Effect of Natural and Synthetic Fibers and Film and

Effect of Natural and Synthetic Fibers and Film and Moisture Content on Stratum Corneum Hydration in an Occlusive System BRUCEA. CAMERON' AND DONNA M. BROWN Deynrtnrent of Family ar~dConslcriler Sciences, U~rivrrsityof \Vyor?tirtg, hrnnrie, \Vyonzirlg 82071, U.S.A.

Departnlcnt of Design, Merchnrldisiirg, n~ldCor~srrr~rrr Scierlces, Colorndo State Urliversity, Giflord Brrilling, Fort Collirrs, Colorado 88523, U.S.A. ABSTRACT The effects of fabric made from natural and synthetic fibers and film on transepidermal water loss (TEWL)from the stratum corneum ( s c ) were investigated using an occluded system. Sixteen fabrics differing in fiber type and construction were placed on the volar forearm of 35 female subjects in a dry state (standard moisture regain) and a wetted state. Each fabric was in place for 40 minutes before m \ n was measured. There was no statistically significant difference in TEIK measurements on a control skin site from the beginning to the end of the 75-minute test session in a controlled conditioned environment. Placement of dry fabrics on the skin did not significantly affect the hydration level of the sc, though all dry fabrics did increase the hydration level slightly. Wetted wool and cotton fabrics significantly hydrated the sc when levels were compared to either normal skin or skin covered by dry fabrics. Of the seven synthetic fiber fabrics tested in a wetted state, three (acrylic, m,and spun nylon) significantly increased the sc hydration level. These three fabrics and the natural fiber fabrics had comparable wetted moisture content.

Over the past two decades, consumers and medical professionals have become increasingly aware of possible health and comfort problems associated with the use of textiles on human skin. Placement of a textile over human skin may change the stratum corneum (sc) hydration state, since fabrics serve as a barrier to water dissipation from the sc. The potential for sc hydration is greatest when an occlusive banier is present, as in the case of a diapered baby or a person wearing waterproof rain gear. Increases in normal levels of sc hydration pose several possible problems. The skin becomes more susceptible to abrasive damage due to increased textilclskin friction, more readily absorbs chemicals, and is more prone to microbial growth [21]. Comfort can be compromised when textiles change the hydration state of the sc; as human sc hydration increases, discomfort also increases. The outermost layer of human skin is the sc. While the underlying epidermis is composed of living cells, the sc is composed of 12- 15 dead keratinized cell layers. Though relatively dry, the sc is hydrated from underlying tissues when sweat glands are activatcd, and To whom correspondcncc should be addressed.

from external sources such as washing the skin, high air humidity, and wet fabric on the surface. The sc controls the rate of transepidermal water loss (EWL), which is influenced by relative humidity of the air, skin condition [14], and skin temperature [15]. When fabric is placed on the skin's surface in an occluded system, water first collects within the sc. Over time, water also accumulates on the skin's surface [14]. Studies by Hatch and others 13, 5 , 6, 8, 9, 10, l I, 13, 14, 19,211 have focused on the relationship of wet and dry fabrics worn next to the skin and sc hydration. Wetted fabrics worn on the skin in an occluded system increased sc hydration. Studies using diaper or adult incontinence products found differences in skin wetness between cloth and disposable diaper materials; superabsorbent diaper systems kept the skin driest [6, 19. 211. Hatch er al. [ 9 ] added the variable of hydrating the sc to about 80%of its maximum hydration state, then studied the effect of dry and saturated fabrics on this hydrated sc. The rate of TEWL for cotton fabric saturated fully and at 38.6% moisture content level was statistically greater at the end of the test period than at the beginning. The sc was more hydrated as evidenced by the larger amount of water loss per unit time. Polyester fabric at saturation did not 0010-5 175/52.00

Te.rrile Res. J. 67(8), 585-592 (1997)

