Stretch fabrics are a staple of modern clothing, but they create a major recycling challenge. Most garments contain spandex blended with polyester or nylon, making the fibers difficult to separate and recycle. MIT engineers have developed a recyclable elastic yarn that could offer a practical alternative while maintaining the performance consumers expect, MIT News reports.
The new yarn is made entirely from polyethylene, one of the world’s most common plastics. Unlike conventional elastic yarns, which combine chemically different materials, the MIT design uses two related polyethylene formulations. A flexible polyethylene-based copolymer forms the elastic core, while a stronger polyethylene sheath provides durability. Because both components belong to the same polymer family, the yarn can be melted and remade without chemical separation.
Researchers manufacture the yarn by melting resin pellets and extruding them into hair-thin fibers before twisting the sheath around the elastic core. The process resembles existing industrial fiber-spinning methods, making large-scale production more feasible.
To test recyclability, the team repeatedly melted and re-spun the yarn through 10 recycling cycles. Mechanical testing showed that the recycled versions retained the strength and elasticity of the original material, demonstrating that repeated recycling does not significantly degrade performance.
The research builds on earlier MIT work showing that polyethylene can be spun into textiles with moisture-wicking, stain-resistant, and cooling properties. The new development adds elasticity, expanding the material’s potential for clothing applications.
The researchers believe the yarn could replace conventional spandex-based elastic fibers, which are found in roughly 80% of textiles sold in the United States. At the end of a garment’s life, the material could be recycled into new yarn or remolded into products such as buttons and belt buckles.
Although additional work is needed before commercial adoption, the recyclable yarn represents a promising step toward a circular textile economy in which stretchy fabrics can be reused instead of discarded.