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COMPARISON OF RING, OPEN-END, ROTOR, HOLLOW, VORTEX AND

FRICTION YARNS

A. INTRODUCTION

Within the last two decades, number of new yarns spinning techniques were developed

to increase the yarn productivity and quality other than they found in conventional ring spun

yarns. Modern techniques, open-end, rotor, hollow, vortex and friction spinning systems have

supply much more caution from engineers and technologists due to their high productivity.

These technologies separate from ring spinning not only in the design of the spinning units,

but also in the physical properties of the yarns, which may be identified by the configuration

of the fibres. Many researchers have analyzed the structure of ring spun yarns and structural

differences in staple yarns lead to different yarn properties.Today, yarn production is highly

advanced technology that opportunities the engineering of different yarn structure having

specific properties for particular application. Because yarn structure depend on processing

conditions and spinning technologies. The physical properties of yarn can be supposed to be

influenced by process variables.

According to research: To describe the structures of ring, rotor, and friction spun yarns

and to set up the relationships between the properties and the structures of the three different

yarn types. The physical properties are breaking tenacity, elongation, yarn evenness, and

hairiness.

B.COMPARATION OF STRUCTURES OF RING, ROTOR, AND FRICTION

SPUN YARNS

Many researchers have analyzed the structure of ring spun yarns since the early 1950s,

focusing on fiber migration. Morton found that the intervals of helix profiles decreased as the

twist increased. Hearle and Gupta showed that with increased twist, there was a marginal

decrease in mean fibre position and magnitude of migration, whereas the migration intensity

increased considerably. As for rotor spun yarn, Hearle and his associates concluded that the

low strength of rotor spun yarns could be attributed to poor fibre alignment and inferior fibre

migration within the yarn body. Lord pointed out that the low tenacity of the rotor spun yam

was due to relatively shallower fibre migration, a fairly large number of folded fibres, poor

distribution of load over them fibres, high twist multiple, different twist structure, and

spinning tension. Luenenschloss and Brockmanns used stereo-scanned pictures and cross


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sections of yams interspersed with tracer fibres to determine the structure of friction spun

yarns. They concluded that friction spun yarns had a strongger migration than ring spun yarns,

and the migration moved from the sheath to the core almost without reversal of direction.

Rust Lord found that the migration theory for ring spun yarns was in adequate for friction

spun yarnsdue to the conical disposition of fibres. From a comparison study of the migration

characteristics of staple yarns, Alagha and associates concluded that the differences in

migration characteristics of yarns on different spinning systems were due to different twisting

methods and tension levels present during yarn formation. In general, structural differences in

staple yarns lead to different yarn properties. Because yarn structure depends on processing

conditions and spinning technologies, the physical properties of yarn can be supposed to be

influenced by process variables. Thus, it is very important to understand yarn structure and its

effects on physical properties for various spinning systems, because each kind of yarn

manufactured by a specific spinning method has unique properties. While there have been

efforts to determine yarn properties for various spinning systems in terms of yarn structure,

most of these were handled qualitatively. Our objectives in this work are to characterize the

structures of ring, rotor, and friction spun yarns to establish the relationships between the

properties and the structures of the three different yarn types. For this purpose, we conduct

experimental studies on yarn structure to quantify it in terms of fiber migration, packing

density, spatial orientation angle and helix angle (twist angle). The physical properties we

examine are breaking tenacity, elongation, yarn evenness, and hairiness.

1. ExperimentalSpecimens for ring, rotor, and friction spun yarns were prepared from cotton slivers and

rovings containing 1 % black dyed (tracer) fibers. The linear density of the slivers and the

rovings were 4250 Tex (Ne 0.14) and 580 Tex (Ne 1.0), respectively. The mean fiber length

was 28.6 mm (1 /s inches) and the micronaire value was 4.2. The spinning conditions forsample preparation are summarized in Table I. Yam properties such as yarn tenacity, breaking

elongation, hairiness, evenness, and imperfections were investigated. The test methods and

experimental conditions are shown in Table I. All the tests were performed under a standard

atmosphere of 20 2C and 65 2% RH.


