A VISIT TO one of Unifi’s last remaining US polyester plants, in Yadkinville, North Carolina, can make you feel like an optimist.

After driving through a sweet little neighborhood of small homes, you crest the hill and see the Unifi facility on your right: giant silver-gray buildings perched on a tidy, gently rolling lawn that looks like an advertisement for organic milk. A small solar farm sits off to the side, and 18-wheelers branded in grass-green and sky-blue livery pull in and out of the property, dropping off clean PET plastic flake and picking up shipments of polyester fiber.

This is the flagship factory where one of the world’s most popular so-called sustainable fibers is manufactured: polyester made from recycled plastic bottles. In the last 18 years, more than 42 billion bottles have flowed globally through the owned and partner facilities of Unifi and been turned into a branded polyester fabric Unifi calls Repreve.

Unifi pioneered this eco-friendly fabric, but today it is far from the only recycled polyester maker. According to Textile Exchange, an industry group that has been pushing the fashion industry to commit to recycled polyester, the apparel industry used 32 million metric tons of polyester fiber in 2019, and approximately 14 percent of this was recycled. That’s the equivalent of almost 16 billion bottles a year.