Indian Journal of Textile ResearchVol. 9. December 1984. pp. 154-159

Comparison of the Characteristics of Open-end and Ring Yarnsand Fabrics of Different Structures

G S BHARGAVA·, P K MEHTA & R K GULATI

The Technological Institute of Textiles. Bhiwani 125022

Receired II December 1983: accepted 2J February 1984

As the plying of yarn improves not only the yarn quality but also the fabric quality, a study has been made to compare theextent of improvement resulting from plying in open-end yarn. ring yarn and in fabrics prepared with these yarns as weft. bykeeping the warp and weave identical. Increase in twist and number of plies in open-end yarn produced a plied yarncomparable to nng yarn. However. the use or open-end yarn demands a judicious selection or yarn COUIlt.number or plies In thefinal yarn, twist levels of single- and plied-stage yarn. loom set! and the type of weave for producing fabrics with optimumperformance.

Open-end (OE) yarn differs in structure from ringyarn 1.2, and by virtue of this the fabrics prepared fromthe two vary in their characteristics:' -7.

Salhotra et al.2 found that 2-ply OE yarns arecomparable to 2-ply ring yarns in strength after beingprocessed with a slightly higher twist. Keeping this inview, we made the present study with single-, 2-ply and3-ply OE and ring yarns using three plying twist levelsto determine the changes in breaking strength,elongation and tenacity of the yarn. A quality yarnwould produce a quality fabric, but the level of fabricassistance may further vary in the level ofimprovement of the fabric quality. Therefore, some ofthe important fabric characteristics, viz. change infabric construction, breaking strength, breakingelongation, tear strength, flex abrasion and fabricflexural rigidity, have been examined after usingdifferent yarns as weft, keeping the quality of warp andweave identical.

Materials and MethodsCotton-J-34 Saw gin cotton was used for making

the yarn and fabric samples. The main characteristicsof the cotton used were mean fibre length, 20 mm; fibrestrength (Pressley index), 8.2 lb/mg; and fibre fineness(micronaire value), 4.7 Jig/in.

Preparation of yarn samples-Cotton yarns of 20snominal count were spun by using BD 40 OE and ringframe machines. Open-end yarn was prepared with anequivalent of 20 turns per inch of the ring yarn.

Using open-end and ring yarns, 2-ply and 3-plyyarns, the first with 12, 16 and 20 turns/in. and the

·Present address: Government Central Textile Institute. Kanpur.

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second with 10, 14 and 18 turns/in., were prepared.Thus, in all, 12 yarn samples, six from open-end and sixfrom ring yarn, were prepared. Each yarn sample wasallotted a reference number (Table 1). In the yarnreference number the first two letters represent ply (Si,single: Tw, 2-ply: and Th. 3-plyJ. the third letter thesystem of yarn preparation i.e. O--open-end and R-ring. and the digit, the plying twist.

Preparation of fabric samples-Two weaver'sbeams, one with single 20s ring yarn and the other with2-ply ring yarn having 16 turns/in. plying twist, wereprepared. Two fabrics of 56 x 48 nominal constructionwere prepared by using the same single warp and singleopen-end and ring yarns as weft.

Six fabric samples of 36 x 36 nominal constructionwere prepared by using 2-ply ring warp and sixdifferent 2-ply weft yarns. Another six fabric samplesof 36 x 30 nominal construction were prepared byusing 2-ply ring warp and six different 3-ply weft yarns.

The fabric samples were desized and scoured underactual mill conditions. Before. testing, all the yarn andfabric samples were conditioned in standardatmosphere (65 ± 5/.) RH and 27 ± 2 C) for 24 hr and48 hr respectively.

The breaking strength and breaking elongation ofsingle yarns were measured on an Instron tensilestrength tester and the tenacity was calculated bydividing the breaking strength (gram) by yarn rex.

The diameter of the yarn samples was determinedwith a projection microscope.

