Scouring and bleaching of 100% cotton knitted fabric at combined stage
Experiment Name: Scouring and bleaching of 100% cotton knitted fabric at combined stage.
Theory: Scouring is the process of removing the impurities such as oil, fat, wax dust and dirt from the textile material to make it hydrophilic.
Bleaching is the chemical treatment for removal of natural coloring matter from the fabric. The source of natural color is organic compounds with conjugated double bonds, by doing chemical bleaching the discoloration takes place by breaking chromophore. The material appears whiter after the bleaching. Scouring and bleaching can be done together at a time. This process is more effective for the pretreatment.
Nature of Sample : 100% cotton knitted gray fabric.
Apparatus Required :
Beakers.
Glass Rod.
Pipette.
Measuring Cylinder.
pH meter.
Tripod Stand.
gas burner.
Thermometer.'
Pot.
Process Sequence/ order:
Collection of 100% cotton fabric sample
⇩
Scouring and bleaching at 100deg C for 45 min.
⇩
cold rinsing
⇩
hot wash at 80°C for 5 min.
⇩
cold rinsing
⇩
drying
Recipe of Scouring and bleaching:
Parameters:
Temperature:100@C
Time: 1 Hour
Fabric Weight: 5gm
M:L = 1:30
ph=11
Calculation:
Total Liquor required
Fabric Weight = 5gm
M: L = 1:30
Required amount of liquor = 5 X 30
= 150mL
Detergent: 1g/L
= (150X1g/L) / (1%x1000)
= 15ml
NaOH: 3g/L
= (150X3g/L) / (2%x1000)
= 22.5ml
H2O2: 4g/L
= (150X4g/L) / (3%x1000)
= 20ml
Peroxide stabilizer: 1g/L
= (150X1g/L) / (1%x1000)
= 15ml
Sequestering agent: 1g/L
= (150X1g/L) / (1%x1000)
= 15ml
Initial Water required = Total liquor➖Chemicals
= 150 - (15+22.5+20+15+15)
= 150-87.5 mL
= 62.5mL
Function of Chemicals:
Detergents:
The detergent is a surface active agent which is used for cleaning the surface of fabric. It decrease the surface tension and emulsify fats, oils and waxes, and suspend other dust dirt etc.
NaoH:It neutralizes acidic medium and maintains alkaline medium for perfect operation.
Sequestering agent: Deactivate metal ions.
Peroxide Stabilizer: The decomposition of peroxide under the influence of alkali is adjusted by stabilizer.
H2O2: It is the bleaching agent. It used to produce permanent whiteness on fabric.
Process Curve
Sample Attachment and Observation:
Comments: The treated fabric is whiter compared to the non treated fabric.
Pre-cautions:
- All chemical measures are taken properly.
- Temperature maintains properly.
- Burner used very carefully.
- Time is maintained according to recipe.
No comments