Water absorption of paper/Cobb test

In short — AI-generated

The Cobb test according to DIN EN ISO 535 measures the amount of water absorbed by the surface of paper or board within a defined time period. A metal cylinder is clamped onto the sample, filled with a specific volume of water, and after the set contact time, the excess water is removed and the sample is weighed to determine the mass increase.

The resulting Cobb value indicates the water absorbency of the material, which is critical for assessing its suitability for printing, gluing, or barrier applications. A low value signifies high water resistance, helping developers ensure the packaging maintains its integrity when exposed to moisture or liquid-based adhesives.

Text is AI-generated; based on test method data curated and verified by Innoform.