Melt-spun polymer fibers with liquid core exhibit enhanced mechanical damping

Highlights: • With decreasing fiber diameter it becomes increasingly difficult to post-fill a very long hollow fiber with a liquid. • We demonstrate the continuous production of liquid-filled polymeric fibers using an adapted melt-spinning approach. • The continuous liquid-core fiber exhibits enhanced energy dissipation properties compared to plain polymeric fibers. • This novel fiber represents a new type of damping element to be integrated into fiber-reinforced lightweight structures. We demonstrate the continuous production of liquid-filled polymeric fibers in a stable melt-spinning process at the pilot plant scale. Different polymers and liquids could successfully be combined over a wide range of core-sheath dimensions. The ability to produce a continuous liquid-core fiber (LCF) is attractive since post-filling of a hollow fiber with similar dimensions is not practical. We characterized the mechanical properties of the LCF's with particular attention to their damping properties. A LCF can exhibit significantly enhanced damping properties compared to plain polymeric filaments of same dimensions. Some possible damping mechanisms are discussed. This new type of fiber could find future applications in the enhancement of the damping factor of fiber-reinforced lightweight structures.