Study on Dyeing of 100% cotton (Knitted) fabric with medium shade ''Red'' colour.

 Experiment No : 05.

Experiment Name:

Study on Dyeing of 100% cotton (Knitted) fabric with medium shade red 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. 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 red.

For a bright, uniform blue colour 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 red 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 light shade color like red
  . 
•     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.
•      Digital Balance.
•      Pot.

Recipe:

          Dyes                         : (0.50-2.0) %

          Salt (NaCl)                : (40-60) g/l

          Soda ash (Na2CO3)  : (10-15) 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                         : 60 mins            

Calculation:

Fabric weight= 10 gm (total -50 gm)

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

                                  = 50 gm X 10

                                  = 500 mL

Dyes = (2 X 50) ÷ 100

          = 1 gm

Salt(NaCl) = (60 X 500)÷ 1000

                  = 30 ml

Soda Ash = (15 X 500) ÷ 1000 

                 = 7.5 ml

Sequestering agent =(0.5 X 500) ÷ 1000 

                                = 0.25 ml

Anti-creasing agent =(1 X 500) ÷ 1000 

                                 = 0.5 ml

Levelling Agent = (1 X 500 )÷1000 

                         = 0.5 ml

Wetting agent =(0.5 X 500) ÷ 1000 

                       = 0.25 ml

Water required = Total Liquor - (chemicals)

                     = 500 - 40

                     = 460 mL

Working Diagram & Procedure:

Result: 

Conclusion:

     

   This study demonstrates a successful process for dyeing 100% cotton knitted fabric with a bright knitted shade using reactive dyes. By optimising factors such as dye concentration, pH, and temperature, a uniform, vibrant blue 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. This study highlights the precision required in dyeing to achieve both vibrant and consistent colors on knitted fabric.

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.