#Research & Development

2023-11-02

Lignin coating makes geotextiles made from environmentally friendly natural fibers durable

Textiles are a given in civil engineering: they stabilize water protection dams, prevent runoff containing pollutants from landfills, facilitate the revegetation of slopes at risk of erosion, and even make asphalt layers of roads thinner. Until now, textiles made of highly resistant synthetic fibers have been used for this purpose, which have a very long lifetime. For some applications, however, it would not only be sufficient but even desirable for the auxiliary textile to degrade in the soil when it has done its job. Environmentally friendly natural fibers, on the other hand, often decompose too quickly. The German Institutes of Textile and Fiber Research Denkendorf (DITF) are developing a bio-based protective coating that extends their service life.

Depending on humidity and temperature, natural fiber materials can degrade in the soil in a matter of months or even a few days. In order to significantly extend the degradation time and make them suitable for geotextiles, the Denkendorf team researches a protective coating. This coating, based on lignin, is itself biodegradable and does not generate microplastics in the soil. Lignin is indeed biodegradable, but this degradation takes a very long time in nature.

Coating process of a cellulose-based nonwoven with the lignin compound using thermoplastic processing methods on a continuous coating line. Photo: DITF

Together with cellulose, Lignin forms the building materials for wood and is the "glue" in wood that holds this composite material together. In paper production, usually only the cellulose is used, so lignin is produced in large quantities as a waste material. So-called kraft lignin remains as a fusible material. Textile production can deal well with thermoplastic materials. All in all, this is a good prerequisite for taking a closer look at lignin as a protective coating for geotextiles.

Nonwoven fabric based on cellulose, coated with the lignin compound as a protective layer against degradation in the soil. Photo: DITF

Lignin is brittle by nature. Therefore, it is necessary to blend the kraft lignin with softer biomaterials. These new biopolymer compounds of brittle kraft lignin and softer biopolymers were applied to yarns and textile surfaces in the research project via adapted coating systems. For this purpose, for example, cotton yarns were coated with lignin at different application rates and evaluated. Biodegradation testing was carried out using soil burial tests both in a climatic chamber with temperature and humidity defined precisely according to the standard and outdoors under real environmental conditions. With positive results: the service life of textiles made of natural fibers can be extended by many factors with a lignin coating: The thicker the protective coating, the longer the protection lasts. In the outdoor tests, the lignin coating was still completely intact even after about 160 days of burial.

Textile materials coated with lignin enable sustainable applications. For example, they have an adjustable and sufficiently long service life for certain geotextile applications. In addition, they are still biodegradable and can replace previously used synthetic materials in some applications, such as revegetation of trench and stream banks.

Cotton yarns: with lignin coating as a protective layer against degradation in soil and reference material without coating. Photo: DITF

Thus, lignin-coated textiles have the potential to significantly reduce the carbon footprint: They reduce dependence on petroleum-based products and avoid the formation of microplastics in the soil.

Cross-section of a cotton yarn coated with lignin by extrusion process. Photo: DITF

Further research is needed to establish lignin, which was previously a waste material, as a new valuable material in industrial manufacturing processes in the textile industry.

Fabolose: Fabricating vegan and circular leather alternatives from bio-tech-derived cellulose

Fabulose is an EU funded project coordinated by the German Institutes of Textile and Fiber Research (DITF). Its consortium consists of leading research institutes, biotech innovators, and industry stakeholders who aim to create high-performance, biobased and recyclable leather-like fabrics, using efficient biotech production routes for bacterial cellulose, cyanophycin and bacterial pigments

More safety and comfort for protective clothing thanks to auxetic fabrics

When everyday materials are pulled, they stretch or elongate in the direction of the pull and become narrower in cross-section. We can also observe this property in two-dimensional textiles. Auxetic structures behave differently here. They have the striking property of not changing under tensile stress or even increasing their width or thickness. These properties are advantageous, for example, in protective textiles or textile filter media. The DITF are researching auxetic fabrics for various applications.

Panty liners prevent bacterial vaginosis

Worldwide, almost one third of women of childbearing age suffer from bacterial vaginosis. This is when the sensitive microbiome of the vagina becomes unbalanced. Such a disorder of the vaginal flora can cause urogenital infections, abscesses on the ovaries or fallopian tubes or premature births. This significantly increases the risk of infertility in women and of contracting a sexually transmitted disease or HIV.

Fraunhofer IAP paves the way for "Green" carbon fibers

A new pilot plant in Guben is set to enable the production of bio-based carbon fibers. The plant is part of the Carbon Lab Factory Lausitz and will make an important contribution to the transformation of the Lausitz region—from a traditionally raw material- and basic industry-oriented region to a hub for innovative high-performance materials. The German federal government and the state of Brandenburg are providing the Fraunhofer Institute for Applied Polymer Research IAP with 53.3 million euros for this purpose.

Hof University develops sustainable textile coating for the fashion of tomorrow from mushrooms

Clothing is often treated as disposable: T-shirts for events, general merchandise, or short-term campaigns frequently end up in the trash after only a few uses. This is particularly problematic given that their production still largely relies on fossil-based materials. This is precisely where a new research project at Hof University of Applied Sciences comes in.

Textilfabrik 7.0 launched: Mönchengladbach becomes a real-world lab for sustainable textile production

With the official kick-off event of the Textilfabrik 7.0 (T7), a major transformation project for the German textile and apparel industry has been launched in the Monforts Quarter in Mönchengladbach. At the “Textile Roundtable,” an event format organized by the Zukunftsagentur Rheinisches Revier, representatives from industry, research, politics, and the regional economy came together to jointly lay the foundation for CO₂-neutral, circular, and economically viable textile production in Germany.

STFI presents concepts for the textile circular economy and solutions for a healthy and safe life at Techtextil

Sächsisches Textilforschungsinstitut e.V. (STFI) has been supporting companies in developing marketable innovations for over 30 years. With a clear focus on sustainability, the environment, health and protection, the STFI offers future-oriented research, textile testing for tailor-made solutions and certification of per- sonal protective equipment. At Techtextil 2026, the institute will present ideas for the textile circular econ- omy and showcase solutions for healthy and safe living.

VANDEWIELE Group at Techtextil 2026 – Textile innovations together

The VANDEWIELEGroup will showcase its latest technologies for technical textiles at Techtextil 2026 in Frankfurt from April 21–24 (Hall 12.0, Stand C21). As a global leader in textile machinery, the group brings together specialised brands to support the evolving demands of high-performance textile applications. Visitors will discover solutions in laboratory testing, yarn joining, yarn feeding and thread tension monitoring, designed to create measurable value across the textile value chain.

LineONE – Smart performance, smart investment at Techtextil 2026

At Techtextil 2026 in Frankfurt (April 21–24, Hall 12, Booth C79), AUTEFA Solutions will present its LineONE concepts for cost-efficient nonwoven production. As a full-line supplier for nonwoven production lines, AUTEFA Solutions covers the entire process chain – from fibre opening through to web bonding. With its LineONE line concepts, the company combines proven technologies into well-balanced, cost-efficient turnkey solutions. These concepts are designed for capacity expansions, modernisation projects and new production lines, offering robust design and high flexibility for applications such as filtration, geotextiles and automotive.