Water absorbtion to Cobb

Water absorbtion of raw paper is determined with the Cobb Test. Standards for this test are ISO 535, EN 20535 and TAPPI T 441. 

The principle is:

• The dry specimen is weighed
• The specimen is placed under a cylinder with an inner diameter of 100 cm². Specimen and cylinder lie on a rubber and a steel plate
• Approx. 100 ml water is poured into the cylinder
• After a specified waiting time, the water is poured out. Excess water is removed from the specimen with blotting paper and roller.
• The specimen is weighed while wet and the amount of water is calculated that 1 m² of specimen material would absorb.

The advantages:  

• Operator friendly instrument with quick clamping
• Also available for corrugated board