How Three Revolutionary Fabrics Are Greening the Industry
Replacing Old stock 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 hipora fabric 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 taffeta 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.
That’s where biopolymers come in. Biopolymers are macromolecules—long chains of smaller molecular units strung together. These basic units can be amino acids, nucleotides, and monosaccharaides. The most common biopolymer is cellulose, which makes up one third of all plant material on earth. Cotton is 90 percent cellulose, but there are other, less polluting alternatives.
Biopolymers can be grown or harvested from other plants like kelp or from living organisms like bacteria or yeast, which produce biopolymers as part of their lifecycle. The resulting fibers can be woven into a variety of textiles akin to polyester, leather, or a cellulose-like yarn. To a certain extent, these materials can sequester carbon from the atmosphere, acting as wearable carbon sinks. And when they’re thrown away, these biopolymers will decompose. Just as a cotton t-shirt will break down in a compost heap after a few years, so will any biopolymer-based textile.
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 stretch 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.
Replacing Old stock 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 hipora fabric 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 taffeta 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.
That’s where biopolymers come in. Biopolymers are macromolecules—long chains of smaller molecular units strung together. These basic units can be amino acids, nucleotides, and monosaccharaides. The most common biopolymer is cellulose, which makes up one third of all plant material on earth. Cotton is 90 percent cellulose, but there are other, less polluting alternatives.
Biopolymers can be grown or harvested from other plants like kelp or from living organisms like bacteria or yeast, which produce biopolymers as part of their lifecycle. The resulting fibers can be woven into a variety of textiles akin to polyester, leather, or a cellulose-like yarn. To a certain extent, these materials can sequester carbon from the atmosphere, acting as wearable carbon sinks. And when they’re thrown away, these biopolymers will decompose. Just as a cotton t-shirt will break down in a compost heap after a few years, so will any biopolymer-based textile.
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 stretch 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.