Abstract
The testing of fabric moisture management is crucial for textile development in healthcare, activewear, personal protective equipment (PPE), etc. Research and industry rely on efficient quantitative testing by moisture management instruments, yet a deeper understanding of these devices and their ability to assess fabric moisture management is needed. This paper provides a thorough comparison of two fabric moisture management testing instruments, Moisture Management Tester (MMT) and WickView, by looking at each instrument’s performance in assessing various aspects of transverse and in-plane liquid transport. Based on the polyester and viscose fabrics tested in this study, the results indicate that MMT is more suitable for testing initial wetting and rapid transverse wicking in fabrics, whereas WickView is unique in detecting directional in-plane wicking in one dimension and two dimensional in-plane wicking. The study also highlights limitations for both instruments. Limited spatial resolution for MMT and temporal resolution for WickView affect the test results’ accuracy. WickView’s ability to provide raw data allows for customizable analysis, which makes it preferable for development and research, whereas MMT is more efficient for routine quality control. Furthermore, the importance of adapting grading systems and general moisture management values according to the intended end use is emphasized. This study is useful for professionals seeking a deeper understanding of instrument-based fabric moisture management testing.
Fabric moisture management is an important aspect of thermophysiological comfort, which has a major effect on overall comfort.1–3 Sufficient moisture absorption and transport is critical to functional textiles in apparel such as activewear 4 and protective clothing 5 but also in healthcare products,6,7 mattresses, 8 hygiene products,3,9 and drug delivery. 10 Textiles used in these applications must therefore be tested specifically for their moisture management performance.
There are several methods for examining moisture-related properties of textiles, including standard tests of absorbency,11–13 wetting or repellency, 14 horizontal and vertical wicking15,16 to name a few. The standard testing techniques are limited to their use of either infinite or limited, but large volumes of liquid, which are far from real-life circumstances, like human sweating. To overcome the limitations of these tests, several nonstandardized test methods for water absorption and moisture transport have been developed to test under purported realistic conditions.4,17,18 The Forced Flow Water Transport Tester 6 and Spontaneous Uptake Water Transport Tester 6 by Tang et al., Single-Pore Wicking Evolution Apparatus for Textiles 17 by Kim et al., Novel Sweating Simulator 4 by Shahzad et al. are some examples of nonstandardized methods. Many of the newer tests have evolved from the principles of earlier methods, highlighting their versatility. However, most of them require extensive manual handling, making them sensitive to operator variability and human error. Different individuals conducting the tests may obtain different results due to subjective interpretations and inconsistencies in the testing procedure. This subjectivity affects reproducibility and might affect the reliability of the results. Furthermore, manual tests are usually more time consuming, especially for those methods involving image analysis after testing, as mentioned by Parada et al. 19 As a result, extensive testing can decrease productivity for large sample sizes. These concerns can slow down research and development, quality control, and increase costs.
The Moisture Management Tester (MMT) is a testing device developed in 2002, manufactured by SDL Atlas, to objectively characterize moisture transport in and through fabric surfaces in a single step.9,20 Based on the MMT, AATCC (the American Association of Textile Chemists and Colorists) developed Test Method 195 Liquid Moisture Management Properties of Textile Fabrics in 2009. The MMT and its standard has been used extensively to assess moisture management performance in a wide range of materials developed for different purposes such as clothing apparel,21,22 sportswear, 23 disposable diapers, 24 food packaging, 25 wound dressings, 26 and membranes for oil–water separation, 27 to name a few.
WickView is another instrument developed more recently to mimic real-life use of clothing and nonwovens through its ability to test fabric moisture management both vertically and horizontally. Employing image technology and various light sources, WickView tracks the transverse and multidirectional movement of moisture in fabrics’ surfaces. 28 Based on WickView, a new test method, AATCC TM 217-2025 Liquid Moisture Management: Vertical and Horizontal Wicking – Image Analysis, has been developed and will be included in the upcoming AATCC 2026 Manual of International Test Methods and Procedures. 29 Until then, a test method, JHTM-017 similar to AATCC 195, and grading system JHTM 17 is provided inside WickView’s software TestWise.
MMT has been widely used in both industry and research in recent years, whereas WickView is newer to the market and has shown promising results in documented cases.30,31 For both instruments, a more comprehensive review of their performance in fabric moisture management assessment is lacking. Therefore, this paper aims to provide a thorough comparison between MMT and WickView, focusing on their operating principles and ability to assess fabric moisture management, which is referred to here as the fabric’s ability to transport water through its thickness, or along its surface.
MMT
MMT is an instrument designed to evaluate the moisture management properties of fabrics and provides results such as wetting time (s), absorption rate (%/s), wetted radius (mm), spreading speed (mm/s), accumulative one-way transport index (%), and overall moisture management capacity (OMMC). These results can also be graded according to MMT’s grading table, see Table I in AATCC 195. 32
Product features for MMT and WickView
Fabric specifications
P, polyester; V, viscose; F, multifilament yarn; S, spun yarn.
