Investigation of the properties of sirospun yarns

In ring spinning technology, twisting and winding processes are performed by the same element and this causes some technological limitations. Besides, doubling and twisting processes used in conventional ply-yarn spinning technology are generally applied by low-productive machines. All these limitations triggered new investigations and new developments on spinning technology. One of them is called twist spinning. A conventional ring-spun machine can be modified to a twist spinning machine easily by changing and adding couple of machine parts. As it can eliminate doubling and twisting processes, twist spinning technology provides numerous important advantages such as lower energy, lower machine and investment expenses. Siro-spun spinning system is the most widely used technology in twist spinning. Siro-spun spinning is one of the most widely used spinning technology invented by CSIRO and IWS. The main principle in siro-spun spinning is, two parallel fibre strands are fed simultaneously in the drafting zone and these two fibre strands twist together on each other when they leave the front roller. In this study, 100% cotton, 100% Tencel, 100% micro Modal and 100% polyester yarns were produced by using ring and siro-spun spinning technologies. Yarn counts were kept stable as Ne 40/2 for siro-spun yarns and plied-yarns for all raw materials. Physical, mechanical and structural properties such as unevenness, hairiness, imperfections, breaking force, breaking elongation, diameter, density, roughness, shape and friction of all yarn types were measured and spinning technologies were compared with each other statistically by using ANOVA. Results show that considering all raw material groups, hairiness values of siro-spun yarns have lower hairiness degree. For unevenness values, results showed that cotton and polyester siro-spun and plied yarns have approximate values which makes siro-spinning a good alternative of ring spinning. In addition, it can be easily realized that siro-spinning has an improving effect on unevenness values of micro Modal and Tencel yarns. Siro-spun yarns and plied yarns have quite approximate quantities of thin places and thick places. Besides, cotton and micro Modal plied yarns have lower neps quantities. In general, in all material groups yarn-to-yarn friction coefficients are lower for siro-spun yarns. Homogenous twist structure of siro-spun yarns causes smaller diameter and lower roughness and at the same time density and shape values are greater.