Thermo-physiological Comfort Characteristics of Fine-denier Polypropylene Fabrics

Three types of polypropylene knitted fabrics in terry pile (uncut) structures with a similar knit design are developed by using fine denier filaments to make the inner layer for extreme cold weather clothing. The denier per filament is varied to assess its influence on thermo-physiological comfort properties, viz. thermal conductivity, thermal resistance and absorptivity, air permeability, water vapour permeability and wicking. The thermal properties are measured with an Alambeta instrument, and in-plane liquid flow through the fabrics is measured by using a gravimetric in-plane wicking tester. A statistical analysis is carried out at the 95% significance level for different experiments to establish the specific trend exhibited by the fabrics. It is observed that the water uptake increases, but water vapour permeability decreases with a decrease in filament denier. The thermal properties and air permeability values do not show any specific trends with filament denier. The porosity value is observed to be similar for all three developed fabrics.