A review on manufacturing, characterization, and applications of melt-spun bi-component fibers

Bi-component fibers, formed by co-extruding two polymers into a single filament, offer superior versatility and performance compared to conventional monocomponent fibers. This review presents a unified structure–processing–property–application correlation model for melt-spun bi-component fibers, systematically linking cross-sectional geometry, polymer compatibility, and spinning parameters to end-use performance–an approach not comprehensively consolidated in earlier reviews. Emphasis is placed on polymer selection, fiber cross-sectional configurations (e.g., core/sheath, side-by-side, segmented-pie), and processing parameters such as draw ratio, take-up velocity, and heat setting. State-of-the-art spinning equipment and computational simulations of fiber formation dynamics are also examined. The mechanical, thermal, and dynamic properties of various polymer combinations are compared, highlighting their suitability for specialized applications such as artificial turf, hygiene products, smart textiles, and energy-harvesting fabrics. The review also outlines commercial developments and the growing role of bi-component fibers in sustainable, functional textiles, showcasing their potential as next-generation high-performance materials.