Viscose rayon is a mysterious textile: it goes by many different names and is often marketed as eco-friendly, but it has a checkered past (and present). So a crucial question remains for the fashion industry: is a more sustainable alternative even possible on a large scale?
Last week at a trade show in London, among several new alternatives, two textiles were highlighted as the potential next generation of viscose.
Every year, 300m of trees are felled to produce viscose rayon, according to the non-profit environmental group Canopy.
In April, Canopy received a $60 million grant from The Audacious Project (a funding initiative aligned with Ted Talks) to accelerate commercialization of next-generation viscose made from cotton waste, coconut water , citrus, wheat straw, corn, molasses and hemp.
Canopy founder Nicole Rycroft says their goal is to work with companies to bring 60 million tons of new materials to market by 2033. She says they need to focus on “bold levels of change ” to transform the pulp sector (which also covers paper and packaging) because “the fastest, easiest and cheapest way for us to stabilize our climate is to stop cutting down forests and keep them upright.
Here we explore the two viscose alternatives that are ready to scale up to commercial capacity.
Viscose made from recycled cotton
According to Rycroft, clothing waste is the most exciting alternative raw material because it is so abundant. “There are 100 billion pieces of clothing produced each year and 60% of them are landfilled within 12 months,” she says.
But transforming old garments into viscose is not without its challenges. Collecting textile waste is difficult – apart from charity bins and drop-off points, there is limited infrastructure to do so and clothes have to be sorted manually or mechanically by fiber type.
To be recycled into viscose, clothing must be made of plant fibers such as cotton, linen or hemp. Currently available technology focuses on processing 100% cotton, as it is by far the most common natural fiber.
Globally, there are a few companies with textile recycling technologies, including Evrnu, Södra and Lenzing, but Rycroft describes Renewcell – a Swedish textile recycling company – as the most exciting. It has launched its first pulp mill for the production of next-generation viscose, which will be able to produce 120,000 tons of material by early 2024, making its business capacity much higher than that of its competitors.
At Renewcell, 100% cotton garments are shredded, then chemicals are used to turn the fragments into a pulp which is bleached and dried to produce sheets of cellulose that look like thick white cardboard. These sheets are then sent to be processed into a viscose substance which is extracted into yarn.
The resulting material is called Circulose. According to Rycroft, compared to traditional viscose, the process emits “5 tonnes less carbon per tonne of product than a conventional wood product and uses 90% less water and fewer chemicals”.
Circulose has already made a few public appearances in the market. In 2022, Levi’s released a line of 501s made with a Circulose blend; and earlier this year, Canadian pop singer Shawn Mendes’ capsule for Tommy Hilfiger featured a Circulose fiber rugby jersey.
At the Future Fabrics show, the Circulose material on display looked like a thick, slightly stretchy cotton jersey, but without the softness, sheen or stretch of modal or lyocell, or the warmth and weightlessness of pure cotton. .
The material used to be one part recycled cotton and two parts virgin wood pulp, but this reliance on virgin materials will decrease as the capacity for plant scale and the technology for the use in the supply chain will improve.
Viscose based on coconut water
In the context of viscose production, food waste refers to the by-products of large-scale industrial food processing, such as fruit peels, or leftovers from beer making.
Nullarbor fiber, from Australian company Nanollose, is a next-generation viscose derived from coconut water, a by-product of coconut processing.
Nanollose executive chairman Wayne Best said the company could, “in theory…use a whole bunch of different types of food waste” to produce viscose rayon cellulose, as long as the waste contains a sugar. .
To create cellulose, bacteria are added to coconut water, which triggers a fermentation process similar to making yogurt. “The bacterium converts sugars into cellulose, and in doing so, it generates its own heat,” says Best.
Cellulose is made into a viscous substance which is pushed through spinnerets to make translucent yarn, which is the staple fiber used in lyocell.
According to Valerie Langer, strategist at Canopy, since the process requires very little land, water or energy and the production cycle is only 18 days, the potential for scale is enormous. This is distinct from other food waste raw materials like orange peel, which has large scale limitations – the peel must be refrigerated to prevent it from going moldy.
“You can actually get more fiber per hectare by growing microbial cellulose than by growing trees, because it grows in weeks rather than years,” she says.
While Best says a “small number of garments” made from coconut waste will be available by the end of the year, late 2022, Nanollose has proven their concept by creating their first wearable item – a sweater. The material exhibited at the London Expo is soft, thin and very stretchy. It has a feel similar to a lightweight lyocell or bamboo that might be good to wear next to the skin like you would with underwear or workout gear. But it lacks the drape and density that would make it suitable for other garments such as blouses or pants.
Since the process can be applied to other forms of food waste, Nanollose is looking to Indonesia to manufacture commercial quantities of Nullarbor fiber and develop a supply chain and ecosystem around food waste.
By Lucianne Tonti