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Table1:Test Conditions For Yarn Properties

Property Test

method

Testing

machine

Sample

length

/test

Testing

speed

No, of

testing

Other

conditions

Tenacity

an

elongation

ASTM

D2256

USTER

Tensorapid

250

mm(gauge

length)

300mm/min 100 Pre-tensional

force, 0.5 g/tex

hairiness ASTM

D 5647

Zweigle

G565

hairiness

tester

500 mm 50 mm/min 5 Tension

applied during

test, 10 g hair

length

measured over

1 mm and 3

mm

U%, IPI Uster

method

Uster

Tester 3

1000 mm 400mm/min 5 Setting of

imperfection

indicator(IPI)

Thin places (-

50%)

Thick places

(+50%)

Neps (+200%)

2. Comparisons of Three Types of Yarn (Friction, Rotor, Ring)

The yarn properties are tenacity, breaking elongation, thickness variation, and

hairiness. Ring spun yarn has the highest tenacity and the friction yarn a considerably lower

one.Thickness variations show that the ring spun yarn has the best yarn evenness with 7.8%(U %) and the least imperfections. The evenness values of the rotor and friction spun yarns are

almost at the same level, whereas the friction spun yarn exhibits more imperfections than the rotor


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spun yarn. This may be accounted for by the folded and entangled fibers in the friction spun

yarn. Yarn evenness and fewer imperfections of the ring spun yarn seem to contribute to

better yarn tenacity. Another factor in yarn tenacity is fiber migration. The higher the fiber

migration, the greater the resistance of fibers to slippage under loading. According to the

experimental results for the relation between yam tenacity and the migration factor, fiber

migration indeed contributes positively to yarn tenacity, this positive contribution can be

described by the increased self-locking structure of yarn, which increases the resistance to

slippage between fibers and better utilization of fiber strength for yarn tenacity. One of theimportant mechanical properties distinct differences for various kinds of yarn is breaking

elongation. The processing conditions for many successive processes where ring spun yarns

are used are not available for rotor or friction spun yarns, mainly due to the difference in

breaking elongation. Friction spun yarns can be more extensible despite its low tenacity and

weak migration. According to experimental results, the friction spun yam has the highest

breaking elongation. Rotor spun yarn is known to have better breaking elongation than ring

spun yarn.

3. Yarn Hairiness of Three Type of Yarn

Yam hairiness plays an important role in fabric roughness, luster, and shade, etc. Toinvestigate the relation between hairiness and the structural parameters, detested hairiness.

The rotor spun yarn obviously shows less hairiness than the others, independent of hair

length. The friction spun yarn exhibits almost the same hairiness as the ring spun yarn.Yamhairiness can be influenced by fiber distribution across the yam cross section or the mean fiber

position. In according to research, the rotor spun yarn shows the lowest mean fiber position of

0.40, and the friction spun yam has the highest value of 0.60.

The major findings of researches, the ring spun yarn exhibits the highest fiber migration, and

the friction spun yarn shows the lowest. The friction spun yarn is most compact near the yarn

surface, while the rotor spun yarn is most dense around the yarn axis. The fibers in a ring spun

yarn are moderately spread across the yarn cross section.

C.COMPARATION OF OPEN END YARN AND RNG YARN

1. Quality Characteristics Of OE Yarn As Compared To Ring Yarn


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Production Increased 3-3.5 TimesPackage Size Increased 20 TimesTex Range- 20-30

Twist- 10-15% HigherAverage

Strength- 15-20% WeakerVariation In

Strength LessExtensibility- 10% Higher

Work Of

Rupture-Same

Regularity- 10-20% BetterCount

Variation BetterAppearance-

More UniformBulkiness Spinning Volume Increased By 10%Hairiness- 20-40% LessCleanliness BetterNeppiness- Fewer Neps

