Sorption hysteresis of spruce wood – Measurement and modelling.

This paper focuses on the sorption hysteresis of spruce wood (Picea Abies). First, its hysteretic behaviour was measured under laboratory conditions at a constant temperature in several steps covering the entire hygroscopic range. The measurement had the form of loops with the same relative humidity at the beginning and end of each step. Then two hysteresis models, the independent domain theory based IPM model and empirical Frandsen's model, were successfully fitted to the measured data. To do so, modifications to their shape parameters have been proposed. Only a minor change was necessary in the case of the IPM model, more extensive in the case of Frandsen's model. Testing and application in dynamic simulation showed that the IPM model is able to capture more accurately and reliably the hysteretic behaviour of spruce wood. The use of the Frandsen's model should be preceded by a critical analysis due to the risk of pumping error. [ABSTRACT FROM AUTHOR]