Sheep breed – an important parameter for ultrasonic wool scouring

Abstract

Abstract During the scouring of sheep wool in an ultrasonic bath without detergents at a frequency of 38 kHz, the effect of sheep breed on scouring efficiency was investigated at temperatures of 20 °C and 40 °C. The breeds Merino, Zwartbles, Cigája, and Valaška, which differed in fiber fineness and wool grease content, were studied. Scouring mass loss after 10 and 20 min of scouring, residual wool grease content, and fiber surface morphology were evaluated. The residual wool grease content remained highest in Merino wool (approximately 30% after 10 min and 19% after 20 min), whereas Cigája wool contained less than 2% residual wool grease under all experimental conditions. The measured results were supplemented with microscopic images of the fiber surface. During ultrasonic scouring, the following parameters were identified as statistically significant: sheep breed, bath temperature, and the interaction between sheep breed, bath temperature, and scouring time. In the measurement of residual wool grease content, sheep breed and scouring time were found to be significant, with sheep breed having the dominant effect. The results indicate that the efficiency of ultrasonic scouring depends on breed-specific wool characteristics and that the scouring conditions should be optimized.