Stretch fabric is nearly impossible to recycle—but this startup just made it simple

Stretch fabrics are notoriously hard to process. When your old leggings wear out, they will probably end up in a landfill—even if you try to drop them off for recycling. But a Manhattan startup has developed a new material that could finally make this corner of the apparel industry circular.

“There’s a reason why billions of pounds of textiles ends up in landfills,” says Gangadhar Jogikalmath, cofounder and chief technology officer of the startup, called Return to Vendor. “When we dial it down to the microscopic scale, it’s because everything that we wear has blends of yarn put together to create this apparel— nylon blended with spandex, wool with nylon, cotton, polyester.”

Any fabric blend is hard to disassemble, and stretch fabric is especially challenging. “You can’t shred it,” says Jogikalmath. “The spandex melts at a lower temperature, gums up the recycling machinery, and your recycling system really suffers from having even a small amount of spandex in it.”

To tackle the challenge, the startup has spent the last four years designing fabric that uses a single material—nylon—and transforms it so that a material with fibers that normally wouldn’t stretch suddenly can. Then, at the end of its life, since it’s a “mono material,” it can easily be recycled and turned into new fabric for new clothing.

Making stretch fabric from a single material

Jogikalmath, who started his career as a protein chemist, took inspiration from the way that proteins are structured. Normally, nylon has tight hydrogen bonds that make the material stiff and resistant to stretching. Using a protein-inspired approach, the startup re-formulated the structure so that the molecules can slide past each other under stress and then spring back when the stress is released.

After making a proof of concept and raising a seed round of funding from Khosla Ventures, the team went through years of R&D. This year, it worked with a mill that specializes in stretch fabric to make samples of the final material. “They were equally as excited with the results,” says CEO and cofounder William Calvert. “And now we’re putting it through the paces where it can be commercialized.”

With the use of the startup’s chemistry, the material can be made in any mill that makes nylon yarn, not just those that specialize in stretch. After the yarn is made, it can be made into fabric without adding any new machinery or process changes, meaning that it could easily scale up, unlike some other novel materials.

The material is made from recycled nylon—turning old fishing nets or carpet into new fiber—and is already at cost parity with virgin nylon. But the cost will keep going down the more it’s recycled; as brands collect their old clothing for recycling, the next generation feedstock will cost even less.

There’s strong demand across multiple categories, says Calvert, from athleisure to intimate apparel and outdoor wear. Brands are now beginning to test it in pilots. “When I put it on LinkedIn, the brands started calling,” says Jogikalmath.

A bigger vision for circularity

To ensure that final garments are fully recyclable, the company has also redesigned smaller components like zippers and buttons so they’re also made from 100% nylon. (One designer, Willy Chavarria, has already worked with the startup to use some of these materials to make baseball hats, swim trunks, and eyewear.)

The startup’s basic approach for stretch fabric—tweaking nylon so that the material has new characteristics—can also be used in applications outside apparel. The company is currently working with a large motorcycle brand to make new injection molded parts, for example.

The company will work with brands to get back the clothing that’s made with its material at the end of life. Brands can include a label so customers know that the garment or other product is fully recyclable. “We want to be the ‘Intel Inside’ of circularity,” says Jogikalmath.

In the fashion world, where brands are continually looking for new ways to cut their carbon footprints, the stretch fabric has the potentially to quickly scale. “When you have a huge carbon savings, when it’s recycled, it’s recyclable, and it comes in at cost and performance parity, why wouldn’t they adopt it?” says cofounder and chief recycling officer Adam Baruchowitz. “It’s a complete win for them, and for everyone: for the brand, for the customer, for the planet.”