1. Comparison of Conventional Ring, Mechanical
Compact and Pneumatic Compact Yarn Spinning Systems
Sevda Altas1, Hüseyin Kadoğlu2
1Ege University Emel Akın Vocational School, İzmir TURKEY
2Ege University Textile Engineering Department, İzmir TURKEY
Correspondence to:
Sevda Altas email: sevda.altas@ege.edu.tr
ABSTRACT
This research is a comparative study of the physical
properties of mechanical compact and conventional
spun yarns and fabrics knitted from these yarns. To
experiment the relational behavior, mechanical
compact and conventional spun cotton yarns were
produced in three different yarn linear densities
having three twist levels. In order to examine the
effect of spinning systems on fabric properties single
jersey fabrics were knitted from these yarns. Results
showed that, compact spun yarns have less hairiness,
higher strength and higher elongation ratio than
conventional spun yarns. Also, fabrics produced with
compact yarns were found to have less pilling
tendency.
In the second part of the study, we compared the yarn
properties produced with conventional ring,
mechanical compact and pneumatic compact
spinning systems. Analysis showed that, yarns
produced with the pneumatic compact spinning
system had the highest strength and the lowest
hairiness.
Keywords: Mechanical compact spinning,
conventional ring spinning, carded cotton, combed
cotton, yarn physical properties, fabric physical
properties.
INTRODUCTION
In conventional ring spinning, the zone between the
nip line of the delivery rollers and the twisted end of
the yarn is called the “spinning triangle”. This is the
most critical part of the ring spinning system. In this
zone, the fiber assembly doesn’t have any twist. The
edge fibers play out from this zone, and make little or
no contribution to the yarn tenacity. Furthermore,
they lead to yarn hairiness [1].
In compact spinning, the “spinning triangle” is
eliminated and almost all fibers are incorporated into
the yarn structure under the same tension. This leads
to significant advantages such as increasing yarn
tenacity, yarn abrasion resistance and reducing yarn
hairiness [2 and 3].
There are different compact spinning systems on the
market from different manufacturers. The main
difference of these systems is the condensing unit.
Most of the pneumatic compacting systems are
composed of perforated drums or lattice aprons over
the openings of the suction slots. With the air flow,
the fibers move sideways and they are consequently
condensed. Today, pneumatic compact spinning
system is widely used in compact yarn production.
However the adaptation of this system to
conventional ring spinning machine is very complex
and expensive; also this method cause high additional
energy consumption during spinning process.
Mechanical compact spinning is an important
alternative for compact yarn production. The system
is cheaper and less complicated than pneumatic
compact yarn spinning systems. Furthermore, there is
not any additional energy consumption during the
spinning process [4].
In this study Rotorcraft mechanical compact spinning
system (RoCoS) was used in the production of
compact yarns. In RoCoS compact spinning system,
the compact yarn is produced by adding positive nip
at the end of the drafting unit. The condenser is held
against the bottom front drafting roller by means of a
magnet. By the help of the “groove” in the ceramic
compactor, fibers are brought closer and spinning
triangle is eliminated [5 and 6]. The view of the
RoCoS mechanical compact spinning and the back
view of magnetic compactor are given in Figure 1.
Journal of Engineered Fibers and Fabrics 87 http://www.jeffjournal.org
Volume 7, Issue 1 – 2012
2. FIGURE1. The view of RoCoS mechanical compact spinning and
the back view of the magnetic compactor.
The compacting zone of the compactor is the distance
between the two nipping points (A and B). The front
top roller and delivery rollers have the same are
peripheral speed; therefore fibers are not drafted in
this area.
A roving guide is attached to the top roller mill shaft.
By the help of it, roving is fed into the center of the
ceramic compactor. Roving guide movement is
critical, during compacting process for the best
compact yarn production roving guide should be
stopped. However in bulk production to increase the
life time of the roller, traversing distance must be
reduced.
According to previous research, mechanical compact
spinning significantly improves yarn tensile
properties and reduces its hairiness [7 and 8]. Until
now there are many studies about the comparison of
the conventional ring and compact yarns properties
[9-12].
In the first part of the study, in order to understand
how the effect of spinning system varies on yarn
linear density and twist coefficient, we produced
various compact and conventional spun yarns. In the
second part of the study, we compared conventional
ring, mechanical compact and pneumatic compact
yarn spinning systems.
EXPERIMENTAL
Yarn Samples Production
In the experimental part of the study 100 % carded
cotton and 100 % combed cotton rovings having Ne
1.04 and 45 T/m were collected from one spinning
mill.
