The end-of-life management of textiles is more and more focus of public discussion. The amount of textiles that need to be recycled is constantly increasing. But the process is complicated by the fact that the majority of textiles produced by the industry consist of two or more types of fibers that are unsuitable for recycling. Available technologies are only suitable for fabrics made from a single fibre material. Austrian researchers have looked at the so called enzymatic hydrolysis as a way to manage mixed textiles, namely textiles made of polyester and cotton.
"The concept is based on removing cotton from the textile blend and providing a pure PET fraction feasible for a recycling process", researchers around Andreas Bartl of the Technical University of Vienna say. "The present study demonstrates that it is possible to recycle mixed textiles made of polyester and cotton, the most important fibre types in terms of quantity by far, by means of enzymatic hydrolysis. The process enables the treatment of one of the most popular fibre mixtures on the market whereat pure PET and glucose are obtained. The PET fibres obtained in this way can be used as feedstock to produce new textiles with state-of-the-art technologies."
The process described by Bartl and his colleagues has not yet been realized on an industrial scale. The second limitation of the presented results is, according to the authors, the fact that the use of the obtained glucose has not been addressed yet.
"Finally, it must be admitted that the process of enzymatic hydrolysis shown is a method of symptom control. In the sense of the circular economy, it is necessary to bring together all stakeholders. Design for recycling should have the effect that, for example, certain material combinations, pigments or finishes are avoided if they make recycling difficult or impossible. Last but not least, it is absolutely essential to replace the fast fashion business model by more sustainable concepts and to significantly reduce the volume of EOL textiles", the researchers say.
The study was published in the Special Issue for the ISWA Conference of Waste Management & Research and is publicly available till the end of October.