Some Torsional Properties of Wool Fibers

The variation of torsional rigidity of wool fibers with relative humidity is investi gated by dynamic methods at frequencies ranging from 115 to 0.00028 cycles/sec. Measurements are reported of the equilibrium values at various humidities and of the kinetics of change of rigidity as the humidity is altered. It was found that any change in the relative humidity surrounding the fiber first led to a reduction and then to a partial recovery of the rigidity. Equilibrium values of the rigidity varied about 3.5 to 1 over the frequency range used, the effect being most pronounced at the higher humidities. A qualitative discussion of the data is given.