A Study On Wet Comfort Of Summer Clothing Fabrics Under Non-standard Conditions

Water vapor discharged from human body continuously, and the differences between thelevels of environmental conditions and physical activity will affect the quantity of water vapor,namely the insensible evaporation. With the rising of ambient temperature and human bodyactivity level, the amount of insensible evaporation increases. The wet comfort of clothing cannotbe explained well by the measured water vapor permeability and the moisture absorption offabrics under standard conditions.In this paper,9normal summer clothing fabrics were collected and their water vaporpermeability and the moisture absorption were measured at20℃,25℃,30℃,35℃,40℃,45℃and50℃water temperature respectively by using evaporation method to simulate the insensibleevaporation and wearing status at different ambient temperature and human body activity level.Based on the experimental results and analysis to these results, the following conclusions canbe drawn out.(1) For the fabrics composed by same fiber, looser and thinner fabrics had better water vaporpermeability.(2) The rotation of the moisture cup stage increased the relative speed between the air andthe surface of the fabrics, and this promoted the diffusion of water vapor near the fabric outersurface and kept the higher gap of water vapor pressure between the outer and inner surfaces ofthe fabric, and finally resulted in the increase of fabric water vapor permeability.(3) with the increasing of water temperature, the amount of water evaporation increased, so did the value of fabric WVP’, while the percentage of water vapor transmitted through the fabricsdecreased. This will cause the increase of humidity of the under clothing microclimate and lead tothe decrease of clothing wet comfort.(4) The relation between the amount of water evaporation without the fabric coveringWVPemptyand the temperature T under the non-standard conditions in this paper can be given inthe form of power equation：WVPempty=0.026·T3.686. With the increasing of water temperature, theamount of water evaporation without the fabric covering increased, and the rate of increasing risetoo.(5) With the increasing of water temperature, the average amount of nine fabrics’ moistureabsorption increased with it.(6) For summer clothing fabrics, the effect of the fabrics’ hygroscopic capacity to the wetcomfort is much less than the fabrics’moisture permeable ability.