Yarn Faults- Decreased By 80%

Resistance To

Abrasion

20-30% Better

Handle Harsher

Structure Different

Fiber

Blending-

Much Better

Take Up Of

Size

Better ( Less Size Required)

Take Up Of

Dyes

Better ( Vivid Colors)

End Breaks

In Spinning

Reduced 75%

Fly

Liberation

Less


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2.Characteristics Of OE Yarn In Use And Of Fabric Made From Them- Comparison

With Ring SpinningEnd Breaks Reduced By 50%

Knots (After Winding) Decreased By 15-17/Kg

Warp Breaks In Weaving Decreased By 70%Weft Breaks In Weaving Decreased By 25%

Tensile Strength Reduced

Tearing Strength Reduced

Bursting Strength Reduced

Appearance More Uniform

Barring More Better

Cover 10% Better

Cleanliness Better

Neppiness Fewer Neps

Resistance To Abrasion 5-7% Better

Handle Harsher

Thermal Insulation 10-15% Better

Air Permeability 15-25% Better

Take Up Of Dyes Better ( Vivid Colors, Clear Definitions)

Absorption Of Water Much Better

Shrinkage Same

D. COMPARATION OF MURATA VORTEX SPUN YARNS WTH RING ANDOPEN-END ROTOR SPUN YARNS

The structure and properties of Murata vortex spun yarns are investigated and compared

with ring and open-end rotor spun yarns. According to research, Matsuo show that cottonyarns are spun from the same lot of Australian raw cotton fibers using the Murata vortex, ring,

and open-end rotor spinning methods. Yarn structures are observed with an optical

microscope equipped with a digital camera. The differences in measured yarn properties such

as evenness, hairiness, bulkiness. Tenacity, compression properties, and bending properties

can be explained by the observe differences in the yarn structure (2004, ss.819-816). Ring

spinning has a low production rate; the ring spun yarn structure is generally accepted as the

fundamental or basic structure in spun yarn technology

Recently, Murata vortex spinning (MVS), based on the air jet spinning technology by the

Murata Machinery Company in Japan, has been commercialized. With the MVS system, it

becomes possible to use a wider fiber length range for 100% cotton yarn, allowing spinning of

a wider yarn size production range.


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One of the great advantages of MVS is that it can deliver yarn at up to 400 m/min. Although

the number of MVS frames operating in mills is still much lower than the number of Ring

spinning (RS) and Open End Rotor Spinning (OERS) frames, MVS installations are growing

rapidly because of high production rates compared with Ring Spinning (RS) and Open End

Rotor Spinning (OERS).However, there has been no research in which the structure and yarn

properties of MVS are systematically compared with number of Ring spinning (RS) and

Open End Rotor Spinning (OERS).

According to research;MATSUO used the same Australian cotton fibers arranged by CSIRO,Australia, was used to produce 100% cotton yarn on the RS, OERS, and MVS systems in

research(2004, s 820) .

MVS yarns possess higher core fiber parallelization than OERS and RS yarns. Wrapper fiber

parallelization in MVS yarns is closer to the core fiber parallelization of RS yarns. In the

MVS yarn structure, core fibers are considered to have zero twist, which differs from RS and

OERS yarn structures. MVS yarn structure, it is also clear that the core fiber strand is

enveloped by a thin layer of wrapper fibers with good parallelization

1. Yarn PropertiesA) Yarn Evenness the physical properties of yarns.


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Researcher used the same lot of cotton fibers for all the spinning methods, which was

a great advantage when comparing them evenness results for all yarns. Researcher found no

significant evenness differences in the three kinds of yarns, except for a higher frequency of

thick places and neps in the MVS yarn. The hairiness length (1 mm) for the MVS yarn was

similar to the OERS yarns and lower than the RS yarns. For the hairiness length (3 mm),

MVS yarn hairiness is much lower than the other two kinds of yarns.

