Study on conductive yarn-integrated knitted heating textiles with various wearability functions

Wearable heating textiles are increasingly popular for thermotherapy applications; however, ensuring their durability and comfort presents a significant challenge in design and material selection. Herein, rib-knitted heating fabrics were modified in the active regions by adjusting knitting structural parameters, including knit, float, and tuck stitches. Four sample types were fabricated: 3R (three courses of knit), 3F (three courses of float), 3 T (three courses of tuck), and FTF (first-course float, second-course tuck, third-course float), using stainless steel and cotton yarns. The durability and comfort properties of these knitted heating textiles, tailored for wearable heating textiles, were evaluated. The 3F sample exhibited the highest thermal resistance, air permeability, and water vapor permeability due to its structural characteristics. Moreover, after six washing cycles, surface temperature reductions of 10.31% (3R), 12.21% (3 T), 8.85% (3F), and 9.12% (FTF) were recorded. Bending cycles, perspiration, and detergent exposure showed no notable effects. However, in the 3 T structure, loosely bound fibers resulted in significant fiber breakage, leading to an 8.92% temperature change following 5000 abrasion cycles.