Shoes made from plastic are no longer a novelty or the object of fashion ridicule. As sustainability has attracted greater attention over the past few years, the footwear industry has responded and there are now various eco-friendly options on the market (Allbirds is one such example). Yet beyond the store shelves, there is a wave of innovation upgrading recycled plastic from a polyester replacement into multipurpose technologies.

Repreve, a brand of fibers made from recycled materials, was originally developed by Unifi as a way for the company to recycle its own fiber waste. Now, it counts 14 individual performance technologies that range from temperature control to stretch and easy-clean. All fibers are designed to seamlessly replace, if not improve upon, standard polyester while repurposing the billions of plastic bottles that go into landfill every year.

“The great thing about Repreve is that it’s versatile,” said Chad Bolick, vice president for brand sales at Unifi Manufacturing, Inc. “In terms of footwear, it can be used in liners, laces and uppers — basically any part of the shoe where polyester is used.”

Plastic bottles can be turned into fabric by being chopped into bottle flake, which is melted first into chip and then melted again and extruded into a fiber. Companies like Rothy’s, Nike and Adidas have all launched products using these fibers, demonstrating that the textiles are able to compete with traditional non-recycled fabrics. Adidas intends to use recycled plastic in all of its products by 2020.

This makes the emergence of newly enhanced fibers more important than ever, for all areas of the footwear industry. For use in activewear, Repreve’s TruResistH₂O fiber is designed to minimize water absorption and speed up drying time, resulting in a yarn that is water resistant on its own but that also combines well with other finishes. On the fashion side, the TruEcoDye textile ensures strong inherent color while using less energy and water than most commercial dyeing.

Previous concerns about sustainable footwear have included the aesthetic sacrifices made in order to keep the product fully eco-friendly, and the potentially weaker performance qualities of recycled fabrics. After all, brands want to produce the best shoes for their customers. Companies like Parley Ocean Plastics and Repreve are hoping to combat any industry reluctance through consistently revising and improving the quality of their fibers.

“Thirty-three percent of consumers actively seek out and purchase from brands they know to be socially and environmentally responsible,” said Bolick. “We feel that people will make a more conscious effort to recycle when they realize that a bottle can become their shirt, their shoe, a part of their car, or the hat on their head.”

Repreve has recycled more than 13.75 billion bottles to date and aims to reach 20 billion by 2020.

Want more?

7 Men’s Sneakers That Are Leading the Sustainability Movement

Sustainability Helped Allbirds Take Flight in 2018

These Eco-Friendly Shoes Are Made With Recycled Plastic Bottles