More than 11 million tons of textiles end up in landfills or incinerators every year in the US alone. Now, engineers at the Massachusetts Institute of Technology hope to make a dent in that fabric waste with a recyclable elastic yarn.
The yarn is made from polyethylene, the widely produced plastic used in milk bottles and grocery bags. That means that a discarded garment made from the yarn could be melted and then re-spun into new yarn for fabrics.
Many modern high-performance fabrics contain a blend of materials that impart stretchiness and strength while being lightweight. The yarns are made of a spandex core sheathed in a polyester or nylon. Spandex, or polyurethane, is highly elastic and makes high-performance fabrics stretchy and comfortable. The nylon or polyester add durability and strength. But the blended material make garments difficult to recycle because the polymers have to be separated.
“Eighty percent of textiles on the U.S. market currently contain some amount of spandex, which makes them nonrecyclable,” said Svetlana Boriskina, a researcher in MIT’s mechanical engineering department, in a press release. “There’s no widely adopted technology now that recycles textiles into textiles. With our new yarn, we hope to change that.”
The new yarn, reported in the journal ACS Materials Letters, mimics the strength and stretchiness of spandex-polyester and spandex-nylon blends. But it is made from just one type of plastic, which makes it easier to recycle. Both the stretchy core and tougher sheath are made of polyethylene-based polymers. So the entire fiber can be recycled without the chemical separation required for traditional yarns.
To demonstrate this, the researchers spun a spool of yarn, melted it, and re-spun it into new yarn several times. Even after 10 cycles, the yarn was as strong and flexible as conventional blended fibers. “Because they are exactly the same chemistry, they play nicely together,” Boriskina said. “That’s what makes this yarn very recyclable.”
The researchers believe the technology can be scaled up for industrial production.
Source: SeongHyeon Kim et al. Polyethylene-Based Thermo-Mechanically Recyclable Stretchable Yarns for Circular Sustainable Textiles. ACS Materials Letters, 2026.
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