Methodology for determining the vapor permeability of waterproof materials

The article is devoted to the assessment of vapor permeability of composite membrane textile materials, which are widely used in the production of waterproof light industry products. These are clothes and shoes for active leisure and tourism, special clothes and shoes for workers, firefighters, medical workers, uniform for military personnel and many other products. The range of composite textile materials opens new possibilities for manufacturers of garments to provide protection from adverse weather conditions, improvement of microclimate in underwear space with significant weight reduction of package of materials. Vapor permeability index of composite membrane textile materials is the basic one for determining the level of their comfort. The indicator of water resistance is considered decisive in assessing their quality, since the purpose of composite membrane textile materials is to be waterproof. The authors propose a methodology for determining the vapor permeability of waterproof materials, allowing to simulate various operating conditions, and a device for its implementation. In contrast to the existing means of vapor permeability studies, the device used in the described method allows to create different air flow rate over the samples and to conduct tests at different water temperatures to simulate human sweating. With its help, it is possible to determine the vapor permeability of composite membrane textile materials under conditions close to operating ones and compare these materials with each other. With the help of the developed method and device, eight articles of composite membrane textile materials with different polymer layer structures were tested. According to the results of the study, it was found that the samples of materials with a hydrophilic membrane have the best ability to remove evaporation.