Improved denim dyeing eliminates hazardous spray

REINACH – Archroma has partnered with US-based CleanKore to improve the environmental credentials of denim through a new yarn dyeing process that claims to give jeans bright white abrasion effects without the need for hazardous potassium permanganate sprays.

The new indigo ring-dyeing process works by altering the oxidation/immersion ratio of dyed yarns, coupled with tweaking processing speeds, to inhibit indigo dye penetration from the surface to the inside of the yarn. This then gives a circular bright white cotton – or blended fibre – core of the yarn, with only a shallow ring of indigo dye on its surface.