Carded and combed rovings used in the study were
produced from (ait olmak) one type of cotton (Ege
St.1) raw material. By this way we could compare the
physical properties of mechanical compact spun
carded and conventional spun combed yarns. The
fiber properties measured with High Volume
Instrument (HVI) test machine were given in Table I.
The first part of the study was carried out in Ege
University’s Textile & Apparel Research and
Application Centre while the second part of the study
was carried out at one of the textile mill in Turkey.
For this reason the spinning particulars of two set of
experimental yarns could not be the same as can be
seen in Table II for the first part of the study and
Table III for the second part of the study.
In the first part of the study, during mechanical
compact and conventional yarn spinning, the same
rovings and the same spindles were used in order to
eliminate any possible effect of roving and spindle on
yarn quality properties. Yarn linear densities were
chosen as; 29.5/1 tex (Ne 20/1), 19.6/1 tex (Ne 30/1)
and 14.7/1 tex (Ne 40/1). For each yarn count, three
twist coefficients were chosen as;
α
tex
= 103 (αe = 3.4),
α
tex
= 115 (αe = 3.8)
α
tex
= 127 (αe = 4.2).
In the second part of the study, we compared
conventional ring, mechanical compact and
pneumatic compact yarn spinning systems. Rieter
K44 pneumatic compact spinning system was used in
the production of pneumatic compact yarns. We used
100 % combed rovings which were used in the first
part of the study. Yarn linear densities were chosen
as; 13.1/1 tex (Ne 45/1), 9.5/1 tex (Ne 62/1) and 7.8/1
tex (Ne 75/1) having the same twist coefficients as;
α
=120 (αe = 4.0).
tex
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Volume 7, Issue 1 – 2012
3. TABLE I. Raw Material Physical Properties.
Measured fiber properties Carded
cotton Combed cotton
Fiber fineness, micronaire 4.30 4.35
Fiber strength, gr/tex 37.00 39.02
2.5 % span length, mm 28.43 29.57
Uniformity, % 85.40 86.62
Short fiber percentage, % 6.83 5.75
Elongation at break, % 4.40 4.82
TABLE II. Spinning particulars for conventional ring and mechanical compact yarn spinning systems.
Technological/machine set parameters
Yarn linear density
29.5/1 tex 19.6/1 tex 14.76/1 tex
Ring yarn type Conventional /
Mechanical Compact
Conventional /
Mechanical Compact
Conventional /
Mechanical Compact
Theoretical twist coefficient (α
tex
) 103 115 127 103 115 127 103 115 127
Theoretical twists (turns/m) 602 667 735 735 818 902 838 947 1044
Spindle speed (rpm) 10.000 10.000 10.000
Ring diameter (mm) 42 42 42
Traveller type (ISO No) 80 45 35.5
Traveller design and finishing treatment SFB 2.8 pm dr Saphir SFB 2.8 pm dr Saphir SFB 2.8 rl dr Saphir
Cradle spacer thickness (mm) 3.75 3.25 2.75
TABLE III. Spinning particulars for conventional ring, mechanical compact and pneumatic compact yarn spinning systems.
Technological/machine set parameters
Yarn linear density
13.1/1 tex 9.5/1 tex 7.8/1 tex
Compacting system Ring / RoCoS /
Rieter K44
Ring / RoCoS /
Rieter K44
Ring / RoCoS /
Rieter K44
Theoretical twist coefficient (α
tex
) 121 121 121
Theoretical twists (turns/m) 1056 1239 1363
Spindle speed (rpm) 18.500 17.000 16.000
Ring diameter (mm) 42 42 42
Traveller type (ISO No) 25 25 23.6
Traveller design and finishing treatment c1 el udr Safir c1 el udr Safir c1 el udr Safir
Cradle spacer thickness (mm) 2.75 2.75 2.75
Yarn evenness, faults, hairiness and diameter
properties were tested using an Uster® Tester 5
(UT5). We tested each type of yarn 10 times with
400 m/min test speed. Yarn tenacity and elongation
properties were tested with a Tensojet. We tested
each type of yarn 25 times with 200 m/min test
speed.
For a comprehensive examination of yarn hairiness,
the average hairiness of yarns was also measured
with a Keisokki Laserspot Hairiness Diameter
Tester. This instrument measures hairiness and
yarn diameter at the same time using a laser beam.
The instrument counts the number of hairs in
different length classes including 1 mm, 2 mm, 3,
mm and calculates the hairiness index. In this
study, we tested each type of yarn 5 times with a 50
m/min test speed and evaluated the hairiness index
results.
All tests were performed after the yarns were kept
in standard atmospheric conditions for 24 hours
(65±5 % relative humidity, 20±2ºC).
