Textile Insight

TECHNOLOGY | DENIM Indigo Goes Green Innovative Ways to Keep Denim True Blue Sustainably. hat makes jeans, jeans? The answer isn't as obvious now compared to generations ago when pants made of denim were called "blue jeans." But in fact, the critical, defining feature of jeans is indigo, as it was in the past, is today and forever will be. However, as the denim industry increasingly seeks sustainable solutions to all practices throughout the supply chain, interest in how to clean and green indigo has intensified. Announcements of new, innovative indigo technology entered the marketplace one after another this Spring. Wrangler launched its Indigood foam-dye technology; San Francisco-based start- up Tinctorium pioneered development of natural indigo dye. And Archroma introduced its new Diresul Smartdenim Blue, advancing its Indigo Reflection coloration system. The core tenet of all three initiatives is reduction of chemi- cal use and enhanced water conservation. It's estimated that to make a single pair of jeans conventionally takes a brew of harmful chemicals and hundreds of gallons of water. Here's how three companies achieve greener blue jeans: Wrangler's Indigood Foam-Dye entirely replaces the traditional water vats and chemical baths of conventional indigo dyeing, reducing by 100 percent the amount of water required to turn denim a true shade of indigo blue. (Small amounts of water are used to clean machinery and mix solutions, 99.99 percent of wastewater is eliminated.) The new dyeing process also reduces energy use and waste by more than 60 percent compared to the conventional denim dyeing process, according to the Greensboro, NC-based brand. In addition, the Indigood products incorporate recycled cotton, laser finishing and ozone finishing without compromise to quality, "Indigood raises the bar on what consumers can expect from us in terms of environmental performance," said Roian Atwood, sustainability director at Wrangler. Tinctorium launched as a company earlier this year and enters the apparel supply chain looking to transform tradi- tion. "Current chemical synthesis of indigo involves dangerous chemicals such as formaldehyde, cyanide and petroleum. For every kilogram of indigo, over 100 kilograms of petroleum are used to produce that small, incremental unit," said Tinctorium co-founder Michelle Zhu. "Indigo isn't water soluble. To apply indigo as a dye, a chemical-reducing agent, which is also a water pollutant, must be added." Tinctorium co-founder Tammy Hsu identified a naturally occurring enzyme as a bioengineering PhD candidate at the University of California, Berkeley. She discovered that this microbe-created pigment could be used as an indigo alternative to toxic synthetic dyes. The pigment could also be applied in a water-soluble state by adding an enzyme that finalized this natural dyeing process. Recently Adriano Goldschmied was named Tinctorium's denim innovation adviser. Through his company, House of Gold, Goldschmied is developing Tinctorium-dyed fabric with Blue Diamond, a mill located in China's Hebei province. Within the next few months, Goldschmied has said he will begin fabric testing. "One of our advantages is that we see this as an easy plug-in solution for the supply chain," Zhu was quoted as saying. "It's not something that requires a ton of additional investment into a lot of new capital and machines." Archroma's new Diresul Smartdenim Blue is a liquid sulfur blue dye designed to mimic indigo and developed to address the limitations of the company's Indicolors earlier technology. The new Diresul Smartdenim Blue has a greener shade, better fastness to minimize back staining, and allows the creation of overall wash-downs much closer to actual indigo than any other dyestuff, while avoiding greyish cast especially in bleaching with hypochlorite. Diresul Smartdenim Blue can be applied in all standard dyeing methods recommended for sulfur dyes. l W w w w . s u p e r d r y e r s . c o m MOLD? MOISTURE DAMAGE? AVAILABLE WORLDWIDE No Silica gel Captures and Isolates Moisture in excess of 200-450% of its dry weight Prevention is better than cure No clay No BIOCIDES Michael H anrahan > > micha el@ superdryers.com (201) 679 4703 Steve R y an > > steve@ superdryers.com (312) 371 5438 Alex Chisholm > > alex@superdryamericas.com (904) 210 8602 For orders in the Americas : "One of our advantages is that we see this as an easy plug-in solution for the supply chain. It's not something that requires a ton of additional investment into a lot of new capital and machines." Michelle Zhu, co-founder, Tinctorium 16 • Textile Insight ~ July/August 2019 textileinsight.com

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