Water Absorption According to Cobb/Cobb Test

 ISO 535, EN 20535 and TAPPI T 441

The Cobb test is used to determine the water absorptivity of paper, cardboard and corrugated cardboard. The Cobb Test is carried out according to the following standards: ISO 535, EN 20535 and TAPPI T 441.
Cobb water absorption test

Cobb Tests with Zwick

  • Easy operation.
  • The dry specimen is weighed and placed under a vertical cylinder with an internal cross-section of 100 cm².
  • Specimen and cylinder rest on 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 is 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.

Specimen Preparation

Good testing starts with a good specimen. One might say truism. But, as is so often the case, the devil is in the details. Testable specimens are produced by clean cuts, precise angular specimen, parallelism, service life of knives and quick work. To ensure cutting devices are designed for real world application we leave the production to our partners; the specialists who do this on a daily basis.