Dyeing textiles is a dirty business.
With as much as 70 percent of China’s waterways affected by pollution, the traditional “wet processing” of textiles–dyeing, washing, printing, and finishing–accounts for about 8 percent of the sewage generated by all Chinese industries.
And while China’s government has increased pressure on the textile industry to clean up its act, textile manufacturing has begun to move elsewhere, contributing to increased levels of water pollution in other low-cost manufacturing regions.
Thanks to the efforts of Greenpeace, Textile Exchange, and other NGOs, industry leaders are innovating and collaborating to develop new, cleaner technologies to convert griege goods into colourful finished fabrics.
DryDye, launched in 2010, is the much-touted, waterless CO2-based dyeing technology developed and manufactured by DyeCoo® Textile Systems in the Netherlands. Using unique dyestuffs and super-critical CO2, the process is said to dye a 400-lb. batch of polyester fabric in half the time, saving 7,000 gallons of water, while recycling 95 percent of the CO2.
The company is 10 percent owned by Thailand’s Yeh Group, which manufactures knitted polyester performance fabrics under the brand Tong Siang. Yeh Group currently has seven DyeCoo machines producing for customers such as Adidas, who has already used more than one million yards of DryDye fabric. Adidas claims that the DryDye process reduces the chemicals and energy used by 50 percent.
The technology is being marketed by Jim Hind and Brad Poorman, who are part of the team which brought the environmentally-friendly performance technology Cocona to the industry. At January’s Outdoor Retailer show in Salt Lake City, Yeh exhibited over 50 different DryDye fabrics in vibrant colors.
“The technology is emerging and we’re seeing interest from top customers,” reported the duo. “Now it’s about brands stepping up and partnering with us in a more sustainable way to make product.”
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Poorman said, “Everyone thought this would be difficult, but the reaction has been through the roof.” He added, “But you need a company that is dedicated to getting it done.”
In 2012, Nike made a financial investment in DyeCoo, followed by IKEA in 2013. Recently Nike purchased its own machine, which is being housed in Taiwan at a contractor, Far Eastern New Century Corp. Nike will call their fabrics ColorDry, and expects to have products on the market shortly.
While DyeCoo’s revolutionary technology, currently usable only on polyester, is expensive and requires a learning curve; low-impact dyestuffs, chemicals, and detergents from the industry’s chemical suppliers are already available. Among other products, Huntsman has developed waterless dyestuffs for DyeCoo, and Archroma’s Advanced Denim sulphur dyestuffs are changing denim dyeing.
New processes in denim dyeing and finishing such as the IndigoRope Genius/C dyeing machine, marketed by Italy’s Master, and Jeanologia’s E-Soft nano bubble technology, are vastly reducing the chemical discharge created by the denim industry.
Other new chemistries modify the fiber or fabric to improve the uptake of low-impact dyes. Using cationic technology, ColorZenâ„¢ pre-treats cotton for increased dye affinity, reducing water and energy consumption and eliminating the discharge of toxic chemicals.
Developed in partnership with Dow Chemical, EcoFRESH™ is a new cationically-treated cotton yarn from spinning giant BROS Eastern Co. The EcoFRESH yarns require less dye, lower temperatures, and no fixatives. Using their mélange yarn spinning process, BROS combines the EcoFRESH cotton with regular cotton in varying amounts to create wonderful color effects.
Printing technologies are also shifting to cleaner, more efficient processes. A new heat-transfer printing method called AirDyeâ„¢ Technology uses proprietary dyes which provide superior penetration and color fastness. The process reduces water consumption by 95 percent, energy consumption by 86 percent, and greenhouse gas emissions by 84 percent over traditional water-based printing.
Newtech Textile Technology Development in Shanghai has developed a process called COOLTRANS technology which uses an inkjet or roller printer to place dye or pattern on cellulosic fabric. The process operates at room temperature with a dye fixation rate of over 95 percent, using cold batch or steaming for fixation.
Without the need for screens or sample runs, digital printing eliminates much of conventional printing’s water and chemical waste. A range of water-based inks called Elvajet® Alpha, developed for Miroglio by Sensient Technologies for digital printing on polyester fabrics, does away with pre-treating, washing, or steaming. Water consumption is reduced to 1 liter per printed linear meter (vs 50 liters for traditional inks); energy use is reduced by 57 percent and CO2 emissions by 90 percent.
The tools for creating a more sustainable textile industry are within reach. The question is: When will our industry’s brands and retailers commit to using them?