#Research & Development

2024-01-18

Carpets - flame retardant and yet recyclable

Reactor in the polymer pilot plant of the DITF Denkendorf. Photo: DITF

Textile-based carpets with flame retardants reduce the risk of fire. Such carpets are used in large quantities in commercial buildings. However, it is difficult to recycle these materials because the carpets consist of several interconnected layers and the established flame retardants are usually ecologically problematic.

The German Institutes of Textile and Fiber Research (DITF) and the Institut für Bodensysteme (TFI) have developed a concept that reduces the amount of flame retardants in the carpet yarns - while maintaining the same high level of flame retardancy. The structure of the textile product is optimized for material recycling.

The newly designed carpet yarn is made of flame-retardant polyamide 6 (PA6) and will be fully recyclable. The PA6 has been equipped with intrinsic flame retardancy. This means that the flame-retardant chemical, in this case a phosphorus compound, is not applied to the surface of the fibers, but is chemically bound to the molecular structure of the PA6. As a result, the flame retardant is permanent and cannot be washed out or emitted into the environment. The concept of intrinsic flame retardancy is not new. It was developed at the DITF around ten years ago, but has since been optimized: The polyamides used in the current research project have been precisely adjusted in terms of their viscosity and phosphorus content. As a result, the two requirements for spinnability and high flame retardancy, which are difficult to reconcile, were fully met.

The new material is spun into fibers on a bicomponent spinning machine at the DITF pilot plant. This way, so-called bicomponent fibers are produced, which have a core of conventional polyamide and a sheath of PA6 with a highly concentrated flame retardant. On the one hand, the core and sheath components of the fibers complement each other perfectly: the fiber core ensures good technical spinnability and sufficient strength of the fibers. The sheath, on the other hand, contains the flame retardant exactly where temperature and flames attack: on the surface of the fiber. The phosphorus content of about 0.2% by weight is precisely adjusted so that the fiber sheath is not flammable. As a side effect, the yarn is cheaper to produce because the expensive flame retardant is only added to part of the fiber volume. Flame tests in DITF's own laboratories verify the flame retardant effect and help to determine the optimum level of flame retardant.

The second aspect of the research project deals with the production and recyclability of the carpet. On the one hand, this involves separating the flame-retardant top layer of the carpet from the textile backing. On the other hand, this will provide proof that the materials are fully recyclable.

Using the polymers and bico-yarns produced at the DITF, the project partner TFI is developing the carpet with a top layer of flame-retardant modified multifilament yarn and the textile backing. The backing coating is designed to allow thermal separation of the backing from the flame-retardant top layer. Hot melt adhesives are used for this purpose and their flammability is also taken into account. The TFI determines the flammability of the textile products. The separability of the top layer and the backing is verified in laboratory tests.

The research project will allow to render the production of commercial carpets more cost-effective and environmentally friendly.

Stylish design made from sustainable materials – two DITF research projects receive Techtextil Innovation Awards

Materials made from domestic, renewable raw materials reduce CO₂ emissions, prevent microplastics from entering the environment, and close the material cycle. The German Institutes for Textile and Fiber Research Denkendorf (DITF) are developing nature-based alternatives to synthetically produced and predominantly petroleum-based materials. Two research projects have received a prestigious Techtextil Innovation Award. NUO Flexholz and the lignin-coated material FormLig demonstrate that sustainable concepts can meet high standards of functionality and design. Both projects were carried out in close collaboration with 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.

Smart textiles can also be sustainable, eco-friendly and AI-powered – ITA at Techtextil 2026

Sports shoes made from algae, leggings made from mushrooms, filtering (diesel) oil from water, 4D textiles, recyclable, sustainable and featuring AI – this is what the ITA Group is presenting at three individual stands run by ITA Aachen, ITA Augsburg gGmbH and ITA Technologietransfer GmbH on the joint stand of Elmatex in hall 12.0 D05.

Hohenstein publishes 2025 Sustainability Report

The testing and research service provider Hohenstein has published its latest sustainability report, outlining key progress and strategic initiatives. The report focuses on ambitious CO₂ reduction targets, the company’s new mission statement and the systematic expansion of sustainable services for customers worldwide.

ITM presents cutting-edge textile research at Techtextil

From April 21 to 24, 2026, the Chair of Textile Machinery and High Performance Material Technology (ITM) at TUD Dresden University of Technology will be presenting its current research at Techtextil, the leading international trade fair for technical textiles and nonwovens. In Hall 12.0, Stand D41, the team will be demonstrating how it combines high-performance fibers, AI-supported digital development tools and innovative machine technologies to develop textile solutions for lightweight construction, construction, medical technology and sustainable production from atom to product.

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.

Techtextil & Texprocess 2026: Global benchmark for textile innovation – Performance Apparel Textiles takes centre stage at the opening

With 1,700 exhibitors from 54 countries, Techtextil and Texprocess 2026 showcase the full range of innovation within the international textile industry – from new materials and recycling technologies to finishing solutions and high-performance textile manufacturing and processing technologies. The opening press conference centred on a key theme where innovation is especially strong: Performance Apparel Textiles.

Circulose and CTA announce collaboration to enable lyocell fibers using CIRCULOSE® pulp

Circulose has announced an agreement with China Textile Academy Green Fibre (CTA) to offer lyocell fibers produced using CIRCULOSE® pulp. Producing lyocell from recycled pulp at commercial scale is an important step in making textile-to-textile recycled materials available across a wider range of textile applications.