Concurrent and real-time measurement of fabric liquid moisture management properties using a novel sweating simulator

Abstract

Evaluation of fabric liquid moisture management is an indispensable requirement while making new fabric or choosing the right kind of fabric for developing effective personal moisture management clothing. However, existing methods and instruments for measuring fabric liquid moisture management, though they have been effective in some ways, lack sufficient simulation of fabric-perspiring skin interaction, active body posture, and concurrent determination of dynamic liquid accumulation, evaporation, draining, and drying. This article explains a new instrument, the novel sweating simulator (NSS), for evaluating the fabric dynamic liquid moisture management properties in proximity to true wearing conditions. In addition to investigating the fabric wetting, wicking, and multidimensional liquid transport, thanks to its regional sweating zone and gravimetric measuring principle, the instrument accurately measured the dynamic liquid distribution by recording the real-time changes in mass of liquid supplied, evaporated, and dripped through the fabric. On the NSS, eight different kinds of moisture management knitted fabrics were tested to evaluate and distinguish their dynamic liquid moisture management properties. The findings showed that fabric construction and constituent fiber nature are the most important elements in controlling fabric weight and liquid dynamic distribution. In addition, the liquid distribution of fabric was found to be significantly affected by the effect of the adjustable supply rate and slope of the sweating plane. Owing to its comprehensive testing potential and versatility, it is anticipated that the NSS will be extremely useful in developing and evaluating the next-generation high-performance moisture management fabrics for various clothing and industrial applications.

Evaluation of fabric liquid and moisture management properties at simulated skin and sweat temperatures using an advanced novel sweating simulator

“…The NSS accuracy of measurement for all 24 tests was analyzed in terms of the agreement between the cumulative mass of liquid evaporated, dripped, and left in the fabric by the end of test, against the known mass of liquid supplied. 47 As shown in Figure 5, the accuracy varied from just over 99–100% in 22 of 24 tests, while it was still more than 98% in the remaining two tests.…”

“…The fabric specimen was fixed on the sweating plane delicately with the specimen transporting template. 38 A constant extension of 5 mm was applied to each specimen. Immediately after the test specimen was fixed, the instrument load measuring system was set into operation.…”

“…A detailed description of the NSS construction, methodology, operations, and measuring of the liquid mass distribution can be found in our previous work. 38 However, in the present study, the sweating plane of NSS was further equipped with temperature sensors (k-type thermocouples, ETA, TT-K-30, 260 degrees, wire diameter: 0.25 mm) to monitor and regulate the surface temperature of the sweating plane around the average sweating skin temperature.…”

“…Comparison of measurements at temperature controlled and non-temperature-controlled versions of NSS In this section, the liquid and moisture management properties measured at temperature controlled NSS were compared to those for non-temperaturecontrolled NSS, reported recently. 38 As shown in Figure 13, the values of liquid evaporation, accumulation, and discharge corresponding to P1, while the values of drying efficiencies corresponding to P2 were chosen for comparison. Figures 13(a) and 13(b) demonstrate that liquid evaporation during P1 and drying efficiencies during P2 are significantly greater for temperature controlled NSS (simulating skin and sweat temperatures of about 36.0 C and 35.3 C, respectively) than for non-temperature controlled NSS (with sweat and sweating plane temperatures adapted to 20 C of the ambient temperature).…”

“…Recently, a non-temperature control version of the NSS was reported to measure the fabric liquid accumulation, evaporation, draining, and drying properties simultaneously in real-time, whereas the measurements were not made at the simulated skin and sweat temperatures. 38 Besides, characterization of the fabric's in-plane directional liquid flow rates at the employed sweating rate was also missing in that version. As a result, it was envisioned that an improved version of NSS with the ability to measure the in-plane directional liquid flow rates through the fabric under simulated skin and sweat temperatures, would be more informative for realistic estimation of fabrics' personal sweat management performances considering real-life scenarios.…”