A visit to one of Unifi’s* last remaining U.S. polyester plants, in Yadkinville, N.C., 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.