SIEVE RESIDUE

This method covers the best procedure for the determination of fesidue on sieve for water insoluble pigments and extenders.

APPARATUS AND REAGENTS :

1. Sieve of the reqired specification.
2. Soft camel hair brush.
3. Evaporating dish 250 ml.
4. Beaker 250 ml.
5. Glass rod.
6. Oven.
7. Ethanol.

PROCEDURE :

1. Weigh accurately to the nearest mgs about 15 to 20 gms of the test sample. 25 gms should used for heavier pigments/extenders.

2. Transfer the sample into a 250 ml beaker. (Add few drops of ethanol or any suitable wetting agent for organic pigments)

3. Add 100 to 150 ml of water into the beaker and slowly stir with the help of a glass rod, till the sample in thoroughly wetted.

4. Transfer the contents of the beaker into the specified sieve and hold the sieve under tap water. Such that the tap water flows at a low pressure.

5. Gently brush the contents with brush till washings flowing out the sieve and hold the sieve done not contain any sample particles. Generally it takes about 5 to 10 mns for the completion of the above procedure.

6. Collect the residue life in the sieve carfully into a previously weighed clean evaporating dish. Take care to transfer the particles adhering to the brush.

7. Dry the dish along with the residue in an oven at 120^o C.

8. Test to be done in duplicate.

CALCULATION :

A = Wt. of the test sample.
B = Wt. of empty evaporating dish.
C = Wt. of evaporating dish and the residue.
C-B = Wt. of the residue.