In the analysis of test results, Factorial ANOVA
and Multiple ANOVA (LSD) methods were used
with SPPS statistical pocket program at 0.05
significance level.
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Volume 7, Issue 1 – 2012
4. Fabric Samples Production
Ring and compact yarns were knitted with 48-
gauge, 12-inch diameter Mesdan 294 E laboratory
knitting machine with 225 turn/min production
speed.
The pilling properties were measured with a
Martindale Abrasion and Pilling Tester by 2000
revolutions. The pilling tendencies due to friction
of 6 different fabric surfaces were determined
according to the ISO 12947-1 standard. Later we
used an SDL Atlas Automated 3D Pilling and Fuzz
Grading test machine to assess pilling grade values.
The bursting strength measurements of 5 different
type of fabric were determined according to ISO
13938-2 (7.3 cm2 area; 30.5 mm diameter) with
James Heal Truburst® test device.
All tests were performed after the fabrics were kept
in standard atmospheric conditions for 24 hours
(65±5 % relative humidity, 20±2ºC).
RESULTS AND DISCUSSION
Evaluating the Yarn Properties
According to experimental results of yarn linear
densities, compact yarns were found to be coarser
than conventional yarns due to elimination of fiber
fly in compact yarn spinning system.
We analyzed the main effects which are yarn linear
density, twist coefficient and spinning system on
yarn properties. We also analyzed the interaction
effects of spinning system versus yarn linear
density and spinning system versus twist
coefficient.
Figures 2-7 shows the main effect plots on both
carded and combed yarns. The effect of spinning
system is shown as X1 and X4. The effect of yarn
linear density is shown as X2 and X5. The effect of
twist coefficient is shown as X3 and X6. M
represents the mean value for each observed yarn
property. In the graphics R represents the ring
spinning system and C represents the compact yarn
spinning system.
According to the statistical analysis the effect of
yarn linear density is significant on all observed
yarn properties. As the yarn linear density increase
evenness, the number of thin place, the number of
thick place and neps values increase, hairiness,
diameter, tenacity and elongation values decrease.
In carded yarns, increase of twist coefficient
increases the evenness, tenacity and elongation
values and decreases hairiness (Uster and Keisokki)
and diameter values significantly. On the other
hand, we couldn’t observe any significant relation
between twist coefficient and the number of thin
place, the number of thick place and neps values.
In the combed yarns, the increase of twist
coefficient increase tenacity and elongation and
decreases the number of thick place, neps, Uster
hairiness and diameter values significantly. On the
other hand, we couldn’t observe any significant
relation between twist coefficient and Keisokki
hairiness, evenness and the number of thin place
values. Due to having different measuring
principles, the effect of twist coefficient on Uster
and Keisokki hairiness results are not similar in all
type of yarns observed in this study.
Table IV represents the Factorial ANOVA
statistical results of the yarn properties. F value
represents whether a significant difference among
treatment means or interactions exists. Significance
(Sig.) value represents the homogeneity of
variances, if it is less than 0.05 than we can say that
the effect is statistically significant.
FIGURE 2. The main effect plots for yarn evenness.
FIGURE 3. The main effect plots for yarn hairiness (uster).
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Volume 7, Issue 1 – 2012
5. FIGURE 4. The main effect plots for yarn hairiness (keisokki).
FIGURE 5. The main effect plots for yarn diameter.
FIGURE 6. The main effect plots for yarn tenacity.
FIGURE 7. The main effect plots for yarn elongation.
TABLE IV. The F and significance values of factorial ANOVA analysis for conventional ring and mechanical compact spun yarns.
Compared pairs
Spinning
system
Spinning system*
Yarn linear density
Spinning system* Twist
coefficient
Carded cotton Combed cotton Carded cotton Combed cotton Carded
cotton Combed cotton
F Sig. F Sig. F Sig. F Sig. F Sig. F Sig.
CV (%) 260.40 .000* 44.54 .000* 22.39 .000* 28.78 .000* 0.57 .562 0.915 .403
Thin place (-%50) 16.54 .000* 2.70 .102 3.19 .043* 5.13 .007* 0.006 .994 0.736 .481
Thick place(+%50) 94.34 .000* 4.44 .036* 5.78 .004* 18.94 .000* 0.20 .811 1.01 .364
Neps (+%200) 40.35 .000* 36.87 .000* 53.67 .000* 58.12 .000* 2.74 .067 6.18 .003*
Hairiness (Uster) 1428.3 .000* 4055.2 .000* 7.11 .001* 25.66 .000* 1.01 .366 15.19 .000*
Hairiness (Keisokki) 629.0 .000* 259.58 .000* 4.70 .045* 8.62 .010* 1.47 .284 0.39 .689
Diameter (mm) 1392.7 .000* 2255.9 .000* 31.86 .000* 63.55 .000* 2.61 .076 13.63 .000*
Tenacity (cN/tex) 329.35 000* 219.92 .000* 12.02 .000* 7.44 .001* 0.79 .454 1.16 .317
Elongation (%) 133.94 .000* 137.32 .000* 6.14 .000* 10.82 .000* 0.36 .693 1.55 .217
* Statistically significant.
