Effect of Varying the Twist Multiplier of Open-End Yarn on Pilling and Other Fabric Properties

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<ul><li><p> http://ctr.sagepub.com/Journal</p><p>Clothing and Textiles Research</p><p> http://ctr.sagepub.com/content/6/3/41The online version of this article can be found at:</p><p>DOI: 10.1177/0887302X8800600306 1988 6: 41Clothing and Textiles Research Journal</p><p>Soae L. Paek and Helen B. WinsorEffect of Varying the Twist Multiplier of Open-End Yarn on Pilling and Other Fabric Properties</p><p>Published by:</p><p> http://www.sagepublications.com</p><p>On behalf of: </p><p> International Textile and Apparel Association</p><p> can be found at:Clothing and Textiles Research JournalAdditional services and information for </p><p> http://ctr.sagepub.com/cgi/alertsEmail Alerts: </p><p> http://ctr.sagepub.com/subscriptionsSubscriptions: </p><p> http://www.sagepub.com/journalsReprints.navReprints: </p><p> http://www.sagepub.com/journalsPermissions.navPermissions: </p><p> http://ctr.sagepub.com/content/6/3/41.refs.htmlCitations: </p><p> What is This? </p><p>- Mar 1, 1988Version of Record &gt;&gt; </p><p> at UNIV OF SOUTHERN CALIFORNIA on April 4, 2014ctr.sagepub.comDownloaded from at UNIV OF SOUTHERN CALIFORNIA on April 4, 2014ctr.sagepub.comDownloaded from </p></li><li><p>41</p><p>Effect of Varying the Twist Multiplierof Open-End Yarn on Pilling and</p><p>Other Fabric PropertiesSoae L. Paek</p><p>Helen B. Winsor</p><p>Authors Address: Department of Human &amp; Family Resources,Northern Illinois University, DeKalb, IL 60115.</p><p>Abstract </p><p>Pilling has been one of the major consumer problems of man-made staple yarn products. This study evaluatedthe pilling performance of 65/35% Dacron/cotton fabrics woven from open-end (OE) yarns by the RandomTumble Pilling Tester Method (ASTM Test Method D3512-82) and the Elastomeric Pad Method (ASTM TestMethod D3514-81) at five specified test intervals. The effect of twist level of warp and filling yarns on pillingpropensity, flex abrasion, tensile strength, and breaking elongation was also investigated.</p><p>Pilling produced by the Random Tumble Pilling (RTP) procedure was mainly fiber fuzz and loosely anchoredpills; that produced by the Elastomeric Pad Method (EPM) was large scale pills and fiber entanglement whichdid not wear off readily.ANOVA test revealed that the twist level of warp yarns had a significant influence on thepilling characteristics</p><p>as evidenced in both pilling tests. Twist level of filling yarns influenced EPMpilling ratings only intermittently.The effect of twist level of warp yarns was highly significant for the warp direction on flex abrasion, tensilestrength, and breaking elongation. On the other hand the twist level of filling yarns influencedfilling tensile andbreaking elongation.</p><p>The major findings of the study indicate that pilling performance was significantly influenced by pilling testmethod and testperiod. The low and intermediate twist levels of OE yarns investigated did not consistently affectthe pilling and other fabric properties analyzed.</p><p>Textile engineers have made efforts to develop newspinning systems to provide increased productivity anduniformity in yarn and fabric manufacturing. New weavingand knitting technology requires a high degree of yarnregularity and a larger yam package. Ring-spinning (RS) hasinherent limitations in meeting these requirements(Tewksbury, 1981). Open-end (OE) spinning, on the otherhand, provides large yarn packages and uniform products.OE spinning also reduces at least one yarn operation since itis a sliver-to-yam system.The structural and physical properties of OE and RS</p><p>yams, as they affect end-use performance of fabrics wovenfrom those yarns, have been investigated by numerousresearchers. As a consequence of the difference in thespinning methods, RS yarns are better aligned with the yamaxis but are more hairy, whereas OE yams are more likely tohave a twisted core and loosely wraped sheath with trailing</p><p>loops. Consequently, the latter are bulkier and display lowerstrength but higher extensibility than corresponding RSyams. The twist levels necessary to obtain adequate as wellas maximum yam strength are much higher for OE yamsthan for RS yams (Mohamed, Lord, &amp; Saleh, 1975;Simpson &amp; Murray, 1978).Other studies have reported that an increase of twist level</p><p>improves abrasion resistance, strength, elongation, andhairiness of OE rotor spun yarns of cotton and polyester-cotton blends (Barella &amp; Manich, 1984; Manich, Barella &amp;Vigo, 1981; Marino, Garofalo, Barella, &amp; Manich, 1984;Mohamed et al., 1975). However, the effect of twist level ofOE yarns on hairiness for some man-made fibers andpolyester/cotton blends has been reported to be lessimportant than in RS yarns.Mohamed and Lord ( 1973) reported that the effect of yarn</p><p>type and yam twist on fabric properties differed from theproperties of the yams in a free state. The inclusion of OEyams into woven fabrics affects the topography andproperties of the fabrics. Although the effect of yam type</p><p> at UNIV OF SOUTHERN CALIFORNIA on April 4, 2014ctr.sagepub.comDownloaded from </p></li><li><p>42</p><p>(i.e., OE vs. RS) on the strength, soiling, and wear propertiesof fabrics have been investigated by several researchers(McKinney &amp; Broome, 1977; Mohamed &amp; Lord, 1973;Morris &amp; Prato, 1978), the influence of twist level on thepilling and related performance properties of test fabricswoven from blended OE yarns warrants further in-vestigation.