MIT Engineers Develop Recyclable Stretch Yarn From Polyethylene
Engineers made a stretchable yarn from two polyethylene types that can be melted and respun repeatedly to cut waste.
The average American throws out around 81 pounds of clothing each year, and there are few options for recycling it, according to the report. Conventional elastic yarns typically combine spandex with polyester or nylon; recycling those fibers would require separating them, a process the report describes as impractical.
The MIT team instead made a similarly stretchy yarn from two variations of polyethylene, a material commonly used in milk jugs and grocery bags. Because the two variations come from the same chemical family, the yarn can be melted as is, without the separation step needed for mixed fibers.
Svetlana Boriskina, who led the work as a research scientist in MIT’s Department of Mechanical Engineering, said a garment made from the material could then be spun into new yarn for a next generation of clothing. Even after 10 cycles of melting and respinning, the yarn stays as strong and flexible as conventional thread, according to the report. “Now we have something that can be knitted and woven,” Boriskina said. “That is the next stage.”
The researchers hope that someday a polyethylene garment could be dropped in a collection bin and sent to a recycling facility, the report said, promoting a more sustainable, circular textile economy.