Moisture Content (absolute)
31.10.2011 - Cartonboard Know-How
Absolute moisture describes the weight of the water content of cartonboard in relation to its dry weight.
DIN EN 20287
The moisture content is determined in accordance with DIN EN 20287. With the gravimetric method, the moisture amount that evaporates during the drying of the material is determined in % of the initial mass. Drying to constant weight takes place at 105 ° C +/- 2 ° C in an oven.
Additional details – practical relevance
Fibers which are used for cartonboard show a hygroscopic behaviour. They absorb or release moisture until they are in equilibrium with the ambient air. Therefore, substances whose material properties are affected by a change in the moisture content have to undergo a sufficient air conditioning before the actual examination can start. The humidity is dependent on the type of pulp (groundwood pulp, mechanical wood pulp, recycled fibers) and of the grammage. Virgin fiber grades are preferably produced with higher moisture content than recycled grades. Changes in dimensions and flatness, creasing, folding and gluing processes are influenced by the moisture content of the board.