The MMT is box-shaped and stands upright on feet without axis or rotating parts. The device features an upper and lower disc, each equipped with concentric pin-shaped electrodes arranged in seven rings, spaced 5 mm apart (Figure 1). These electrodes detect voltage changes over time, which are used to measure the water content (%) in the fabric, 33 see Figure 2. The detection area is defined by the outermost electrode circuit, which has a diameter of 60 mm (Table 1). Inside the device, there is a container with test solution (or distilled water for priming). The test solution is typically a saline solution (0.9% NaCl) with a conductivity of 16 ± 0.2 mS, which enables the electrodes to track electrical resistance.32,34 However, Meng et al. have documented a study using synthetic urine as a test medium in testing disposable diapers. 24
Sketch of MMT concentric electrodes and their radii in millimeters.
User interface in the MMT system with visualization of water content.
When the MMT is not in use, the supply system is kept filled with distilled water inside the tubes to prevent corrosion. This means that before testing, the system must be manually primed by replacing the distilled water in the tubes with the test solution. During testing, a fabric sample is positioned on the lower electrodes, ensuring it does not cover the metal nodes in the corners. A clear protective shield is manually lowered to cover the test area. The upper electrode disc is then released to rest on the metallic nodes, ensuring contact with the fabric. A predetermined amount of test solution, which can be selected in the MMT software, is dispensed at a fixed rate (Table 1) onto the sample at the center of the electrodes.
After each test, any residues of the test solution must be carefully removed from the electrodes to prevent salt buildup. Liquid residues can be gently absorbed with a paper towel. Thereafter it is recommended to wait at least one minute before starting another test. In the case of salt buildup on the electrodes, it can be removed with distilled water. 32 After a series of tests, the priming procedure is repeated by replacing the test solution with distilled water which is pumped through the delivery system.
WickView
WickView is a device that uses an advanced imaging technology to track and record the transfer of moisture through a fabric, a similar technique to that previously presented by Yotsuda et al. 35 WickView provides several results such as wetting time (s), absorption rate (diff%), max wetted diameter XY (mm), max spreading rate XY (mm/s), spreading length X (mm), spreading length Y (mm), spreading rate X (mm/s), spreading rate Y (mm/s), wetting area (mm2), and overall WickView grade (OWVG), all of which can be graded according to the WickView grading table, 30 see Figure 3. The device has a fixed platform on feet and a mounted rotatable test chamber. The test chamber can be flipped from its original upright position for horizontal testing to a vertical position (Table 1). At the center of the test chamber is an inlet for a test cassette, with a detection area of 100 mm in diameter. A removable prism is situated below the test inlet with the high-resolution cameras positioned above and underneath the test cassette. 28 Using ultraviolet, natural, and infrared light, these cameras capture two frames per second and detect contrast differences between dry and wet fabric. 36
WickView’s grading table inside the software TestWise.
User interface of the software TestWise, including WickView’s image analysis.
Before starting a test, the software prompts the user to perform an automated priming, where the user needs to insert a priming cassette with a lintfree priming medium into the test inlet, then wait until the software has signaled that liquid has been pumped through the entire system. The priming liquid is the same medium used for testing, distilled or deionized water. So far, there are no reports of other test agents being used in WickView. The water supply comes from a water tank mounted outside on the instrument’s platform. The testing procedure involves mounting a fabric sample on the test cassette with a clamp and placing it into the test chamber. The orientation of the test chamber is then set to the desired position, horizontal or vertical. Once the test setup is complete, a specified volume of test solution is dispensed at a controlled rate onto the center of the sample (Table 1). Regular maintenance of WickView includes replacing the distilled water regularly and priming the device after each test. The prism should be kept free from dust, loose particles, grease, or water, which can be achieved using a microfiber cloth. 37
Experimental details
Materials
Three different polyester (polyethylene terephthalate) yarns and two types of viscose yarns, with different yarn configurations, were knitted into five interlock structures on a circular knitting machine, a Mayer & Cie double jersey jacquard type OVJA 1.6 EE. From each interlock fabric and for each test instrument, 10 samples were cut into required dimensions and conditioned for 24 hours according to ISO 139:2005 prior to testing. 38 The porosity of the fabrics was calculated according to Hsieh’s work (Table 2).33,39
MMT testing
The MMT was first primed for about 3 minutes. Then, a fabric sample of 80 mm × 80 mm was placed on the lower electrodes (without covering the metal nods in the corners) and the clear shield was pulled down over the test area. Thereafter, the test solution (0.9% NaCl) of 0.2 ml was dispensed onto the sample for 20 s. The total test time was 120 s in accordance with AATCC 195. After each test finished, test files and AATCC 195 measurements were exported to Excel®. All samples were tested with the wales aligned in the vertical direction (Y) and courses in the horizontal direction (X).
