Initial dispersion mechanisms of chopped glass fibers in polystyrene

Abstract

AbstractUnderstanding the mechanisms contributing to the initial stage of dispersion for individual fibers from chopped glass bundles is important for optimizing process conditions and obtaining fiber composites with optimal properties. These studies have shown that under model flow conditions, bundles have two separation modes, rupture and erosion. Both of these occur in a stochastic manner and are dependent upon the internal structure of the bundles. Under chaotic flow, both strain rate and total strain to which the material is exposed are important, though the effect of increasing strain rate decreases at higher total strains. To Obtain consistent minimal dispersion in model flows, the maximum nominal stresses required are higher than 104 Pa for simple shear and 106 Pa for squeezing flows. In contrast, stress levels around 104 Pa yield good dispersion under chaotic flow, implying the flow field is a more significant factor than the stresses imposed.