A phenomenological study of the mechanical properties of long-fiber filled injection-molded thermoplastic composites

摘要

Tensile and flexural tests on specimens cut from rectangular injection-molded plaques show that long-fiber filled thermoplastic composites are complex, nonhomogeneous, anisotropic material systems. Like all fiber-filled materials, they exhibit through-thickness nonhomogeneity as indicated by differences between tensile and flexural properties. The in-plane orientation of fibers in through-thiekness layers causes the material to have in-plane anisotropic properties. However, these long-fiber filled materials exhibit an unexpectedly large level of in-plane nonhomogeneity. Also, the effective mechanical properties of these materials are strongly thickness dependent. The thinnest plaques exhibit the largest differences between the flow and cross-flow tensile properties. These differences decrease with increasing thickness. A methodology for part design with this class of materials is discussed. [References: 12]