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significantly hydrate the sc. Researchers concluded that, in general, the greater the moisture in the fabric, the greater the sc was hydrated, and that cotton fabrics were more likely to hydrate the skin than polyesters. In addition, they reported that sc hydration occurred rapidly after placement of the fabric on the skin surface [9,10, 19, 211. Other studies [12, 17, 201 investigating factors that influence fabric comfort and discomfort also have mentioned the importance of the absorptive capacity of fibers present in a fabric. Hollies et al. [12], in a study using wear trials to investigate the comfort of shirts made of various fiber types, concluded that the most important factor influencing wearing comfort was the ability, of the fibers to absorb water, regardless of whether they were synthetic or natural. They made no inferences to fabric structure. Niwa [17] reported that the ability of fabrics to absorb liquid water is more important than water vapor permeability in determining the comfort of fabrics. In a study investigating the effect of the chemical nature of fibers on water vapor transport through layered fabrics, Yasuda et al. [20] found that the absorption ability of fibers is a controlling factor. Even for fabrics with the same porosity, the water vapor or transport rate is different when the fibers' water absorption abilities differ. Because fibers differ in the amount of moisture they absorb and hold, the mechanisms by which moisture vapor or liquid water pass into and through fabrics also differ. Moisture vapor and liquid water may penetrate through the space between fibers by diffusion, be absorbed by the fibers and transported within them, be transferred through capillary interstices in yams, and migrate along fiber surfaces [16]. Generally, fabrics with high liquid absorption and transport ability are assumed to have a substantial comfort advantage. The sensation of wetness should be reduced as moisture is drawn away from the skin. Fabrics containing hydrophilic fibers such as cotton and wool are expected to hold more moisture within the fibers at regain and saturation than are fabrics containing hydrophobic fibers. Hydrophilic fibers allow water molecules to penetrate them. Saturation is commonly used to describe the liquid content of a porous medium. With respect to fabric, saturation is defined as the fraction of the void space in a fabric that is filled with liquid. At zero saturation, there is no liquid present in a fabric, though fibers may have absorbed moisture from the air. At 100% saturation, all void space in the fabric is filled. Water is held within fibers (absorbed water), on the surface of fibers (adsorbed water), and between fibers in yams and between yarns (imbibed water).

Conversely, hydrophobic fabrics from synthetic fibers, such as polyester and polypropylene, have low or no capacity to absorb moisture; rather the moisture is adsorbed-held on fibers and in interstices. The degree of moisture absorption of synthetic fibers can be modified by applying hydrophilic finishes and modifying the polymers, which increases the amount of absorbed moisture in the fabrics. Wicking along the outside portion of the fibers is necessary to transport water through a hydrophobic fabric, and occurs when fabric water content is high [3]. Fabric wicking determines how quickly and how widely liquid water spreads out laterally on the surface or within the matrix of a hydrophobic fabric. Thus, wicking is an important factor in the overall water vapor transport rate through these fabrics [20]. Both the sutface energy of fibers and the separation between fibers in yarns are believed to influence wickability. In poromeric films, membranes may absorb water, while micropores allow water vapor to be transported from the skin to the outer environment. In thisstudy using an occluded system, we investigate factors that account for how sc hydration changes as a result of fabric construction, fiber composition, and moisture content. The objective of the study is to assess change in sc hydration before and after placement of dry fabrics (standard moisture regain) and wetted fabrics on the 'skin surface. We further examine the importance of fiber type, fabric construction, and fabric moisture content on sc hydration of normal (typical state of hydration) human skin. We include fiber types and fabric constructions not included in previous sc hydration research. Our chosen fabrics represent hydrophilic fibers, hydrophobic fibers, and woven, knit, and nonwoven fabric constructions, yielding fabrics of varying moisture content. Our study enhances previous sc hydration research by using fabrics containing fibers other than cotton and polyester, thus enabling us to determine how different fibers and fabric constructions interact with the skin to produce a response in the sc.

Methodology TEWL We used the Evaporimeter EPlc (ServoMed, Sweden) to assess TEWL from normal human skin. Measurement of TEWL using this Evaporimeter is well documented in the literature [4, 6, 9, 10, 111. The instrument has a hand-held probe that rests gently on the skin, while moisture sensors and temperature sensors within a Teflon pipe detect the water vapor gradient existing within a centimeter of the skin surface.


Based on information from the sensors, TEWL in g/m2/ h and relative Iiumidity are calculated internally and displayed on a digital readout. The TEWL data are recorded electronically by connecting the Evaporimeter to a personal computer adapted with a card and software spreadsheet program. We established the time period to calculate TEW and recorded it into the spreadsheet program. The total time for each reading was set to 120 seconds, but the initial 30 seconds of each reading were not recorded, based on a recommendation from the manufacturer [7]. Prior research [19] also indicated this amount of time allowed for the immediate burst of moisture evaporation to be excluded from the TEWL measurements. The speadshket program averaged the TEWL values obtained during the testing period. Additional standard Evaporimeter procedures were to rest the probe gently on the skin surface to be measured, to keep the probe upright, and to keep the technician's hand away from the pipe section of the probe to reduce measurement error [7].

