What makes an indigo dye process “sustainable”? And how high is the average amount of water that is used for coloring by denim nowadays? The answer is: We do not know because so far there has been no comparative value that compares the processes of denim factories worldwide.
However, there were numerous claims about water savings, but here too it is difficult to judge without a comparison, which is real efforts for more sustainability and what Greenwashing is. Expert: Inside, the fact that between three and five billion (!) Denim articles are produced annually, a large part of them in water-poor regions.
The Transformers Foundation, the platform of the Denim supply chain and thinking factory for ethics and sustainable innovation in the jeans industry, is of the opinion that there should be a universal comparison value in which sustainability in denim production can be measured, and has therefore decided to deliver one. The result is the report “A Reference for Water Consumption During Indigo Dying. To Indigo Council Study”.
“Our task was not easy: the indigonation is a long and complicated process that contains both chemical and physical reactions and is influenced by the quality and type of raw materials, production methods and environmental factors such as weather, moisture, water quality and more,” says the organization.
In addition, these factors vary not only from country to country and from region to region, but also from operation to operate. If you add tradition and craftsmanship, even from day to day within the same factory, with recipes, conditions and practices that differ depending on the culture and region.
The Transformers Foundation has succeeded in bringing the world’s leading denim manufacturers together and participating in the study. The aim was to define, establish and validate a standard for conventional coloring from denim web chains. “Our goal is to equip denim-producers with the knowledge and tools they need to promote a wider, industry-wide change towards sustainable practices.”
Who took part?
All seven participating weaving mills are recognized world market leaders who are known for their high quality standards and operational efficiency. It was Advance Denim from China, Candiani Denim from Italy, Crescent Denim, Diamond Denim, Naveena Denim and Soorty from Pakistan and Orta Anadolu from Turkey.
Two mechanical engineering companies – Karl Mayer from Germany and Morrison Textile Machinery Co. from the USA – provided technical knowledge, while certified Bluesign took over the independent supervision. In addition to visiting factories and literature research, interviews were also carried out in order to be able to dispose of data from various sources.
“This is a group of companies that are in competition with each other: Morrison and Karl Mayer, for example, compete for every coloring machine in the world, such as Coca-Cola and Pepsi [Rivalen in ihrem Bereich sind]. And yet they sat down and helped us create a standard-or not not a standard, but when creating information, “said Transformers founder Andrew Olah, the extent of the cooperation in the introductory webinar.
Coloring: strands, lanes and indigo
Indigo is the dye, which gives denim its characteristic blue tone, its bleaching and wear effects. However, use is extremely difficult: Indigo – in a natural or synthetic form – is a pigment and not a dye. It is not water -soluble and has no affinity with cellulose fibers.
In the case of strand or rope coloring (Rope DYEING), separate ends are summarized to form a rope, while a chain set- consisting of a yarn beam that is flat in a location around the entire width of a cylinder or kett tree- is being dipped into the color baths during tree dyeing (slasher or sheet dying). In contrast to a tree machine that stains a sentence at once, a rope coloring machine – depending on the version – can color up to five sets at the same time.
“The aim of this study is not to prefer a procedure to another: rope coloring and kett tree dyeing have different applications, advantages and disadvantages, and many weaving mills, including some in our study, use both procedures in their company,” the study clarifies right from the start.
The examination only focused on coloring and not on the entire water consumption, including staining, coloring and dying. As a result, the water consumption in the laundry boxes was limited according to the indigilation, since the largest amount of fresh water is used here.
Constant and variable
The study then lists the constants and variables, such as the two methods- rope or tree dyeing- the use of 100 percent cotton kett cooking (no mixed yarn), a similar thread fine, 100 percent pure indigo in liquid form and no additional chemicals on the constant side. The variables included the water consumption, the number of the kett yarn delivered in a single coloring, the speed at which the yarn runs through the machine, the number of indigo boxes or baths in which a yarn is bathed, the oxidation length and others.
Taking these constants and variables into account, the study showed that the average amount of water used in the subsequent washing systems is between 13 and 15 liters per kilogram for rope coloring and 7 to twelve liters per kilogram for tree color. “In some exceptional cases, a significantly lower consumption was found, with the minimum values at 3.85 liters per kilogram for rope coloring and 3.4 liters per kilogram for tree dyeing.”
When asked about the possibilities that arise from these results for the weaving mills, Olah said: “The idea of the report was to help buyers: to find their way around in a labyrinth of allegations. If you are interested in sufficient water, you now have a way to check the claims, and of course Transformers are always ready to help. But also have a real interest in the water consumption at Reduce coloring the results of the results and can also help you here if you wish.
Knowledge
The most important finding is that a reduction in water consumption is possible in the standard indiginum processes for kett yarn-provided that the challenge is addressed with a scientific and data-controlled way of thinking.
When asked by Fashionunited whether the study can be used to review Green Claims, Olah explained: “This report provides a basis, a way for manufacturers and weaving mills to check their claims using data from third parties. In the case of denim production, every manufacturing process has a negative effect on our environment. However, as soon as we have things, we have an impact.
Before this study, there was no all -encompassing method for recording and comparing data on the various chemicals, machines and other factors involved in the indigolofin process. This prevented the industry from measuring and comparing the water consumption through various colored recipes and procedures. “We hope that [die Studie] As an industry benchmark, claims on the water consumption for new dyeing processes or technologies can be measured, ”said the Transformers Foundation.
The study is a must for everyone who wants to find out more about the indigilation, from veterans in this area to newcomers who only want to get a taste of once. The latter will make the many images of common processes and procedures easier, while the former can benefit from the proposed questions that can be used in denim sourcing and visiting the factories.
The weaving mills were even asked about their considerations about investments in plants for the two most common color methods- rope and tree staining. The study ends with a view of future studies that could deal with water and indigo recycling, coloring with less water or even waterless coloring and creating benchmarks for refinement processes.
The study “A Reference for Water Consumpte During Indigo Dying. To Indigo Council Study” even contains a glossary of the most common terms used in indigilation and can be accessed together with a recording of the introductory webinar on the Transformers Foundation website.
