Denim dyeing process with indigo dyes | whats is the process of denim jeans dyeing?| Rope dyeing process | Slasher dyeing process and loop dyeing. | Advantages and disadvantages of indigo dyeing.

 Denim dyeing process with indigo dyes | whats is the process of denim jeans dyeing?| Rope dyeing process | Slasher dyeing process and loop dyeing. | Advantages and disadvantages of indigo dyeing.

Denim Dyeing Process with Indigo Dyes

 

Introduction

Denim is a strong, durable fabric where warp thread is dyed but not durable. The fabric is usually 3/1 1 of warp-faced twill. Denim is different from other cotton fabrics in that it has diagonal ribs on one side. Indigo is specially used to produce shiny green shades that have the desired effect of washing the floor. Despite the fact that indigo is a vat dye, it has no cellulosic adhesion in a reduced and dissolved form, unlike other vat dyes. Dyeing the exhaust fails to show the absorption of the dye, requiring the use of a medium-sized multi-dip-nip padding process to achieve a continuous shade formation. PH is the most important parameter of dyeing in order to achieve the deepest dyeing effect and to achieve the desired result.

Indigo Dyeing Indigo Dyeing

The almost magical appeal of denim is largely due to its blue color. The fabric takes on a bright blue color due to the dye. No other dye that produces such a deep blue color has a small amount of carbon atoms in its molecule. Due to the slow penetration of cotton fibers, indigo is uncommon in its ability to transmit more color. When indigo-dyed cotton thread is not woven, the inner layers remain colorless. The color is also always dull and itchy. With a few types of wash and finish procedures, indigo allows the denim fabric to achieve its ultimate worn look. It allows the denim fabric to respond to finishing applications, giving it a more realistic look.

Indigo continued its popularity by dyeing denim despite the discovery of other blue dyestuffs. The ability to achieve bath effects in multiple baths without losing color burns is a unique quality of indigo dye for denim. Another advantage of dyed indigo dime is that, unlike many other colors, it does not cause health problems. Indigo is so safe for living things that it has long been used to color polyester sutures for medical purposes. Indigo is also used as a dietary dye and as an intravenous therapy.

The Process of Producing Denim Jeans

Indigo's technical features include the ability to dye at room temperature, popular shades ranging from dark to navy to light blue or dull blue, the reduced indigo solution is not sensitive to water intensity, allowing greige dyeing or slow treatment. cotton, does not blend strongly with fiber, repeated baths gradually remove the dye without losing youth, and a reduced indigo solution is less sensitive to water hardness, which allows for dyeing.

Methods Used For Denim Dyeing With Indigo Dyes

Three ways to dye denim with Indigo are as follows

1. Rope / Ball warp / Chain dyeing

2. Slasher / Open warp / Dyeing sheets

3. Loop dyeing

Rope Dyeing Process:

Rope dyeing uses a ball bending machine to pull the creel strings, which are then carried out in a rented rental area with rental rods to ensure accurate registration. These ends are then pulled together into a pile and sent through a condenser tube assembly, which is then passed to form a cord with 350-400 ends. After that, the strings are tied to drums. The beam is lowered and placed in a dye creel when fully integrated. The strings are dyed by passing them to the pre-treatment bath, and then repeatedly immersed in a different indigo bathtub, with medium pressure and flight. A schematic diagram of the dyeing unit is as below,

 Benefits of Rope Dyeing

 

No cross-shade variation

Low wire loosening

High productivity and flexibility in production

The use of a slight reduction agent

No wasting time during the change of lot

 Variety in denim production

 

Disadvantages of Rope Dyeing

There is a lot of space needed

 Immersion times and oxidation are very long

 An additional step to open the wires after dyeing is required

 Less color variation

 Production costs are high

 Slasher Dyeing:

Slasher dyeing involves pre-treatment of denim strips in the form of a warp sheet in the first chambers, followed by multiple dip / nip indigo dyeing; the process is completed after washing, drying, measuring, and final drying. Because the warp sheet is quickly processed and transported to the weaving department to be converted into fabric, there is very little handling of the yarn. The width of the slasher dye can be made with a single indigo dye width or a continuous indigo dye width with a built-in width. In the first type, the cord sheet passes through one or two pre-treatment boxes, through the immersion, squeezing, and flight stages; the only treatment available for washing and drying. A schematic diagram of the slasher dye unit is as below,

Benefits of Slasher Dyeing

Due to the compact design, a small room is required

 Oxidation and immersion times are reduced

The process continues

 Color variation

Production costs are modest

Disadvantages of Slasher Dyeing

 Cross-shade variations are possible; cord breakage may occur; and productivity and flexibility are limited.

 Changing the lot requires more time.

 There is a lack of flexibility in producing denim.

 The cost of reducing agent use is high.

 Dye loop:

It's almost like dyeing with a slasher, but there's only one dye bath. It involves applying thread wires to indigo vat dye before releasing them from the factory roof to release oxidize before returning them to the dye wash. Loop dye produces indigo colorless colors and takes up less space than other dyeing methods. Multiple dips and laying skying are used in the process. Dyeing sheets are used for warp fibers. After each immersion, the air is released and oxidized. The warp sheet rotates in a closed circle, like a loop. Due to the significant decrease in dye and chemical saturation after each immersion, immediate intensification of the bath is essential for proper results. Planned duplicate loop drawings are provided below

Advantage of Loop Dyeing

Because it is an integrated system, it requires less space.

 The initial expenditure is minimal.

 Low maintenance costs and energy costs.

Anzi Water, dye, and the use of chemicals are all kept to a minimum.

Disadvantages of Loop Dyeing

Selvage center variations and cable breakage are both possible.

During the change of article, the strings are lost.

 It takes a long time to change drastically.

 Low productivity and lack of flexibility.

 Conclusion

Although Indigo is a type of vat dye, due to its low compatibility with cotton, it cannot be dyed using traditional vat dyeing processes. Instead, a more moderate dip / nip should be used. At least 95% of worldwide denim production is done by dyeing and cutting.