Structure and Properties of MVS Yarns in Comparison with Ring Yarns and Open-End Rotor Spun Yarns

The structure and properties of Murata vortex spun yarns are investigated and compared with ring and open-end rotor spun yarns. Cotton yarns are spun from the same lot of Australian raw cotton fibers using the Murata vortex, ring, and open-end rotor spinning methods. Yarn structures are observed with an optical microscope equipped with a digital camera. Based on the digitized photographs, fiber arrangements are classified as wild, wrapper-wild, wrapper, belly-band. and core. Yarn diameter, yarn helix angle, wrapper fiber pitch, wrapper fiber crest, wrapper fiber length for a one-turn twist, and wrapper fiber helix angle to the yarn axis are examined, and yarn parameters such as tenacity, evenness, and hairiness are evaluated. The mechanical properties of dry relaxed yarns are measured with Kawabata Evaluation System instruments. Attempts are made to relate yarn structure differences to differences in the yarn formation mechanism for the three spinning meth ods. The differences in measured yarn properties such as evenness, hairiness, bulkiness. tenacity, compression properties, and bending properties can be explained by the observed differences in the yarn structure.