Denim innovation company CleanKore, which owns and distributes a patented yarn dyeing technology, has bettered black denim.
CleanKore’s know-how produces sustainable black sulfur denim with white abrasion highlights without using potassium permanganate (PP) or other chemicals. It reworks sulfur dyeing of cellulosic yarn on a continuous warp dyeing machine by keeping the natural whiteness of the cotton inside the fibers and dyeing the outer layer only. Lasers are then used to create abrasion effects.
It took a year and a half of research and development to achieve ideal results.
“Laser technology does a good job to create the worn look on blue denim. The same was not possible with sulfur black since the cotton becomes dull and yellow. Garments will look very artificial. Conventional sulfur dyeing also led to deep penetration of dyes inside the cotton yarn,” said Alpesh Patel, CleanKore’s executive director of international markets, about trying to recreate the whiteness achieved with PP and lasers.
CleanKore partnered with Archroma to combine its technology with Archroma’s Diresul pre-reduced liquid black dyes. The result is a fully sustainable sulfur black denim that substantially lowers the carbon footprint, which can be determined with Archroma’s One-Way Impact Calculator. Pakistani mill Kassim, for instance, started using the new process and lowered its water consumption by 10 percent, energy consumption by 42 percent and CO2 emissions by 38 percent compared to its previous black sulfur dyeing method.
Other mills that have adopted it are Amber Denim (Bangladesh), Arvind Ltd (India), Ha-Meem Denim (Bangladesh), Pioneer Denim (Bangladesh), Square Denims (Bangladesh), Tak Sang (China) and XDD Denim (China). Arvind, Pioneer and Square debuted their CleanKore black denim at Kingpins New York in July while others will show it at Kingpins Amsterdam and Denim PV later this year.
Ohio-based CleanKore is keen to share this new dyeing method with other mills. “This is truly a groundbreaking innovation that provides sustainability savings and a reduced carbon footprint throughout the supply chain,” Patel said. “We are happy to serve the industry with this new opportunity of playing with black shades the same as indigo. Most importantly, CleanKore can also be implemented on the mill’s existing rope or slasher range without any new equipment or capital expense. Anyone can take advantage of sustainable black denim.”