Forever Young: Indanthren® Dyes

Can fashionable clothes be sustainable? With the right production technology and expertise, sustainable products can be achieved by using
better raw materials to produce higher quality products with better physical aspects, long-lasting fabrics, and colors. The current technologies offer a lot of possibilities and even existing options can be re-explored, such as DyStar’s Indanthren® dyes.

Rediscovering Indanthren Dyes for Fashion and Sportswear
Indanthren dyes provide the highest possible fastness performance and durability for cellulosic fibers. It has outstanding fastness properties to light, weather, washing, bleaching, hypochlorite, mercerization, etc.

Due to their outstanding performance, Indanthren dyes are commonly used in specific segments such as workwear, military/outdoor articles, etc. But why not use Indanthren dyes for fashion and sportswear to achieve sustainable designs and products?

Given that their light, perspiration light, chlorine, weather, and multiple washing fastnesses are unique, Indanthren dyes can create a difference in fashion products during their life cycle.

Prominent Features of Indanthren® Vat Dyes
As Reactive dyes are the major dye class for cellulosic fibers in the market, an overall assessment between both would be meaningful. In general terms, reactive dyes are water-soluble and create chemical covalent bonds. They have good general fastnesses and provide solutions for brilliant colors on cellulosic fibers.

Indanthren dyes are water-insoluble and can only migrate into fiber in reduced water-soluble form. They provide the highest possible fastness properties on cellulosic fibers in many aspects especially for difficult conditions and highly specific areas, beyond what reactive dyes can provide. Accordingly, a longer product life cycle can be maintained with help of the best available fastness properties against aging. Contrary to what is known, Indanthren recipes are very well reproducible with relatively short dyeing processes than alternatives. In fact, one bath process for Polyester/Cellulosic blends is also possible.

Apart from that, the energy and water consumption of Indanthren dyeing is also fairly reasonable. Due to their fastness properties against post-bleaching, we can apply a special process named Cadira® VAT. It is a combined scour-dyeing, using a state-of-the-art high-performance auxiliary Sera® Sperse C-CAD, followed by post-bleaching during soaping. This reduces the environmental impact, saves resources, and increases the production output, just by implementing small changes in the dyeing process.

In comparison with Reactive dyes, we can now see that due to a more efficient dyeing process, Indanthren dyes are more competitive in terms of saving precious resources, such as energy, water, machine capacity, etc. These contributions may go beyond expectations especially when we consider the whole life cycle of the product.

Ensuring Product Ecology
In terms of ecological and toxicological aspects, Indanthren dyes can be easily removed from wastewater and very stringent eco-specifications were implemented to ensure Indanthren dyes comply with legal and Brands & Retailers’ requirements. These eco-specifications are met with tremendous effort and dedication to maintain the highest possible levels of product quality and environmental
responsibility and are backed up by the most extensive eco-testing program of any textile chemical supplier, which is known as the econfidence® program.

At this point, the majority of Indanthren dyes comply with many of the widespread MRSLs and RSLs. For instance, currently, out of 61 globally offered Indanthren Coll and Coll liq dyestuffs:
• 54 dyes are bluesign® approved.
• 28 dyes are GOTS (Version 06) certified
• All of them are recommended for Standard 100 by OEKO-TEX® (special footnotes to be considered)
• All key Indanthren dyes are published on ZDHC

Gateway, complying with ZDHC MRSL Version 2.0 As seen, Indanthren dyestuffs are waiting for us to be re-discovered to contribute to Sustainability in many dimensions, both with their promises in terms of resource-saving and what they provide in terms of extending the product’s lifecycle.