The days of pulling your favorite sweater from the wash, only to find it more suitable for a Chihuahua, may be over. Newly developed processes for wool production promise not only an unshrinkable sweater, but one that is silky smooth and shinier to boot.
The new process, called "bio-polishing," was developed by the Agricultural Research Service branch of the USDA. Bio-polishing uses a series of chemical and enzyme treatments to provide smoother and softer wool than by conventional methods.
In the first step, researchers bleached the wool with activated peroxide. The peroxide whitens the wool and removes a protective layer from the fiber.
Once the protective coating has been removed, the wool is treated with an enzyme that snips off the ends of fibers that poke out from yarn. It’s these little projections that make wool itchy.
"The enzyme digests the fiber ends, and that smoothes the fibers," Jeanette Cardamone, a textile chemist at the ARS, told LiveScience.
The enzyme treatment also makes the wool worry-free washable. The surface of each wool fiber is covered in scales, much like a fish’s skin. When wool gets wet and heated, these scales overlap more and lock in place, which shortens the fibers and thus the length of your sleeves.
The enzyme treatment smoothes down the surface of the fibers — preventing them from locking — without reducing the strength or elastic recovery of the fabric.
Bio-polishing will actually produce stronger wool than traditional methods. Current dyeing methods call for high temperatures to get the dye past the protective layer on the fibers.
"Although wool has resilient properties, those high temperatures weaken the fiber," Cardamone said. "Our process lets wool be dyed at lower temperatures, preserving its strength."
While the softer wool will likely appeal to designers in the fashion industry, it is also drawing the attention of an unlikely group — the U.S. military. The military uses wool for blankets and berets, and would like to add underwear to that list. Currently, military issued undies are made from synthetic materials, which according to Cardamone, can burn and melt into wounds during combat situations.
Wool, on the other hand, if made soft and unshrinkable, would be the perfect underwear for battle. If caught on fire, it self-extinguishes its flame. It turns to ash, which scatters easily, instead of being trapped in a wound.
Most wool produced in the United States is a byproduct from sheep raised for meat, and in general is not soft or high in quality as wool from countries like Australia, which produces soft, fluffy Merino wool. Softer, unshrinkable wool could give the US wool industry a sales advantage.