Purpose & Scope:

This test method gives the procedure to determine the size content of sized yarn. This is applicable to sized yarn or greige fabric.


  1. 0.1 N Hydrochloric acid,
  2. Hot plate/water bath.
  3. Glass beaker 250m1,
  4. Glass rod, Strainer, Scissors.
  5. Weighing balance.
  6. Measuring cylinder.
  7. pH paper.
  8. Hot Air Oven.
  9. Watch glass, stop watch, thermometer.
  10. Desiccators etc.


A.Take the sample and dry in hot air oven to remove any moisture.

B. Weigh about 2gm sample (note the exact weight, as A gm).

C.In the 250 ml glass beaker take 0.1 N Hydrochloric acid and heat the beaker on hot plate/ water bath at 90°C, After reaching 90°C when liquor starts to boil then cool down the temperature to 60°C.

D.Then add the preconditioned sample (“A” gm) in liquor and continue heating for 20 min ± 2min by maintaining the material to liquor ratio of 1:50.

E. After 20 min. remove from hot plate/ water bath. Carefully strain through strainer, rinse with cold water till free from acid.

F. Dry in hot air oven at 110°C for 01 hour. Cool in desiccator.

G. Weigh the dried sample and note the weight, as “B” gm,

H.Calculate the weight loss and size content and report.


Size Content = [(A-B) x100] /A

A= Weight of sample.

B= Weight of sample after acid treatment.

°/o Size Add-on = [(A-B) x100] /B

Actual Size %Add-on = % Size Add-on – % impurity present in raw yarn.


Report the % Size content and % Size add-on value.