Name of the Experiment: - Scouring and bleaching of cotton yarn at double stageScouring and bleaching of cotton yarn at double stage..

Scouring: Scouring: Definition: Definition: The tern scouring applies to the removal of impurities such

as oil, wax gum, soluble impurities and solid dirt commonly found in textile material. The process consists essentially of treatment with alkali, a good supply of water is essential.

Objects: - Objects: - The main object of this process is to iron the fabric. To remove natural as well as added impurities of essentially

hydrophobic character as completely as possible. To increase absorbency of textile materials. To leave the fabric in a highly hydrophilic condition without

undergoing physical or chemical treatment or damage. Scouring process depends on: - Scouring process depends on: -

The type of cotton. The color of cotton. The cleanliness of cotton. The twist and count of the yarn. The construction of the fabric.

Recipe: -Recipe: -Recipe for scouring: -Recipe for scouring: -

Caustic soda (NaOH): 3 gm/L

Soda ash (Na2CO3): 4 gm/L

Wetting agent: 0.5 gm/L

M: L: 1 15

Temperature: 90 c

Time: 2 HourRecipe for scouring: -Recipe for scouring: -

Hydrogen Peroxide (H2O2) : 5 gm/L

Stabilizer = 0.6 gm/L

M:L : 1 15

Temperature: 90 c

Time: 2 Hour CalculationCalculation: - (for scouringscouring)

Sample weight = 5 gm Amount of liquor = 5 15 = 75 mL

Caustic soda require = = 0.225 gm

Soda ash require = = 0.3 gm

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Wetting agent = gm

(For bleachingbleaching)

H2O2 require = gm

Stabilizer require = = 0.045 gm

Amount of water = 75 ml

Stock solution: -Stock solution: -

Stock solution for scouring:

2 % stock solution for solid = 100 gm liquor + 2 gm material

2 % stock solution for liquid = 98 ml liquor + 2 ml cc

1. Amount of 2 % solution caustic soda = (100 0.225) 2 = 15 cc

2. Amount of 2 % solution soda ash = (100 0.3) 2 = 11.25 cc

3. Amount of 1 % solution wetting agent = (100 0.0375) 1 = 3.75 cc

4. Amount of additional water = 75- (11.25++15++3.75)

= 75- 30

= 40 cc

Stock solution for bleaching:

5. Amount of 2 % solution H2O2 = (100 0.375) 2 = 18.75 cc

6. Amount of 1 % solution stabilizer = (100 0.045) 1 = 4.5 cc

7. Amount of additional water = 75- (18.75+4.5)

= 75- 23.25

= 51.75 cc

Precaution:-Precaution:-

1. Chemical should mix with water uniformly.

2. In this case scouring is done in closed vessel; so, the time of heating

should be observed.

3. We should take the wt of different chemicals very carefully.

Conclusion: -Conclusion: - Scouring process is very important practical for weight processing technology lab. It removes different impurities and increases the absorbency of water.

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