The number of threads/in. in the warp and weftdirections of each fabric sample was determined in theusual way by counting the number of threads in 1 in.with a standard I in. pick glass. The warp and weftcrimps of the fabrics were measured on a Eureka crimp

BHARGAYA 1'/ (I/. CHARACTERISTICS or OPEN-END & RING YARl'<S AND FABRICS

tester (Shirley type) and the percentage of total crimpwas calculated as follows:

Total crimp, /,,=(C1)1 2+(C2)1 2

where C1 and C2 are percentage warp-and weft crimpsrespectively.

The fabric weight was determined with a quadrantbalance.

The breaking strength and breaking elongation inwarp and weft directions of each fabric sample weredetermined with an Instron tensile strength tester andusing the standard method for ravelled strip, with20 em gauge length and 5 cm wide specimen. Thetraverse speed was 300 mm/rnin.

Each fabric sample was tested for flex abrasion onan ASTM flex abrasion tester in both warp and weftdirections. The end point was determined when thestrip was worn off and was specified by the number ofcycles.

The bending length in warp and weft directions ofeach fabric sample was determined with the Shirleystiffness tester.

The flexural rigidity in warp and weft directions ofeach fabric sample was calculated by using thefollowing relation:

Flexural rigidity (mg-cm)= We(warp or weft)

where W is the weight (mg/cm") of the fabric; and L,the bending length in em.

To observe the general effect of the variableparameter on the fabric characteristics, the overallvalue of each characteristic was determined for eachfabric sample by taking the geometric mean of warpand weft values.

Results and DiscussionYarn Characteristics

The yarn count, breaking strength, breakingelongation, tenacity and diameter of the experimentalyarns are given in Table I. A comparison of the valuesof these characteristics for SiO 19 and SiR 19 yarnsreveals that SiO 19 yarn is weaker, more extensible, lesstenacious and more bulky than SiRI9 yarn by 28.5,12.7.27.7 and 3.4% respectively. This is attributed tothe structural difference between open-end and ringyarns. This is in agreement with the findings of Lord I

and Salhotra 1'1 al. 2.

Similar trends are observed with 2-ply and 3-plyyarns for different yarn characteristics. A comparisonof the breaking strengths of 2-ply yarns having thesame level of plying twist shows that 2-ply open-endyarns are weaker than the corresponding ring yarns by32.9,33.0 and 23.2"" at 12, 16 and 20 plying twist levelsrespectively. This shows that initial plying twistinsertion does not reduce the difference between the

Table I-Characteristics of YarnsYarn Yarn Breaking Breaking Yarn Yarnref. count strength elongation tenacity diameterNo. Ne g 0 g/tex mm x 10-2

, 0

SiOl9 20.12 286.25 8.00 9.76 23.08

SiRI9 19.89 400.25 7.10 13.49 22.32TwOl2 10.01 474.00 8.36 8.04 42.16TwRI2 9.91 706.60 7.50 11.86 37.68TwOl6 9.92 483.33 8.52 8.12 42.00TwRI6 9.79 721.33 7.90 11.97 36.75Tw020 9.72 600.66 9.29 9.89 34.75TwR20 9.58 782.66 9.16 12.71 33.66ThOIO 6.72 814.00 8.29 9.27 45.09ThRIO 6.64 1096.66 7.94 12.34 43.24ThOl4 6.52 1030.66 9.42 11.39 44.63ThRI4 6.21 1413.13 9.33 14.87 41.85ThOl8 6.40 1026.66 11.88 11.14 43.86ThR IX -6.10 1366.66 11.88 14.13 40.92

strengths of the two yarns, but higher plying twist levelresults in a significant reduction in the difference inyarn breaking strengths. A similar trend is observedfor tenacity, which shows that 2-ply open-end yarnshave a lower tenacity than the corresponding ringyarns by 32.2. 32.1 and 22.2% at 12. 16 and 20 plyingtwist levels respectively.

A comparison of the values of breaking strength for3-ply yarns shows that open-end yarns are weaker thanthe corresponding ring yarns by 25.8. 27.0 and 24.9°"at 10, 14 and 18 plying twist levels respectively. Thisshows that there is a significant reduction in thedifference between the strengths of two types of yarnon increasing the number of plies. Since plying isuneconomical, open-end yarn may substitute ring yarnin the structures where 2-ply and 3-ply yarns are usedto meet the specific requirements. e.g. canvas. ducks,industrial fabrics. etc.

