The Mechanics of Fiber Migration

Abstract

In this paper the theories of fiber migration have been reviewed. Modification of an analysis of migration in a 7-ply structure has been carried out. The frequency of migration is predicted for two models, and it suggests that slack forma tion is the mechanism for outward migration in an open structure, while forced buckling of the central fiber is the corre sponding mechanism for a packed structure, such as occurs in practical spinning. The slack needed to initiate outward migration was analyzed and found to be dependent on the geometry and fiber arrangement in the zone hetween the roller nip and the point of yarn formation. On the other hand, the buckling strain in practical spinning theoretically depends on the surrounding fiber matrix, the twisting tension, and the mechanical properties of the fiber.