Archroma, Swiss color and specialty chemicals company based in Basel, has presented an aniline-free denim indigo dye at the recent Planet Textiles 2018 Conference in Vancouver, Canada. The brand new dye provides a non-toxic way to produce the traditional, iconic indigo blue that consumers associate with denim and jeans.
Currently, aniline impurities are an unavoidable element of producing indigo-dyed denim. Unlike other chemical impurities, aniline is locked into the indigo pigment during the dyeing process and therefore cannot be washed off the fabric. Scientific testing has shown that aniline impurities are toxic to humans, causing skin allergies, damage to major organs and genetic defects, as well as being linked to cancer. Aniline is also toxic to aquatic life, which is an issue as two thirds of the 400 metric tons of aniline waste on an annual basis ends up in the environment as wastewater discharge.
«We have tested denim garments and found that aniline concentrations are frequently higher than expected» says Alexander Wessels, CEO, Archroma. «This could put some manufacturers over the limits agreed on their RSLs.»
Archroma decided to take a closer look at the issue with its R&D experts and developed the Denisol® Pure Indigo 30 dye, an alternative system that is aniline free; then they proceeded to successfully test Denisol® Pure Indigo 30 at Absolute Denim mill in Thailand. «During the testing everything performed exactly the same as it would with conventional indigo» says Vichai Phromvanich, Board Member, Absolute Denim. «There was just one important difference: no aniline.» The new dye will be produced in Archroma’s facility in Pakistan, a plant that made the headlines in 2012 for being what Archroma believed to be the industry’s first zero liquid discharge plant.
The Denisol® Pure Indigo 30 dye is the latest in a long line of sustainable innovations for denim started in 2009. That year, Archroma introduced its Advanced Denim technology which uses up to 90% less water during the dyeing process. The product now also makes it possible to produce indigo-dyed denim without high levels aniline impurities.