The reason for open-end yarn being weaker thanequivalent ring yarn is the lack of proper orientation offibres when they are deposited in the rotor freely andwraper fibres which do not contribute to yarnstrength:'. The same effect is observed in plied yarn.though plying reduces the difference in strength andtenacity at higher levels of plying twist.

A similar trend is observed for the tenacity of 3-plyyarns, which shows that open-end yarns have a lowertenacity than ring yarns by 24.9. 23.4 and 21.2~" at 10,14 and 18 plying twist levels respectively. It is alsoobs-rved that a gradual increase in plying twist reducesthe difference between the tenacity values of the twoyarns gradually.

The breaking elongation values of plied yarns showthat open-end yarns are more extensible than thecorresponding ring yarns. 2-Ply open-end yarns aremore extensible by II. 5. 7.8 and 1.4~" at 12. 16 and 20plying twist levels respectively. while 3-ply open-end

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INDIAN J. TEXT. RES .. VOL. 9. DECEMBER 1984

yarns are more extensible by 4.4 and O.9~Jat )0 and) 4plying twist levels respectively. It is interesting that at18turns/in. plying twist, the extensibility of 3-ply yarnswas almost the same. The results show that at a higherlevel of plying twist, the extensibility of plied yarns iscomparable. These findings are in agreement withthose of Salhotra et a/. 2.

The values of yarn diameter show that single open-end yarn is 3.4~;;)bulkier than single ring yarn; 2-plyopen-end yarns are 11.9, 14.3 and 3.2% bulkier at 12,16 and 20 plying twist levels respectively; while 3-plyopen-end yarns are 4.3, 6.6 and 7.2,/~bulkier at l O, 14and 18 plying twist levels respectively. This shows thatin 2-ply yarns, increase in twist initially increases thedifference and later decreases it, whereas in 3-plyyarns, a gradual increase in twist reduces the differencebetween the bulkiness of the two types of yarn. Thismay be because of the changed behaviour of twist onthe surface of multi-plied yarns.

Fabric Characteristics

Threads per in., crimp and fabric weight have adirect influence on most of the fabric characteristics,which change in a different manner when the yarn andfabric structures are changed as a result of wettreatment. Therefore, the fabric sett, crimp and fabricweight of desized and scoured fabrics were determinedto study the influence of such changes on fabriccharacteristics, like breaking strength, breakingelongation, tearing strength, flex abrasion resistance,bending length, flexural rigidity,. and stiffness. The

values of various fabric characteristics' are given InTables 2-4.

Threads/in.-From the values of threads per in. inboth warp and weft directions (Table 2), it is observedthat the scouring and desizing treatment brings aboutmore shrinkage in the cross-direction than in thelongitudinal direction, ends/in. increasing by 5-6 andpicks/in. by 2-5. The reason for this trend is that thewet treatment swells the fibres, causing increase in yarndiameter and demanding additional yarn length,which is not available. Since the cloth is notconstrained at the ends, the threads come closer,resulting in a higher number of threads/in. Further,increase in threads/in. is dependent on yarn structureand fabric construction and is little affected by the typeof yarn.

Crimp-A comparison of the values of warp andweft crimps for open-end and ring yarn fabrics of thesame weft yarn twist and construction (Table 2) showsno particular trend but the values of total crimps arehigher (though marginally) for open-end fabrics thanfor ring fabrics.

Fabricweight-The fabric weights of open-end andring yarn fabrics having the same weft yarn twist andconstruction (Table 2) show that ring yarn fabrics areheavier than the corresponding OE yarn fabrics andthe trend is independent of the weft yarn folding twistand fabric construction.

Pulay ' and Mohamed and Lord4 also observedsimilar trends for threads/in., crimp and fabric weight.

