It’s no secret that garments are thrown out at an alarming rate due to fast fashion and the rapid-fire cycling of trends. Furthermore, we are doing a poor job of recycling textile waste. In the United States, less than 15 percent of the 92 million tons of clothes and other textiles are recycled each year, resulting in approximately 17 million tons of textiles being disposed of in landfills.
Much of the problem stems from recyclers’ inability to determine what exactly the item is made of, making these mountains of fabrics exceedingly difficult to sort. Tags are frequently ripped off or washed until they are illegible, while tagless (printed) information is prone to fading. Missing or incorrect information about an item’s fiber composition makes textile recycling expensive.
An invisible tag
To address these problems, a team led by the University of Michigan (U-M) is working on a method to make a tag composed of low-cost photonics fibers that describe the textile that is woven into the cloth and remains invisible until it needs to be read.
“It’s like a barcode that’s woven directly into the fabric of a garment,” said Max Shtein, a materials science and engineering professor at the U-M and the study’s corresponding author. “We can customize the photonic properties of the fibers to make them visible to the naked eye, readable only under near-infrared light or any combination.”
The intrinsically recyclable, low-cost labeling system is made up of drawn photonic fibers woven into fabrics and “characterized by near-infrared spectroscopy and short-wave infrared imaging,” according to the study’s abstract.
According to U-M’s Gabe Cherry in a press release announcing the research, recycling companies currently employ a similar technique for some materials. “Recyclers already use near-infrared sorting systems that identify different materials according to their naturally occurring optical signatures,” writes Cherry. “The PET plastic in a water bottle, for example, looks different under near-infrared light than the HDPE plastic in a milk jug.”
Various fabrics, like different polymers, have distinct visual characteristics. However, as lead author Brian Iezzi says, those signatures don’t aid recyclers enough because so many fabrics combine elements.
“For a truly circular recycling system to work, it’s important to know the precise composition of a fabric—a cotton recycler doesn’t want to pay for a garment that’s made of 70% polyester,” Iezzi explained. “Natural optical signatures can’t provide that level of precision, but our photonic fibers can.”
The future of garment labeling
Shtein adds that the labels may be used to inform consumers about “where and how goods are made, and even to verify the authenticity of brand-name products,” in addition to making recycling more practical.
“As electronic devices like cell phones become more sophisticated, they could potentially have the ability to read this kind of photonic labeling,” Shtein explained. “So I could imagine a future where woven-in labels are a useful feature for consumers as well as recyclers.”
What we truly need is fewer clothes to recycle in the first place; we need a cultural shift away from fast-changing fashion fads and the low-cost clothing that feeds them. Nonetheless, loads of textiles will very certainly continue to end up in landfills. If weaving in a specific fiber can help textiles enter a circular recycling system, then we’re all for it. As of now, the team has applied for patent protection and is considering commercialization options for the concept.
Source study: Advanced Materials Technologies— Polymeric photonics crystal fibers for textile tracing and sorting
