Validation of the integrated upward-horizontal-downward wicking test for providing intensive properties of textile fabrics

Traditional wicking tests provide information that is specific to the test fluid, apparatus, and conditions. As a result, this information cannot be used to make predictions about wicking rates beyond the respective test parameters. In contrast, a new upward-horizontal-downward (UHD) wicking test has been presented that provides intensive properties of fabrics in the form of permeability (k) and effective capillary radius (R-c) as functions of saturation (S). The UHD test was developed using water as the test fluid. If the k-S-R-c relationships are truly intrinsic to a given fabric, then they should not depend on the test fluid. Here, we conducted the UHD test on a knit fabric using three different test fluids characterized by different surface tensions, densities, and viscosities: dodecane, tetradecane, and hexadecane. All fluids fall on the same k vs. S and k vs. R-c curves, proving that these curves are intrinsic characteristics of the fabric. We then used the k-S-R-c properties to successfully predict the in-plane horizontal and downward wicking rates of two different fluids, octanol and water, in the fabric. These results validate the UHD wicking test as a method for providing intensive properties of textile fabrics which can then be used for predicting wicking rates.