Tensile properties and fracture morphology of viscose yarn at high strain rates

The tensile behavior of textile yarns at high speeds is a problem of great practical interest. Higher speeds induce higher strains and, consequently, a higher probability of yarn breaks. In order to ensure acceptable quality even at the highest spinning or weaving speeds, tensile instruments and testing conditions have to be improved. Therefore, we have developed a new high-speed dynamometer and a new method to subject yarns at strain rates similar to those found in current textile operations. We use this high-speed dynamometer to investigate the influence of high strain rates on the tensile properties and fracture morphology of a technical viscose multifilament yarn. Data reveal that rapid straining usually results in higher yarn tensile properties. SEM photos show a characteristic granular fracture morphology, but the yarn surface becomes less granular as the strain rate increases.