Yarn porosity and its relationship with the dyeing behavior

PurposePorosity is one of the most important properties of the textile substrate. It can influence the comfort of a garment by affecting its breathability and thermal conductivity. During the process of dyeing, the dye liquor comes in contact with the substrate; the absorption of the dye liquor into the substrate will be dependent on its porosity. The concept of porosity between the yarns of fabric is a common phenomenon; however, the porosity between the fibres in the yarn can also influence the dyeing behaviour of the fabric.Design/methodology/approachIn this research, ring and rotor yarns of 25/s and 30/s counts are considered as textile substrates. The porosity of yarns was determined theoretically and experimentally using the image analysis method.FindingsIt was found that theoretical porosity is independent of the yarn manufacturing method. In addition, 30/s yarn was more porous as compared with 25/s yarn having a higher pore area. Rotor yarns had higher porosity, dye fixation and K/S as compared with ring yarns. Dyeing behaviour was also dependent on the count of yarn. Specifically, 30/s yarns have higher dye fixation as compared with 25/s yarns. However, 25/s yarns were dyed with deeper shades showing higher K/S values. Also, 25/s yarns are coarser than 30/s yarns having higher diameters and cross-sectional area, thus resulting in deeper shades and higher K/S values.Originality/valueThis novel technique is based on the comparative study of the porosity of various types of yarns using the image analysis technique. This investigation shows that the porosity between the fibres in the yarn can also influence the dyeing behaviour of the yarn.