Melt Spinning of Highly Stretchable, Electrically Conductive Filament Yarns

Electrically conductive fibers are required for various applications in modern textile technology, e.g., the manufacturing of smart textiles and fiber composite systems with textile-based sensor and actuator systems. According to the state of the art, fine copper wires, carbon rovings, or metallized filament yarns, which offer very good electrical conductivity but low mechanical elongation capabilities, are primarily used for this purpose. However, for applications requiring highly flexible textile structures, as, for example, in the case of wearable smart textiles and fiber elastomer composites, the development of electrically conductive, elastic yarns is of great importance. Therefore, highly stretchable thermoplastic polyurethane (TPU) was compounded with electrically conductive carbon nanotubes (CNTs) and subsequently melt spun. The melt spinning technology had to be modified for the processing of highly viscous TPU-CNT compounds with fill levels of up to 6 wt.% CNT. The optimal configuration was achieved at a CNT content of 5 wt.%, providing an electrical resistance of 110 ohm cm and an elongation at break of 400%.

Automated summary

Electrically conductive fibers are essential for various applications in modern textile technology, especially for highly flexible textile structures like wearable smart textiles and fiber elastomer composites. Combining highly stretchable thermoplastic polyurethane with electrically conductive carbon nanotubes through melt spinning technology can achieve both electrical conductivity and elasticity in the resulting yarns, with optimal performance achieved at a CNT content of 5 wt%.