The analysis of mechanical yarn properties in cyclic loads

Abstract

The paper presents how deformation properties of single ring-spun cotton yarns depending on yarn fineness are determined. For this purpose mechanical properties of cotton yarns with a yarn count of 20, 30 and 50 tex were analyzed. The methods of determining yarn breaking properties and the cyclic method of determining elastic, viscoelastic and plastic deformation of yarn on the yarn tensile tester were used. The above tested properties were analyzed, and the areas of elastic, viscoelastic and plastic yarn deformations were calculated and graphically displayed. By applying cyclic tests yarns were plastically deformed even at low load percentages (5 % of elongation at break). When there are further increases, elongations to the area of plastic deformation remain almost unchanged in contrast to the elastic and viscoelastic areas which by increasing the load undergo certain changes. Relevant knowledge can contribute to a better regulation of weaving conditions as well as to an increase in quality and weaving efficiency.