If adopted on a wide scale, waterless dyeing technologies from companies including AirDye, ColorZen and DyeCoo could drastically reduce pollution from the clothing industry, reports Yale 360.
The textile dyeing industry uses trillions of liters of fresh water and returns that water, often untreated, into the water system. Some estimates say that China produces than discharges roughly 40 percent of all dyeing chemicals worldwide, the website reports.
The processes developed by AirDye, ColorZen and DyeCoo — the latter’s process is being used by Adidas — differ greatly, but their results are similar: water use is cut to near zero sharply cutting pollution, the quantity of chemicals used is greatly reduced and faster drying cycles cut energy consumption.
The DryCoo process (pictured) doesn’t use any water and the manufacturing process also uses 50 percent less energy and 50 percent fewer chemicals than conventional methods, Adidas said in 2012. Instead of water, DryDye uses a pressurized form of carbon dioxide, which takes on liquid-like properties. The “supercritical” carbon dioxide is able to penetrate textile fibers and disperses the preloaded dyes without using extra chemicals.
AirDye’s process uses printing machines to color fabric. Heat and pressure are used to move dye from paper to fabric. The process is faster and uses 95 percent less water and 86 percent less energy than traditional dyeing methods.
ColorZen’s method changes the molecular composition of cotton fibers, making it more receptive to dye. After treatment, the process uses 90 percent less water, 95 percent fewer chemicals, 75 percent less energy and 50 percent of the energy of traditional processes.
A dyeing process unveiled by fabric supplier Wah Fung Group in 2011 can achieve 13 percent carbon savings and more than 50 percent water savings in fabric manufacturing when compared to certain conventional processes. According to a Wah Fung report, the company’s Cold Pad Batch dyeing technology achieved the savings when compared to conventional processes using exhaust dyeing.
But despite these advantages there are still doubts as to whether such processes will ever reach wide-scale adoption. Waterless dyeing machines are expensive and typically only work with certain fabrics, Yale 360 reports.