1. Selection of dyes
There are many varieties of reactive dyes, and their quality varies greatly. It is crucial to choose dyes that meet the dyeing quality standards.
1. Choose dyes with dual reactive groups and multiple reactive groups
S-triazine reactive dyes react with fibers to form ester bonds and have poor acid resistance and stability. Vinyl sulfone dyes react with fibers to form ether bonds and have poor alkali resistance. Dyes with dual reactive groups have improved acid and alkali resistance.
2. Choose dyes with suitable directness
If the directness of reactive dyes (such as vinyl sulfone-based reactive dyes) is too high, the diffusion performance will be poor. The dyes will easily gather on the surface of the fabric and will not easily diffuse and transfer into the fiber. This will easily cause floating colors and be difficult to clean, but the directness cannot Too low will affect the fixation rate, so the substantivity of reactive dyes should be medium. The degree of substantivity can be obtained from the data provided by the dye supplier.
3. Choose dyes with high color fixation rates
Dyes with a high fixation rate have less floating color, with a fixation rate of >80%. The amount of floating color after dyeing is relatively small, which is beneficial to removing floating color; the fixation rate is The floating color of 15% reactive dye is difficult to remove and is not suitable for dyeing medium and dark colors.
4. Choose dyes with high lifting power
In the design of the dyeing process, the amount of dye should generally not exceed 10% of the dyeing saturation value. Excessive dye cannot be completely dyed, and the fixation is insufficient. The unfixed dye adheres to the surface of the dyed object, affecting the wet rubbing fastness of the dyed object. For dark colors, dyes with high absorption rate, high fixation rate and high lifting power must be used, such as reactive dyes with double reactive groups and multi-reactive groups.
2. Choose a gray fabric with uniform yarn count and smooth surface. When pre-treatment is required, use a high-efficiency pre-treatment agent.
3. Soft water or deionized water should be used as much as possible for dyeing, which can reduce the impact of calcium, magnesium and other ions in the water on dyeing.
4. Selection of color-fixing agent
High-efficiency fixatives should be able to “bridge” between dyes and fibers to form compounds. When reacting with dyes, they can react and cross-link with cellulose fibers, so that the dye fibers can be closely and firmly connected to prevent the dye from The fiber will fall off to avoid reducing the dye fastness. The color-fixing effect is achieved by the color-fixing agent acting on the fibers in the medium and the cationic groups forming salts with the dye anions to achieve the color-fixing effect.
Excellent formaldehyde-free color fixing agent can improve the wet rubbing fastness of fabrics dyed with reactive dyes by 0.5-1 level. The performance of the fixing agent is: a polymer compound that can form a film, polyurethane or silicone with -OH, -NH2, and a cross-linking agent to cross-link the polymer to make it durable and fast film-forming It is non-toxic, does not change color, does not turn yellow, and does not reduce the light fastness. It can make the dyed objects feel smooth, reduce the surface friction coefficient, and maintain the breathable and moisture-permeable performance of the dyed objects.
5. Special additives can reduce the amount of dye used in finishing to obtain deep and concentrated color effects, and the wet rubbing fastness is also improved.
6. The pH value of the cloth after dyeing.
A high amount of alkali is used when dyeing dark-colored cotton fabrics. After dyeing, it is necessary to strengthen washing, soaping, neutralization and alkali removal. Do not allow alkali on the fabric, otherwise it will cause the dye to be hydrolyzed after dyeing and the wet rubbing fastness will be reduced. Usually the pH value of the cloth is controlled at 6.5-7.5, and cannot exceed 9 or less than 3.
7. Improve the surface properties of dyed cloth. Fabric finishing can be done by biological enzyme polishing, etc. The smoothness of the cloth surface can also be improved, and its wet rubbing fastness can also be improved.
8. It is difficult to remove the floating color after dyeing with reactive dyes. After the soap is boiled, you can use an appropriate stripping agent to remove the floating color and improve the wet rubbing fastness.
Extended reading: https://www.alltextile.cn/product/product-12-607 .html
Extended reading: https://www.brandfabric.net/dobby -checked-pongee-breathbale-fabric/
Extended reading: https://www.yingjietex.com/product/Polyester-T400-Spandex-Waterproof-Twill-Weaving-Imitated-Memory-Cloth -Fabric-for-Dresses-Garment-Jacket-Beach-Short.html
Extended reading: https://www.yingjietex.com/product/Polyester-dobby-3-Laminated-Fabric.html
Extended reading: https://www.alltextile.cn/product/product-85-410.html
Extended reading:https://www.alltextile.cn/product/product-9-239.html
Extended reading:https://www.alltextile.cn/product/product-17-43.html
Extended reading: https://www.tpu-ptfe.com/post/7718.html
Extended reading: https://www.yingjietex.com/product/750D-Polyester-Straw-Mat-Dobby-OXFORD-Fabric.html
Extended reading:https://www.yingjietex.com/product/polyester-taffeta-Printing-fabrics.htm
