HIGH-STRENGTH CHEMICALLY RESISTANT THIN SHEATH FIBERS AND METHODS OF MANUFACTURE

摘要

Compositions and methods are directed to a sheath core fiber with a core and a sheath that comprises a fluoropolymer. Contemplated sheath materials include PVDF, ECTFE, and ETFE, and may have an apparent shear viscosity equal to or less than the apparent shear viscosity of the core material. Especially contemplated sheaths have a weight of 30% or less of the weight of the fiber. Preferred fibers are spun in a spin pack having a sheath material conduit with a ratio of open volume to sheath material mass flow of less than 0.75 for a fiber with a 30wt% sheath, of less than 1.15 for a fiber with a 20wt% sheath, and of less than 2.30 for a fiber with a 10wt% sheath.