Breathability and Dynamic Evaporative Cooling Heat Flow of a Ripstop Defence Fabric

This study investigated the breathability and dynamics of evaporative cooling heat flow through a defence fabric. Two ripstop fabrics were developed by changing the floats in the delimiting plain grid. The influence of fibre kinds was studied using weft threads made of 100% cotton, 65% polyester/35% cotton and 100% polyester. First, the breathability of used materials was evaluated using relative water vapour permeability (RWVP), resistance (Ret) and air permeability. Second, a more in-depth examination was conducted using evaporative cooling heat flow kinetics, and certain distinguishing variables that describe the various evaporative cooling heat flow phases were found. Those parameters consider the evaporative heat flow at 0 seconds, defining the skin’s first contact and the time spent to reach equilibrium. The results demonstrated that adding polyester to a fabric makes it more breathable, cooler, faster drying, and provides a more refreshing sensation on initial contact with the skin. Adding floats to the delimiting plain grid reduces the fabric's porosity and breathability.