In this article, we are going to know about the reactive dyeing process of cotton fabric. Here, three recipes are followed for dyeing cotton of light, medium and deep shades. All the procedures are followed according to the recipes and the final results are found in the dyed shades. So, Let's get started with the new recipes.
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Theory
Reactive dyeing is the most important method for the coloration of cellulose fibers. Reactive dyes have a low utilization degree compared to other dyestuffs, since the functional group also bonds to water, creating hydrolysis. The Reactive dye reacts with fabric in the presence of alkali and adheres as a part of the fiber.
The three main mechanisms of reactive dyeing are exhaustion, fixation, and finally washing off. First, exhaustion happens in the presence of electrolytes. Then fixation happened under the influence of alkali. Finally, wash off the fabric to remove unfixed dye from the material surface. Softeners can be used to soften the surface of the fabric. Thus, the total reactive dyeing process is done.
Functions of the Chemicals Required
Wetting agent: It accelerates the wettability of material in solution, thus helping to easy penetration of the chemicals into the substrate. It reduces the surface tension of water to allow it to spread drops on a surface, increasing the spreading abilities of a liquid.
Sequestering agent: A sequestering agent is a substance that suppresses as property or reaction of metal ions without the removal of that metal from the system.
Leveling agent: Leveling agent tends to slow down the dye uptake on the fibers, helping to produce a more uniform color in the textile fiber.
Common salt: Salt is used as an electrolyte. This electrolyte neutralizes the negative charge formed in the fiber surface and puts extra energy to increase dye absorption.
Soda ash: Soda ash creates proper pH in the dye bath and does as the dye-fixing agent. It helps in forming a strong covalent bond between the dye with the fabric.
Recipes
Recipe Calculation
Here, M: L= 1:20
Sample weight: 5 gm
Total liquor: 5✕20= 100 ml
For light shade;
Dye= (Shade%✕Fabric weight)/Stock solution%
Reactive red= (0.20%✕5)/1%= 1 ml
Reactive blue= (0.10%✕5)/1%= 0.5 ml
Reactive yellow= (0.10%✕5)/1% = 0.5 ml
Chemicals= (g/L✕Total liquor)/1000
Glauber salt= (20✕100)/1000= 2 gm
Soda ash= (8✕100)/1000= 0.8 gm
Wetting agent= (1✕100)/1000= 0.1 ml
Leveling agent= 0.1 ml
Sequestering agent= 0.1 gm
Total= (1+0.5+1+0.1+0.1)= 2.7 ml
Freshwater= (100–2.7)= 97.3 ml
For medium shade;
Dye= (Shade%✕Fabric weight)/Sock solution%
Reactive red= (0.40%✕5)/1% = 2 ml
Reactive blue= (0.20%✕5)/1% = 1 ml
Reactive yellow= (0.40%✕5)/1%= 2 ml
Chemicals= (g/L✕Total liquor)/1000
Glauber salt= 40✕100)/1000= 4 gm
Soda ash= (14✕100)/1000= 1.4 gm
Wetting agent= (1✕100)/1000= 0.1 ml
Leveling agent= 0.1 ml
Sequestering agent= 0.1 gm
Total= (2+1+2+0.1+0.1)= 5.2 ml
Freshwater= (100–5.2)= 94.8 ml
For deep shade;
Dye= (Shade%✕Fabric weight)/Sock solution%
Reactive red= (0.60%✕5)/1%= 3 ml
Reactive blue= (0.40%✕5)/1%= 2 ml
Reactive yellow= (0.80%✕5)/1%= 4 ml
Chemicals= (g/L✕Total liquor)/1000
Glauber salt= (60✕100)/1000= 6 gm
Soda ash= (20✕100)/1000= 2 gm
Wetting agent= (1✕100)/1000= 0.1 ml
Leveling agent= 0.1 ml
Sequestering agent= 0.1 gm
Total= (3+2+4+0.1+0.1)= 9.2 ml
Freshwater= (100–9.2)= 90.8 ml
Shade Attachment
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| Reactive Dyed Fabric Samples ©Textile Pad |
Dyeing Curve
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| Reactive Dyeing Curve ©Textile Pad |