Name of the Experiments: Dyeing of PC blended fabric with disperse and reactive dye (Cross effect).

1. Objective:
To learn about dyeing of blended fabric.
To learn about factors achieving to cross effect in case of blended fabric dyeing.

2. Theory:
In case of PC blended dyeing in a lab, the two bath process is more suitable to achieve optimum shade. In this experiment, the objective is to achieve a cross effect on fabric, which means to different fibers dye with different dyes and both shades should like a different color. So we have to achieve the multi color of fabric with noticing the difference between different fibers.


3. Experimental Procedure:
Sample:  Pre-treated PC blended knit fabric.
Dyes & Chemicals:
Table 5.1: List of dyes and chemicals
Dyes & Chemicals
Function
Disperse dye
To dye polyester part of the blended.
Dispersing agent
It assists in the process of particle size reduction of dye.
Acetic acid
Control pH of disperse dye bath.
Carrier
Use to transport dye molecule to fabric surface.
Reactive dye
To dye cotton part of the blended.
Levelling agent
Use to reduce the surface tension of water.
Glauber salt
Use as electrolyte.
Soda ash
Control pH of reactive dye bath.

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 5.2 :  Recipe of Disperse dyeing
SL
Process Parameter
Unit
Dossing
Stock Solution
01
Disperse Dye (Blue)
%
2
1%
02
Dispersing Agent
g/L
1
1%
03
Acetic Acid
g/L
1
1%
04
Carrier
g/L
2
1%
05
Sample Weight
gm
5
------
06
M:L
------
1:40
------
07
Temperature
°C
100
------
08
Time
min
20
-------

Calculation:
                Total Liquor:                       Material Weight X L        { M:L }
                                                                = 5gm X 40
                                                                = 200 mL
               
                Disperse Dye:                    = (5 X 2%)/(1%) mL 
                                                                =  10 mL


Dispersing Agent :           =  (200 X 1)/(1% X 1000) mL 
                                                =  20mL


 Acetic Acid :                       =  (200 X 1)/(1% X 1000) mL 
                                                =   20mL


Carrier:                                 =  (200 X 2)/(1% X 1000) mL 
                                                =   40mL


            Initial Water :                     = Total Liquor - (chemicals)
                                                                = 200 - (10+20+20+40)mL
                                                                = 200-90 mL
                                                                = 110mL



Table 5.3 :  Recipe of Reactive dyeing
SL
Process Parameter
Unit
Dossing
Stock Solution
01
Reactive Dye (Red)
%
2
1%
02
Levelling Agent
g/L
1
1%
03
Glauber Salt
g/L
40
20%
04
Soda Ash
g/L
10
5%
05
Sample Weight
gm
5
------
06
M:L
------
1:40
------
07
Temperature
°C
60
------
08
Time
min
20
-------

Calculation:
                Total Liquor:                       Material Weight X L        { M:L }
                                                                = 5gm X 40
                                                                = 200 mL
               
                Reactive Dye:                    = (5 X 2%)/(1%) mL 
                                                                =  10 mL


Levelling Agent :               =  (200 X 1)/(1% X 1000) mL  
                                                =  20mL


 Glauber Salt :                    =  (200 X 40)/(15% X 1000) mL 
                                                =   40mL


Soda Ash:                            =  (200 X 10)/(5% X 1000) mL 
                                                =   40mL


            Initial Water :                     = Total Liquor - (chemicals)
                                                                = 200 - (10+20+40+40)mL
                                                                = 200-110 mL
                                                                = 90mL






Process Flow Chart:
Collection of PC blended pre-treated fabric.
↓
Dyeing of polyester part of the fabric by disperse dye.
↓
Dyeing of cotton part of the fabric with reactive dye.
↓
After treatment. 

Figure 5.1 : Process Flow Chart





Figure 5.2: Process curve of disperse dyeing
 
Figure 5.3: Process curve of reactive dyeing

Process Description:
                At first, we need to collect PC blended pre-treated fabric. Then we first dye the polyester part of the fabric with disperse dye here we used carrier method so 100°C is enough for dyeing polyester part. Then we dye the cotton part of the fabric with reactive dye here the temperature we used 60°C then some hot wash and cold rinsing is 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.
o   Observe the shade carefully to achieve cross effect.

5. Result & Discussion:
Sample Attachment:








Discussion: Here we observed the fabric absorbed dyes very well and we are not able to achieve our desired cross effect in case of both type of fibre.  


6. Conclusion & Comments: By doing this experiment we have learned about the dyeing of PC blended fabric with respectively by reactive and disperse dyes. Here we not able to achieve our desired cross effect, further we have to modify our recipe to achieve our desired cross effect.