Thermal Resistance Properties of Paratrooper Clothing

Abstract

Combat free fall paratroopers’ (CFF) protective clothing, comprising of non-woven insulating material, inherently flame retardant Nomex fabric and cotton fabric combinations are studied under simulated conditions of conduction and sweat using Thermolobo-II technique. The results show that Non—woven insulating materials exhibit high thermal resistance in dry contact method under moderate wind velocity, whereas the thermal resistance values measured under wet conditions is significantly lower. The effect of air layer thickness, permeability and other important parameters, such as porosity, surface area have also been considered and correlated to assess the overall performance of protective clothing ensemble.

Analysis of thermal comfort characteristics of moisture management finished knitted fabrics made from different yarns

“…As mentioned in literature [15], the structures with increasing thickness need not necessarily exhibit higher values since thermal resistance is found to be independent of the nature of fabric.…”

“…Indu shekar et al [15] stated that the water vapor sorbed by substrate replaces the entrapped air in the interstices between fibers and yarns, and hence, it reduces the insulating effect of the material. The extent of reduction in clothing insulation falls in proportion to the amount of moisture, which is expected to vary with the component fibers.…”

Thermal comfort properties of simulated multilayered diaper structures in dry and wet conditions

“…The reduction in thermal resistance values could be explained by the replacement of the entrapped air with water. As mentioned in the literature [37], structures with increasing thickness do not necessarily exhibit higher values since thermal resistance is found to be dependent on the nature of material.…”

Experimental Measurement and Prediction of Thermal Resistance in Paratrooper Clothing

“…Specific surface area of nonwoven samples was calculated taking into account fineness and density of fiber [1]. The air permeability of nonwoven samples was measured and correlated with fiber fineness to calculate the surface area.…”

“…The most serious problem however, is that the soldier varies his activity frequently and at a short notice, hence the level of insulation that he requires varies frequently. This appears to be an area open to considerable research work to achieve full understanding of the most important factors for heat and moisture loss under actual wearing conditions [1].…”