Fiber Innovators Explore Next-Gen Silk, Inditex Debuts Jacket Made From Textile Waste
Move over, mycelium. The new year is kicking off with a new next-gen material in mind: the queen of fibers.
Silk is one of the oldest fibers, first emerging in China around 2600 BCE, according to the International Silk Association. But recent revelations about silk’s environmental footprint and impacts on human rights and animal welfare have inspired scientists and bio-innovators to cultivate the next generation of the heritage fiber.
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The Material Innovation Initiative’s (MII) “What Makes Silk, Silk?” report is an update to its original 2021 report and is full of highlights from the first compendium as well as updated findings from the past two years. It explores silk’s unique properties and innovation opportunities, as well as the challenges inherent in creating alternatives to conventional silk.
“[T]he silk industry accelerates climate change and environmental degradation, relies on inhumane and unsustainable animal agricultural practices, and offers few protections for workers in processing plants,” Thomasine Dolan Dow, director of materials innovation and design at MII, said. “Popular synthetic alternatives to silk like polyester and nylon contain microplastics which accumulate and persist in ecosystems for hundreds of years.”
“Next-gen materials are a solution to these problems and it’s very exciting to see so many innovators developing next-gen silk,” he added.
The report highlights over two dozen material innovators developing next-gen silk through diverse methods, including leveraging waste streams and replicating processes found in nature.
Orange Fiber was among the first to offer a silk alternative, developing circular fabrics from citrus fruit waste, while Toronto-based biomaterials startup Alt Tex uses patent-pending food-to-fabric fermentation technology to reengineer food waste into fiber for circular textiles. Japanese biotech firm Spiber’s Brewed Protein, used by The North Face, attempts to replace silk from silkworms and other animal fibers as well as petroleum-based plastic fibers.
Cellulose fibers have also been found to convincingly replicate silk’s properties. Virginia-based textile recycling body Circ’s proprietary hydrothermal process separates polyester-cotton blended textiles and recovers both fiber portions to be made into like-new ones. The certified B Corp regenerates the cellulose from the cotton portion to create Circ Lyocell, creating fibers that look and feel like silk.
Material innovator Eastman’s Naia also leverages cellulose, making filament yarn and staple fibers for sustainable textiles. The resulting materials feature a silky-smooth handfeel and are biodegradable, compostable and compatible with molecular recycling. Meanwhile, California-based Ettitude’s Clean Bamboo woven material has a high thread count with a refined silken hand and surface sheen. Lenzing’s silk-like EcoVero, sourced from sustainably harvested wood pulp, uses fewer production resources than traditional viscose and is also fully biodegradable.
Brooklyn biosythentics startup Kintra Fibers‘ bio-based and biodegradable polyester is applicable to a wide range of knit and woven textiles, such as a satin, developed with a silk-like handfeel.
“New fibers came as a result of trying to create a replacement for silk,” John O’Brien of DuPont Central Research said in the report. “Now we have the possibility of a replacement that really is silk.”
Several companies have turned to arachnids for inspiration.
German fermentation company AMSilk’s Biosteel is made of spider silk protein produced by genetically engineered microbes and spun into fiber. The high-performance filament fiber is thinner and more delicate than traditional animal-derived silk. However, it’s biodegradable, petrochemical-free, hypoallergenic and can be dropped into the existing value chain for knitting, weaving and dyeing. In fact, the world’s first industrial supplier of vegan silk biopolymers secured $27 million in an extended Series C financing round last April.
“It’s possible to make silk proteins synthetically, but it’s very hard to assemble the individual proteins into a fiber or other material forms,” Markus Buehler, MIT professor, said in the report. “The spider has a complex spinning duct in which silk proteins are exposed to physical forces, chemical gradients, the combination of which generates the assembly of molecules that leads to silk fibers.”
It’s worth noting that silk fabric produced by spiders was never commercialized, however, due to the difficulty in farming the cannibalistic spiders, according to research done in 2014.
Spidey Tek’s founders claim to be the first scientists to determine the molecular structure of spider silks. In 2015, the company implanted spider silk protein genes into the leaves of alfalfa plants to mass-produce those spider silk proteins.
Unexpected sources have served as springboards for innovation. Tandem Repeat was inspired to create a new fiber upon discovering the performance attributes of squid ring teeth. Silk and squid ring teeth share a similar molecular architecture. Tandem Repeat’s co-founder, DR. Melik Demirel, began investigating whether these characteristics were transferable to other fibers almost 10 years ago. He and his team at Penn State spent five years developing the company’s protein-based filament fiber, Squitex.
“In our report, we connect the dots so that next-gen silk innovation can meet the needs of the fashion industry and beyond,” said Nicole Rawling, CEO and co-founder of MII. “We’re already seeing some promising innovation in this area, and our goal with this report is to inspire a new generation of scientists and entrepreneurs to develop high-performance, luxurious, and sustainable next-gen silk materials.”
BASF and Inditex debut mono-material ‘Loopamid’ jacket
Geography-spanning chemical producer BASF has joined hands with Inditex on Loopamid, a polyamide 6 (PA6), also known as nylon-6, made from 100-percent textile waste. Zara has created a jacket with Loopamid following a “design for recycling” approach: all elements, including zippers and buttons, are made from the polyamide material.
“BASF has reached an important milestone towards circularity in the fashion industry and pioneered an approach to close the loop for nylon textiles,” said Dr. Ramkumar Dhruva, president of BASF’s monomers division. “Our Loopamid has the potential to revolutionize the PA6 market for the better. We are in the process of scaling up our technology to serve our customers with commercial quantities. The capsule jacket together with Inditex is the proof that circularity is possible, and we are eager to further drive the sustainable transformation of the textile industry.”
The technology powering Loopamid allows for textile-to-textile recycling of post-industrial and post-consumer waste. The materials can be recycled repeatedly and maintain the same characteristics of virgin polyamide.
Inditex collaborated with various manufacturers to integrate Loopamid into each element of the jacket. The take-back program ModaRe sorted and supplied discarded textiles as feedstock, while YKK and Velcro played “crucial roles” in using Loopamid to make zippers, snap buttons, hooks and loop fasteners. Italian company RadiciGroup transformed the polymer into multiple yarns with different characteristics.
“Driving innovation is key to advancing toward a more responsible industry,” Javier Losada, Inditex’s chief sustainability officer, said. “This collaboration is a great example of how, by collaborating all together, we can use the new technology to transform textile waste into a new resource. This project is also a first step to move toward a circular solution, as the industry still needs to boost new collecting and recycling capabilities in order to close the loop and scale recycling for post-consumer waste.”
