Why Clothes Are So Hard to Recycle and How Scientists Plan to Reduce Fashion Waste

University of Delaware researchers are propose a new recycling technique that breaks down blended fabrics using chemicals and microwaves. Researchers say the process takes 15 minutes and can dissolve any blend of cotton, polyester, nylon and spandex into molecules that can be used to make new fabrics or products such as dyes, electronics and tires.

Catch-all recycling techniques like this could be a last line of defense to keep clothes out of landfills, says Tasha Lewis, a clinical associate professor of fashion and retail studies at Ohio State University. There are other, simpler, and less expensive solutions to fashion waste: People can buy secondhand clothes and make their wardrobes last longer. Companies can make clothes more durable and make them from a single material so they’re easier to recycle. Used textiles can be cut up and used as insulation in buildings.

But when there are no other options, chemical recycling could save the day. It would be the last step for leftovers that simply have no other use, Lewis said.

The state of textile recycling

The need to recycle clothing is becoming increasingly urgent with the rise of fast fashion, a business model in which retailers quickly produce cheap, flimsy clothing to keep up with ever-changing fashion trends. The world is now throwing away 92 million tons of clothing per year and only about one eighth is recycledaccording to an analysis by the Ellen MacArthur Foundation, a nonprofit organization focused on recycling. The rest ends up in landfills or incinerators where it pollutes the air and water.

Most recycled clothing is upcycled, meaning it is shredded into a lower-value material that is used for things like stuffing or insulation. Less than 1 percent of all clothing is transformed into a new garment, according to the Ellen MacArthur Foundation.

This rare form of recycling is central to many environmentalists and fashion designers' vision of a future where most clothing will be made from recycled materials and the same fibers can be used again and again in new garments.

Ideally, if we recycled all textile waste, we would have enough materials to last forever and would not need to produce new materials, said Miriam Ribul, a senior researcher in materials circularity at the Royal College of Art in London.

Today, this process takes place in a small number of facilities that take old fabrics and transform them into new fibers and yarns. Just as glass and metal can be melted and reshaped to create new products, synthetic fabrics like polyester can be melted into plastic pellets and spun into fibers. And just as paper can be turned into pulp and rolled into new sheets, natural fibers like cotton can be shredded and spun into new yarns.

Most of these mills focus on a single type of material, such as cotton or polyester, and some have difficulty finding companies willing to buy their recycled yarns, which are often of lower quality than new fabrics. Renewcell, a Swedish startup that opened a factory to turn old cotton into new rayon in 2022, filed for bankruptcy in February.

What about blended fabrics?

The challenge is even greater for blended fabrics that must be separated before they can be recycled. The fashion industry isn’t always transparent about what’s in its clothes, said Erha Andini, lead author of the University of Delaware study on recycling blended textiles. It’s common for retailers to incorporate a little spandex or nylon into modern clothing to make it stretchier and fit better, but they don’t always list it on the label. Companies also rarely list the dyes and finishes they add to fabrics to make them wrinkle-resistant or waterproof.

To deal with complex garments made of mysterious materials, Andini and his colleagues have developed a chemical recycling process that reduces fabrics to their molecules. Using microwaves and chemical solvents, the researchers can break the bonds that hold synthetic fibers together, leaving behind the basic molecules used to make polyester, nylon and spandex, as well as the cotton fibers intact. The molecules can be turned into fibers for clothing or used to make other products such as seat belts and airbags.

Unlike existing recycling methods, the researchers can use this technique even if they don't know exactly what's in a garment. But they've only demonstrated it in the lab. They estimate it could take a decade or more for companies to turn the idea into a profitable business.

In the meantime, experts say the fashion industry should also consider other ways to reduce waste, such as making clothes from a single material so they are easier to recycle and making fewer garments in the first place.

“We can’t just recycle our clothes to solve this problem,” says Sophie Scanlon, a textiles specialist at WRAP, a British waste management non-profit. “We really need to address the fundamental problem: why are we producing and consuming more and more clothes?”