Thermal Properties of Different Kinds of Polyester Knitted Fabrics

Thermal comfort behavior of four different types of polyester yarn single jersey knitted fabric has been studied. Spun, micro denier, continuous filament and hollow polyester yarns of 2 linear densities (106 denier and 177denier) have been used to prepare single jersey fabrics with three loop lengths (0.26 cm, 0.28 cm and 0.3 cm). The air permeability of continuous filament and micro denier yarn knitted fabrics is found to be higher than that of the spun yarn knitted fabrics. It is observed that 106 denier (0.3 cm loop length)micro denier fabric has the highest air permeability while 177 denier (0.26 cm loop length) spun yarn fabric shows the lowest air permeability, as compared to other fabric samples. Comparatively, the low air permeability characteristics are shown for coarser spun yarn fabric than the finer microdenier fabric. A significant difference is observed in water permeability among spun yarn, continuous filament yarn and micro denier yarn knitted fabrics at both linear densities of the yarn. The spun yarn of 177denier single jersey fabric has higher water vapour permeability and the continuous filament yarn fabric of 177 denier has lower water vapour permeability. The thermal conductivity value of 106 denier continuous filament polyester fabric is higher while that of microdenier polyester is lower. The statistical analysis shows significant difference between two different yarn linear densities and three different loop lengths of polyester yarn fabrics. Besides, different yarn and different count have impact on the comfort properties of single jersey fabrics.