Based on the analysis results following conclusions
can be drawn:
Yarn Evenness Results
The experimental results of conventional and
compact spun yarns evenness are given in Figure 8.
According to statistical analysis, the effect of
spinning system is statistically significant on both
carded and combed yarn evenness as shown in Table
IV.
Carded compact yarns have higher evenness values
than carded conventional ring yarns. The interaction
effect of spinning system and yarn linear density is
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Volume 7, Issue 1 – 2012
6. statistically significant. The difference between the
evenness values of conventional and compact spun
carded yarns increases as the yarn becomes coarser.
Combed compact yarns have higher evenness values
than combed conventional ring yarns. The interaction
effect of spinning system and yarn linear density is
statistically significant. While at 29.5 tex and 19.6 tex
combed compact yarns have higher evenness than
conventional ring yarns, at 14.7 tex conventional ring
yarns have higher evenness values than combed
compact yarns.
The reason behind the higher irregularity of the
compact yarns can be explained by the use of front
bottom roller in mechanical compact spinning system
(Figure 1). Rollers cause irregularities in the drafted
strand since there is an incomplete control of the
motion of each individual fiber or fiber group
especially for coarser yarns. Similar result is obtained
with previous study about mechanical compact
spinning [8].
In both carded and combed yarns the interaction
effect of spinning system and twist coefficient on
yarn evenness isn’t statistically significant.
Yarn Imperfection Results
In carded yarns, the effect of spinning system is
statistically significant on the number of thin places,
the number thick places and neps values (Table IV).
Carded compact yarns have higher thin place, thick
place and neps values than carded conventional ring
yarns. The interaction effect of spinning system and
yarn linear density is statistically significant. The
difference between the number of thin places, the
number of thick places and neps value of compact
and conventional spun carded yarns increases as the
yarn becomes coarser.
FIGURE 8. The evenness of compact and conventional spun yarns.
In combed yarns the effect of spinning system is
statistically significant on the number of thick places
and neps values (Table IV). Combed compact yarns
have higher thick place and neps values than combed
conventional ring yarns. The interaction effect of
spinning system and yarn linear density is statistically
significant. While at 29.5 tex and 19.6 tex combed
compact yarns have higher number of thick places
and neps, at 14.7 tex conventional combed ring yarns
have higher number of thick places than compact
yarns. This result can be explained with the weak
control of fibers in coarse yarn due to the increased
number of fibers in the yarn cross section.
The interaction effect of spinning system and twist
coefficient is only statistically significant on neps
values of combed yarn. However the effect is
irregular and the trend is unclear to accept the
presence of any meaningful relation.
Yarn Hairiness Results
The Uster and Keisokki hairiness test results of
conventional and compact spun yarns are given in
Figure 9 and Figure 10 respectively. According to
statistical analysis, the effect of spinning system is
statistically significant on both carded and combed
yarn hairiness as shown in Table IV.
Carded and combed compact yarns have lower
hairiness (Uster and Keisokki) than carded and
combed conventional ring yarns. This could be
explained by the elimination of spinning triangle in
compact yarn spinning system.
With both Uster and Keisokki hairiness test result,
the interaction effect of spinning system and yarn
linear density is statistically significant on carded and
combed yarn hairiness (Table IV). However the effect
is irregular varying yarn linear density and the trend
is unclear to accept the presence of any meaningful
relation.
The interaction effect of spinning system and twist
coefficient is only statistically significant on Uster
hairiness values of combed yarn. The differences
between compact combed and conventional combed
yarn hairiness values increases as the yarn twist
coefficient decreases. This shows that the advantage
of the compact spinning system on combed yarn
hairiness property is more noticeable at lower twist
levels.
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Volume 7, Issue 1 – 2012
7. FIGURE 9. The hairiness (uster) results of compact and
conventional spun yarns.
FIGURE 10. The hairiness (Keisokki) results of compact and
conventional spun yarns.
Yarn Diameter Results
The diameter measurement results of conventional
and compact spun yarns are given in Figure 11.
