Durable Water Repellent (DWR) Test Methods and Acceptable Limits
Durable Water Repellent (DWR) is verified through AATCC 22 after ISO 6330 washing. Knowing how the method works avoids rejecting fabric that actually meets the requirement.
Method overview
AATCC 22 after ISO 6330 washing defines sample size, conditioning and calculation, so values are comparable only within the same revision. Working figures for Durable Water Repellent (DWR) normally sit around after 20 washes still grade 3+ in mainstream production. Note AATCC 22 after ISO 6330 washing on the tech pack so nobody tests against an older revision.
Result interpretation
Read the value together with construction notes; after 20 washes still grade 3+ is only meaningful for similar fabrics. Record elastane content alongside Durable Water Repellent (DWR), because blends shift the measured value. A result outside after 20 washes still grade 3+ usually points to process drift rather than to the fibre itself.
Typical limits
Buyers commonly write after 20 washes still grade 3+ with a stated tolerance, then verify against AATCC 22 after ISO 6330 washing. Keeping reference values for Durable Water Repellent (DWR) lets suppliers quote without extra sampling rounds. Ask for conditioning details together with AATCC 22 after ISO 6330 washing, since both affect the reading.
Sources of variation
Conditioning time, operator technique and shade all influence the result. Working figures for Durable Water Repellent (DWR) normally sit around after 20 washes still grade 3+ in mainstream production. Note AATCC 22 after ISO 6330 washing 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 Durable Water Repellent (DWR), because blends shift the measured value. A result outside after 20 washes still grade 3+ usually points to process drift rather than to the fibre itself.