</p><p>Pilling has long been recognized as a problem with staplefibers. Since the advent of man-made fibers, pilling hasbecome one of the major consumer complaints with knittedand woven fabrics having low twist yarns and loose fabricstructure. Pilling itself is not believed to influence yambreakdown and fabric failure but it affects fabric aesthetics.Findings of recent studies revealed that yarn and fabricfailure can be formed in localized fabric areas when pillformation and pill growth occur at a high rate (Cooke, 1984,1985).</p><p>Pilling is a complex process and the mechanism involvedvaries according to fiber type, yam and weave geometry, andthe nature and velocity of abrading forces. It was reportedthat pills were generated from the area with highly densefuzz fibers (Cooke, 1983). When fuzz fibers becameentangled and could no longer align themselves withabrading force, pill growth was promoted through fiber pull-out and fiber roll-up. Hence, pilling propensity wasdetermined by the balance between the rate of fuzzformation, fiber entanglement, and fuzz and pill wear-off(Cooke, 1983, 1984; Gintis &amp; Mead, 1959).</p><p>Hairiness, low twist level of yams, and slack fabricstructure were reported to favor fuzz formation and fiberentanglement and pill growth (Cooke, 1983, 1984; Gintis &amp;Mead, 1959; Mohamed &amp; Lord, 1973; Mohamed et al.,1975). Long staple lengths also promoted the developmentof large pills. On the other hand, high tensile strength andflex life decreased the rate of pill wear-off (Cooke, 1983).Gintis and Mead (1959) reported that man-made fibers,especially polyester and nylon, displayed only moderate rateof pill formation but low rates of pill loss. The rate of fuzzformation and pill wear-off were believed to have a greatereffect on pilling while the fiber entanglement stage was lessimportant to pilling.</p><p>Pilling test methods which accurately measure the typeand degree of pilling as it occurs in wear situations have notbeen investigated extensively. Farmer, Earl, and Balfrey(1972), after a review of pill test methods, reported that theBrush and Sponge Test and the Appearance Retention Testwere inappropriate due to inaccuracy and proceduraldifficulties. The investigation of the Random Tumble PillingTester Method revealed a lack of rating reproducibility and afailure to produce the type of pills found in actual wear forsome fabrics. To remedy the situation, the Elastomeric PadMethod (EPM) was developed and adopted by ASTM(1985). This test method was reported to predict pilling for avariety of fabrics (Farmer et al., 1972).The overall objective of the present study was to</p><p>investigate the pilling performance of low and intermediatetwist OE yams spun from low pilling propensity Dacron andcotton. The specific objectives were (1) to compare thepilling performance of test fabrics evaluated by two ASTMpilling test methods, namely, the Random Tumble Pilling</p><p>Tester Method (ASTM Test Method D3512-82) andResistance of Apparel Fabrics to Pilling (Elastomeric PadMethod) (ASTM Test Method D3514-81) and (2) toinvestigate the effect of the twist level of warp and fillingyams on pilling propensity, stress-strain characteristics, andabrasion properties of 65/35% polyester/cotton fabricswoven from open-end yams.</p><p>Materials and Procedures</p><p>Test Fabrics. All open-end yarns in the study were spunon a Schlafliurst auto-core open end frame. Sixteen testsamples were woven from 65/35% Dacron/cotton blendwarp and filling yarns spun from 1.25 denier 3.81 cm hightenacity and low pilling propensity Dacron fiber and carded2.22 cm Texas cotton. The fiber was spun into size 16 countwarp and filling yams of 3.25, 3.50, 3.75, and 4.0 twistmultipliers (TM). Test fabrics were woven by combiningfour TM of warp yams with those of filling yams resulting in16 (4X4) samples of different warp and filling twist levels.The mean thread counts and weight of test fabrics were 28 X17 per CM2 and 182.80 g/m2 respectively.All test fabrics underwent mercerizing and sanforizing in</p><p>addition to singeing, desizing, and cold bleaching. They werelaundered three times in a top loading automatic washer withthe manufacturers recommended amounts of a heavy dutypowder detergent, then tumble dried using the permanentpress cycle for both laundering and drying processes.</p><p>Pilling Evaluation. The tendency of fabrics to form pillswas evaluated by two test procedures, the Random TumblePilling Tester Method (ASTM Test Method D3512-82) andResistance of Apparel Fabrics to Pilling (Elastomeric PadMethod) (ASTM Test Method D3514-81) (ASTM, 1985).For the Random Tumble Pilling (RTP) test, three specimensof 10.6 cm were cut on the 45 degree bias and sealed withUbagrip cement before they were conditioned and tumbledfor 30 minute test intervals under the prescribed testconditions (65% 2% RH and 70 2F). A panel ofthree judges evaluated each specimen after one, two, three,six, and eight 30-minute test intervals of tumbling bycomparing samples to the standards developed as indicatedin the test procedures on a 1-5 rating, ranging from 1= severepilling to 5=slight or no pilling.