High-strength thin sheath fibers

摘要

A fiber comprises a core, a sheath, and an additive that determines a desired physico-chemical parameter of the fiber, wherein the fiber is spun such that without increasing the concentration of the additive the desired parameter increases when the volume of the sheath decreases. Especially preferred additives include chromophores (e.g., a UV absorbing agent), flame-retardants, and adhesion promoters.