Name of the Experiments: Dyeing of 100% cotton fabric with natural dye.

1. Objective:
·         To learn about dyeing of cotton fabric with natural dye.
·         To learn about mordanting of the fabric.

2. Theory:
Nowadays natural dyes become popular due to its environmentally friendly and bio-degradable act. But still, textile scientists are busy to find out the parameters to achieve optimum colorfastness in case of natural dyeing. The common disadvantages of natural dyeing is the poor color fastness, high cost, high consumption of dyes to achieve normal shade compare to reactive dyeing.

3. Experimental Procedure:

Sample:  Pre-treated 100% cotton woven fabric.
Dyes & Chemicals:

Table 6.1: List of dyes and chemicals
Dyes & Chemicals
Function
Natural dye(Turmeric )
To dye the fabric
 Mordanting agent
Pre-treat the fabric to increase absorbency of dyes.



Equipment List:
o   Beaker.
o   Measuring Cylinder.
o   Pipette.
o   Pot.
o   Digital Balance.
o   Scissor.
o   Tri-pod stand.
o   Gas Burner.
o   Thermometer.







4.Working Procedure:
Table 6.2: Recipe of Mordanting
SL
Process Parameter
Unit
Dossing
Stock Solution
01
Alum
g/L
5
2%
02
Sample Weight
gm
5
------
03
M:L
------
1:30
------
04
Temperature
°C
100
------
05
Time
min
20
-------



Calculation:
                Total Liquor:                       Material Weight X L        { M:L }
                                                                = 5gm X 30
                                                                = 150 mL
               
               
                  Alum :                   =  (150 X 5)/(2% X 1000) mL
                                                =  37.5mL


            Initial Water :                              = Total Liquor - (chemicals)
                                                                = 150 - (37.5)mL
                                                                = 150-37.5 mL
                                                                = 112.5mL















Table 6.3: Recipe of Natural dyeing
SL
Process Parameter
Unit
Dossing
Stock Solution
01
Turmeric Powder
%
4
1%
02
Sample Weight
gm
5
------
03
M:L
------
1:30
------
04
Temperature
°C
80
------
05
Time
min
20
-------

Calculation:
                Total Liquor:                       Material Weight X L        { M:L }
                                                                = 5gm X 30
                                                                = 150 mL
               
                Natural  Dye:                      = (5 X 4%)/(1%) mL  (   )
                                                                =  20 mL


            Initial Water :                     = Total Liquor - (chemicals)
                                                                = 150 - (20)mL
                                                                = 150-20 mL
                                                                = 130mL





Process Flow Chart:
Collection of 100% cotton pre-treated fabric.
↓
Mordanting of the fabric by sodium alum.
↓
Dyeing of the fabric with natural dye.
↓
After treatment. 

Figure 6.1: Process Flow Chart



Figure 6.2: Process curve of mordanting.
 
Figure 6.3: Process curve of natural dyeing

Process Description:
                At first, we need to collect cotton pre-treated fabric. Then we first mordanting the fabric with sodium alum. Then we dye the fabric with natural dye here the cold rinsing done to remove excessive dye molecule from the fabric surface.  


Precautions:
o   Taking chemicals as per recipe provided by the Instructor.
o   Taking every weight of chemicals carefully.


5. Result & Discussion:
Sample Attachment:








Discussion: Here we observed the fabric absorbed dyes very well.


6. Conclusion & Comments: By doing this experiment we have learned about the dyeing of cotton fabric with natural dye. Here we able to achieve our desired shade of color.