Three Dimensional Numerical Simulation of Continuous Filaments Migration in Polypropylene Twisted Yarn Part I: Qualitative Study

A three dimensional (3D) numerical model of filaments assemblies has been developed in this paper. The twist behaviour of the multifilament is simulated by using the ABAQUS finite element package and modelling the yarns as 3D continuum elements. This study describes the phenomenon of migration with different levels of twist and tension. The filament trajectory has been visualised for yarn made of a 3 layered structure (external, internal and central) of 19 filaments to show the existence of the migration phenomenon. Furthermore, a study of the mean filament position is evaluated for all filaments in the yarn. The twisting tension and twist values appear to be the most influential variables that control filament migration in twisted yarns.