The push to do so through chemical means is a response to the shortcomings of other strategies they’ve tried. Traditional mechanical recycling through shredding and grinding causes fibers to break down. The resulting fabric must be blended with 70 to 80 percent virgin material so that anything made with it doesn’t pill and tear.
The much more prevalent strategy involves turning discarded plastic bottles into new polyester. Patagonia pioneered this approach in the early ’90s, and by the start of this decade virtually all recycled polyester was sourced from old bottles. Today, however, companies have increasingly faced lawsuits and regulatory scrutiny from those who would rather see bottles turned back into bottles.
Chemical recycling is supposed to be the next best thing. The term refers to using solvents to dissolve fibers into their base chemical units—building blocks that can be spun into new fabrics. On its face, this is a truly “circular” solution, because it doesn’t depend on bottles, and proponents say it can turn your used polyester shirts or running shorts into new ones over and over again, with no loss in fabric quality.
That’s the vision now being promoted by fast-fashion brands like Gap, H&M, and Levi’s, many of which have signed multiyear agreements with a handful of chemical recycling startups. Last fall, Nike agreed to source “circular” polyester from two of them: the Swedish firm Syre and Loop Industries in the US.
Research does bear out some of the hype. Technically, chemical recycling can produce virgin-quality polyester, and at least one method, called methanolysis, is capable of preserving that quality through repeated rounds of recycling. But there are significant constraints.
Diana Ferreira, a textile researcher at the University of Minho in Portugal, said textile-to-textile chemical recycling remains limited by the availability of suitable fabric to work with. “If we are dealing with clean, well-sorted, polyester-rich waste streams, chemical recycling can, in principle, produce material with properties comparable to virgin polyester,” she said. “However, if we are talking about postconsumer textile waste, the situation is much more complex.”
In other words, chemical recycling works best with industrial scraps, which are more uniform than piles of used clothes. The latter may include blends of cotton, nylon, wool, spandex, and acrylics, not to mention dyes, chemical coatings, thread, labels, and zippers. All of this stuff makes chemical recycling much less feasible—at least, not without meticulous sorting and repeated rounds of pretreatment to chemically remove all of those contaminants.
“If we wanted it to work, we would have to have our clothes … be 100 percent polyester, and we’d need to get rid of so many toxic chemicals,” Singla said.
Beth Jensen, of the nonprofit Textile Exchange, is more sanguine. She said “all solutions,” including chemical recycling, are needed to reduce the fashion industry’s dependence on fossil fuels. But she agreed that establishing the infrastructure required for companies to accept used clothing and use technologies like methanolysis to make it into new apparel remains a ways away. Plus, it’s not clear who will build it. Companies like Nike? Governments? Recyclers? Some combination of those entities working collaboratively?