Table 2-Characteristics of Experimental FabricsFabric Threads/in. Crimp. % Fabric Weightref. No * g/m"

Warp Weft Warp Weft TotalNominal construction, Reed x Pick: 56 x 48

SiOl9 6:2 53 14.5 9.3 6.9 151.9-SiRI9 61 53 16.0 8.0 6.8 154.3

Nominal construction. Reed x Pick: 36 x 36

TwOl2 42 38 14.5 14.0 7.5 219.2TwRI2 42 38 15.0 13.0 7.5 223.5TwOl6 42 38 16.0 13.0 7.6 220.4TwRI6 42 38 16.3 12.0 7.5 226.9Tw020 42 38 18.0 13.0 7.8 222.4TwR20 42 38 16.3 13.0 7.6 227.5

Nominal construction. Reed x Pick: 36 x 30ThOIO 41 33 20.0 9.0 7.5 246.7ThRIO 41 32 17.3 10.0 7.3 251.6ThOl4 41 34 25.0 10.5 8.2 257.4ThRI4 41 34 24.0 6.7 7.5 262.3ThOl8 41 34 23.0 13.0 8.4 258.4ThRI8 41 34 23.0 8.0 7.6 263.1

*Fabric reference number is the same as the yarn reference number and depends on the type of yarn used asweft in the preparation of fabric sample.

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BHARGAVA 1'/ al.. CHARACTERISTICS OF OPEN-END & RING YARNS AND FABRICS

Table 3-Breaking Strength, Breaking Elongation and Tearing Strength Values of Experimental Fabrics

Fabric Breaking strength, kg Breaking elongation, % Tearing strength, kgref. No.

Warp Weft Overall Warp Weft Overall Warp Weft OverallNominal construction, Reed x Pick: 56 x 48

SiOl9 38.3 36.6 37.44 5.9 5.5 5.70 3.2 1.7 2.33SiR19 39.2 40.9 40.04 5.8 4.4 5.05 3.6 3.0 3.28

Nominal construction, Reed x Pick: 36 x 36Tw012 38.3 39.8 39.04 6.1 6.2 6.15 7.2 5.5 6.29TwR12 41.2 43.0 42.09 6.1 6.1 6.10 7.6 6.4 6.97TwOl6 40.2 4O.S 40.35 6.8 6.8 6.80 7.2 5.7 6.41TwRI6 42.6 43.8 43.19 6.3 6.3 6.30 7.7 6.5 7.07Tw020 41.6 41.5 41.55 6.7 7.4 7.04 7.3 5.8 6.51TwR20 43.4 44.3 43.85 6.3 6.9 6.59 7.8 6.8 7.28

Nominal construction, Reed x Piclc 36 x 30ThOIO 39.2 52.5 45.36 8.6 8.4 8.50 6.1 6.0 6.05ThRIO 40.0 61.0 49.40 7.9 8.2 8.05 6.3 7.6 6.92ThOl4 41.1 57.6 49.24 7.8 7.5 7.65 6.2 7.1 6.63ThR14 42.6 66.2 53.10 7.3 7.1 7.2il 6.4 7.8 7.06ThOl8 47.6 59.9 53.39 7.6 6.3 6.92 6.6 7.3 6.94ThRI8 48.6 68.4 57.65 7.3 6.0 6.62 6.8 8.1 7.42

Table 4-Flex Abrasion, Bending Length and Flexural Rigidity Values of Experimental Fabrics

Fabric Flex abrasion, cycles Bending length, em Flexural rigidity, mg emref. No.

Warp Weft Overall Warp Weft Warp Weft Overall

Nominal construction, Reed x Pick: 56 x 48

SiOl9 287 167 218.92 1.80 1.55 88.6 56.6 70.81SiR19 300 209 250.40 1.86 1.61 99.3 64.4 79.97

Nominal construction, Reed x Pick: 36 x 36

TwO 12 470 430 449.55 2.00 1.70 175.4 107.7 137.44TwRI2 490 475 482.44 2.03 1.75 181.0 119.8 149.67Tw016 460 420 439.54 2.01 1.72 179.0 112.1 141.65TwRI6 487 470 478.42 2.05 1.89 195.5 153.2 173.06Tw020 450 401 424.79 2.05 1.75 191.6 119.2 151.12TwR20 460 425 442.15 2.08 1.92 204.7 161.0 181.54

