Washability and Electrical Performance Evaluation of Jacquard Conductive Knitted Fabrics Based on Fuzzy Comprehensive Assessment

This study presents a systematic evaluation of 2-layer conductive Jacquard knitted fabrics with a birdseye backing designed for wearable electronic applications. Three sets of samples with 9 different proportions of conductive yarn (27 samples) are designed on a computerized flat-knitting machine, and three indicators (conductive yarn usage ratio, resistance change ratio after washing, and temperature variation) are examined. The 2-layer Jacquard structure enables conductive yarns to form loops on both the technical face and back, thus producing continuous and interlocked conductive pathways. The experimental results show that the proportions of pattern dots for the conductive yarns determine the amount of conductive yarn used in a 2-layer Jacquard structure with the same technical parameters. For the samples with 10–90% pattern dots, the conductive yarn consumption ratio ranges from 34.80% to 65.18%. After 10 washes, resistance change ratio ranges from 27.66~55.54%, which show a moderate electrical stability. After 10 washes, the heating temperature increases by 15.6 to 19.67 °C, which show good thermal properties. Finally, a fuzzy logic evaluation is conducted with objective indicator weights. The findings provide quantitative evidence for the material–structure integration of conductive knitted textiles and support their potential for applications in next-to-skin smart garments.