According to statistical analysis, the effect of
spinning system is statistically significant on both
carded and combed yarn diameter as shown in Table
IV. The diameter values of carded and combed
compact yarns are lower than the carded and combed
conventional ring yarns.
Due to elimination of spinning triangle in compact
spinning, the migration of fibers in compact yarns is
deeper and as a result of this compact yarns diameter
is smaller than conventional spun yarns [8 and 13].
The interaction effect of spinning system and yarn
linear density is statistically significant on both
carded and combed yarns diameter. The difference
between the diameter values of conventional ring and
compact yarn increases as the yarn becomes coarser.
FIGURE 11. The diameter results of compact and conventional
spun yarns.
The interaction effect of spinning system and twist
coefficient is statistically significant on combed yarn
diameter. The difference between the diameter values
of conventional and compact spun combed yarns
decreases as the twist coefficient increases.
Yarn Tenacity and Elongation Ratio Results
The tenacity measurement results of conventional and
compact spun yarns are given in Figure 12.
According to statistical analysis, the effect of
spinning system is statistically significant on both
carded and combed yarn tenacity and elongation
properties as shown in Table IV. The tenacity and
elongation values of carded and combed compact
yarns are significantly higher than carded and
combed conventional ring yarns. The diameter values
of compact yarns were smaller than those of
conventional ring yarns. In other words the density of
these yarns was higher. The higher density would
also infer higher fiber to fiber interaction and thus
higher strength [8 and 13].
The interaction effect of spinning system and yarn
linear density is statistically significant on both
carded and combed yarn tenacity and elongation
ratio. The difference between the tenacity and
elongation values of conventional and compact spun
yarns decreases as the yarn becomes coarser.
For both carded and combed yarns, the interaction
effect of spinning system and twist coefficient isn’t
statistically significant on yarn tenacity and
elongation ratio.
Journal of Engineered Fibers and Fabrics 93 http://www.jeffjournal.org
Volume 7, Issue 1 – 2012
8. Evaluating the Knitted Fabric Properties
Table V shows the thickness and the weight per unit
area of fabrics knitted with conventional and compact
yarns. The weight per unit area of fabrics knitted with
compact yarns is higher than the fabrics knitted with
conventional ring yarns. The difference in the weight
per unit area of the fabrics is due to the difference
between the yarn liner densities of conventional ring
and compact spun yarns. However we couldn’t
observe any significant difference between the
thicknesses of the knitted fabrics.
FIGURE 12. The tenacity results of compact and conventional
spun yarns.
TABLE V. The thickness and weight per unit area of fabrics knitted with conventional ring and mechanical compact spun yarns.
Fabric property
Yarn
linear
density
(tex)
3.4 3.8 4.2
Weight
per unit
area
(gr/m²)
%CV Thickness
(mm) %CV
Fabrics knitted
with carded
ring yarn
29.5/1 140 4.38 0.73 0.01 149 4.91 0.75 0.02 146 7.93 0.77 0.02
19.6/1 94 5.85 0.69 0.03 95 0.38 0.72 0.02 102 2.09 0.75 0.02
14.7/1 62 1.13 0.57 0.02 66 1.30 0.68 0.01 69 2.98 0.73 0.03
Fabrics knitted
with carded
compact yarn
29.5/1 151 1.90 0.72 0.01 157 2.00 0.73 0.02 164 2.58 0.78 0.02
19.6/1 100 3.07 0.69 0.02 103 1.72 0.74 0.02 111 1.72 0.79 0.02
14.7/1 66 0.99 0.62 0.03 72 0.99 0.69 0.04 81 0.50 0.73 0.03
Fabrics knitted
with combed
ring yarn
29.5/1 148 1.30 0.70 0.05 153 2.83 0.76 0.02 153 2.64 0.77 0.02
19.6/1 98 7.64 0.69 0.03 96 1.96 0.67 0.02 103 3.05 0.73 0.02
14.7/1 70 4.42 0.62 0.04 69 0.38 0.67 0.02 70 2.28 0.70 0.02
Fabrics knitted
with combed
compact yarn
29.5/1 152 1.40 0.70 0.03 163 1.26 0.74 0.03 163 1.61 0.77 0.03
19.6/1 92 2.07 0.66 0.02 99 5.55 0.73 0.03 110 1.30 0.78 0.02
14.7/1 68 1.35 0.65 0.01 76 3.34 0.75 0.02 81 6.54 0.75 0.01
FIGURE 13. The main effect plots for fabric bursting strength.
Twist coefficient (αe)
%CV Thickness
(mm) %CV
Weight
per unit
area
(gr/m²)
%CV Thickness
(mm) %CV
FIGURE 14. The main effect plots for fabric pilling grade.