WickView testing
A piece of dish cloth (Wettex®) of 60 mm in diameter was used as a priming medium and placed in the priming cassette when priming took place. The priming step took about 13 s, while the test cassette was prepared with a fabric sample of 150 mm × 150 mm. The WickView tests were carried out in accordance with the James Heal (JHTM-017) proscribed method similar to AATCC 195, but with a dosage time adjusted to 20 seconds to better match AATCC 195 test conditions. The WickView results with grades are only generated by the software automatically if using normal dosage time of 10 seconds. However, since we wanted to use WickView’s grading system for slow dosage time, these results were selected and graded manually with the help of WickView’s grading table (Figure 3). The manual data selection used in this study is presented in Table 3. The authors chose to add wetting time for the top side to match AATCC 195 measurements and to use the same threshold as WickView has for wetting time on bottom/face side. The top wetting time is therefore included when giving the OWVG. In the following text, the skin side (application side of liquid) is referred to as the fabric’s top side while the face side is referred to as the bottom side of fabric. In addition, test files and WickView JHTM 17 graded measurements were exported after each completed test. As with MMT testing, all samples were placed with wales aligned in the vertical direction and courses in the horizontal direction.
Test and result settings for WickView
Results
Technical differences and limitations of the instruments
MMT and WickView both test fabric moisture management by measuring the fabrics’ transverse and in-plane liquid transport capacity. However, there is a noticeable difference between how these measurements are taken and interpreted by the two devices. Comparing the instruments side-by-side shows that they have their individual strengths and limitations.
The MMT operates with a radial spatial resolution of 5 mm, detecting only at its circuits with up to a maximum radius of 30 mm. This means that any features or variations that may occur between these 5 mm intervals go undetected, limiting the precision of spatial localization. Because the measurements are restricted to the fixed circular paths, wicking that follows a non-radial pattern cannot be characterized by the MMT.
WickView has a time resolution of 0.5 seconds, meaning it can only detect changes that occur at or persist over half-second intervals. As such, fast initial wetting or rapid wicking occurring within shorter timeframes cannot be captured. In addition, its spatial detection is limited to a maximum radius of 50 mm, meaning that in-plane wicking beyond that cannot be observed.
Definitions of the measurements
In addition to the differences in how MMT and WickView measure, the instruments also differ in how they present their results to the user. MMT generates preselected measurements and data processed by the device’s algorithm, whereas WickView’s measurements can either be preselected similarly to MMT or customized by the user as it also provides the raw data. To limit the scope of this study and make a reasonable comparison between MMT and WickView, the analysis focuses mainly on the preselected gradable data for both devices. However, as the opportunity for users to process raw data themselves may be of interest for future research, an overview of the raw data that can be obtained from WickView is presented in Table 4.
Options for raw data in WickView
Based on the terminology used for MMT’s and WickView’s gradable measurements, there seem to be some measurements that could be directly compared as they both refer to wetting time, absorption rate, maximum wetted diameter/radius, and spreading speed. But because the instruments measure in different ways, they have individual definitions for each measurement (Table 5).
Gradable measurements given by MMT and WickView
Top surface is the surface where the test solution is applied.
Wetting time is a measure of initial wetting on the fabric side that first comes into contact with moisture, which is detected on the specimen’s top side by MMT’s upper center pins whereas WickView captures it by using its upper camera. Wetting time measurement on a fabric’s bottom side is a way of determining the time it takes for the moisture to pass through the thickness of the fabric. In the MMT, the bottom wetting time is detected by the bottom electrodes whereas WickView detects when the water is first seen on the bottom side by its bottom camera. In addition, MMT’s definition of wetting is when the slopes for top or bottom of total water contents become greater than 15°.
According to WickView, the absorption rate is the ratio of boundary wicking areas in fabric’s bottom and top surfaces at 120 s and is expressed in diff% (Equation 1).
A value over 100% indicates that the fabric’s bottom surface wets over a larger area than the top surface. MMT’s accumulative one-way transport index (%) is similar to the definition of WickView’s absorption rate. However, the accumulative one-way transport index is used to determine the wicking through a fabric and is explained as the difference between the area below the water content curves for top and bottom fabric surfaces, divided by the total test time, see formula A1.4 in AATCC 195. 32 In Figure 5, the top water content curve in green is larger than the bottom water content curve in blue, leading to a negative accumulative one-way transport index. Note that due to MMT’s construction, the water content is determined based on the conductivity of the wetted part detected at the fixed circuits and should not be confused with wicking area.
Water content versus time curves from a single test of P-F48, showing the water content increase until it peaks around 22 s.
Theoretically, the MMT’s and WickView’s bottom wetting time can be a good measurement for how fast liquid moves through the fabric thickness, for relatively thin fabrics. Comparing the in-plane wicking in one dimension (MMT) or two dimensions (WickView) on the upper and lower sides of the fabric can, for relatively thin fabrics, be a good approximation of how much liquid has transferred from one side to the other. This is why both instruments’ bottom wetting time measurements, WickView’s absorption rate and MMT’s accumulative one-way transport index are categorized as measurements of transverse wicking (Table 5). However, for thicker fabrics, where the liquid might remain inside the structure, these measurements might be less relevant for transverse wicking.