B) Yarn Tenacity

The yarn tenacity value of RS yarn is higher than tenacity of OERS and MVS yarns.

The reason for the lower tensile values in the OERS yarn structure is the lack of fiber

parallelization, which causes a non-uniform load distribution. With regard to Mvs yarns, the

twisted fiber core of RS yarn as opposed to the nontwisted core of the MVS yarn creates a

stronger bond between the fibers. While these fundamental structural effects cause the higher

tenacity value of RS yarn compared with MVS yarn, it is important to note that there is no

optimal selection of twist factor for this MVS yarn production from the view point of tenacity.

C) Yarn Mechanical Properties

MVS yarn had the highest compression energy value (WC of these three kinds of

yarn, which can be partly explained by its bulkiness. Another factor for the higher WC may

be the higher resistance to compression pressure found in Mvs yarn particularly in the

displacement range from 0.02 to 0.055 cm. The bending rigidity of MVS yarn is higher than

OERS and RS yarns. At the end of research, many properties of MVS, RS and OERS yarns

are found in the tables.


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2. ConclusionAs modified fiber classification scheme to analyze fiber arrangements in ring spun yarn,

open-end rotor spun yarn, and Murata vortex spun yarn. Researcher investigated the yarnproperties and yarn formation mechanism for a better understanding of the basic differences


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in these yarns. This research has shown that ring and OERS yarns are mainly composed of

core fibers, which are generally highly parallel, although the core fiber parallelization of open

end rotor spun yarn is much less uniform than that of ring yarn. In this research, MVS

wrapper fiber parallelization is regarded as the same as the arrangement of core fibers in a

ring yarn. MVS core fibers, which are also highly oriented in parallel, have almost no twist.

More than half of the surface area of MVS yarns is covered and packed by the layer of

wrapper fibers. The uniformity arrangement of these wrapper fibers makes the Murata vortex

spun yarn the least hairy of the three yarn types. The structural differences can be reasonably

explained by the yarn-forming mechanism of each spinning method. The structural

differences of each yarn type confer different tensile, compression, and bending rigidity

values.

According to research; in this regard, Murata vortex yarns are stiffer than ring and open-end

rotor spun yarns, while ring yarns have the highest tenacity values. Klein show that Murata

vortex spinning are compared by Ring Yarn (1993, Sections 1.6.1 & 1.6.2)

A) Murata vortex systems Yarn Properties (compared with Ring Yarn) 15% lower strength Less extensible

Stiffer and harder Rougher & duller Less untwisting tendency Less pilling More evenB) Main Advantages Of Murata Vortex Spinning According To Ring Spinning High speed (to 300 m/min) Short processC) Main Disadvantages Of Murata Vortex Spinning According To Ring Spinning Limited fiber range Limited yarn count Lower yarn strength/elongation Harsher handle


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E. COMPARATION OF RNG YARN WTH AIR JET/ ROTOR or FRICTION

Single yarn strength of air jet/ rotor or friction yarn is less than that of ring yarn. So fabrics

made from ring yarn will be stronger than those made from air jet/rotor or friction yarn. The

fabric made from ring yarn will be weaker than those made from the other yarns. The

presence of wrapper fibers inside the rotor, air jet and friction yarns increase the frictional

force inside the fabric and therefore resistrupture, among other factors such as the rupture ofwrapper fibers inside the fabric for these yarns are more than ring yarn, which enhance further

frictional force.


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F. COMPARATION OF MURATA VORTEX SPUN YARNSWTH AR JET SPUNYARNS

In order to have a general knowledge about this yarn spinning systems, we need tocompare the properties of air-jet and vortex yarns. Also, no work to date has been reported

regarding the difference between these yarns. A study was conducted to reveal the difference

between the properties and structure of the vortex and air-jet spun yarns.

