Textination Newsline

At the world exhibition in Japan, the Thuringian research institute TITK Rudolstadt presented a polo shirt made from triple-recycled cellulose fiber. The fiber used is also TITK's innovation Lyohemp® – the first Lyocell fiber made from hemp pulp.

TITK's managing director, Benjamin Redlingshöfer, wore the polo shirt at the Expo in Osaka on June 17. During the Thuringia Country Days, he was interviewed on stage by presenter Marco Schreyl. Redlingshöfer proudly showed off his polo shirt with the “300% Recycling” print. This means that the shirt is made from a fiber that has undergone three consecutive recycling processes for the first time. And it did so so well that it could be easily processed into a fashionable polo shirt with excellent wearing comfort. “With our 300% recycled fiber, we are demonstrating that closed textile recycling loops are feasible thanks to our technology,” says Redlingshöfer. “This innovation proves that we can take recycling in the textile industry to a whole new level.” 

When textiles are recycled at all, it often involves what is known as downcycling. This means that the originally high-quality textile fibers are used to manufacture lower-quality textile products as part of material recycling. The fiber-to-fiber recycling pursued at TITK, however, aims to produce a recycled fiber from a high-quality textile fiber with the same high level of quality and the same good usage properties. But even in these recycling loops, only 20 to 40 percent of recycled materials are often mixed with a larger proportion of virgin grade material. 

“TITK has now impressively demonstrated that not only is 100 percent recycling of cellulose fibers possible, but that this process can even be used three times in a row without compromising the desired characteristics of the fiber, such as a pleasant, soft feel, a slight sheen, and very good, uniform dyeability,” says Redlingshöfer. 

Recycling process also applicable to cotton
The result is a fully-fledged, sustainable product that now sets the standard for future recycling processes in the clothing industry. This will enable the consumption of new virgin-grade fibers to be drastically reduced in the future. This outstanding innovation was achieved thanks to a further adaptation of the very robust Lyocell process established at the institute – specifically in terms of pulp extraction and pretreatment, says Redlingshöfer. “In principle, this recycling loop can also be applied to cotton fibers as the raw material.” TITK invites industry partners to work together on the further development and implementation of these technologies. 

Under the banner of the Demonstration and Innovation Center for Textile Circular Economy (DICE), which was founded at the Rudolstadt institute and is currently under construction, developments in the holistic recycling of textiles are already being driven forward. TITK researchers are now transferring findings from the Lyohemp® recycling project to so-called polycotton textiles, whereby the two material streams of synthetic and cellulosic fibers are additionally separated in order to then recombine them into a material quality suitable for fiber spinning (fiber-to-fiber recycling).

“However,” adds the institute director, “we cannot rely solely on technological solutions to absolve us of our responsibility to use our resources responsibly.” For good reason, the RRR rule often cited in the circular economy has two additional Rs before recycling: reduce and reuse – in other words, consume less and reuse more. Redlingshöfer: “Only in combination with a more conscious use of our raw materials will we be able to make a significant contribution to practical sustainability.” 

Rags and unmanageable textile waste can help with the transition to a fossil-free steel industry. This is the aim of a new innovation project from Science Park Borås at the University of Borås, where worn-out textiles will be turned into biochar.

The majority of our textile waste has historically been incinerated instead of being reused or recycled. In the textile flows, there is always low-value, tattered material that Swedish municipalities now receive many questions about: What should we do with our old socks?

Today, this type of material comes in as a fraction that overburdens the sorting systems without generating any benefit. By sorting out the worst material, converting it into biochar, and using it in industrial processes, the project hopes to create new types of raw material for the steel industry.

"The project aims to make use of 'the worst material' and combines technical innovation with policy development to circulate material between industries," said Birgitta Losman, project manager at the University of Borås.

Connecting industries
The project was initiated by actors from the Swedish textile and steel industry jointly, and involves parties throughout the whole value chain:

• The municipal company Borås Energi & Miljö will sort out about 100 kg of rags from its pilot plant for textile sorting in Borås.
• The material is then sent to the Research Institute of Sweden’s (RISE) test and demo environment in Piteå, where the textile waste is converted into biochar through so-called slow pyrolysis (in pyrolysis, the organic material is broken down in an inert atmosphere at temperatures around 500–800 °C.)
• The product – biochar – is delivered to the metal powder manufacturer Höganäs AB, where it is evaluated as a possible reducing agent to produce sponge iron. Biochar is an important part of the company's work to phase out fossil raw materials.
• Fashion company Kappahl is the initiator of the project and contributes material knowledge as the initial producer in the value chain.

"For us as a brand, this is an important innovation project to ensure that the upcoming extended producer responsibility (EPR) for textiles creates environmental benefits," said Sandra Roos, Vice President of Sustainability at Kappahl Group.

Biochar replaces fossil materials
According to the Swedish Environmental Research Institute (IVL), about 3 million tonnes of fossil coal are used in Sweden every year, of which about 70 percent goes to iron and steel production. Finding new raw materials based on waste streams for sustainable production of biochar is an opportunity to both create great climate benefits and improve resource utilisation in society while also increasing the availability of biochar at an attractive price, according to Pontus Hydén, Technical Expert at Höganäs AB.

"This project is exciting as it creates collaboration between two industries that normally do not have much exchange of material streams," said Pontus Hydén.

At RISE in Piteå, there are flexible test beds for the pyrolysis process that will transform the waste textile into biochar.

"In the project, we contribute to the circular transition by converting textile waste into usable products," said Ann-Christine Johansson, researcher at RISE.

Will help municipalities – and residents
Science Park Borås will coordinate the project and contribute with policy development at local and national level for material circulation. The project is also linked to the University of Borås's national work with the government assignment Textile & Fashion 2030 and the innovation project System Demonstrator for a Sustainable Textile System.

"We hope that the project will give us experience and knowledge in both technical innovation and policy issues, which in the long run will support the municipalities in their task of collecting and circulating textile waste," said Birgitta Losman.

At Borås Energi & Miljö, which recently started up its pilot plant for textile sorting in Borås, they hope above all to be able to give residents an answer to their eternal question.

"Everyone is wondering what to do with their old socks – soon we may be able to tell them to sort them correctly so that they can become steel," said Felicia Fernstedt at Borås Energi & Miljö.

About the project
The project "Old socks become biochar in the steel industry" at Science Park Borås at the University of Borås intends to carry out real-world tests to highlight how Sweden’s recently implemented regulation on municipal responsibility for textile waste collection can be used in combination with groundbreaking technology. This technology means that waste textiles are converted into biochar through pyrolysis for the steel industry's needs. This provides context for the broader regulatory environment, which is currently undergoing rapid change.

The project runs from April 2025 to April 2026 and is funded by Vinnova.