YARN DYEING
Dec 12. 2022
According to the required pattern design, the laboratory creates a dyeing formula.
The original yarn is then introduced into the dyeing vat for production.
Based on the required yarn quantity and yarn type for each color, the process is divided into skein dyeing and cone dyeing.
Commonly employed chemical dyes for cellulose fibers.
Direct Dyes
The first direct dye, Congo Red, was synthesized by German chemist Bottiger in 1884. These dyes are capable of directly coloring a variety of fibers, offering a simple application process and cost-effectiveness. However, they are characterized by poor color fastness.
Reactive dye
In 1954, British chemists Rattee and Stephens invented reactive dyes. Reactive dyes can
chemically react with fibers for fixation. They offer a complete color spectrum, excellent
dyeing uniformity, vivid colors, high color fastness, and a wide range of applications.
However, they are relatively higher in cost.
Sulphur dye
In 1873, French chemists Groissant and Bretonniere synthesized the first brown sulfur dye by combining wood shavings with alkaline bisulfite. Sulfur dyes exhibit better color fastness compared to direct dyes. They are cost-effective but may have subdued and less vibrant colors.
Vat dye(Indanthrene dye)
In 1901, German chemist René Bohn synthesized the first chemical vat dye – Indanthrene blue. In 1906, Bayer introduced the first red vat dye, along with a series of other colors. Despite the challenges in dyeing and a higher price, these dyes are renowned for their vibrant hues, excellent wash and light fastness. The use of vat dyes can significantly extend the lifespan of products.
Starting from the early Republic of China era, these dyes were widely marketed in China and extensively
used for making garments such as long robes, cheongsams, and school uniforms.
Dyeing Techniques Introduction:
1. Solution:
Dye dissolves in water.
Dye molecules dissolve into a liquid medium, usually water.
2. Diffusion:
Dye molecules move and spread like fibers.
Dye molecules disperse within the medium, exhibiting movement similar to the diffusion process.
3. Adsorption:
Fibers attract and adsorb dye molecules.
Dye molecules are attracted to and adhere to the surface of fibers.
4. Attachment:
Dye enters the interior of fibers.
Dye molecules penetrate and attach themselves within the fiber structure.
5. Fixation:
Completion of chemical and physical bonding.
Dye molecules establish stable bonds with the fibers, involving both chemical and physical interactions.
These dyeing techniques collectively contribute to achieving the desired coloration of textiles, with each step playing a crucial role in the overall dyeing process.
