non-crimp fabrics on the COP MAX 5 multiaxial warp knitting machine in the KARL MAYER Technical Textiles technical centre.

The STOLL Business Unit will be focussing on thermoplastic materials. Several knit to shape parts with a textile outer surface and a hardened inner surface will be on display. The double-face products can be made from different types of yarn and do not need to be back-moulded for use as side door panels or housing shells, for example. In addition, the ready-to-use design saves on waste and yarn material.

Textiles for technical applications often derive their special function via the application of coatings. This way, textiles become, for example wind and water proof or more resistant to abrasion. Usually, petroleum-based substances such as polyacrylates or polyurethanes are used. However, these consume exhaustible resources and the materials can end up in the environment if handled improperly. Therefore, the German Institutes of Textile and Fiber Research Denkendorf (DITF) are researching materials from renewable sources that are recyclable and do not pollute the environment after use. Polymers that can be produced from bacteria are here of particular interest.

These biopolymers have the advantage that they can be produced in anything from small laboratory reactors to large production plants. The most promising biopolymers include polysaccharides, polyamides from amino acids and polyesters such as polylactic acid or polyhydroxyalkanoates (PHAs), all of which are derived from renewable raw materials. PHAs is an umbrella term for a group of biotechnologically produced polyesters. The main difference between these polyesters is the number of carbon atoms in the repeat unit. To date, they have mainly been investigated for medical applications. As PHAs products are increasingly available on the market, coatings made from PHAs may also be increasingly used in technical applications in the future.

The bacteria from which the PHAs are obtained grow with the help of carbohydrates, fats and an increased CO₂ concentration and light with suitable wavelength.

The properties of PHA can be adapted by varying the structure of the repeat unit. This makes polyhydroxyalkanoates a particularly interesting class of compounds for technical textile coatings, which has hardly been investigated to date. Due to their water-repellent properties, which stem from their molecular structure, and their stable structure, polyhydroxyalkanoates have great potential for the production of water-repellent, mechanically resilient textiles, such as those in demand in the automotive sector and for outdoor clothing.

The DITF have already carried out successful research work in this area. Coatings on cotton yarns and fabrics made of cotton, polyamide and polyester showed smooth and quite good adhesion. The PHA types for the coating were both procured on the open market and produced by the research partner Fraunhofer IGB. It was shown that the molten polymer can be applied to cotton yarns by extrusion through a coating nozzle. The molten polymer was successfully coated onto fabric using a doctor blade. The length of the molecular side chain of the PHA plays an important role in the properties of the coated textile. Although PHAs with medium-length side chains are better suited to achieving low stiffness and a good textile handle, their wash resistance is low. PHAs with short side chains are suitable for achieving high wash and abrasion resistance, but the textile handle is somewhat stiffer.

The team is currently investigating how the properties of PHAs can be changed in order to achieve the desired resistance and textile properties in equal measure. There are also plans to formulate aqueous formulations for yarn and textile finishing. This will allow much thinner coatings to be applied to textiles than is possible with molten PHAs.

Other DITF research teams are investigating whether PHAs are also suitable for the production of fibers and nonwovens.

Hermann Finckh received the JEC Composites Innovation Award in the category Equipment Machinery & Heavy Industries for the innovation MAXIMUM WEIGHT REDUCTION OF COMPOSITE TOOLS. The research team from the German Institutes of Textile and Fiber Research Denkendorf (DITF) developed a new modular cutting tool for woodworking machines, which was produced and successfully tested by the industrial partner Leitz GmbH & Co. KG.

The extremely lightweight planing tool was made from carbon fiber-reinforced plastics (CFRPs) instead of aluminum using a completely new modular construction principle. As a result, it weighs 50 percent less than conventional tools. It enables significantly higher working speed, which enables a one-and-a-half-fold increase in productivity. The development of the extreme-lightweight principle was performed by numerical simulation and every solution was virtually tested in advance. A patent application has been filed for the concept.

Haelixa, the trailblazer of physical traceability solutions, has partnered with Trudel Silk, a market leader for sustainable organic and recycled silk products. This collaboration brings traceability and transparency to silk production.

Silk is one of the finest and smoothest fabrics; the better the quality of the silk, the more luxurious it feels to the touch. To create the best quality silk, the conditions for mulberry cultivation must be up to the highest standards. A healthy micro-ecosystem in the fields translates to top-grade silk cocoon quality. At Trudel, this is the environment they have created for the vertical integration of their business. Trudel aims to succeed at every stage of the process, which can only be accomplished through the active involvement and visible cooperation of all market players. These players include farmers, reeling mills, twisting/spinning mills, weaving mills, dyeing and printing mills, and brands. They are involved in every step, from the cultivation of mulberry trees to the production of silk fabrics.

Haelixa and Trudel have collaborated to improve silk’s robust and consistent traceability. As the demand for validation of the silk value chain increases, they have partnered with groups from Italy and Asia to develop a unique solution that uses DNA markers to trace the entire supply chain of silk production. This innovative approach ensures each silk product’s ethical sourcing.

The silk fibers used in their spun silk yarns are marked with a specific DNA per farm set selected by Trudel. Throughout the supply chain, samples of yarn, fabrics, and finished products undergo testing to verify the presence of original silk fibers. Based on the reporting, the brand can trace the finished accessories or garments to Trudel.