Study on Dyeing of 100% cotton Knitted fabric with yellow colour.

Experiment No : 02 .

Experiment Name:

Study on Dyeing of 100% cotton Knitted fabric with yellow colour.

Introduction:

Cotton is one of the most widely used natural fibers due to its softness, breathability, and comfort. When dyeing cotton, achieving vibrant and consistent colors can be challenging, particularly in knitted fabrics. Knitted cotton fabrics have a unique structure, allowing flexibility and stretch, but also making them prone to uneven dye absorption if not handled carefully. For vibrant colors, reactive dyes are frequently used because they form covalent bonds with cellulose fibers, resulting in strong color fastness, making them ideal for producing bright shades such as yellow.

Yellow, a primary color, can be challenging to achieve with consistency due to the high visual contrast it creates on fabric. For a bright, uniform yellow on cotton, proper control over the dyeing parameters is critical, such as dye concentration, pH, temperature, and fixation methods. This study investigates the process and conditions needed to achieve a uniform yellow dye on 100% cotton knitted fabric, focusing on reactive dyes, which are known for their vivid color and high fastness properties. 

Objective :

•    To learn about dyeing process of cotton fabric by reactive dye.
•    To dye cotton fabric by reactive dye.
•    To make a combined shade using red,         yellow, blue color substances.
•     To write a report according to the experiment.

Raw Materials: 100% cotton knitted fabric.

Chemical Required: 

                 

                        Dye        
                     Salt (NaCl)
                     Soda ash (Na2CO3)
                     Sequestering agent
                     Levelling agent
                     Wetting agent 

Apparatus Required :

•       Beakers.
•         Glass Rod.
•       Pipette.
•       Measuring Cylinder.
•      Digital Balance.
•      Tri-pod stand.
•       Thermometer.
•      Pot.

Recipe:

          Dyes                                : (0.0001-0.5) %

          Salt (NaCl)                   : 30 g/l

          Soda ash (Na2CO3)    : 8 g/l

          Sequestering agent    : 0.50 g/l

          Anti-creasing agent   : 1.0 g/l 

          Levelling agent           : 1.0 g/l

          Wetting agent             : 0.5 g/l   

           M : L                             : 1 : 15

           pH                                : 10 – 11

           Temp                           : 60° C

           Time                             : (45 – 60) mins            

Calculation:

Fabric weight= 50 gm

Total Liquor: Material Weight X L { M:L }

                                  = 50 gm X 15

                                  = 750 mL

Dyes: = (0.5 X 50) ÷ 100

           = 0.25 cc

Salt(NaCl): = (30 X 750)÷ 1000 cc

                              = 22.5 cc

Soda Ash: = (8 X 750) ÷ 1000 cc 

                    = 6 cc

Sequestering agent: =(0.5 X 750) ÷ 1000 cc 

                                      = 0.375 cc

Anti-creasing agent: =(1 X 750) ÷ 1000 cc

                                      = 0.75 cc

Levelling Agent: = (1 X 750 )÷1000 cc

                              = 0.75 cc

Wetting agent: =(0.5 X 750) ÷ 1000 cc

                           = 0.375 cc

 Initial Water : = Total Liquor - (chemicals)

                          = 750 - 31

                          = 719 mL

Working Diagram & Procedure:

Result:

Fabric sample 

Conclusion:

     

    This study demonstrates a successful process for dyeing 100% cotton knitted fabric with a bright yellow shade using reactive dyes. By optimizing factors such as dye concentration, pH, and temperature, a uniform, vibrant yellow shade was achieved. Additionally, the importance of salt and soda ash as auxiliaries for better dye absorption and fixation was confirmed. Results from fastness tests support the durability of reactive dyes, making them ideal for long-lasting color on cotton fabrics. This study highlights the precision required in dyeing to achieve both vibrant and consistent colors on knitted cotton.

Precautions:

1. We use deal with chemicals use hand gloves. 

2. Carefully mix all the chemical with water. 

3. Carefully Set up all the pots in machine.