Droplet Drying Kinetics During Evaporation from a Defence Textile Fabric: A New Method

During physical activities, sportswear and protective garments are frequently exposed to perspiration, which aids in regulating body temperature. The excess skin moisture must be swiftly evacuated from the fabric to prevent discomfort. Therefore, comprehending the drying kinetics of textile fabrics utilised in defence and sports garments is crucial. Regrettably, the current drying rate methodologies are unreliable due to non-isothermal conditions and uncontrolled velocities. This study investigated the droplet drying kinetics during evaporation from a ripstop defence fabric. A novel method was developed based on a modified Permetest skin model test protocol that adheres to the ISO 11092 standard. The proposed mathematical model incorporates structural and geometrical parameters of the sample fabric (average warp and weft diameters, warp and weft densities, weft and warp crimp, and sample thickness), as well as evaporation parameters (liquid properties and environmental test conditions). Visualising the droplet drying kinetics revealed three distinct evaporation phases. It was determined that the raw materials and fabric design structures significantly influence the evaporation kinetics. Fibres with hydrophilic character exhibit faster drying rates compared to hydrophobic fibres. In the context of ripstop defence fabrics, incorporating floats in the delimiting grid results in slower fabric drying.