Weight
per unit
area
(gr/m²)
Journal of Engineered Fibers and Fabrics 94 http://www.jeffjournal.org
Volume 7, Issue 1 – 2012
9. Figure 13 and Figure 14 show the main effect plots
of fabric bursting strength and pilling grade
respectively. The effect of spinning system is shown
as X1 and X4. The effect of yarn linear density is
shown as X2 and X5. The effect of twist coefficient
is shown as X3 and X6. M represents the mean value
for each observed fabric property. In the graphics R
represents the ring spinning system and C represents
the compact yarn spinning system.
For the fabrics knitted with carded yarns, the effect of
yarn linear density is statistically significant on the
pilling grade and bursting strength properties
according to the statistical analysis. The pilling grade
and bursting strength values of the fabrics increase as
the yarn becomes coarser.
For the fabrics knitted with combed yarns, the effect
of yarn linear density is statistically significant on the
bursting strength property. The bursting strength
values of the fabrics increase as the yarn becomes
coarser. On the other hand, we couldn’t observe any
significant relation between combed yarn linear
density and pilling grade of the fabrics.
In both carded and combed yarns, the effect of twist
coefficient on pilling grade and bursting strength
properties of fabrics isn’t statistically significant.
As it can be seen in Table VI, fabric produced from
compact yarn has significantly higher bursting
strength than fabric produced from conventional
ring yarn. The bursting strength results of fabrics
produced with compact and conventional spun yarns
are shown in Figure 15.
The yarn tenacity contributes the bursting strength of
the fabrics. The increase of yarn tenacity increases
the bursting strength property of fabrics. The
difference between the bursting strength values of
fabrics knitted with conventional ring and compact
yarns are less noticeable than the difference between
the tenacity values of these yarns.
The difference between bursting strength results of
the fabrics produced with compact and conventional
spun yarns doesn’t change according to yarn linear
density and twist coefficient used in the knitting.
The pilling results of the fabrics knitted conventional
and compact spun yarns are shown in Figure 16.
Fabrics produced from compact yarns significantly
have higher pilling grade than the fabrics produced
from conventional ring yarns.
Pilling tendency of fabrics is affected by the yarn
hairiness. The fabrics knitted with compact yarns
have better pilling performance compared to the
fabric knitted from conventional ring yarns.
The interaction effect of spinning system and yarn
linear density effect is significant on fabric pilling
grade. However we couldn’t find linear correlation of
the interaction effect of spinning system and yarn
linear density.
TABLE VI. The F and significance values of factorial ANOVA analysis for knitted fabrics with
conventional ring and mechanical compact spun yarns.
Compared pairs
Spinning system Spinning system*Yarn linear
density
Spinning system*Twist
coefficient
Carded cotton Combed cotton Carded cotton Combed cotton Carded cotton Combed cotton
F Sig. F Sig. F Sig. F Sig. F Sig. F Sig.
Bursting strength (kPa) 24.92 .001* 13.94 .006* 0.92 .434 1.52 .275 0.04 .956 0.51 .617
Pilling grade 104.04 .000* 12.36 .008* 11.08 .005* 2.39 .153 2.52 .142 1.09 .380
* Statistically significant.
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Volume 7, Issue 1 – 2012
10. FIGURE 15. The fabric bursting strength of compact and
conventional spun yarns.
FIGURE 16. The fabric pilling grade results of compact and
conventional spun yarns.
The Comparison of Conventional Combed and
Compact Carded Yarns and Fabrics Produced
with Them
Table VII shows the statistical analysis for
conventional combed and compact carded yarns.
Compact spun carded yarn has significantly higher
evenness, the number of thin places, the number of
thick places and neps values than conventional
spun combed yarn.
Carded cotton has higher short fiber ratio than
combed cotton. Due to the incomplete control of
the short fibers in compact yarn spinning system
carded compact yarn has higher evenness and
imperfection values than conventional combed
yarn.
However, due to elimination of spinning triangle,
compact spun carded yarn has lower hairiness,
diameter and similar tenacity and elongation values
with conventional combed yarn.
TABLE VII. The F and significance values of factorial ANOVA analysis for conventional combed and compact carded yarns.
Compared pairs
Spinning system Spinning system*
Yarn linear density
Spinning system* Twist
coefficient
F Sig. F Sig. F Sig.
