Water Soluble Matter
- Reflux Condenser
- Oven – 105° to 110°C
- Flat Bottom Flask- 250 ml
- Heating element.
- Filtration assembly
- Distilled water.
CONDITIONING OF TEST SPECIMEN
Prior to test, test specimens shall be conditioned for 24 hours to moisture equilibrium in a standard atmosphere at 65±2 percent relative humidity and 27°± 2°C temperature
Preparation of evaporating dish:-
- Heat the evaporating dish at 110°C in Hot air oven for one hour.
- Remove the dish and cool in Desiccator.
- Weigh quickly and note the dry weight of dish
- Condition the rest specimens to moisture equilibrium in the standard atmosphere and weigh accurately 1 or 2 g of test specimen.
- Put the specimen in the flask and add water to make the liquor to material ratio of 20:1(i.e. 20 ml of water for 1 g of test specimen) for all textiles, except wool.
- If the test specimen is wool, the liquor to material ratio should be, 50: 1
- Connect the flask to condenser and rapidly bring to boiling.
- Continue to boil the liquor under reflux for 60 minutes.
- After one hour, disconnect and remove the flask while liquor is still boiling.
- Immediately close the flask with glass stopper.
- Rapidly cool the flask and its content to room temperature (27±2°C).
- Filter the extracted liquid and wash the residue with amount of water.
- Take the filtrate and washings in previously weighed evaporating dish and evaporate the extract to dryness on a hot plate or steam bath.
- After evaporation, shift the evaporating dish into a hot air oven and dry the residue at 110°C for two hours.
- Cool the dish in a Desiccator and weigh quickly.
- Repeat the process of drying in oven till the weight change between two successive weighing is less than 0.005 gm.
Calculate the total water soluble matter as follows
W1 = weight in gm, of the conditioned test specimen