Waterproof, so that no wet penetrates the garment in rain or snow. Windproof, to protect the body against chilling. Breathable, i.e. perspiration is channelled out as water vapour, while the skin is able to breath. Furthermore, functional clothing today is expected to be fashionable, a requirement that is not difficult to meet however, as membranes protect invisibly from within against the weather, leaving the outer fabric to focus on fashion. The membrane Different systems.
Membranes vary in basic material and structure.
The hydrophilic membrane Sympatex is made of polyester and has no pores. Water-proofing against moisture from the outside is achieved by a closed surface. The perspiration is transferred outwards by moisture-absorbing molecules. The temperature difference between body and air outside ensures that the direction is correct. This is also used in kitchen technology under the name Teflon.