Nominal construction, Reed x Pick: 36 x 30

ThOIO 525 454 488.21 2.00 1.90 197.4 169.2 182.76ThRIO 527 474 499.79 2.05 1.93 216.7 180.9 197.99ThOl4 503 445 473.11 2,11 1.99 241.8 202.8 221.44ThRI4 512 460 485.30 2.20 2.00 279.3 209.8 242.07ThOl8 497 430 462.28 2.14 2.05 253.2 222.6 237.41ThRI8 505 450 476.70 2.25 2.08 299.7 236.8 266.40

Breaking strength-The values of warp and weftbreaking strengths for various fabrics having OE/ringyarn as a weft show that ring fabrics are stronger thanOE fabrics, irrespective of the weft yarn structure andfabric construction (Table 3). The overall breakingstrengths of ring fabrics are, in general, higher thanthose of the corresponding OE fabrics. This is inagreement with the findings of several researchers? -7.

The reason for such a trend may be that ring yarnsare stronger than OE yarns. From the results, it is alsofound that increase in plying twist increases the warp,weft and overall breaking strengths.

Further, increase in the number of plies increases thewarp, weft and overall breaking strengths, as expected.This may be due to increased strength as a result ofincrease in twist or of the number of plies in the yarn.

A comparison of the values of overall breakingstrength for OE and ring yarn fabrics having differentfolding twists, but the same fabric construction,reveals that the breaking strengths of the fabricshaving maximum folding twist OE yarn, i.e. Tw020and ThO 18, are comparable with those of the fabricshaving minimum folding twist ring yarn, i.e. TwR 12and ThRIO.

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INDIAN J. TEXT. RES .. VOl. 9, DECEMBER 1984

Breaking elongation-The breaking elongations forwarp and weft directions of various fabrics having OE/ring spun yarn as a weft show that ring fabrics are lessextensible than the corresponding OE weft fabrics,irrespective of the weft yarn structure and fabricconstruction (Table 3). The overall breakingelongations of ring fabrics are also, in general, lowerthan those of the corresponding OE fabrics. Similarobservations were made by Pillay ' and Rakshit". Thereason for such a trend may be that ring yarns are lessextensible than OE yarns.

With increase in plying twist, the values of warp,weft and overall breaking elongations increased in thecase of 2-ply yarns and decreased in the case of 3-plyyarns. Increase in the number of plies increases thebreaking elongation. This may be because of increasein crimp and extensibility of yarn with increase in thenumber of plies in the yarn. It is also observed thatincrease in the number of plies makes the two fabricscomparable in breaking elongation at higher twistlevels.

Tearing strength-The tearing strengths for warpand weft directions of various fabrics having OE/ringyarn as a weft show that the ring fabrics have a highertearing strength than the OE fabrics, irrespective ofweft yarn structure and fabric construction (Table 3).The overall tearing strengths of ring fabrics are alsogenerally higher than those of the corresponding OEfabrics. The reason for this is that the ring yarn has ahigher tenacity than the OE yarn (Table I). Similarobservations were made by Pillay ' and Mohamed andLord". Increase in twist and the number of pliesincreased the warp, weft and overall tearing strengthsof fabrics, irrespective of the type of yarn and fabricconstruction.

In the case of 2-ply weft yarn fabric, warp tearingstrength is higher than weft tearing strength, while inthe case of 3-ply weft yarn fabric, weft tearing strengthis higher than warp tearing strength. This is becauseboth the fabrics have the same warp but different weftsarid 3-ply weft is stronger than 2-ply weft. The valuesof overall tearing strength for OE and ring yarnfabrics, having different folding twists but the samefabric construction, reveal that the tear strengths of thefabrics having maximum folding twist OE yarn, i.e.Tw020 and ThOI8, are comparable with those of thefabrics having minimum folding twist ring yarn, i.e.TwRI2 and ThRlO.·

Flex abrasion-Table 4 shows that the values ofwarp, weft and overall flex abrasion resistance arehigher for ring fabrics than for corresponding OE weftfabrics. irrespective of the weft yarn twist and thenumber of plies. Similar observations were made byPillay3 and Mohamed and Lord4 with single yarns andby Rakshit" with 2-ply yarns.

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Increase in twist decreased the flex abrasionresistance of fabrics, irrespective of the type of yarn.Further, increase in the number of plies in the weftyarn increased the warp, weft and overall flex abrasionresistance.

