Impact of Ultrasound on Physical Properties of Wool Fibres

Abstract

The paper discusses the impact of the ultrasound treatment on physical properties of wool fibres. Wool samples of different fineness grades (from grade 70s to grade 40s) are treated by ultrasound waves of 30 kHz frequency, for 30-minute periods, in water as medium and at room temperature. The changes of the dimensional and morphological properties - length, linear density, diameter and degree of crimp, as well as mechanical properties - tensile force, resistance to torsion and resistance to friction, are estimated employing the standard test methods, mostly the single fiber test methods. A number of observations on the wool sample was necessary for the confidence level of 95 %. Testing results suggest that the changes imposed by ultrasound occur on the structural and the morphological level, as well as on the fiber surface. The beneficial impact of ultrasound on wool properties was estimated especially regarding the increased resistance to friction and increased degree of crimp on the fine wool samples.