Interview with denim expert Uwe Kippschnieder
Uwe Kippschnieder is Closed’s Denim Developer. He knows everything about denim – that’s why we call him our “walking denim lexicon” or simply refer to him as Dr. Denim. Uwe joined our company in 2002 and his passion for denim has been growing ever since. He is fascinated by sustainable denim innovations and is always pushing them vigorously for Closed. Inspired by his regular visits to weaving mills and laundries in Italy, he developed our eco-friendly denim line A BETTER BLUE with the clear message: style and eco-awareness can go hand in hand.
What are the sustainable advantages of using natural dyes?
Natural dyes use natural pigments instead of chemicals. They are more sustainable than conventional dyes from start to finish. No harmful chemicals are involved in the creation of the dye. In the dyeing process of the garments later on, less energy and less water are required. The wastewater does not contain any chemicals, which makes water treatment much easier, again saving energy. The dyeing process alone needs 30 per cent less water, 70 per cent less energy and 40 per cent chemicals in comparison to conventional dyeing. By using natural dyes, we can lower the environmental impact of our garments tremendously – for example, for a pair of jeans we achieved an EIM score of 8 instead of 14 after switching to natural dyes. Some information on the EIM score while we are at it: the Environmental Impact Measurement system by Jeanologia, a Spanish company for sustainable textile solutions, monitors the impact of garment finishing processes to improve their environmental performance, taking into consideration water and energy consumption, chemical impact and workers’ health. The lower the score (between 0 and 100), the better and more eco-friendly. Every pair of our A BETTER BLUE jeans has an EIM score below 33, which means “low-impact”. Having these kinds of objective, comparable numbers is important to us as they help us to further improve and track our progress.
Where are the natural dyes obtained?
Natural dyes are either mineral-based or plant-based. Mineral-based pigments are obtained in quarries, in our case in Italy, Cyprus or Morocco. As the pigments are very intense, only a very small amount is needed – so the environment is not harmed during this process. Plant-based dyes are obtained from bark, vegetables or dye plants such as curcuma. Many plant-based dyes even upcycle food waste, for example orange peel or nutshells, which is great as there is a steady supply without needing new resources. And there is even another advantage for some botanical dyes: the pulp, which remains after the dyeing process, can be reused as fertiliser. So far, we use the mineral dyes for denim – their colourfastness and resistance to fading are great. The botanical dyes are not used for denim, but mainly for jersey and nylon. We will soon introduce natural dyes for even more product groups.
Can every possible colour be achieved with natural dyes?
Although a very wide range of shades and intensities is possible with natural dyes – from pale yellow to orange, greens and blues – not every colour can be achieved. You can never get a very deep black, for example. Every dye producer has a colour chart to show the different options. The colours are a bit different from conventional colours, not as bright but rather powdery – which we like a lot. Naturally dyed denim can also react a bit differently when washed.
Which other eco-friendly dyeing treatments are used for Closed jeans?
Our Italian partner Candiani uses many different sustainable techniques to dye the denim for our jeans. One of them is prereduced indigo. Unlike conventional indigo, it does not require treatment with chemicals – it is already water-soluble and can be used directly for dyeing. 50 per cent less chemicals are needed and prereduced indigo meets the strict requirements of the Oeko-Tex® Standard 100 for textiles tested for harmful substances. It has the GOTS seal and complies with the new EU chemicals regulation REACH. Another example is the patented Kitotex® technology which upcycles waste products from the food industry for sizing the denim: mushrooms or the shells of shrimps. Sizing is the process of preparing the yarn for the dye, making it smooth, uniform and resistant. With the Kitotex® technology, the dyeing process needs 70 per cent less water, 50 per cent less chemicals and 30 per cent less energy than conventional methods. Thanks to the natural components, it is completely biodegradable and microplastic-free. The so-called easy-to-fade process is another dyeing innovation: the colour pigments do not penetrate as deeply into the yarn as in conventional processes, requiring 15 per cent less water and 15 per cent less energy in the denim manufacturing process. Since the dye is more likely to sit on the surface, it is easier to wash out again with industrial washing methods – saving even more water in the washing process that follows.