To assure instrument performance over the extended time period for the study, a standard T E ~ L reading was taken the first time the data were collected each day. The probe rested on a breathable membrane covering a 25-mm diameter multiwell chamber filled with 3 ml of distilled water. The instrument gave a reading of the relative humidity in the room at the time of testing. The conditions of the environmental room were controlled to 20°C and 65% relative humidity. Any calibration problems with the instrument alerted us to a possible variation in the standard room conditions. Skin temperature measurements were taken with an NIST digital thermometer equipped with a YSI (model 409B) standard skin temperature probe to standardize the TEWL results.

Thirty-five subjects with normal (typical state of hydration) skin volunteered to wear dry and wetted fabric samples of varying fiber contents and fabric constructions. They were instructed to avoid using moisturizing lotion that day; if this condition was not met, the subject was rescheduled. Once inside the controlled environment, the subject relaxed for 10 minutes while signing the subject information sheet and consent form. Subjects scheduled appointments for testing until they had worn all the patches assigned to them in a dry state and all the patches in a wetted state. Subjects did not test

all sixteen fabrics; each subject tested a maximum of eight fabrics, with four fabric samples tested for each session. A minimum 4-hour period between appointments was required of all subjects. While we chose the 4-hour interval based on subject and technician convenience, an exploratory study [4] on the Servo Med Evaporimeter determined that after 1 hour, TEWL measurements are very similar to those taken on the same subject after 24 hours. Wilson and DaIlas [I91 plotted the decay curves for TEWL for the most popular brands of diapers worn on the volar forearm as saturated patches for 2 hours. After the diaper patch was removed, TEWL readings lasting 2 minutes were taken between 2-minute rest periods until six readings had been completed (i.e., 22 tqtal minutes). The sixth reading was used as the background reading, since all readings had returned to this level after 22 minutes.

We selected fabrics as representative samples of test fabrics in the W-175 study, "Human Physiological and Perceptual Responses to the Textile-Skin Interface." The fabrics in the W-175 study were either donated or purchased based on the projected end-use and potential for fabriclskin intedace for such user groups as older adults, clean room environment personnel, medical field personnel, and the general public. We selected sixteen fabrics with differing fiber contents which are described in Table I. Test methods used to determine the geometry of the sixteen fabrics were as follows: woven fabric weight was measured according to ASTM D3776 [I], a similar procedure was also used for the knits and nonwovens; standard moisture regain was determined according to ASTM D2654 [2]. Fabric samples were wetted according to the method of Hatch et al. [9]. Wet samples were prepared by immersing 2.5-cm square samples in distilled water for 20 minutes, putting each swatch between two pieces of chromatography paper and blotting moisture through a wringer with a uniform load of 27.216 kg and surface speed of 2.54 c d s to achieve as uniform saturation as possible [9]. However, moisture content was determined using the following formula: Wetted moisture content - wetted weight - oven dry weight oven dry weight

We measured sc hydration, a function of ihe rate of the skin surface, and skin temperature ac-

TEWL from


TABLEI. Fabric characteristics. Fabric number

Fiber type

Fabric construction

100% cotton 100% cotton 100% rvooI 65% cotton/35% polyester 100% acrylic 100% nylon 100% polyethylene Tyvek 1422 100% mw Comfort-Gard-IRFX-c 100% wool 100% wool 100% cotton 100% cotton 100% cotton E 100% ~ F Con~fort-Gard-11 100% polyethylene Tyvek QC 100% nylon

Weight, dm2

Moisture con~cntat 20°C. 65% R ~ I ,rnmglc~n'

