New research on how animals spin silk could open the door for more sustainable synthetic fiber production.
The University of Sheffield’s Department of Material Science and Engineering discovered that animals, including silkworms, spin silk by pulling the material out of their bodies. Published in the Nature Communications journal, the university’s research suggests that if this method can be replicated in an industrial environment, it could potentially improve how synthetic fibers are manufactured and lead to more eco-friendly alternatives.
Today, conventional synthetic textiles are produced by extrusion, which involves pushing a liquid through a dye, drastically changing the temperature and then exposing it to harsh chemicals for solidification. Unlike this manmade process, silk can solidify into fibers at room temperature and only leave water—a process could reduce the textile industry’s carbon footprint.
“Silk is one of the most promising green biomaterials, and could be the perfect replacement for nylon and polyester based clothing,” University of Sheffield PhD student Jamie Sparkes said. “Traditional production process for silk is both arduous and time-consuming, but if we can bypass that by mimicking nature in an industrial setting, we could improve not only silk, but also how we process our synthetic materials.”
University of Sheffield researchers studied how animals, such as silkworms and spiders, create these materials.
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Combining computer models with experimental data, the researchers found the forces needed to squeeze unspun silk down the animal’s silk glands and spin fibers. If an animal spun silk by pushing, the animal would have to squeeze itself hard enough to produce more pressure than the average diesel engine—which would be too much pressure for the animal’s body.
Researchers then measured the forces needed to pull silk from the animal’s body and they discovered that silkworms and spiders could pull fibers from their bodies, known as pultrusion. This scenario was copied by adapting a rheometer, a machine used to measure the consistency of liquids, into a sensitive spinning wheel that can measure the forces required to spin silk.
Conducted by the Natural Materials Group at the University of Sheffield, the research recently was provided funding by the European Union’s Horizon 2020 research and innovation program and an Engineering and Physical Science Research Council Grant. Both grants aim to provide U.K. industries with financial support for future innovation and scientific developments.