CV (%) 6327.6 .000* 15.60 .000* 1.10 .334
Thin place (-%50) 248.06 .000* 106.02 .000* 0.55 .578
Thick place(+%50) 1528.5 .000* 231.36 .000* 0.77 .465
Neps (+%200) 1026.7 .000* 110.97 .000* 8.20 .000*
Hairiness (Uster) 759.2 .000* 6.97 .001* 2.96 .054
Diameter (mm) 148.3 .000* 7.85 .001* 2.36 .097
Tenacity (cN/tex) 0.70 .404 9.57 .000* 6.36 .003*
Elongation (%) 0.11 .732 3.54 .033* 0.69 .501
* Statistically significant.
Journal of Engineered Fibers and Fabrics 96 http://www.jeffjournal.org
Volume 7, Issue 1 – 2012
11. TABLE VIII. The F and significance values of factorial ANOVA analysis fabrics produced with conventional combed and compact carded
yarns.
Compared pairs
Spinning system Spinning system*Yarn linear
density
Spinning system*Twist
coefficient
F Sig. F Sig. F Sig.
Bursting strength (kPa) 23.00 .001* 6.59 .020* 0.34 .719 23.00 .001* 6.59 .020* 0.34 .719
Pilling grade 7.82 .023* 1.08 .384 0.43 .659 7.82 .023* 1.08 .384 0.43 .659
* Statistically significant.
Table VIII shows the statistical analysis for fabrics
knitted with conventional combed and compact
carded yarns. Although carded compact and
conventional combed yarn has similar tenacity
values, fabric produced with compact carded yarns
has lower bursting strength than fabric produced with
conventional combed yarns. This can be explained by
non-uniform fiber arrangement in carded cotton raw
material.
Fabric produced with compact carded yarn has better
pilling properties because carded compact yarn has
less hairiness than conventional combed yarns.
The Comparison of Yarn Properties Produced
with Conventional Ring, Mechanical Compact and
Pneumatic Compact Yarn Spinning Systems
In this part of the study, we compared the properties
of yarns produced with conventional ring, mechanical
compact and pneumatic compact spinning systems.
Table IX shows the multiple comparison of
conventional ring, mechanical compact and
pneumatic compact yarn spinning systems.
According to statistical analysis results, pneumatic
compact spun yarn has the least evenness, the number
of thin place, the number of thick place, hairiness,
diameter and the highest tenacity and elongation
values.
Conventional spun yarn has the highest neps value
compared to mechanical and pneumatic compact
spun yarns. There isn’t any statistically significant
difference between the neps values of pneumatic and
mechanical compact spun yarns.
Conventional ring yarn has the highest thin place,
neps, hairiness, diameter and the lowest tenacity and
elongation values. Pneumatic compact spun yarn has
lowest number of thick place value compared to
conventional ring and mechanical compact spun yarn.
There isn’t any statistical significant between the
number of thick places between conventional ring
and mechanical compact spun yarns.
While the pneumatic compacting system uses
vacuum effect in the compacting zone, mechanical
compacting system uses the magnetic force. The
force applied to fibers in pneumatic compact spinning
system is stronger than mechanical compact spinning
system. As a result of this pneumatic compact spun
yarn has less evenness, fewer imperfections, lower
hairiness and has higher tenacity and elongation
values compared to mechanical compact spun yarn.
Journal of Engineered Fibers and Fabrics 97 http://www.jeffjournal.org
Volume 7, Issue 1 – 2012
12. TABLE IX. The multiple comparisons (LSD) of conventional ring, mechanical compact and pneumatic compact yarn spinning systems.