Absorption rate is determined by MMT as the average speed of absorption for the fabric’s top and bottom surfaces during the initial rise of water content, i.e., from wetted point to the peak value point, and it is expressed in %/s. The initial rise of water content can be observed in the water content curve shown in MMT’s software and the value of absorption rate is presented in a table underneath (Figure 5). To determine the absorption rate at another time during the test interval would require raw data from the water content curves which are not accessible to the user.
WickView’s maximum wetted diameter XY (or maximum wetted length XY) is the largest distance across the wetted surface, which is not necessarily a circular surface and is independent of where the liquid application point is (Figure 6). WickView also determines the spreading length (mm) in X and Y directions, which are other ways of determining one dimensional in-plane wicking. As opposed to the maximum wetted diameter, the spreading length is the measured distance in either the horizontal (X) or longitudinal (Y) direction from the application point to the perimeter of the wicking area (Figure 6). The maximum wetted radius is the radius of the largest electrode ring that the liquid has reached in the MMT (Figure 6). Neither maximum wetted radius by MMT nor maximum wetted diameter by WickView should be seen as the true diameter of the wicking area, as liquid spreading on textiles does not usually form a circle.32,40
Max wetted length XY (a), max wetted length X (b) and Y (c) in WickView, and max wetted radius r in MMT with largest targeted concentric ring (d).
Spreading speed (mm/s) by MMT is the one dimensional in-plane wicking rate defined by the time it takes for the surface wetting in fabric to go from ring i to ring i + 1. The accumulative spreading speed is the sum of all rates from the inner concentric ring to the maximum wetted ring, which is the result provided by MMT, see formula A1.3 in AATCC 195. 32 WickView defines multiple one dimensional in-plane wicking rates (Table 5). First there is maximum spreading speed XY (mm/s) which is the peak rate defined by the maximum length of wetted area within a time interval of 0.5 s detected at any time during the test. Then there are spreading speed X and spreading speed Y which are peak rates as well but determined by the change of width (X) or height (Y) of wetted area within time interval of 0.5 s at any time during the test.
WickView is able to capture two types of two dimensional in-plane wicking, actual area (mm2) and boundary area (mm2), however it is only the latter that is gradable according to JHTM 17 and therefore listed in Table 5. As the name suggests, the boundary area is determined by the boundary between the wet and unwetted areas, and is given as the wicking area by WickView. Actual area takes into account voids in a fabric and considers these as unwetted areas and subtracts them from the final result. Actual area is not included in this study.
Overall moisture management performance
OMMC and OWVG are, as the names suggest, MMT’s and WickView’s definitions of the overall moisture management performance based on several measurements. However, these definitions differ in terms of what measurements are considered and how much they contribute to the overall value. OMMC, given by MMT, is an index determined by a formula including manipulated values of bottom absorption rate, the accumulative one-way transport index, and the maximum spreading speed on the bottom surface, and weighting values (0.25, 0.5, and 0.25, respectively). As for the other measurements, OMMC by the MMT can be graded from 1–5 according to the thresholds presented in AATCC 195. In the development of the MMT, the weighting values have been defined based on certain human perception studies, but these values are recommended to be adjusted depending on the fabric’s end use. 32 However, the effect of adjusting the weighting values remains unclear since manipulated values (ndv-index stands for non-dimensional value) are the basis of the calculation and are inaccessible by the user.
OWVG is according to WickView, the average grade of 16 graded parameters, which are listed in Figure 3. In a mathematical sense, this means that all parameters are weighted equally, but we can see that these values are not necessarily independent of each other, nor do they have equal influence on the OWVG. Max wetted diameter XY, spreading length X, and spreading length Y are all ways of defining the one-dimensional in-plane wicking as well as max spreading speed XY, spreading speed X, and spreading speed Y are all measurements of the one dimensional in-plane wicking rates. As there are totally six values of each of these two measurements (considering both fabric sides), they each take up 3/8 of the OWVG. On the other hand, wetting time contributes only 1/16 whereas the remaining 3/16 of OWVG is attributed to wicking areas and absorption rate, with absorption rate being dependent on the wicking areas.
MMT results
Based on AATCC 195, all fabrics in this study were given the maximum grade of 5 for wetting time on both sides. P-F48 exhibited the fastest wetting time 1.86 ± 0.08 s on the fabric’s top side, and 1.89 ± 0.07 s on the bottom, whereas V-F44’s wetting times were 1.94 ± 0.15 s on the top and 1.96 ± 0.15 s on the bottom (Table 6). The spun yarns P-S30 and V-S30, and the filament yarn P-F96, all had wetting times around 2.3 s. P-S30 had a higher standard deviation (SD) of about 0.4 s compared with 0.1 s for the other fabrics (Figure 7).
MMT test results
Mean wetting times and standard deviations of tested fabrics (a), WickView visuals of wetted areas and max wetted lengths of bottom fabric sides at 120 s (b), and mean and standard deviation of MMT (c) and WickView (d) tested fabrics.
