Abstract:

The spinning triangle is a critical region in the spinning process of yarn. Its geometry influences the distribution of fibre tension in the spinning triangle and, thus, affects the properties of spun yarns. Therefore, taking appropriate measures to influence the spinning triangle geometry and thus improve the quality of yarn has attracted great interesting in recent years. During the geometry parameters, the horizontal offset of the twisting point to the symmetric axis of the nip line of the spinning triangle d has attracted more and more attention and is considered as one of the most critical factors influencing the quality of yarn. Therefore, in this paper, the effects of the horizontal offset d of the ring spinning triangle on yarn qualities is investigated. Firstly a theoretical model of the fibre tension distributions in the spinning triangle is given. Relationships between the fibre tension and horizontal offset of the spinning triangle are analysed theoretically. Secondly, as an application of the model proposed, the spinning triangles of a modified ring spinning system with a pair of offset devices which can change the horizontal offset ‘d’ continuously are studied. The distributions of fibre tension in the spinning triangle are simulated numerically, with the horizontal offset varying continuously. Furthermore the properties of spun yarns produced by the modified system are evaluated and analysed by using the simulation results.