A new insight into the dynamics of fibre migration in ring spinning

Fibre migration in yarns is thought to take place in the spinning triangle (ST), where high tensioned edge fibres tend to compete for a low tension state by displacing inner fibres outwards to occupy the core position–the tension mechanism. The angular alignment of fibres in the drafted roving–the geometric mechanism–is also considered to contribute to this movement. Although there is an understanding of the mechanisms of fibre migration, the outward movement of core fibres, from a low to high tension state and through a thick web of gripped fibres–moving inwards–has not been fully understood. In this study, we have attempted to reanalyse the classical migration mechanism from a new perspective and establish its relationship with a real ST using a new reflective imaging technique. The study findings suggest that pre-twist region in the ST, which is generally considered to be stable at one location, shows a rather dynamic oscillatory movement–a result of continuous change in ST tension profile. Spinning trials were conducted to confirm a relationship between pre-twist movement and degree of fibre migration.