Yarn property Compared pairs Mean Difference Significance
CV (%)
Conventional Ring Mechanical Compact .1760 .192
Pneumatic Compact 1.5353 .000*
Mechanical Compact Conventional Ring -.1760 .192
Pneumatic Compact 1.3593 .000*
Pneumatic Compact Conventional Ring -1.5353 .000*
Mechanical Compact -1.3593 .000*
Thin place (-%50)
Conventional Ring Mechanical Compact 54.000 .001*
Pneumatic Compact 136.833 .000*
Mechanical Compact Conventional Ring -54.000 .001*
Pneumatic Compact 82.833 .000*
Pneumatic Compact Conventional Ring -136.833 .000*
Mechanical Compact -82.833 .000*
Thick place (+%50)
Conventional Ring Mechanical Compact 10.666 .372
Pneumatic Compact 101.333 .000*
Mechanical Compact Conventional Ring -10.666 .372
Pneumatic Compact 90.666 .000*
Pneumatic Compact Conventional Ring -101.333 .000*
Mechanical Compact -90.666 .000*
Neps (+%200)
Conventional Ring Mechanical Compact 65.166 .000*
Pneumatic Compact 86.333 .000*
Mechanical Compact Conventional Ring -65.166 .000*
Pneumatic Compact 21.166 .072
Pneumatic Compact Conventional Ring -86.333 .000*
Mechanical Compact -21.166 .072
Hairiness (Uster)
Conventional Ring Mechanical Compact 1.770 .000*
Pneumatic Compact 1.949 .000*
Mechanical Compact Conventional Ring -1.770 .000*
Pneumatic Compact .1787 .008*
Pneumatic Compact Conventional Ring -1.949 .000*
Mechanical Compact -.1787 .008*
Hairiness (Keisokki)
Conventional Ring Mechanical Compact 12.740 .000*
Pneumatic Compact 14.066 .000*
Mechanical Compact Conventional Ring -12.740 .000*
Pneumatic Compact 1.326 .000*
Pneumatic Compact Conventional Ring -14.066 .000*
Mechanical Compact -1.326 .000*
Diameter (mm)
Conventional Ring Mechanical Compact .0235 .000*
Pneumatic Compact .0299 .000*
Mechanical Compact Conventional Ring -.0235 .000*
Pneumatic Compact .0064 .000*
Pneumatic Compact Conventional Ring -.0299 .000*
Mechanical Compact -.0064 .000*
Tenacity (cN/tex)
Conventional Ring Mechanical Compact -4.033 .000*
Pneumatic Compact -6.320 .000*
Mechanical Compact Conventional Ring 4.033 .000*
Pneumatic Compact -2.286 .000*
Pneumatic Compact Conventional Ring 6.320 .000*
Mechanical Compact 2.286 .000*
Elongation (%)
Conventional Ring Mechanical Compact -.2733 .004*
Pneumatic Compact -.6067 .000*
Mechanical Compact Conventional Ring .2733 .004*
Pneumatic Compact -.3333 .001*
Pneumatic Compact Conventional Ring .6067 .000*
Mechanical Compact .3333 .001*
* Statistically significant.
Journal of Engineered Fibers and Fabrics 98 http://www.jeffjournal.org
Volume 7, Issue 1 – 2012
13. CONCLUSION
In the first part of the study, we compared the
properties of yarns produced with conventional ring
and mechanical compact yarn spinning systems.
Compact yarns were found to have lower hairiness
than conventional ring yarns. The reason behind the
lower hairiness in compact spun yarn is the
elimination of spinning triangle in spinning system.
Compact yarns were found to have smaller
diameter and better tensile properties than
conventional ring yarns. As the yarn diameter
decreases the fiber to fiber interaction increases and
this leads to higher yarn tenacity and elongation
ratio.
The mechanical compact spinning system slightly
increases the evenness and imperfection values of
yarns. However, as the yarn becomes finer these
effects gradually disappear.
The superior properties of compact yarns are seen
clearly on the fabric quality. Fabrics knitted with
compact yarns were found to have better pilling
properties and higher bursting strength than fabrics
knitted with conventional ring yarns.
Compact spun carded yarn was to found to have
lower hairiness and similar tensile properties
compared to conventional combed yarn; however it
has significantly higher evenness, number of thin
places, number of thick places and neps values. If
the evenness property of carded compact yarn can
be improved, it will have a potential for improving
quality and profitability of cotton yarn
manufacturing.
Fabrics knitted with compact carded yarns were
found to have better pilling properties than fabrics
knitted with conventional combed yarns. Although
carded compact and conventional combed yarns
were found to have similar tenacity values, fabrics
knitted with compact carded yarns had lower
bursting strength than fabrics produced with
conventional combed yarns. This can be explained
by non-uniform fiber arrangement in carded cotton
raw material.
In the second part of the study we compared the
properties of yarns produced with conventional
ring, mechanical compact and pneumatic compact
yarn spinning systems.
Pneumatic compact spun yarns were found to have
better yarn properties than mechanical compact
spun yarn. They had less evenness, less
imperfections, lower hairiness, higher tenacity and
higher elongation values. The reason behind
unsatisfactory test results could be the weak
compacting power of mechanical compacting
system.
There are different compact spinning systems on
the market from different manufacturers. In this
study we compared only the most commonly used
pneumatic compact spinning system. A further
study about the comparison of mechanical compact
spinning with other pneumatic compacting systems
should be a valuable contribution to the decision-makers
in the short-staple spinning industry.
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AUTHORS’ ADDRESSES
Sevda Altas
Ege University
Emel Akın Vocational School
İzmir, Bornova 35500
TURKEY
Hüseyin Kadoğlu
Ege University
Textile Engineering Department
İzmir, Bornova 35500
TURKEY
Journal of Engineered Fibers and Fabrics 100 http://www.jeffjournal.org
Volume 7, Issue 1 – 2012