Abstract
This paper presents a two-fluid shear cell model that may apply to the long-discontinuous-fiber melt system made from AS4 carbon/poly-ether-ketone-ketone. As a 370°C melt at rest, PEKK forms a thermotropic liquid crystal structure. An LDFMS extended in the direction of the fibers generates a magnified local shearing strain rate through relative fiber motion. The boundary between the LCP and isotropic fluids could be a function of the fiber volume fraction, the generated shear strain rate, and the nucleation strength of the fiber surface. The two-cell model shows some of the consequences of generating a two fluid system within the LDFMS. The experimental data in this paper demonstrate the LCP character of PEKK and the nucleation effects of the AS4 fibers.
