Monofilament melt spinning of PET-based antimicrobial composite fibers with hybrid fillers

Antibacterial fibers play a crucial role in enhancing hygiene, safety, and comfort in textiles. This study explores the monofilament melt spinning of polyethylene terephthalate (PET) composite fibers incorporating hybrid fillers of copper (Cu) and a low-melting-point alloy (In₅₁Bi_32.5Sn_16.5). The research evaluates the impact of these fillers on spinnability, morphology, thermal degradation, and electrical resistance of the melt spun fibers across various loading levels. A key motivation for this approach is the incorporation of copper as an embedded antimicrobial agent. Unlike surface-coated treatments, copper dispersed within the fiber matrix has the potential to deliver durable antimicrobial functionality, making these fibers particularly attractive for medical, hygienic, and performance textile applications. Additionally, the use of low melting alloy, which is significantly more cost-effective than copper, provides a low-cost pathway to functional fiber production without compromising melt processability. The study identifies some challenges but successful translation of polymer-metal composites from extrusion to continuous, spinnable monofilament fibers of good strength and well dispersed metal particles inside the polymer matrix. This work stands out as one of the few efforts to scale up lab-formulated composites into melt-spinnable and post-drawable monofilaments. Overall, the research lays a foundation for affordable, scalable antimicrobial fibers with potential applications in advanced textile systems.