Replacing Old Fabrics With New Biopolymers
Two types of textiles—petroleum-made polyester and field-grown cotton, often woven together—have been the fashion industry’s darlings for decades. “Much of [what we wear now] is a blend of PET, a petroleum-based fiber, and cotton fiber,” says Ramani Narayan, a professor in the Department of Chemical Engineering and Materials Science at Michigan State University. But these Sportswear Fabrics have their issues. Cotton, which makes over 30 percent of our clothes’ yarns, is a natural material, but it’s a thirsty crop that siphons 3 percent of the fresh water, and accounts for almost 20 percent of pesticides and 25 percent of the insecticides used in agriculture worldwide, before it’s even picked. Processing cotton—knitting, weaving, and dyeing—also takes water and energy, yielding more pollution. The production of polyester, the demand for which has doubled in the last 15 years, is an energy intensive process that requires a lot of oil and generates harmful emissions, including volatile organic compounds, particulate matter, and acid gases, like hydrogen chloride, all of which contribute to respiratory disease. “Adding PET to a textile gives you better performance—it makes Coarse Needle Fabrics more moisture-resistant and gives them more washability,” says Narayan, but these textiles don’t break down naturally, and instead fill up our landfills and oceans. Polyester threads discarded from washing machines have recently been found in fish, including some species we eat. Unless PET threads are decoupled from cotton and recycled, they don’t decompose, but separating fibers is very difficult.
AlgiKnit extracts alginate from kelp by adding certain salts to the seaweed base. After the so-called “salt bath” pulls the alginate from the kelp’s cell walls, the biopolymer is extracted from the seaweed residue, dried into a powder and fused into a yarn that can be turned into a variety of Fleece Fabric types. “The process is similar to that of synthetic materials, where one long continuous strand is produced,” says Tessa Callaghan, the co-founder of AlgiKnit. “The filament can be plied and twisted to increase strength, or cut into short fibers for other purposes.” AlgiKnit won National Geographic’s Chasing Genius Competition for developing this technology.
Using yeast to grow collagen eliminates the animal part of the equation—including slaughter and subsequent hide processing. It yields higher quality materials—perfectly shaped hides without branding marks or scars, and yields very large spans of leather, much bigger than a cow’s body. It also offers nearly endless creative design ideas. The new collagen can be sprayed on top of another Polar Fleece Fabric to create never-before-seen leather fashions, like the t-shirt that is currently on display at the Museum of Modern Art in New York as part of its Items: Is Fashion Modern? exhibit. This material can also be embossed or textured in ways that cow or pig leather just can’t.
Modern Meadow will be introducing Zoa to market in 2018. The production facilities are already available from related industries such as biofuels. “We use 200,000 or 500,000-liter fermentation tanks [for the yeast],” says Schofer, “So the infrastructure already exists around the globe to take this from lab to commercial levels.”
Sequester Methane and Wear it Too
A sewage plant and a fashion show couldn’t possibly be further apart—but methane sequestered from wastewater is slowly creeping up onto the runways. California startup Mango Materials makes its fabrics by feeding wastewater methane to methanotrophic bacteria that eat it and produce PHA-based polyester that can be woven into threads or molded into various shapes. Unlike the oil-based PET Knitted Casual Wear Fabrics, PHA threads are biodegradable. “Because it’s a naturally occurring polymer, there’s a sister organism, a methanogen, that will break it down,” said Anne Schauer-Gimenez, vice president of customer engagement for Mango Materials. But that doesn’t mean that a shirt made from PHAs will be less durable than one made from PET. “If you’re wearing it, and you’re sweating, it won’t break down,” Schauer-Gimenez explains. “But once it ends up in a microbial-rich environment, degradation will occur. It could even degrade in a backyard compost.”