On average, T-shirts, blouses and sweaters are given away to charity after just three years. Approximately 113.8 million tonnes of textile fibres, 87.6 million tonnes of which were chemical fibres, were produced globally in 2022 according to the Federal Statistical Office of Germany. To date, however, it has been difficult to recycle used textiles. This is where the TexKreis project led by Prof. Dr.-Ing. Hans-Josef Endres at Leibniz University Hannover’s Institute of Plastics and Circular Economy comes in. The project aims to produce high-quality and ecologically sustainable plastic recyclates from textiles and textile composites. The German Federal Environmental Foundation has provided the project with approximately 160,000 euros in funding.
Given the increasing production of clothing – particularly as a result of fast fashion – the associated resource use and the resulting waste, the research team aims to identify solutions to address both the environmental issues and the stricter legal regulations in various branches. The mechanical recycling of textiles could be a sustainable solution, as this method makes it possible to process large amounts of material for further use with a minimum of logistical effort. The challenges involved are the limited technological possibilities to date and the frequently poor quality of the resulting recyclates.
In order to innovate this recycling process, the TexKreis project is focusing particularly on the treatment processes, so that high-quality and ecologically sustainable plastic recyclates with characteristics optimised specifically for their further use can be produced from textiles and textile composites.
In general, mechanical recycling processes use significantly less energy and resources. The principle is simple and also applies to other materials that require recycling: The first step is to shred and purify the plastic waste. The resulting material is then melted in an extruder at high pressure and high temperatures, cleaned further, enhanced through the addition of additional materials where necessary, and ultimately processed into a type of granulate. This recyclate – fine grains of plastic – then forms the basis for new components that can be reused elsewhere. As part of this process, thermoplastic textile wastes consisting of mixed polyurethane/polyester (TPU/PES) fabrics and pure polyamide (PA) and PES fabrics are a particular focus, with the aim of developing a suitable, economically feasible and sustainable recycling technology.
In addition to recycling, the transport distances should be kept to a minimum. This functions best if it is known exactly which materials need to be recycled, how these are composed, where they occur and where there is subsequently demand for this recyclate. For this reason, the IKK is cooperating with Vaude and Gerry Weber as part of the TexKreis project. It is clear which materials both producers’ textiles are composed of, which makes for a good starting point in the case of offcuts and production waste.
The process is more difficult for second-hand clothing, as many different types of materials, which are in some cases also dirty, are frequently disposed of together. “At our institute we are looking at those textiles that are frequently made up of plastic fibres such as plastics or plastic composites, as listed on the clothing labels,” said Prof. Dr.-Ing. Hans-Josef Endres. “This is why here, too, the following applies: the purer the materials are when we get them, in this case the textile waste from our industry partners, the more effectively they can be recycled and reused.” In future, textiles could then be made into plastics for the production of new textile fibres or into plastic components for new branches such as the auto, furniture or leisure industries or for transport technology.
The project is being carried out in close cooperation with companies from various branches. They include Barlog Plastics, EREMA, Gross+Froelich and forbo. TecPart (Association for Technical Plastic Products) and AFBW (Baden-Württemberg Alliance for Textile Based Materials) are conducting the knowledge and technology transfer process. The overarching goal is the development of effective and sustainable recycling processes that are also transferable to other input streams for textile material composites.
Note to editors:
For further information, please contact Prof. Dr.-Ing. Hans-Josef Endres, head of the Institute of Plastics and Circular Economy at Leibniz University Hannover (tel. +49 511 762 13302, email: endres@ikk.uni-hannover.de).
