Physical Properties of Wool Fibers at Various Regains

The paper reports determinations of stress changes which take place in wool fibers held at constant extension of 1.5 or 10% and subjected to various relative humidity changes. Stresses may be very different according as equilibrium at a given relative humidity is approached by absorption or desorption of water by the fiber. At 1.5% strain, when approach was by absorption, for all relative humidities used the stress fell to a level lower than when the fiber was in water and then increased. A qualitative explanation is given in terms of changes analogous to sol-gel transformations.