MIT engineers have developed a recyclable elastic yarn with a core-and-sheath structure made from related polyethylene formulations, delivering spandex-like stretch while enabling thermoplastic recyclability.

This approach offers a recyclable alternative to traditional spandex-based yarns that mix polyurethane cores with polyester or nylon sheaths, which are difficult to recycle as a single material.

The project aims to reduce the massive U.S. textile waste by shifting away from non-recyclable spandex-containing garments.

Ultimately, the effort supports a circular fashion economy by cutting textile waste, addressing a problem measured in millions of tons annually.

The study detailing the yarn appears in ACS Materials Letters, with MIT collaborators including Svetlana Boriskina and others, and support from the U.S. Army and naval research offices as well as the MIT Portugal Program.

In addition to Boriskina, the research team includes SeongHyeon Kim, Duo Xu, Volodymyr Korolovych, Domingo Flores-Hernandez, Kaniz Moriam, and Daniel Braconnier, with funding from DEVCOM Soldier Center and ONR Global.

There is scale-up potential for industrial spools, enabling garments that can be melted down and reformed into new yarn or other plastic components, and integrating this yarn into knitted or woven fabrics.

The researchers envision a circular recycling workflow where polyethylene-based garments are recycled at scale by melting and respinning into new textiles or components like buttons, belts, and accessories.

A central challenge—chemical separation in current recyclable textiles—is avoided here by using identical chemistry throughout the yarn.

The ACS Materials Letters study presents a thermo-mechanically recyclable yarn recipe designed for industrial scaling and spool production, signaling a possible shift away from traditional spandex recycling dead ends.

By reducing the need for chemical separation and avoiding toxic processing, this approach offers a more practical path to recycling textiles containing elastics.

The work centers on circular textiles, polyethylene-based engineering, fiber spinning, and sustainable textile innovation.