The lowest score among all measurements was the accumulative one-way transport index with grade 1 for V-F44 and V-S30, and grade 2 for P-F96, P-F48, and P-S30. The index value is negative for all fabrics. P-F48 achieved the highest value (–3.29 ± 8.57%) of the tested fabrics whereas V-S30 had the lowest (–60.8 ± 9.99%). P-F96, V-F44, and V-S30, had averages of –32.4 ± 7.72%, –51.3 ± 7.03%, and –60.8 ± 9.99%, respectively. P-F48 and P-S30 have values ranging from negative to positive, leading to values of –3.29 ± 8.57% and –15.4 ± 17.1%, respectively. For some fabrics, the averages become close to zero. Therefore, only standard deviations and means are presented to characterize the spread and central tendency of the accumulative one-way transport data (Table 6).
The negative accumulative one-way transport indices are expected since this index depends on the absorption rate, which appeared to be faster on the top side than on the bottom in all cases. All fabrics’ absorption rate measurements were graded 4 on both sides. Note that based on the values, they all absorb the fastest on their top sides. P-F48 had the fastest top absorption (68.3 ± 1.46%/s), followed by V-F44 (66.3 ± 1.23%/s). Then V-S30, P-F96, and P-S30 have top absorption around 64%/s, however the results of P-S30 fluctuate more than the other two, by reaching both the lowest and highest score with a SD of 4.14%/s and 6.48%/s for the top and the bottom results, respectively.
All fabrics scored a 5 for MMT’s maximum wetted radius. P-F48 reached the maximum electrode ring of 30 mm on both sides in all tests. The bottom side of P-S30 also reached 30 mm in all tests whereas its top side reached both the largest and the second largest (25 mm) rings, leading to a mean of 28 ± 2.58 mm. P-F96 wetted to the second largest ring consistently throughout the testing, followed by V-F44 reaching mainly 25 mm but sometimes 20 mm. V-S30 showed the smallest wetting radius, reaching either 20 or 25 mm.
In terms of spreading speed, all fabrics exceeded the threshold for grade 5. P-F48 had the fastest results for top (8.86 ± 0.12 mm/s) and bottom (8.78 ± 0.18 mm/s) spreading.
P-S30 interestingly was found to have faster spreading on its bottom side (6.99 ± 0.74 mm/s) than its top side (6.89 ± 0.77 mm/s) in the majority of the tests, with the difference between the means being 0.1 mm/s. The filament polyester fabrics P-F48 and P-F96 had faster spreading on their top sides compared with their bottom sides, although the differences between the top and bottom sides were only about 0.07 mm/s. For both viscose fabrics V-F44 and V-S30, having the slowest results overall, spreading showed just as many times faster on one side as on the other.
Finally, all fabrics received an OMMC grade of 3 except V-S30 which had a 2. P-F48 had the highest value (0.45), followed by S30 (0.42), and then V-F44 and P-F96 (0.40). However, V-S30’s of 0.39 is only 0.01 lower than V-F44 and P-F96.
WickView results
All fabrics had a grade 9 out of 10 for wetting time on both sides. Looking at the measured values, V-F44 demonstrated the fastest wetting time of 1.8 ± 0.5 s on the bottom side and 1.9 ± 0.5 s on the top side, whereas P-S30 had the slowest wetting time of 3.11 ± 0.8 s on bottom side and 2.78 ± 0.7 s on top side (Table 7). Overall, the wetting time results are around 2 ± 0.5 s with relatively high SDs, which are comparable to the 0.5 s temporal resolution of WickView (0.5 s). This led to high coefficients of variation (CV), being above 25% for fabric V-F44, V-S30, and P-S30 (Figure 7).
WickView test results
The absorption rate was graded 7 for V-S30 and 8 for the remainder of the fabrics. V-F44 and P-S30 had the highest values of 103 ± 1.5% and 101 ± 2.61%, respectively, indicating that the wicking area more often appeared slightly larger on the bottom side than the top side. V-S30 had the lowest absorption but also a relatively large variation of 95 ± 13% which is a result of the wicking area variations in both bottom and top sides. For the other fabrics, the SDs were relatively small, indicating good measurement consistency in these tests.
From the maximum wetted diameter measurements, both viscose fabrics V-F44 and V-S30 and the polyester fabric P-S30 have the highest grade 10 whereas V-F44 reached the largest wetted diameter 111 ± 3 mm on the bottom side and 107 ± 0.5 mm on the top side. The smallest wetted diameter was seen in P-F96 with bottom side appearing to be 55.5 ± 0.6 mm and top side 55.7 ± 1 mm, resulting in a grade 8.
V-F44 had the longest spreading length (108 ± 5 mm) of all fabrics with similar results in the Y direction as in the X direction for both top and bottom sides of the fabric. In comparison, V-S30 tend to spread approximately 9 mm further in the X direction than the Y direction, which was shown on both fabric sides. P-S30 had dominate spreading in its Y direction of 80 ± 2 mm on its top and bottom side, whereas the spreading in the X direction was 37 ± 2 mm on both sides (Figure 7). For the fabrics consisting of polyester filament yarns, they spread similarly in the X direction, with P-F48 reaching 49 ± 4 mm and P-F96 45 ± 2 mm, however P-F48 spread about 10 mm further in the Y direction than P-F96. P-F96 only showed 1 mm further spreading in the Y direction than the X direction.
