Advanced Denim
for more Sustainable
Denim Colors and Effects
Almost 2 billion pairs of jeans are manufactured every year, no item of clothing is more popular then the starting material is cotton. which passes through numerous processing steps from the cotton field to the finished thread in the textile factory.
The raw cotton is fluffed up cleaned and the single fibers are pressed into loose strands before being spun into yarn.
Since the gold digger era the yarn for jeans has been dyed blue with indigo. With advanced denim , now a days a more eco-friendly era of traditional dyeing, in which indigo requires the use of long production lines. Some stretching to more than half a mile in length.
These machines consume enormous amounts of water and energy. Moreover when the color is changed most batches create large amounts of cotton waste, because of the metre dispose off, all the fibres still inside the machine.
After spinning up to 4500 cotton threads of simultaneously pre wedded, decreased with chemicals and cleaned in several preparation lines, now the actual dyeing process begins with an average of 10 % immersed in the first indigo dyeing box.
Indigo in its natural agglomerate state is not soluble in water and in this state cannot penetrate into the fiber material. The molecules have to be separated to make them water-soluble. This is done by reduction of the double bonded oxygen in this reduction process.
The strong reducing agent sodium hydrosulfide causes the indigo to take up negative charges. The molecules repel each other making the indigo soluble in water.
In this process indigo loses its the resulting finely dispersed indigo molecules can L settle on the top layer of the cotton fiber the yarn fibers are then exposed to atmospheric oxygen which removes the negative charges from the indigo molecule causing the oxidant groups to return to the original form in other words they are oxidized the indigo.
molecules turn blue again the dye is no longer water-soluble and adheres to the fiber for intensive and uniform dyeing the cotton has to pass through 6 to 15 consecutive dyeing that's because the fiber absorbs the indigo only very slowly this process not only consumes vast amounts of energy but also an above all .
Large quantities of water in the next step removes the chemicals previously added for cleaning and reduction as well as the unbound indigo in several washing boxes.
This produces large volumes of coloured waste water contaminated with sulfides which adversely impact the aquatic ecosystem.
The yarn fibers are now dried and during the sizing process ,same coated with a film of starch to protect them during the stressful weaving process that follows the conventional production process.
According to National Geographic magazine an estimated water consumption of 11,000 litres for each pair of the groundbreaking technology of advanced denim the new pad sizing ups process provides savings of up to 92% water 30% energy and 87% cotton waste during dyeing and sizing and generates absolutely no waste water.
Central to the new process is the more eco-friendly, concentrated liquid sulfur dyes with a high affinity for cotton just a single dyeing bugs and one sugar base reducing agent are needed to obtain a medium color intensity for the next step is a combined sizing and oxidation box in which the dye is fixed and the protective starch layer is applied all the other working steps are eliminated.
In chemical terms dyeing with sulfur dyes closely resembles the traditional indigo process but sulfur dyes not only have the oxygen groups but also sulfur containing functional groups known as tiles in the first step as with indigo the dye molecule is reduced causing it to dissolve in the water and change color in the oxidation process. That follows the dye is fixed to the fiber by a strong ionic bonds and the final color develops the sulfur groups can cross link with each other and can also bond very strongly to the fiber via the fixing agent this improves the strong color fastness and high abrasion.
Link may be utilized:
https://bindaprocess.blogspot.com/2022/02/denim-rope-dyeing-automation-2022.html
https://bindaprocess.blogspot.com/2022/02/denim-fabric-stucture-application.html
https://bindaprocess.blogspot.com/2022/02/denim-production-process.html
