Structure-property development in the spinning of composite fibers

Two novel approaches were utilized to generate drawn composite fibers from thermoplastics and thermotropic liquid crystalline polymers (TLCPs) with non-overlapping processing temperatures. In one process, a single TLCP melt stream was surrounded by a sheath of polypropylene (PP) just prior to melt spinning to generate fibers possessing a sheath-core structure. The other process involved the distribution of continuous TLCP melt streams within a separately plasticated PP melt to form a composite melt which was drawn to create matrix-fibril fibers consisting of a PP matrix reinforced with VB fibrils. The effect of fiber drawing on the development of mechanical properties was investigated for these two distinct fiber structures.