Wetted moisture content, mdcm2

rib knit twill flannel twill fiannel plain weave sheeting plain \veave lricot knit nonwoven film nonwoven film worsted shirting woolen shirt flannel plain weave jersey knit twill nonwoven film nonwoven film lain weave

cording to methods developed by Hatch et al. [9]. Us- change by subtracting the adjusted baseline measureing a pen and a flexible measuring tape, the technician ment (skin at normal regain using the second dry sc marked the subject's left and right volar forearms with baseline reading) from the adjusted sc hydration measmall dots 8, 12, and 16 cm from the wrist. The midarm surement (fabric treatment site) for each subject. We position (at 12 cm) was reserved for baseline sc hy- made a statistical analysis of subject variability using dration and skin temperature measurements. The other box and whisker plots, which indicated that variability two positions were for fabric testing. A subject wore between subjects for each fabric tested, wet or dry, was four fabrics during each session. negligible. We adjusted the TEWL rates for temperature We established a baseline TEWL for each subject to according to the method of Mathius et al. [15]. control for intrasubject variability [4, 101. After 10 We used the SAS program [18] for statistical analyses minutes, the first fabric patch was applied to the left of the data. Scheffe's analyses determined the signifiarm at the 8 cm position. A 2.5-cm square of fabric was cance of painvise comparisons made between dry and placed on the skin followed by a Hilltop chamber ( a wetted fabrics to assess how sc hydration was affected water vapor impermeable plastic dome from Hilltop by moisture content of the fabric. In addition, we made Corporation, Cincinnati, OH) held in place by hypoal- statistical analyses of all dry and all wetted samples to lergenic tape. At 6-minute intervals, an additional patch determine whether there were any significant differwas placed on another premarked site until all four fab- ences between the various fabrics. The level of signifrics were in place. Because Hatch et nl. [9] found no icance for all tests w a s p < 0.05. significant differences between identical locations on left and right arms, we repeated the same sites for the Results and Discussion same fabric, whether wet or dry. After the first fabric patch had remained on the skin for 40 minutes, it was removed and the treated site was Table I1 shows the mean sc hydration levels for normeasured for mv~ and skin temperature. This procedure mal skin after a subject sat in a conditioned atmosphere was repeated after each of the remaining samples had (20°C, 65% relative humidity) for 10 minutes, and been in place for 40 minutes. A second baseline mv~ and skin temperature reading were taken on the untreated TABLE11. Hydration levels of the S C without placement of fabrics. (12 cm location) site at the conclusion of a session. We tested two treatments (either wet or dry fabrics) Skin hydration level, mean' for all sixteen fabrics. During a testing session, the four fabrics a subject wore were either all dry or all wet. Before placement of fabrics (after 10 minutes in

DATAANALYSIS We assessed the effect of fabrics on the hydration level of the sc as change in TEWL, calculating this

conditioned atmosphere) After all EWL measurements taken at a session (after 1 hour in conditioned atmosphere) Not statistically significant.


2.17 dmzih 2.16 g/mz/h

again at the conclusion of a test session, a period of 75 minutes, during which fabrics were placed on the skin using the occluded system. These data show that there was no significant change in sc hydratior1 during a session. Thus, we can corlclude that any alteration in sc hydration at the test sites was due to the placement of dry or wet fabric at those sites. The average normal sc hydration observed in this study (2.17 g/m2/h) is lower than those reporied in other studies [9, 141 (6.S g/m2/ h). This could be attributed to the fact that subjects came into the environmental chamber from a low humidity environment due to the higher altitude where they reside, which nleans their skin would have lower normal sc hydration.

Table I11 shows the results of sc hydration after cotton fabrics were placed on skin in dry and wetted states under an occluded dome. The results indicate that when dry cotton fabrics are placed 011skin and remain there for 40 minutes, there is no significant change in sc hydration, i.e., the skin does not become wetter nor less hydrated. This would be expected, because at standard regain, all the cotton fabrics have the ability to absorb moisture from the sc. Thus, the hydration of the sc remained consistent from the beginning to the end of a test period. This finding agrees with that of Hatch ct al. [9], who found that for a cotton fabric at standard regain, there was no statistically significant change in sc hydration. TABLE Ill. Change in TE\VL from the sc before and after placement of dry and \vet cotton fabrics.

fabric is removed. It is interesting to note that sc hydration under the two cotton twill fabrics (2 and 13) was greater than for the other cotton fabric constructions. A possible explanation for this result is that the woven flannel construction has the ability to hold more moisture and thus pass it onto the sc, as indicated by the fact that these two napped fabrics did have higher wetted moisture contents (Table I).

