Moisture Vapor Transmission Rate
The Moisture Vapor Transmission Rate ( MVTR ), also called Water Vapor Transmission Rate ( WVTR ), is a measured value for the permeability of water vapor through materials (including food and drug packaging , wound dressings , building materials ) and the breathability of functional textiles . To determine the MVTR value, the amount of water that evaporates through an area of one square meter in 24 hours is measured. The MVTR is expressed as the evaporated water in grams per square meter per day. As a result of various methods of determination (ASTM, BS. Iso) and also deviating permissible test parameters, the measurement conditions must also be specified for the measurement results. The results are therefore not readily comparable with one another.
This value allows statements to be made about the water vapor permeability, i.e. the breathability of a material. Depending on the level of the evaporation rate z. B. the wound care materials used for dry or moist wound treatment . In the outdoor industry, for example, breathability plays a crucial role in comfort, so that body sweat can be transported to the outside and not collect under the layer of clothing. Breathability is often also defined by manufacturers in terms of water vapor resistance.
Individual evidence
- ↑ Standard ASTM E96
- ↑ Standard Tappi T 4646 om-12 ( Memento of the original from September 24, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Breathability, MVTR, RET - what does that mean? Accessed February 8, 2019 (German).
