The fashion industry is one of the biggest industries that contribute to global waste, with just 1 per cent of clothing recycled post-use. Most of the time these mixed textiles are incinerated, or worse – end up in landfills.
Fortunately, researchers from the US have found a process that can break down mixed textiles without the need for sorting or separation.
“We need a better way to recycle modern, complex garments because we are never going to stop buying clothes,” says Erha Andini, a chemical engineer at the University of Delaware and lead author of a new study published in Science Advances. “We are looking to create a closed-loop system for textile recycling.”
Recycling used fabric is usually challenging because of its composition, which is a blend of natural and synthetic fibres. These mixed fibres are difficult to separate, complicating the recycling process that usually requires textiles to be of the same material.
To address this, Andini and her team developed a process that uses a solvent to break the chemical bonds in polyester while leaving cotton and nylon intact.
This process is powered by microwave energy and enhanced with a zinc oxide catalyst, which speeds up the breakdown time to just 15 minutes – significantly faster than traditional plastic recycling methods, which can take over an hour.
Afterwards, the polyester is ultimately broken down into BHET, an organic compound that can be reconstituted into polyester, making this the first method capable of recycling mixed-fiber textiles without any prior sorting.
In addition to its speed, the use of microwave energy also reduces the carbon footprint of the process by consuming less power.
“We think of this process as a whole,” Andini explains. “Hopefully, once we are able to get pure components from each part, we can transform them back into yarn and make clothes again.”
However, the path to scaling this process is not as easy as it sounds.
Bryan Vogt, a chemical engineer at Penn State University who was not involved in the study, points out that the solvent used to break down polyester is both expensive and difficult to recover after use.
Moreover, while BHET can be easily converted back into polyester, the fate of the leftover fibres, particularly nylon, remains uncertain. The chemical recycling technique significantly degrades nylon, making it harder to reuse.
Despite these challenges, Andini remains optimistic and is now working on a business model to commercialise this recycling process.
“It’ll be a matter of having the capital or not,” she concluded, “But we’re working on it and excited about it.”
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