A) Comparison of Yarn Structures of Vortex and Airjet Yarns.Yarn structure is one of the most important factors that have an effect on the properties of

spun yarns and Vortex-spun yarn has a two-part structure. In the first part of this study, the

properties of vortex and air-jet spun yarns made from various PES/cotton blends were

compared and a piece of vortex yarn was untwisted and viewed under the Scanning Electron

Microscope and SEM images confirmed that vortex yarns consist of two distinctive parts: the

core and the sheath. (Basal, Oxenham ,n.d.)

The examination of these yarns under the microscope showed that Air Jet fibers are consisting

from approximately %95 untwisted and parallel core fibers and %5 wrapper fibers. On the

other hand, Vortex fibers are nearly consisting from % 90 untwisted and parallel core fibers

and %10 wrapper fibers. This indicates that Vortex yarns have more Ring like appearance and

a higher number of wrapper fibers compared to air jet yarns.

B) Comparison of the Mechanical Properties of yarns

The researches that made with

the blended yarns were produced from

three different blends of black

polyester (1.7 den, 1.5 in) and cotton

fibres (4.1 mic., 0.91 in) (blend ratios:

33/67, 50/50, 67/33), is revealed that

yarns made by Vortex had a higher

evenness, less numbers of thick


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places and lower hairiness values compared by Air Jet systems. Vortex yarns also has a higher

tenacity value for every blend ratio except the 100% polyester case, and as the cotton content

increased in the blend, the difference enlarged. For 100% polyester yarn, on the contrary, the

tenacity values of Vortex and Air jet yarns did not differ so much. Vortex yarns show lower

elongation values compared to Air jet yarns. (Basal, Oxenham ,n.d.)

The higher tenacity values of vortex yarns are because of the higher number of wrapper

fibers in these yarns. Also, the number of wrapper fibers is attributed to yarn strength. In air

jet spinning edge fibers ultimately produce wrapper fibers, and the number of edge fibers

depends on the fibers at the outside. One possible explanation for the reduction in elongation

is the decrease in fiber slippage due to better grip by wrapper fibers. Possibly the drop in

hairiness values is another result of better wrapping.


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G. COMPARATION OF STRUCTURES OF RING AND HOLLOW SPNDLESPUN YARNS

A hollow spindle wrapped yarn is a new yarn consisting of a core yarn and a wrapping

yarn. The structure of a hollow spindle wrap spun yarn depends greatly on the steadiness of

binder tension and of balloon rotation. The two commonly used binder bobbin forms, the cop

type and the flanged type, both as sources of spinning condition fluctuation, are examined in

order to reveal their effects on the wrap spun yarn structure. False twist is introduced on

hollow spindle spinning machines in order to avoid strand breaks before it is tightly wrapped

up. However, an investigation of the false twist g-wrapping process shows that this inevitably

causes irregular yarn tortuosity.

The hollow spindle is designed as a false twisting assembly. The fibre strand does not pass

directly after entering the vertical spindle instead, shortly after entering the spindle; this strand

is led out again and back around the spindle with wrap about one- quarter of the spindle

periphery. In this way, as the spindle rotates, the strand is provided with the twist between the

drafting arrangement and head of the hollow spindle. These turns of twist are cancelled out

again in the spindle head in accordance with the false twist principle. This twist prevents the

strand from falling apart in the length prior to filament staple fibres wrappings with filament.

A wrap spun yarn consists of non-twisted parallel bundle of staple fibres held together by

helically wrapped filament. The proportion of the filament in the yarn is about 2-5 %. Due to

helical wrapping of the filament and by radial pressure, necessary cohesion between the

individual staple fibers is improved. This imparts desired strength to the yarn. The number of

wraps per unit length in a standard PL yarn is approximately the same as the amount of twist

in a comparable ring spun yarn.

As the turns of twist increase, it causes more energy consumption and it is necessary to use

bobbin for the smaller filament yarns. However, the production in hollow spindle systems is

much higher than conventional ring spinning systems and such quality parameters like

evenness, neps, and strength are better than ring systems. Also, the fabrics that are produced

with hollow spindle systems, the resistance to friction and strength is higher.

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