Water Vapor Transfer and Condensation Effects in Multilayer Textile Combinations

Abstract

In cold environments, the moisture produced by the human body will partly condense within the layers of an ensemble. Water vapor transfer and moisture accumulation in the layers of different four-layer combinations are analyzed at several moderately cold temperatures with a sweating arm, which simulates the thermophysiological behavior of a man's arm. The permeability of the samples and their condensation rates strongly depend on the outside climate and the hydrophilicity of the outer layers. The differences in effective water vapor resistances between the ensembles are small in a climate of 20°C and 65% RH, but become larger with decreasing outside temperature. The formation of condensation is the smallest for samples with a hydrophilic membrane laminated on the hydrophilic inner side. Hydrophilic layers placed underneath the outer shell generally absorb more moisture than similar hydrophobic layers, revealing probable liquid moisture transfer from the outer shell to the inner layers of the combinations.