03/12/2026

New high-tech fabric made from old functional clothing: TheKey research project reaches its first milestone

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Polyester-cotton blends are standard in protective, work and sports clothing thanks to their functional advantages. However, recycling them remains difficult: mechanical processes reduce quality and allow only limited reuse, while chemical methods often result in material loss. Better solutions are needed here to advance the circular economy. The ‘TheKey’ project, funded by the Federal Ministry of Research, Technology and Space, has set itself no less a task than finding such a solution. It has now reached its first milestone:

Under industrial conditions, the original components terephthalic acid (TA) and ethylene glycol (EG) can be recovered from polyester-containing waste. Their quality meets applicable industry standards and is suitable for the production of new polyester.

‘This has enabled us to lay the foundation for producing high-quality PET fibres from used textiles,’ explains project manager Dr Diana Wolf, Research & Development in Environmental and Process Engineering at project partner Mewa. This is made possible by a process developed further in the project. The current focus is on the robustness and reproducibility of the process and on optimising the quantity recovered. The next steps in the project will now be dedicated to transferring the process to a continuous process.

An interdisciplinary team on the way to a solution
Eight project partners with different areas of expertise, ranging from chemical process engineering to textile technology and materials science, have joined forces for ‘TheKey’. ‘We work as a team, each of us contributing our specialist knowledge. This allows us to look at the project from unconventional perspectives,’ emphasises Diana Wolf. The following institutes and companies are involved: Mewa Textil-Service, JAKO AG, matterr, the Research Institute for Textiles and Clothing at the Niederrhein University of Applied Sciences, the Institute for Chemical and Thermal Process Engineering at the Technical University of Braunschweig, the ifeu – Institute for Energy and Environmental Research Heidelberg, Klopman and Hero-Textil.

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