Waterless Dyeing Technology Unlocks New Possibilities for Cellulosic Fibers in Lenzing’s Latest Collaboration

Color is a key component in fashion and textile design, attracting shoppers to a particular garment or fabric and helping to convey an aesthetic.

But the processes to create colorful clothes are evolving as dyeing innovations that promote sustainability and efficiency emerge and scale. One of the alternatives on the rise is waterless dyeing technology, which addresses both these points.

Waterless dyeing reduces over 30 percent water usage compared to conventional dyeing by replacing H2O with alternative solvents that help the dye adhere to fabric. Some waterless processes use supercritical carbon dioxide—CO2 that has been pressurized and heated to a point where it is between a liquid and gas—as a solvent to swell fibers and allow dyes to permeate. Others leverage chemical solutions to achieve a waterless dye method.^{1, 2}

Nonaqueous processes have been achieved for substrates including leather, wool and polyester-cotton blends. Although waterless dyeing was first developed decades ago, the technology recently found a new application for cellulosic materials through a partnership among the leading wood-based fiber producer Lenzing, environmental engineer Exponent Envirotech and Hong Kong-based knitwear specialist Cobalt Fashion.

Exponent Envirotech’s ECOHUES™ waterless dyeing solution was created specifically for cellulosic fibers such as TENCEL™ branded lyocell and modal fibers which are responsibly sourced³ and produced⁴. By using a non-water solvent and nearly eliminating the usual post-dyeing soap wash, ECOHUES™⁵ colors a T-shirt with just 2 liters of water compared to the typical 40 liters needed, representing a 95 percent reduction. It shrinks dye usage by 40 percent, while also raising the dyestuff fixation to fabric to 97 percent compared to 62 percent for water-based dyeing. As another benefit, it halves the time needed to color a cotton tee from 12 hours to just 6-8 hours.

“We are thrilled to partner with Exponent Envirotech and Cobalt Fashion, who share the same vision as Lenzing in endeavoring to protect our planet,” said Rex Mok, director of technical marketing and development, global textiles business, Lenzing. “By incorporating ECOHUES™, waterless dyeing technology can be applied to lyocell, modal and viscose fibers for the first time, making a big step forward in reforming conventional practices in the textile industry. We hope that by this breakthrough, more ingredients with a lower environmental impact will be available for manufacturing, thus the creation of more products with a kinder impact to Earth.”

One of the byproducts of traditional dyeing is wastewater with high salinity. Whereas around 400 kilograms of salt is needed for each ton of yarn in conventional dye processing, ECOHUES™ is completely salt-free⁵.

In addition to the great cut in water consumption, waterless dyeing reduces wastewater. Wet processing in fashion—including dyeing—is estimated to be responsible for 20 percent of all wastewater generated globally⁶. A report from Water Witness International found that African rivers had turned blue, and tests showed a pH of up to 12, an alkaline level comparable to soapy water. ECOHUES™ recycles 99.8 percent of the non-water solvent for reuse, preventing waste and the release of chemicals into the environment.

Consumption of resources, including water, is not only an environmental consideration; it is also an economic one. Saving on inputs naturally results in cost savings.  

TENCEL™ Lyocell and Modal and LENZING™ ECOVERO™ Viscose fibers are the world’s first cellulosic fibers to be dyed with ECOHUES™. Leveraging waterless dyed yarns, Cobalt Fashion will create quality knitwear products with love for the planet in mind, bringing this sustainable technology to the mainstream fashion market.

Waterless dyeing is one of Lenzing’s latest efforts at responsible textile practices, where they substantially cut back on water use in yarn dyeing. With yarns made of the inherently white TENCEL™ and LENZING™ ECOVERO™ branded fibers that are produced with at least 50 percent fewer carbon emissions and water consumption, chemicals used in the waterless dyeing process are further reduced with no additional bleaching required, unlike cotton, rendering this technology a more responsible choice for customers and brand partners.

Lenzing has also recently been expanding its portfolio of spun-dyed, pre-colored fibers. After the wood pulp has been dissolved into a liquid, pigment is added to the solution before it is spun into fibers, embedding the hue. To further showcase the versatility of color integration in fibers, Lenzing launched the denim-focused TENCEL™ Modal with Indigo Color technology and more recently introduced LENZING™ ECOVERO™ Viscose in black.

Water scarcity is a growing issue around the globe that is accelerating with climate change. According to UNICEF, as of 2021, 1.42 billion people resided in areas with high or extremely high water vulnerability. The concerns are reaching consumers, with a 2023 survey from GlobeScan showing that 58 percent of individuals consider freshwater scarcity a “serious issue.” Manufacturers in the fashion industry, who are also consumers, understand very clearly the pressing need to address this natural resource crisis swiftly. One effective solution for this would be accelerating the adoption of water-saving innovations—particularly those like waterless dyeing that have no quality tradeoffs.

Click to learn more about TENCEL™ and LENZING™ ECOVERO™.

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