Table IV gives the sc hydr~tionresults using an occluded system for the three wool fabrics in the dry and wetted states. As for the cotton fabrics, there was no significant change in sc hydration as a result of placing the dry wool fabrics on the skin. Again this is logical, becausk at standard regain, the wool fabrics had the ability to absorb the quantity of moisture emitted from the sc during the 40 minutes. When wetted wool fabrics were placed on the skin, the sc hydration level significantly increased. We expected this result because wool fabrics will absorb n~oistureand pass it on to the skin, as indicated by the wetted moisture contents in Table I. TABLE IV. Change in TEWL of the sc before and after placement of dry an$ \vet aool fabrics. Chance in TE\VL, mean Fabric (number, name)

Dry at standard regain moisture content

When \vetteda

3, \vool twill flannel 9, wool worsted shirting 10, \vool \voolen shirt flannel

0.73 2.10 1.65

9.32***

5.60*** 9.81***

" *** Statistically significant differences.

C h a n ~ ein TEIVI., mean Fabric (numhcr, name)

Dry at standard regain moisture content

When \vetted3

1, cotton rib knit 2, cotton twill flannel 4, 65 cotton/35 poly shccting I I, cotton plain weave 12, cotton jersey knit 13, cotton twill

0.99 0.4 I 1.00 1.49 0.79 . I .93

5.34*** 13.07*** 6.05*** 7.14*** 9.83*** 19.43***

Table V shows the results for sc hydration when synthetic fiber fabrics in the dry and wetted states were V. Change in TEIVL. of the sc before and after placement of TABLE

dry and \vet synthetic fib~xrfabrics. Change in TEI\Z, mean

' *** Statistically significant differences. Fabric (number, name)

When wetted cotton fabrics were placed on the skin, however, it became significantly more hydrated. This result would be expected because the wetted fabrics contain significantly more moisture than fabrics at standard regain, so they have no capacity to take up (absorb) additional moisture but instead transfer moisture to the skin. This moisture remains in the sc until the

5, acrylic Acrilan 16 6, Quintessence nylon tricot 7, polyethylene Tyvek I422 8, PTFE Cornfort-Gard-IR~-c 14, PTFEComfort-Gard-11 15. polyethylene T)vek QC 16, spun nylon plain weave

Dry at standard regain nioisture content

When \vetted'

0.87 1.17 I .SO 1.17 1.67 2.62 0.61

5.98*** 3.06 2.93 1.51 5.16*** 3.40 4.23***

' *** Statistically significant differences.


lield on the skin surface for 40 minutes. The results A LEGEND 13 indicate that there was no significant difference in s c A cotlon fabric hydration at the beginning and end of the session for synthetic fabric acrylic, nylon tricot, spunbonded polyethylene, PTFE with Comfort-Gard-IRFX-c, rrrbx with Comfort-Gard-11, and woven spun nylon in the dry state. Also, there was no significant difference between these fabrics and the hydration level of the baseline SC. Wlien wetted synthetic fabrics were placed on the skin, results differed by fabric. The sc became significantly wetter under the acrylic, PTFE with ComfortGard-11, and woven spun nylon, but not under the nylon tricot, Tyvek 1422, Tyvek QC,and l l Comfort-Gard~ ~ -0 0 40 80 120 160 I. Tticse results may be explained by the fact that the MOISTURE CONTENT (rnglcrnn) three fabrics with significantly wetter sc levels had wetted moisture contents comparable to those of natural FIGURE 1. Relationship of moisture content of wetted fabrics and fibers. The exception was nylon tricot: it had a wetted sc hydration for an occluded system. Each point represents the n~ean moisture content comparable to the other three syn- TEIVI. for the fabrics tested. thetic fiber fabrics, but did not yield a significantly wetter sc. This nylon tricot was designed for use in underwear, so it may have the ability to wick moisture nloisture content increased, TEWL also increased. For from the skin and hold it in the fabric. This moisture example; fabrics with the highest wetted moisture contents gave the highest TEWL measurements; conversely, in the fabric may also hydrate the sc. fabrics with the lowest wetted moisture contents gave the lowest TEWL measurements. In this study, the low moisture content bbrics were made from hydrophobic We compared fabrics by their weight, moisture con- fibers in a nonwoven construction. The high moisture tent at regain, and wetted moisture content. A statistical content fabrics were both cotton woven twills. Figure 2 shows the relationship between fabric analysis of conlparisons between all the fabrics at reweight and TEWI. of the wetted fabrics. This figure ingain indicated that there was no significant difference dicates that as fabric weight increased, TEWL for the in the measured s c hydration. This would indicate there wetted fabrics also increased. The relationship is simis no difference in s c hydration nleasured due to the ilar to that indicated in Figure 1. fabric characteristics and fiber types used in this study in an occluded system. Note, however, that all fabrics did increase sc hydration over normal. 20 LEGEND Wlien we examined wetted fabrics, we found signifA cotton fabric icant differences, but there were no well defined relawool fabric tionships between the various fabrics (construction, fisynthetic fabric 14 ber type, weight) in measured s c hydration except for fabric 13. This fabric (cotton twill) caused the sc to become significantly more hydrated than all other fabrics except fabric 2 (cotton twill flannel). The probable reason for this result is that fabric 13 had a much higher wetted moisture content and weight than all other fabrics except fabric 2, as shown in Table I. Fabric 3 (wool twill flannel) did have a co~nparableweight, but its wetted moisture coqtent was much lower because wet04 , , , , , , , , , , , , , , , , , ting agents were not used to help wet the fabrics. Wool 0 40 80 120 160 200 240 280 320 fabrics require wetting agents to enable wetting in short WEIGHT (glrnz) periods of time. Figure 1 shows the relationship between wetted FIGURE 2. Relationship of fabric \veight and sc hydration of wetted moisture content and TEWL in an occluded system. This fabrics for an occluded systenl. Each point represents the mean TELVL figurc indicates that for the fabrics studied, as wetted for the fabrics tested.

