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ABSTRACT
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 methods. 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.
There are three major spinning methods for cottonring spinning (RS), open-end rotor spinning (OERS), and Murata vortex spinning (MVS). Ring spinning is a continuous spinning system in which twist is inserted into a yarn by a circulating traveller. The yarn twist insertion action and winding action take place simultaneously by means of a rotating spindle. Even though ring spinning has a low production rate, the ring spun yarn structure is generally accepted as the fundamental or basic structure in spun yarn technology. In open-end rotor spinning, fiber bundles from the sliver feed stock are separated into individual fibers with an opening roller and an air stream. The separated fibers are re-collected in the rotor groove and converted into a continuous strand of yarn by a passage through the doffing tube [9]. Many open-end spinning methods have been invented, but none have been more successful than open-end rotor spinning. Production speeds up to 200 m/min can be achieved, although the method is generally only applicable for yarn counts up to 20 tex in 100% cotton spinning. Recently, Murata vortex spinning (MVS), based on the air jet spinning technology by the Murata Machinery Company in Japan, has been commercialized. With the...