Water Absorbtion to Cobb
The Cobb Test is used to determine water absorption by paper. Standards for this test are ISO 535, EN 20535 and TAPPI T 441.
Test principle:
- the dry specimen is weighed
- the specimen is clamped between the lower end of a vertical hollow cylinder with an internal cross-section of 100 cm² and a rubber mat supported on a steel plate
- approx. 100 ml of water is poured into the cylinder
- after a precisely defined time the water is poured out and excess water removed from the specimen using blotting paper and a roller
- the specimen is weighed while wet and the amount of water absorbed by 1 m² of specimen material is calculated.
Advantages:
- easy to operate
- also available for corrugated board.
