|Sorption behavior is the term used to describe the characteristic of hygroscopic goods, as a function of temperature and of a particular water content of the product, to absorb or release water vapor from or into the ambient air until a state of equilibrium is established.
Sorption behavior is determined by a partial pressure gradient, in which in accordance with the diffusion law water vapor always flows from the higher to the lower partial pressure until a vapor pressure equilibrium is established. Intake of water vapor is here known as adsorption, while release of water vapor is known as desorption (see Fig. 3).
Adsorption and desorption curve;
Y-axis: water content
X-axis: relative humidity