Investigation of effect of fiber migration and blend irregularity within yarn cross-section on knitted fabric thermal comfort performance

The scope of study, cotton-acrylic yarn samples with 75-25%, %50-50%, 40-60% blending ratios were produced with three different yarn numbers; 20/1 Ne, 24/1 Ne, 30/1 Ne and three twist coefficients; 3.5 α, 4 α, 4.5 α. Knitted fabric samples were manufactured from the yarn samples with same stitch density and pattern. Half of the fabric samples were applied bleaching process other remaining part was evaluated as raw fabric. Thus, totally 27 yarn samples and 54 knitted fabric samples were obtained. The yarn cross-sectional samples were sliced with microtome. The image frames of yarn cross-sections were acquired via digital microscope. Image processing algorithm was developed to calculate yarn structural properties; fiber migration and packing density. On the other hand, fabric comfort properties; were determined by using related standards. The porosity of the fabric samples was also measured by applying image processing algorithm. The results were evaluated statistically and the effect of independent parameters; yarn number, blending ratio, twist coefficient on dependent parameters; yarn fiber migration, yarn packing density, yarn diameter. Also effect on fabric performance; air permeability, water vapor permeability, wickability and porosity were revealed.