Candiani promotes sound and chitosan in dye process
Italian denim mill Candiani has promoted its use of sound dyeing and the use of chitosan-based sizing agents as part of an article to explain the processes behind indigo dyeing.
Sound Dye uses ultrasound waves that create microbubbles in the water. When these bubbles implode, they generate shock waves that remove excess indigo from the yarn.
Candiani said using Sound Dye helps save 30% of the water for every metre of denim produced compared with traditional methods. Given an annual production of 20 million linear metres, this technology could reduce water usage by around 52,287,000 litres, it said.
Kitotex substitutes PVA (Polyvinyl Alcohol) with chitosan, a bio-based polymer derived from chitin, sourced from the fungus Aspergillus niger. “This eco-friendly alternative to PVA is non-toxic, biodegradable and bacteriostatic,” said Candiani. “Moreover, chitosan aids in wastewater treatment, operates effectively at lower temperatures and enhances colour saturation.”
The mill introduced pre-reduced indigo in 1979, as it requires fewer chemicals to bond indigo to cotton fibres than the powdered non-reduced indigo.
It also uses natural indigo dyes from Stony Creek Colors in Tennessee.
