Full text | Abstract: The physical-mechanical properties of yarns, similar to those of other solid matters, are a function of their structure. Yarns are composed of fibres of different lengths and shapes, resulting in yarn spirals with varying radii, which can form kinks at intervals, and even project from the yarn surface. Therefore, it is not the overall length of the fibre that contributes to the yarn strength, but only the spun-in part of it. In this work, the spinning-in coefficient KF was determined for carded and combed rotor-spun yarns, in accordance with the theory of spun-in fibres in yarns. Measurements have shown that the inner structure of cotton rotor-spun yarns, presented by the value of the coefficient, varies with the spinning system used. The KF values for combed yarns show that most of the fibres were incorporated into the yarn, which gives better physical-mechanical characteristics. In carded yarns, this coefficient is slightly lower, indicating a greater number of looped fibres and fibres incorporated into the yarn with less than half their lengths. |