The Influence of Processing Temperature on the Tensile Properties of Melt-Spun PLA Fibres and their Self-Reinforced Composites

The temperature during the consolidation of self-reinforced PLA composites has a significant effect on their mechanical properties. In the present work, the effect of the consolidation or processing temperature on the properties of melt-spun, highly oriented PLA fibres is experimentally studied through single fibre tests. It is shown that the Young's modulus and strain to failure of PLA fibres increases with exposure to consolidation / processing temperature, and the strength decreases more drastically. Using these data and findings from earlier studies, it is demonstrated that the dependence of the tensile properties of self-reinforced PLA composites on the processing temperature can be directly predicted from the single PLA fiber properties as a function of the processing temperature. This prediction holds true provided that the tensile properties of both the PLA fibers and self-reinforced PLA composites are measured using the same cross-head speed or strain rate.