'1


Those that have lower levels of moisture show no significant increases in sc hydration. Examination of fabric characteristics and TEWI. re\Ve found no significant difference between two TEWL measurements of the 35 subjects' normal skin veals that fabric weight is often an important factor in taken after 10 minutes and again after an hour in a sc hydration. As fabric weight and moisture content conditioned environment. This indicates any increase increase, mwL also increases. Thus, the results appear in the moisture content of the sc could be attributed to to show that in the wetted state, fabric geometry may placing fabrics on the skin under an occluded dome. affect the amount of moisture a fabric holds. For exResults of this study show that when fabrics, whether ample, the two cotton twill fabrics had significantly in a dry or wetted state, are placed over the skin in an more moisture than the other cotton fabrics examined occluded system, the sc will become more hydrated. In (knits and plain weaves). Further research is needed to all cases, placing fabrics in a dry state on normally more fully understand the influence of fabric geometry hydrated sc for a period of 40 minutes produces in- on sc hydration. Implications of this study are related to perceptions creased sc hydration, but this increase is not statistiof co~nfortand well-being related to fabric wearability. cally significant. When examining the effect of fiber type and tnois- Increqsed moisture at the skin-fabric interface alters the ture content on sc hydration, it is clear from the re- intensity of the fabric roughness sensation and is also sults that in a conditioned environment (20°C 65% known to increase friction when the wetted fabric reR H ) , with the dry fabrics also conditioned and over mains on the skin surface. Since increases in sc moisthe time period used, fiber type and moisture content ture lead to increases in skin friction, we can conclude do not have a significant effect on sc moisture con- that, particularly in the wetted states, fabrics will be tent. However, when wetted fabrics are placed over more uncomfortable than comparable fabrics in the dry the skin for 40 minutes, in the majority of cases, the state. Fabrics with little or no ability to absorb or transmoisture content of the sc increases significantly. It fer moisture will begin to feel unco~nfortableto the would appear from our results that the arnount of wearer when wet, because moisture will increase at the moisture the fabric holds in the wetted state is the skin-fabric 'interF~ce.,However, fabrics that are permost significant factor affecting sc hydration. In all meable to moisture will remain more comfortable to cases, fabrics from natural fibers (cotton, wool) sig- the wearer. In addition, for all fabrics with high water nificantly increase sc Ilydration when they are placed content, the likelihood of skin abrasion increases. on skin under an occluded dome. For wetted fabrics made fro111synthetic fibers, two situations occur. In those cases where the fabrics hold This report is based upon research conducted and moisture similar in quantity to natural fiber fabrics, a supported as part of Western Regional Research Project significant increase in sc hydration occurs, with the exW-175: Human Pllysiological and Perceptual Reception of nylon tricot. Synthetic fiber fabrics with sponses to the Textile-Skin Interface. Participating stalower moisture content do not significantly increase sc tions are California, Colorado, Iowa, Minnesota, Monhydration levels, although TEWL does increase. We exNew York, Ohio, Oregon, and tana, New Mexico, pected this because many synthetic fiber fabrics do not have the ability to absorb much moisture. These results Wyoming. are similar to those of I-latch et 01. [9], who found the degree of sc hydration depended more on the ability of Literature Cited the fabric to accumulate transepidcrrnal water than on I . ASThl D3776-85, Standard Test hlethods for Mass Per the fabric's ability to transfer fabric moisture to the sc Unit Area (\Veiglit) of Woven Fabric, ASTM Annual (i.e., fabrics at regain are more able to accumulate Book of Standards, vol 7.02, Philadelphia, PA. 1992. transepidermal water than those at saturation). 2. ASThl D265.1-89a, Standard Test Metl~odsfor hloisturc Apparently, fiber type is a significant factor in sc in Textiles, ASl'hl Annual Book of Standards, vol 7.01, hydration, but only in regard to how much moisture the Philadelphia, PA, 1992. fiber holds when wetted. In all cases, fabrics from nat3. Barker, R. L., Radf~akrishnaiah,P., Woo. S . S.. llatch, ural fibers in the wetted state yield significantly inK. L., Markec, N. L.. and Maibach, 11. I., 111 Viro Cutacreased sc hydration levels. In the case of synthetic neous and Perceived Comfort Response to Fabric, Part fiber fabrics, those that hold amounts of moisture sim11: hlechanical and Surface Rclatcd Comfort Property Dcilar to natural fiber fabrics produce significantly interminations for Three Experimental Knit Fabrics, Te.rtilc Res. J. 60,490-491 ( 1990). creased sc hydration, with the exception of nylon tricot.