Maximum spreading speed was captured in the top side (53.1 ± 7.58 mm/s) and bottom side (46.0 ± 6.66 mm/s) of V-F44, being twice as fast as the other fabrics which all had a maximum spreading speed of around 20–25 mm/s. V-F44 also spread faster in the X direction than Y on both fabric sides, and had the fastest spreading in the X direction of all fabrics.
For the other fabrics, the maximum spreading does not differ much between bottom and top sides. V-S30 had the second fastest spreading of about 25 mm/s, followed by P-S30 and P-F48 with around 20 mm/s, and lastly P-F96 with 17 mm/s. For P-F48, F-96, and P-S30 the spreading speed is greater in the Y direction, whereas V-S30 shows similar spreading speeds in both directions. However, all spreading speed values show large variations with CVs at 8–42% which can be explained by WickView’s limited temporal resolution.
The largest wicking area was observed on the bottom side of V-F44 with an area of 8790 ± 263 mm2 and 8529 ± 171 mm2 was observed on its top side. V-S30 had a top wicking area of 5909 ± 545 mm2 and bottom wicking area of 5627 ± 986 mm2. P-F48, P-S30, and P-S30, showed less variation of wicking area between top and bottom sides. P-F48 had about half the wicking area of V-S30, with around 2500 mm2, followed by the wicking area of P-S30 of about 2250 mm2, and lastly P-F96 with a wicking area of 1900 mm2. Looking at the shape of the wicking areas on the fabrics they are all noncircular, especially P-S30 having a distinct higher aspect ratio, being more elongated than the other fabrics. A comparison between P-F96 and P-S30 is shown in Figure 7.
OWVG, which is the mean of all grades of the 17 parameters, was the highest for V-F44 (9.8 ± 0.6), followed by V-S30 (9.6 ± 0.9), P-F48 (8.1 ± 1.4), P-S30 (7.9 ± 2.0), and P-F96 (7.2 ± 1.2).
Discussion
A distinct difference between MMT and WickView lies in how each instrument presents their results. The MMT generates processed data, providing the user with a refined and interpreted set of data. Together with AATCC 195, MMT can therefore be a good instrument for routine quality control of already developed fabrics with known moisture management performance as it simplifies complex measurements into more digestible metrics. Similar to MMT, WickView and its grading system JHTM 17 can also be used for quality control, but the main advantage of the instrument are the raw data it provides. The raw data enable a more tailored or detailed analysis of fabric moisture management, which in turn can benefit research and development of new fabrics. By examining the raw data provided by WickView, users can observe the dynamic changes in moisture content and spreading behavior over time. This level of detail can be particularly useful for identifying specific patterns or deviations in fabric performance that may be overlooked by the MMT algorithm, for example in fabrics with distinct unidirectional moisture transport as we have seen in this study. With access to raw data, users can customize their tests and analyses according to their needs. However, this also means that interpreting WickView’s data is more sensitive to noise and may require more expertise and time than the MMT results. In summary, the preferred instrument depends on the specific needs of the analysis.
Based on the dataset in this study, MMT’s technology is preferable when it comes to detecting initial wetting, as its wetting time measurement is supposed to detect as soon as the saline solution enters the fabric and the conductivity increases. WickView’s wetting time measurement is limited by its time resolution meaning that if initial wetting is fast, WickView will give large errors as in this study (2 ± 0.5 s). The same goes for rapid transverse wicking, i.e., fast wetting time as the liquid enters the bottom surface of the fabric. Due to the limited dataset in this study, with all fabrics initial wetting and transverse wicking happening within only 2–3 seconds, we cannot draw further conclusions, but we can expect that the slower the wicking, the choice of instrument should be less critical.
MMT’s accumulative one-way transport index and WickView’s absorption rate are different ways of expressing the relationship between the in-plane wicking on the examined specimen’s two sides, which can inform about the transverse wicking through the fabric. Both measurements look at the final result of wicking after completed test, which can be an advantage if the overall performance and test duration is relevant for the material’s end use. Since the raw data are embedded in the water content–time curves, the user is unable to interpret this top–bottom relationship at other time stages of the test. However, one would be able to address the accumulative one-way transport index at a different time by changing the test duration. Note that since the dispensing rate is fixed to 0.01 ml/s, the test volume will be determined by the new test time. Although WickView’s absorption rate value is determined by the final wicking area results, the ratio between the bottom and top surface wicking can be accessible at any time during the test since the raw data are available. The user can extract information from anytime during the test in WickView’s software (Table 4) without having to change test conditions and run another test. According to MMT’s formula for its one-way transport index, a negative value indicates that the moisture content on the application side exceeds that on the bottom. A negative index is graded lower than positive indices according to AATCC 195. If the aim of a fabric is to keep as much moisture as possible at the top surface, this index must be interpreted in the opposite way than the standard. WickView allows for a more tailored analysis since the user is able to work with the raw data that are captured every half second, although it comes with more manual effort.