The poor flex abrasion of OE fabrics may be due tothe surface character ofOE yarn, which makes it easierto pull the fibres from the fabric surface.

Bending length and flexural rigidity-The values ofbending length and flexural rigidity for warp and weftdirections of various fabrics having OE and ring yarnsshow that ring weft fabrics exhibit more bendinglength and flexural rigidity than OE weft fabrics,irrespective of weft yarn structure and fabricconstruction (Table 4). These observations accord withthose of Mohamed and Lord4 and Palit7.

All the fabrics had higher warp-way bending lengthand flexural rigidity than weft-way bending length andflexural rigidity. The reason for this may be that warpthreads are more in number than the weft threads perinch in the fabric construction.

Increase in both weft yarn twist and the number ofweft yarn plies increased the bending length andflexural rigidity in both warp and weft directions. Thereason for this may be that the fabric being of acomplex structure, the stiffness of the yarn, which isdependent on twist and the number of plies, wouldaffect the stiffness of the fabric favourably in both thedirections.

A comparison of the values of overall flexuralrigidity for OE and ring yarn fabrics reveals that ringweft fabrics are generally stiffer than OE weft fabrics.Fabrics with maximum twist OE yarn (i.e. Tw020 andThO 14) are comparable to those with minimum twistring yarn (i.e. TwRI2 and ThRIU) in stiffness.

Conclusions(I) OE yarns are weaker than the equivalent ring

yarns and the weakness decreases with increase in twistand the number of plies used in the yarn. OE yarns arealso more extensible than the equivalent ring spunyarns; increase in twist or number of plies in the yarnreduces the difference between the extensibility of thetwo yarns. Further. OE yarns are bulkier than theequivalent ring yarns because of the large diameter ofthe OE yarn.

(2) When fabrics of identical construction areprepared from OE and ring yarns and are processed inan identical manner, fabrics prepared from OE yarnsare weaker than the corresponding ring yarn fabrics.The difference in the strengths of the two fabricsreduces with increase in the number of plies.

(3) Fabrics prepared from OE yarns are moreextensible than the corresponding ring yarn fabrics.The difference between the extensibility of the two

BHARGAVA ct al.: CHARACTERISTICS OF OPEN-END & RING YARNS AND FABRICS

fabrics reduces with increase in twist and the numberof plies.

(4) OE yarn fabrics exhibit lower tearing strengththan the ring yarn fabrics. Increase in twist and thenumber of plies in the weft yarn increases the tearingstrength in the direction in which the yarn is used.

(5) OE weft yarn fabrics show poor abrasionresistance than the corresponding ring yarn fabrics.Increase in twist in weft yarn decreases the abrasionresistance, whereas increase in the number of plies inthe weft yarn increases the abrasion resistance.

(6) Use ofOE yarn in weft results in a fabric with ahigher flexibility, and increase in twist and the numberof plies in the weft yarn increases the fabric stiffness ingeneral.

Hence, the use of open-end yarn demands ajudicious selection of yarn count, number of plies in thefinal yarn, twist levels of single and plied yarn, loom

sett and the type of weave to be used for producingfabrics with the required performance characteristics.

AcknowledgementThe authors are thankful to Prof. R.C.D. Kaushik,

Director, TIT, Bhiwani, for permission to publish thispaper.

ReferencesI Lord P R. Text Res J, 41 (1971) 778.2 Salhotra K R, Sengupta A K & Haldar A K, Indian J Text Res, 5

(1980) 122.3 Pillay K P R, Text Res J, 45 (1975) 366.4 Mohamed M H & Lord P R, Text Res J, 43 (1973) 154.5 Morris M A & Prato H T, Text Res J, 48 (1978) 177.6 Rakshit A K, Comparison of the performance characteristics of

open-end and ring yarn towelling fabrics, M. Text. thesis,Technological Institute of Textiles, Bhiwani, 1983.

7 Palit S K, Comparative study of the characteristics of open-end andring-spun polyester-viscose blended fabrics, M. Text. thesis,Technological Institute of Textiles, Bhiwani, 1983.

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