Scouring Loss for Knitted fabric
SCOPE
This standard prescribes a method for determining the scouring loss in jerseys, Y-neck, plain knitted, WORSTED textile materials.
PRINCIPLE
The test specimen is taken and its moisture is removed. Then test specimen is scoured, washed and its oven-dry mass is determined. The scouring loss is calculated on the basis of oven-dry mass of the test specimen.
APPARATUS
- Desiccator.
- Filter Paper thimbles
- Oven – 102 ± 2°C
- Soxhlet extraction apparatus.
- Extraction Flask- 250 ml
- Rotary evaporator
REAGENTS
Benzene and methyl alcohol Mixture solution (3:2).
Preparation of extraction flask
- Heat the extraction flask at 105 ± 3°C in hot air oven for 2 hours.
- Remove the flask and cool in Desiccator.
- Weigh quickly and note the dry weight of flask.
PROCEDURE
- Cut about 10 g of the fabric. This shall constitute the test specimen.
- Dry the test specimen in the drying oven at 105 ± 3°C, cool in a Desiccator
- Weigh the specimen accurately to nearest 0.05 percent.
- Press the sample evenly into the filter paper thimble covered with cotton wool and place it in a Soxhlet extractor with the tarred flask
- Start the extraction of specimen with the benzene and methanol mixture (3:2) for 4 hours at the rate of 5 extractions per hour.
- Distill off the solvent from the extract in rotary evaporator.
- Dry the flask in oven at 105°± 3°C for 2 hours.
- Weigh to constant mass and determine the mass of dry residue.
CALCULATIONS
Calculate the scouring loss by the following formula
Scouring loss, percent = 100 x W1 / W2
Where
W1 = mass of the dry residue
W2 = mass of the test specimen.
REFERANCE: – IS 2360:1977- Specification for jerseys, Y-neck, plain knitted, worsted Textiles.