WickView’s determination of absorption rate aligns with the principle of the absorbency measurement in Yotsuda et al.’s horizontal method. 35 However, we question the use of “rate” to express this measurement since it is not a velocity and only considers the last stage of the test. For absorption measurement, MMT provides a more relevant result of absorption rate as it considers the initial increase in water content during the first part of wetting and wicking. However, MMT’s absorption rate value is determined by where the water content curves peak, which means that if absorption rate at a particular time is of interest, this information cannot be accessed. Approximating the time of water content peak can be accomplished by looking at the displayed curve, but for exact numbers this becomes more difficult. In summary, we argue that the measured moisture content, neither through spectral images (WickView) nor through conductivity changes (MMT), should replace gravimetric principles for testing fabric absorbency.
If in-plane wicking in fabrics is of importance, both instruments can address this by examining one dimensional in-plane wicking. Although, WickView has better capacity for this measurement thanks to its larger detection diameter of 100 mm, and ability to track spreading behavior in X and Y directions, and the maximum XY length, at anytime. MMT is capable of detecting a distance of maximum 60 mm in diameter by tracking changes at its fixed electrode circuits, leading to poor spatial resolution (±5 mm). In this study, WickView’s measurements showed that some fabrics, especially those of viscose, wick longer than 60 mm in diameter. This means that MMT’s definition of max wetted radius can be unreliable. Note that WickView detected spreading lengths longer than the detection area in the cases of viscose filament fabric. This error has probably occurred due to some faults in the test set-up that could be corrected with minor adjustments. Regardless, for easily wetted fabrics with extensive in-plane wicking, where the moisture reaches the detection limit before the test ends, WickView’s maximum spreading length XY would not necessarily be the true maximum of one-dimensional in-plane wicking. When considering relatively small amounts of liquid, such as human perspiration, and where the moisture transport through the fabric is the focus rather than across the fabric’s surface, the MMT might be the preferable choice. Although for products, or layers within a product, that are relatively thin but take up larger volumes of liquid and where the liquid spreading must be controlled, WickView would be better.
One-dimensional in-plane wicking rate in fabrics can be beneficial to measure when evaluating materials intended to take-up fluid from a localized source such as incontinence, but might be less relevant for a distributed source such as sweating. MMT’s spreading speed measurement is one way of addressing the rate of in-plane wicking, but is limited to only examine at its fixed circuits and summarizes all rates from the inner to the maximum wetted ring. Since this value is also embedded in MMT’s software, the user is not able to see increases nor decreases of the spreading speed at different stages. However, MMT’s water content curves can help the user to understand the in-plane wicking, but with less detailed information. In contrast to MMT’s cumulative spreading speed, WickView provides wicking rates during any 0.5 s of the test. As WickView’s gradable measurements of spreading speed are all maximum, these values are peak rates and explains why the results become highly variable for all fabrics in this study, with CVs as high as 30–40% for some. The large heterogeneity observed in the WickView spreading speed results within the same fabric could be attributed to the sudden increases in moisture content at the second stage of yarn wicking, as described by Parada et al. 41 Yarn wicking is highly sensitive to minor variations in capillary and pore size, as well as yarn torsion or any other deformation affecting the yarns within a fabric. When examining small time intervals, as WickView does, the sudden increases of moisture content significantly impacts the wicking rate result. Therefore, detecting peak rates and sudden jumps in moisture content does not represent the general one-dimensional in-plane wicking rate of a fabric. A better way to evaluate fabric one-dimensional in-plane wicking rate is to use WickView’s raw data to look at spreading over time instead of the given maximum rates. For our results, impurities on the fabrics’ surfaces could also be a possible source of the large CV% but that would also affect other results, which does not seem to be the case.
WickView stands out by providing a measurement of two-dimensional in-plane wicking, i.e., wicking area, which MMT cannot. Together with multiple measurements of in-plane wicking in one dimension, these features highlight that WickView seems very promising in examining in-plane liquid transport in fabrics. In addition, the imaging technology can provide useful information about the pattern characteristics of a fabric. 40 As for most fabrics in this study, wicking has not stopped at 120 s, whereas the measured maximums and test duration could be questioned. Such observations are easy for the user to make thanks to WickView’s visualization.
Considering the reliability of MMT’s and WickView’s measurements based on this study, variations are generally large when wicking is fast, mainly for WickView because of its poor time resolution (±5 s). If initial wetting or transverse wicking is fast, WickView will have large errors. From the testing of viscose fabrics and fabric of spun polyester, these fabrics tend to fluctuate more than more homogeneous multifilament polyester fabrics. In addition, if one-dimensional in-plane wicking is significantly directional, MMT is not appropriate, and if the wicking distance is short, MMT will have large errors.
