UNIFI’s Fashion Waste-Slashing Playbook

Fiber manufacturer UNIFI is trying to change polyester’s narrative through a process that makes the fiber from 100% recycled content.  The company has transformed more than 35B plastic bottles to go into its polyester, branded as REPREVE, not only for fashion, but for home furnishings, automotive interiors, and other products.

Arlene Karidis, Freelance writer

December 20, 2023

5 Min Read
Zoonar GmbH / Alamy Stock Photo

The fashion industry is devouring natural resources and taking its toll on landfills and the environment. One of the top water-consuming industries, and responsible for about 10% of the world’s greenhouse gases, most of its wares end up buried or burned— about 87% of it according to the most recent industry accounts. And the material piles up fast. If today’s consumption patterns continue, apparel makers will crank out 102M metric tons of material a year by 2029—up from 62M metric tons in 2019— projects the Ellen MacArthur Foundation.

More than half of garments are made of synthetic polyester. It’s durable and fairly inexpensive, but this petroleum-based material is among the least environmentally friendly fabrics to make, emitting both tremendous volumes of greenhouse gases and air pollution.

Fiber manufacturer UNIFI is trying to change polyester’s narrative through a process that makes the fiber from 100% recycled content.  The company has transformed more than 35B plastic bottles to go into its polyester, branded as REPREVE, not only for fashion, but for home furnishings, automotive interiors, and other products. The team aims to recycle more than 50B bottles by 2025 while also working fabric scraps into its yarn, which come from UNIFI’s production process and that of other manufacturers.

The proprietary technology works for a broad range of yarn products, which has been key to the company’s growth, says Meredith Boyd, UNIFI's senior vice president of Sustainability, Technology & Innovation.

“There are thousands of variants of yarn required to make different textiles. Our process enables us to engineer products to each manufacturer’s specs with the right attributes while replacing the virgin equivalent because the aesthetic or functional properties are not compromised,” Boyd says.

Two core polyester products are multifilament yarn and a staple fiber.

The multifilament goes into applications like activewear designed to have functional features such as evaporative cooling and antimicrobial performance. Staple fiber is created through a different process enabling it to be made into a spun yarn or blended with other materials, which opens it up to more applications.

A third product is resin made from the bottles UNIFI collects, which go through a multistep process to ultimately be spun into fiber.

Boyd describes the recycling technology as a textile-to-textile thermochemical process whereby solid waste is heated to a liquid, then solidified again, which is key to maintaining the material’s physical properties.

Unlike chemical recycling that leverages gasification or pyrolysis, the material is not broken down to monomers then rebuilt.

“Our process is less energy intensive than gasification. We don’t need to add chemicals to transform the waste. We just use heat. We are minimizing the usage of auxiliary materials and resources as much as we can. This allows for an environmentally mindful, fairly fast process,” Boyd says.

Recycling polyester is not a new concept. Textile processors have been doing it since the 1990s. But the end product had compromised physical properties, so adoption was slow.

“In 2007 we asked, how can we create a product equal to virgin materials so brands can change to a less environmentally intrusive polyester, but with properties they need to deliver on performance and aesthetics?” Boyd said.

The first companies to run with REPREVE were outdoor apparel manufacturers who found that it performed as they would expect.

The word got out, and this new concept began gaining credibility among other apparel brands and industries who were watching and waiting for that test.

Among industry knowns who have since bought into REPREVE are Guess, Patagonia, Speedo, and Gold Toe. Outside of the apparel space the technology is found in sofas, phone cases, and even concrete reinforcement.

A peer-reviewed cradle to gate life cycle analysis found that REPREVE recycled polyester reduces:

  • greenhouse gas emissions by up to 42% relative to virgin filament yarn and by 60% compared to virgin staple fiber;

  • fossil fuels depletion by up to 66% relative to virgin filament yarn and by 76% compared to virgin staple fiber; and

  • freshwater consumption by up to 67% compared to virgin filament yarn.

Nonetheless, some of the machinery required to make yarn, whether from recycled or virgin materials, eats up a fair amount of energy. Equipment manufacturer Oerlikon has been working to lessen that footprint—with UNIFI’s help.

The project entailed upgrading Oerlikon’s texturing machinery to run faster, with more production efficiency, and at up to 25% energy savings.

“UNIFI helped to educate Oerlikon on the complexities of the raw materials, the many yarn variants, properties, and impact of end uses,” says André Wissenberg, vice president, head of Marketing, Corporate Communications and Public Affairs for Oerlikon’s Polymer Processing Solutions division.

Proving it worked across all UNIFI products was a true test and a complex process spanning over two years.

“Through this partnership, Oerlikon was able to ultimately optimize the process reliability and carry out design updates to align the new system to the industrial environment. We knew that if UNIFI approved this machine for their markets and products, it would work for everyone,” Wissenberg says.

As more consumers start to question the environmental ramifications of the products they buy, brands are looking to invest in technologies with a sustainability story to tell. And they want to know the story they were told and share with customers is legitimate.

In answer, UNIFI created a proprietary technology to confirm REPREVE is actually making its way into the final product. The company does not share details about how it works beyond that it’s a physical tracer technology that tracks resin, yarn, and fibers through the article’s life.

It’s proving useful to brands that need and want that level of visibility and validation, Boyd says.

Aiming high for sustainability is the goal. Transparency is a part of that, she says.

About the Author(s)

Arlene Karidis

Freelance writer, Waste360

Arlene Karidis has 30 years’ cumulative experience reporting on health and environmental topics for B2B and consumer publications of a global, national and/or regional reach, including Waste360, Washington Post, The Atlantic, Huffington Post, Baltimore Sun and lifestyle and parenting magazines. In between her assignments, Arlene does yoga, Pilates, takes long walks, and works her body in other ways that won’t bang up her somewhat challenged knees; drinks wine;  hangs with her family and other good friends and on really slow weekends, entertains herself watching her cat get happy on catnip and play with new toys.

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