A dual-scale study on the permeability and wicking performance of plain knitted fabrics based on experiment and simulation

The development of sweat-management knitwear and garments has been a recent research hotspot, but studies on the transfer of liquid water within knitwear based on microstructures are scarce. This study focused on plain knitted structures, using recycled polyester yarn (50D/24F) to knit five samples with different densities. The vertical wicking height was measured within 30 min. The results showed that the higher the density, the greater the wicking height per minute in the first 13 min. After 13 min, the wicking height of Sample 1 (lowest density) gradually decreased compared to Sample 2 (lower density). Through microscopic measurement characterization and macroscopic experiments, using the fabric measurement-calculation method (FMM), the permeability K FMM in the warp and weft directions are between 6.33 × 10 −13 –15.91 × 10 −13 m 2 and 5.97 × 10 −13 –14.81 × 10 −13 m 2 , respectively. Using the empirical parameter C at 15 min, the simulated values at this time point most closely match the experimental values, with the warp error not exceeding 3% and the weft error not exceeding 4%. At 30 min, the maximum error is less than 15.7%; in the weft direction, and the maximum is less than 19.8%; using the Micro-CT scanning-calculation method 1 (method-MSM-1), the permeability K MSM-1 in the warp and weft directions are between 5.11 × 10 −13 –12.42 × 10 −13 m 2 and 4.82 × 10 −13 –11.56 × 10 −13 m 2 , respectively. Similar results were obtained using the method-MSM-1 compared to method-FMM. Additionally, it considered the tortuosity of capillaries in the fabric. Based on method-MSM-2, the warp and weft permeability K MSM-2 are between 6.55 × 10 −13 –23.31 × 10 −13 m 2 and 6.16 × 10 −13 –21.94 × 10 −13 m 2 . In the warp direction, the simulated values for sample 1 remain within 1.5 cm of the experimental values up to 240 s, while those for samples 3 and 5 do so up to 660 s; the respective relative errors for samples 1, 3, and 5 are no greater than 12%, 18%, and 20%, respectively. In the weft direction, the simulated values for sample 1 stay within 1.5 cm of the experimental values up to 300 s, and those for samples 3 and 5 do so up to 660 s; the respective relative errors for samples 1, 3, and 5 are no greater than 13%, 19%, and 21%. Through the simulation analysis of the capillary absorption process, this study provides theoretical support for the development of a new generation of one-way moisture-wicking fabrics.