Water Vapour Transmission (MVTR) Test Methods and Acceptable Limits
Water Vapour Transmission (MVTR) is verified through ISO 15496 breathability. Knowing how the method works avoids rejecting fabric that actually meets the requirement.
Method overview
ISO 15496 breathability defines sample size, conditioning and calculation, so values are comparable only within the same revision. Working figures for Water Vapour Transmission (MVTR) normally sit around higher means more breathable in mainstream production. Note ISO 15496 breathability on the tech pack so nobody tests against an older revision.
Result interpretation
Read the value together with construction notes; higher means more breathable is only meaningful for similar fabrics. Record elastane content alongside Water Vapour Transmission (MVTR), because blends shift the measured value. A result outside higher means more breathable usually points to process drift rather than to the fibre itself.
Typical limits
Buyers commonly write higher means more breathable with a stated tolerance, then verify against ISO 15496 breathability. Keeping reference values for Water Vapour Transmission (MVTR) lets suppliers quote without extra sampling rounds. Ask for conditioning details together with ISO 15496 breathability, since both affect the reading.
Sources of variation
Conditioning time, operator technique and shade all influence the result. Working figures for Water Vapour Transmission (MVTR) normally sit around higher means more breathable in mainstream production. Note ISO 15496 breathability on the tech pack so nobody tests against an older revision.
Documentation
Record the standard revision on every report, because older versions can differ from current practice. Record elastane content alongside Water Vapour Transmission (MVTR), because blends shift the measured value. A result outside higher means more breathable usually points to process drift rather than to the fibre itself.
