Changes in dimensional, mechanical and comfort properties in cotton and wool double weft knitted fabrics caused by washing

This study examines the dimensional, mechanical (bursting strength, ball traverse elongation, compressibility, and compressive resilience), and comfort-related properties (air permeability, water vapor resistance, volume electrical resistivity, and water retention) of double-weft knitted fabrics made from cotton and wool, using 1 × 1 rib and Milano rib structure, that develop during the washing process. The results reveal that yarn composition, knit structure, and washing conditions have a significant influence on the fabric’s performance after washing, particularly in terms of dimensional stability and structural integrity. Cotton fabrics exhibited greater dimensional changes after washing compared to wool fabrics. Isotropic shrinkage was observed in cotton Milano rib and wool 1 × 1 rib fabrics, while anisotropic dimensional changes occurred in cotton 1 × 1 rib and wool Milano rib fabrics. Wool fabrics had shorter initial stitch lengths and a higher mass per unit area, indicating coarser yarns and denser knit structures. Cotton fabrics, particularly those with a 1 × 1 rib structure, experienced notable reductions in bursting strength, compressibility, and air permeability. In contrast, wool fabrics, especially with a 1 × 1 rib structure, showed improved mechanical properties after washing. Across all samples, comfort-related properties declined after washing, with cotton fabrics experiencing more significant deterioration, likely due to increased sensitivity to conducted washing stresses. Overall performance rankings indicated that wool fabrics in the 1 × 1 rib structure maintained the greatest stability after washing, whereas cotton fabrics in the same knit structure exhibited the most substantial deterioration in performance. These findings provide valuable guidance for selecting yarn composition and knit structure type to enhance the dimensional stability, and functional performance of knitted products. The influence of yarn process and structure has not been taken into consideration.