In this study, the OMMC results of MMT seem reliable due to the relatively low variability of the results, but again this has to be balanced against the poor spatial precision of the instrument. Moreover, since the OMMC depends largely on the capacity for one-way transport (weighting value 0.5) and for all fabrics our results of this measurement are quite low compared with the other measurements, we are cautious in drawing conclusions around the relevance of OMMC in this study. If a fabric is developed to have wicking on the top side exceeding the bottom side, MMT’s overall moisture management value would be inappropriate to rely on. In addition, the weighting values used in the OMMC formula are based on studies under selected conditions which may not be relevant for all sorts of fabrics, as it depends on the end use. The OWVG, unlike the OMMC, relies on all WickView’s graded measurements and weights them equally. Although this is true mathematically, some values are related or even dependent on each other and thus give unequal influence on OWVG. According to WickView, the measurements of one-dimensional in-plane wicking and one-dimensional in-plane wicking rate are responsible for as much as 75% of the overall moisture management performance, whereas wicking area contribute with another 19% and initial wetting gives the last 6%.
Although a total value for the moisture management capacity of fabrics can be useful for quick quality control, it is of utmost importance how this value is defined for the purpose of the product, and this should not be overlooked. The advantage of using WickView in this case is that the user can easily choose which parameters to include in the overall moisture management value. However, the decision making on which parameters to consider for a customized OWVG should be based on relevant studies and it requires a good understanding of WickView. In general, grading of tested materials is desirable when creating test standards for industrial applications, 9 but the thresholds for grading must be applicable to the end use of the fabric and is most critical in development of new fabrics.
As this study is concentrated on comparing MMT and WickView in their ways of testing transverse and in-plane liquid transport, the instruments’ interpretation of the tested fabrics are of more interest than fabrics’ actual performance. According to MMT, none of the fabrics stand out in any of the measurements, except that viscose appears to have greater in-plane wicking on the upper side than the bottom. Interestingly, viscose fabrics appeared to have less in-plane wicking in MMT, whereas WickView considers these to have twice as high in-plane wicking than the polyester fabrics. WickView differentiates the tested fabrics especially when it comes to spreading lengths, wetted diameter, and wicking areas. When looking at all the measurement values, P-F48 seems to have the best performance overall according MMT, whereas WickView gives V-F44 the highest values for most parameters. Something only WickView was capable of capturing is polyester fabric of spun yarns (P-S30) having strong wicking along the wales (Y) than the course direction (X). The polyester fabrics of filament yarns (P-F96 and P-F48) also showed differences in directional spreading according to WickView, but not as prominent as the spun yarn fabric. The fabrics of spun viscose (V-S30) and spun polyester (P-S30) yarns were those with the largest standard deviations in most measurements both when tested in MMT and WickView. This could be because spun yarns generally exhibit more unevenness compared to continuous filament yarns. However, this reasoning is based on a limited set of data.
Conclusion
This study is a comprehensive comparison between the two moisture management instruments, MMT and WickView, focusing on their operational principles and measurement capabilities while examining knitted fabrics of polyester and viscose. The study has highlighted the strengths and limitations of each instrument’s capability to test transverse and in-plane liquid transport in taking various measurements such as initial wetting, transverse wicking, absorption, one-dimensional in-plane wicking, one-dimensional in-plane wicking rate, and two-dimensional in-plane wicking. Some findings were that for testing initial wetting, and fast transverse wicking of thin fabrics, MMT is the preferred instrument whereas for one-dimensional in-plane wicking where wicking directionality is important or for two-dimensional (areal) in-plane wicking, WickView is better suited. However, for thin fabrics, the ratio between areal in-plane wicking on fabric’s upper and underside can be good enough to examine the transverse wicking of slower pace by using WickView. Furthermore, MMT’s spatial resolution is poor which means that if wicking distance is short, this leads to large errors, whereas if wicking time is short, WickView will have large errors because of its poor time resolution. For research where details of wicking behavior are important, or the possibility of tailoring the test and extracting raw data are requested, WickView may be the preferable instrument. On the other hand, MMT is beneficial for quick fabric quality control where there is less focus on development. Finally, if a grading system or overall moisture performance value is used, it should preferably be adapted to the intended end use of the product to be tested.
In conclusion, this research has provided valuable insights into the capabilities of MMT and WickView in fabric moisture management examination. Future studies will focus on further testing of different fabrics with various yarn configurations and fiber types including natural fibers, and other textile structures, to extend the review of the instruments. More applied studies will be conducted where we will investigate which instrument is best suited to moisture management testing of fabrics developed for certain fields of applications.
Footnotes
Acknowledgments
The authors would like to thank Stefan Gustafsson, innovation technician at the Swedish School of Textiles, specialized in knitting, for producing the fabrics used in this study. We would also like to thank Dr Rumbidzai Zizhou at RMIT Melbourne, Campus Brunswick, for her demonstration of the MMT and guidance during the testing. Their contributions were essential to the success of this research.
Data availability statement
The data presented in this study are available on request from the corresponding author.
Declaration of conflicting interests
The author(s) declared no potential conflict of interest with respect to the research, authorship and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Swedish Foundation for International Cooperation in Research and Higher Education (grant number Dnr IB2023-9245), Stiftelsen för Kunskaps- och Kompetensutveckling (grant number 20200266), and Sparbanksstiftelsen Sjuhärad (grant number FO2022/99).
