Modelling of flow-enhanced crystallisation in fibre spinning

Abstract

A modified version of an earlier two-phase model and algorithm developed for melt spinning of semi-crystalline polymers is discussed. Modifications include coupling of the flow-enhancement factor in the Avrami crystallisation kinetics based on the melt phase free energy, and introduction of both phases at the start of the integration algorithm to produce a 'seamless' transition. Introduction of the extended Pom-Pom model for the melt phase is used to incorporate chain entanglement effects These modifications provide a framework for modelling the melt spinning of PLA fibres. Excellent fits of literature data for the low and high speed spinning of PLA and racemic mixtures with single sets of parameters are shown. In the latter case, prediction of the co-crystal form is also demonstrated.

Keywords:

• FLOW-ENHANCED CRYSTALLISATION
• FIBRE SPINNING
• PLA
• MODELLING