A Study On Moisture Transmission Through Multi-Layer Fabrics In Cold Climated

In cold environmental condition, clothing is therefore including underwear, the middle sweater and the outer coat. If the moisture from the wearer can't transmit freely through the above three layer textiles to outside, people will feel uncomfortable. It is important for developing new textiles to study the moisture transmission through fabric, even multi layer fabrics under subzero climate, which will guide a right way to dress.The details of this paper are described as follows:At first, the relationship between the water vapor transmission through fabric and climate condition is explored. The water vapor transmission of 9 type fabrics is measured with the distillation cup method at 12℃, 22 ℃, 32℃, and 38℃. The results are showed that the water vapor transmission through fabric will increase if the temperature rises and there are different of this change trends in different fabrics.Second, the moisture transmission through fabric under conventional and subzero climate is compared. The mass of water vapor evaporation from the bath, condensation on the surface of fabric and water vapor transport through fabric, temperature and relative humidity in two sides of fabric of 1, 2, 4 and 6 hours are measured on a novel apparatus under -20 ℃ and 20℃ climate condition. Experimental results are showed that the accumulation of condensation on fabric surface increases linearly with time under both conventional (20℃) and subzero (-20℃) climate and the rate of moisture transfer through fabric is little affected by the accumulation of condensation on fabric surface. Nevertheless, the waterevaporation from the water bath, condensation on fabric surface and vapor transmission through the fabric is greater and the moisture vapor resistance is smaller under the subzero (-20°C) climate than those under the conventional (20 °C) climate.Third, the moisture transmission through multi-layer fabrics is firstly reported. The mass of water vapor evaporation from the bath, condensation on the surface of multi-layer fabrics and water vapor transport through multi-layer fabrics, temperature and relative humidity in two sides of each fabric of 4 hours are measured under subzero (-20 °C) and zero (0°C) climate condition with the same apparatus. The results are showed as follows:(1) Condensation will occur on the surface of underwear and middle sweater fabrics.(2) The average moisture resistance falls gradually when the water vapor transport in the order of underwear, middle sweater and outer coat fabrics. And it is affected by the climate condition. Nevertheless, the water evaporation from the water bath, condensation on underwear and middle sweater surface and vapor transmission through the multi-layer fabrics is greater and the moisture vapor resistance is smaller under the subzero (-20 °C) climate than those under zero (0°C) climate.(3) Of course, underwear, middle sweater and outer coat affect the water vapor transmission through multi layer fabrics.The formula about the total average moisture resistance of multi-layer fabrics is also stated in this paper.