Leonard assured that ColorZen’s pretreatment makes the dyeing process faster while using 90% less water, 75% less energy, 90% fewer auxiliary chemicals and also cuts out almost half the dye compared with processes of using salts in dyeing bath. After the treatment, cotton is spun into yarn for customer facilities.
But ColorZen technology uses a quaternary ammonium compound to permanently attach a positively charged amino site on the cellulose molecule that makes a natural attraction between dye and fiber.” ColorZen treats raw cotton fiber right from the field removing the seeds. Leonard said, “With conventional cotton dyeing, salt is used to negate the charge on the surface of the cotton. ColorZen, a start-up in North Carolina, has developed a cotton pretreatment step where Tony Leonard is the inventor and technical director. This method is cost saving as it is reducing the use of energy and water.Īnother way to improve the bond between dyes and cotton fibers is a process called Cationization. Because of the extra reactive groups, the dye step lasts about four hours, compared with seven hours for conventional dyes. Three reactive groups are attached to the dye formula’s chromophore or color-providing molecule-compared with the one or two reactive groups common for cotton dyes. Around 200 L of water is used to produce 1 kg of fabric.Īs cotton is consumers’ most favorite fiber with an always accretive demand, continuous researches are taking place to reduce the cost of dyeing cotton as well as the use of water and energy.Īn American company named Huntsman has developed a line of dyes for cotton called Avitera that bonds to the fiber directly and require ¼ to 1/3 less water and 1/3 less energy. To ensure the colorfastness, dyed fabric or yarn is washed over and over again in hot water, creating large amounts of wastewater. Even with an assist from salts and alkali added to the dye solution, cotton takes up only about 75% of the dye. As the surface of cotton fibers is negatively charged, it doesn’t react with negatively charged dye compounds easily. But dyeing cotton is a more water- and heat-intensive process. Generally cotton fabric and polyester fabric are colored using synthetic dyes. Farzana Alam Piya, Research Assistant, Textile Focus
0 kommentar(er)
