Effect of knitting structure and yarn composition on thermal comfort properties of bi-layer knitted fabrics

In this work, nine bi-layer knitted samples with varied knitting structures and made up of different yarn compositions were fabricated, and their thermal comfort properties were investigated. The thermal comfort properties were evaluated by breathability, water transfer properties, thermo-physiology properties and dynamic cooling properties, and their relationship with fabric knitting structure and yarn composition were investigated statistically. It was observed that bi-layer knitted fabrics with meshes at one side had better air permeability, moisture management properties, drying performance, thermo-physiological properties and dynamic cooling function, but lower wicking height than bi-layer knitted fabrics with trim and symmetrical structure (without meshes). The composition of nylon and polyester filaments with varied wettability as outer and inners layer of bi-layer knitted fabrics, respectively, improved the water one-way transport capacity significantly. In particular, bi-layer fabrics with asymmetric structure and made up of yarns with varied hydrophilicity as each layer have excellent moisture management capacity. Moreover, fabrics made up of yarns with finer fibers exhibited better thermal comfort properties.