Smart Indigo,
the hydrosulphite-free
dye

PureDenim is the first company in the world to produce the dye, liquid indigo, in-house. ‘Smart Indigo’ is the name of this innovative ecological process. Born from an idea patented in Switzerland by David Crettenand and marketed by Sedo Engineering SA, it was turned into an operational industrial process for the first time thanks to PureDenim.

Indigo is insoluble in water: traditionally used dyes are based on reduction through hydrosulphites, which are often extremely polluting and hazardous to health. ‘Smart Indigo’ uses only indigo pigment, caustic soda (NaOH), water and electricity: it is an electrochemical process, so it does not use hydrosulphites.

BENEFITS

“Smart Indigo”
reduces environmental
impact
compared to traditional dyes

It yields more, so less is needed.

In traditional dyes, indigo powder reaches a concentration of 8%, whereas ‘Smart Indigo’ reaches a concentration of 30%! Due to the higher colouring power, less product can be used, even to produce very dark shades.

It saves a lot of water.

By using less product, there is a consequent saving of water, which is used in large quantities in the dyeing process.

Facilitates water treatment.

Wastewater recycling is simpler and more efficient due to the lack of salts, so the cost of treatment is also significantly lower.

It is a zero-mile product.

Indigo is created, tested, measured on the line and directly sent to the dyeing baths: on-site production reduces CO2 emissions by a factor of six.