Conclusions


4. Blichmann, C. W., and Serup, J., Reproducibility and Variability of Transepider~nalWater Loss hleasurcment, Actn Ilerrl~.Vcrrercol. 67, 206-2 10 ( 1987). 5. Campbell. R. I,., Seynlour, J. L., Stone, I-. C., and hlilligan, M. C., Clinical Studies with Disposable Diapers Containing Absorbent Gelling hlaterials: Evaluation of Effects on Infant Skin Condition, J. Airr. /Icnrl. Derrl~nrol. 17,583-591 (1987). 6. Dallas, hl. J., and Wilson, P. A., Adult Incontinence Products: Performance Evaluation on llealthy Skin, INDA J. Nor~noi.er~s Res. 4(2), 26-32 (1992). 7. DIA-STRON Ltd., Evaporimetry Programinz-Operators hlnnual. 1988. 8. Hatch, K. L., Markee, N. L., Maibach, kl. I., Barker. R. L., Woo, S. S., and Radhakrishnaiah, P., 111 Vivo Cutaneous and Perceived Comfort Response to Fabric, Part 111: Water Content and Blood Flow in Iiurnan Skin Under Garments Worn by Exercising Subjects in a llot, Hulllid Environment, Te.rtilc Res. J. 60, 510-519 (1990). 9. Hatch, Kathryn L., Markee, Nancy L., Prato. Harriet L., Zeronian, S. Haig, hlaibach, Howard I., Kuehl. Robert 0.. and Axelson, Rick D., 111 Vivo Cutaneous Response to Fabric, Part V: Effect of Fiber Type and Fabric Moisture Content on Stratum Corneum Hydration, Textile Rcs. J. 62,638-647 ( 1992). 10. Hatch, Kathryn L., Wilson, Donald R.. and hlaibach, Howard I.. Fabric-Caused Changes in Human Skin: 111 Vivo Straturn Corneum Water Content and Water Evaporation, Te.rtile Res. J. 57, 583-59 1 ( 1987). 11. Hatch, K. L., Woo, S. S., Barker, K.L., Radhakrishnaiah, I'., Markee, N. L., and hlaibacl~,H. I., Iir Vivo Cutaneous and Perceived Comfort Response to Fabric, Part I: Therrnophysiological Comfort Determinations for Three Experimental Knit Fabrics, Te.rtile RCS. J. 60, 405-412 ( 1990).

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