</p><p>Resistance of apparel fabrics to pilling by the ElastomericPad Method (EPM) was conducted on three roundspecimens 10.2 cm in diameter. Specimens were abradedunidirectionally under a 1 lb. load for 300, 600, 900, 1200,and 1500 strokes. Rubbed areas were evaluated by the panelusing small size photographic standards on a 1-6 ratingscale, ranging from 1=severe pilling to 6=no pilling. Anadditional rating of 6 was added for this investigation toaccommodate test specimens which showed little or nopilling after the specified number of abrasion strokes. Pillsproduced under the two test procedures were furtherexamined under the microscope and through scanningelectron micrographs.Flex Abrasion. The resistance of test fabrics to flexing</p><p>and abrasion was determined by the C.S.I.-Stoll-Quarter-master machine according to ASTM Test Method D3885-</p><p> at UNIV OF SOUTHERN CALIFORNIA on April 4, 2014ctr.sagepub.comDownloaded from </p></li><li><p>43</p><p>80. The number of cycles required to rupture wasdetermined for five warp and five filling samples under 1 lb.tension and head loads. Results are reported separately.</p><p>Tensile Strength and Breaking Elongation. One inchravelled strip tests (iR) of five warp and five fillingspecimens were conducted according to ASTM TestMethod D1682-64 (Reapproved 1975) using a constant-rate-of-traverse tester with the machine speed set at 12 1/2 inch per minute. The average dry breaking load andbreaking elongation of warp and filling directions werereported in pounds and percentage at rupture. The abovetests were carried out under standard conditions of 65 2%relative humidity and 70 2 F as specified by the testmethods.</p><p>Statistical Analyses. A two-way analysis of variance wascomputed to determine the significant differences in pilling,stress-strain, and flex abrasion measurements due to TM ofwarp and filling yams. The Duncans multiple range test atthe 0.01 level was used to analyze the difference betweenmeans when F was found to be significant.</p><p>Results and Discussion</p><p>Pilling Measurements. The mean RTP ratings of 16 testfabrics at five specified test intervals are shown in Table 1.Most test fabrics appeared to display noticeable changes inappearance as indicated by the pill ratings after the 30-minute tumble pilling process. Close examination under amicroscope disclosed widely scattered short fiber fuzz inmost test samples and a few small pills on some test samples.The mean pill ratings of most individual samples decreased(2=slight pilling) gradually as testing progressed andreached their lowest ratings at the 90-minute test interval.</p><p>From that point fuzz and pill density seemed to be reducedas pilling ratings increased. To confirm these observations,the number of pills on randomly selected 2 X 2 CM2 areas oftest samples at 90- and 240-minute test intervals wascounted using a microscope. Fiber entanglements whichinvolved more than four fiber ends were regarded as a pill.The number of pills on individual test samples ranged from 2to 6 with an average of 4.8 pills for the 90-minute test periodand 0 to 4 with an average of 2.2 pills for the 240-minute testintervals. This result indicates that pills wore off during thelater test periods, which confirms the pilling processpostulated by earlier researchers (Cooke, 1983; Gintis &amp;Mead, 1959).The mean EPM pill ratings of 16 test samples at five</p><p>specified test intervals are shown in Table 2. The EPM pillratings of most individual samples were higher than RTPratings at the first test interval. However, pill ratings of a fewtest samples decreased considerably at the later testintervals. Microscopic examination revealed that theaverage pill counts of 2 X 2 CM2 abraded areas at 900 and1500 strokes reached 3.8 and 3.5 respectively. The repeatedrubbing action against a confined surface area of this testappeared to promote large scale pill growth through fiberpull-out and roll-up processes as the test progressed. TheSEM of Test Sample 1 illustrates twisted and entangledfibers after 1200 EPM strokes (see Figure 1).</p><p>In contrast to the EPM, the tumbling action of the RTPprocedure involves a cutting, flexing, bending, twisting, andrubbing action which seemed to produce fiber fuzzes andloosely anchored small pills which started to wear off at thelater test intervals. The large pill growth through fiber pull-out and tight fiber entanglement was conspicuously absent.Figure 2 reveals the SEM of fibrillation and longitudinalcracks found in Test Sample 16 after the 180-minute RTP</p><p>Table 1. Mean random tumble pilling rating of test fabrics at the specified test intervals.</p><p> at UNIV OF SOUTHERN CALIFORNIA on April 4, 2014ctr.sagepub.comDownloaded from </p></li><li><p>44</p><p>Table 2. Mean Elastomeric Pad Method Pilling Rating of test fabrics at the specified test...</p></li></ul>