Comparison of standard test methods for measuring the performance of waterproof, windproof, and breathable shell fabrics

The purpose of this study was to create a database of information on the performance characteristics of 28 waterproof, windproof, and breathable (WWB) shell fabrics used in outdoor apparel and to correlate and compare data collected with eight different test methods. Water resistance was measured according to ASTM D 751 (Mullen test—with and without a fabric support and the hydrostatic head test). Wind resistance was measured using the air permeability test (ASTM D 737). Breathability was determined by measuring the water vapor transmission rate (WVTR) (ASTM E 96 upright and inverted cup tests, JIS L 1099 desiccant inverted cup) and the evaporative resistance (ISO 11092 sweating hot plate).; Fabrics with a microporous or monolithic treatment had negligible or no air permeability (i.e., high wind resistance). Fabrics with only a DWR finish had higher air permeability. The air permeability test had negative and statistically significant correlations with all water resistance tests. The fabrics could withstand higher levels of water pressure before penetration on the Mullen test with a support than on the standard Mullen test, and both generated higher pressures than the hydrostatic head test, probably because the pressure was applied at a faster rate. Sixteen of the fabrics were not penetrated at the maximum water pressure on each test. The water resistance tests had high significant correlations with each other. There appeared to be no trade off between water resistance and breathability for the majority of WWB fabrics since microporous and monolithic treatments provide both performance characteristics. High WVTRs and low evaporative resistance values are desirable for fabric breathability and comfort. The WVTRs were consistently highest when measured with the desiccant inverted cup, followed by the inverted cup, followed by the upright cup. All breathability tests showed significant correlations with each other, except for the upright and inverted cup. The desiccant inverted cup and the sweating hot plate showed the highest correlation (−0.93). The Japanese desiccant inverted cup method appears to be the most preferred method for manufacturers to use because it requires less fabric, time, and environmental controls, and the apparatus and supplies are not expensive.