diametric unevenness and fault classification of yarn...
TRANSCRIPT
2018
ISSN 1229-9197 (print version)
ISSN 1875-0052 (electronic version)
Fibers and Polymers 2017, Vol.18, No.10, 2018-2033
Diametric Unevenness and Fault Classification of Yarn Using Newly Developed
Diametric Fault System
V. K. Yadav1*, S. M. Ishtiaque
1, S. D. Joshi
2, and J. K. Chatterjee
2
1Department of Textile Technology, Indian Institute of Technology Delhi, New Delhi 110016, India
2Department of Electrical Engineering, Indian Institute of Technology Delhi, New Delhi 110016, India
(Received April 8, 2017; Revised August 12, 2017; Accepted August 16, 2017)
Abstract: The work presents the applicability of the developed Diametric Faults system through industrial trail to understandthe influence of different yarn spinning systems, yarn fineness and opening & cleaning system on yarn diametric unevennessand yarn faults. The Diametric Faults system measures the diametric yarn unevenness and classifies the faults of yarn basedon their geometric dimensions. Detailed analysis of the yarn fault classes with additional information related to added volumeon faults, fault length and frequency of yarn faults for different classes of yarn fault is also possible. The developed systemcombines the measurement of yarn imperfections and fault classification as one system. The Diametric Faults system provesto be an alternative practical solution to measure the yarn irregularity in terms of diametric unevenness along the yarn length,instead of existing most popular approach considering the variation in mass per unit length. Further, it is established that theresults obtained from the proposed system, are also confirming the expected trends noticed with considered variances in astandard manufacturing process.
Keywords: Classification of yarn fault, Diametric unevenness, Yarn diameter, Yarn fault characterisation
Introduction
The characterisation of yarn faults based on their con-
figuration opens the opportunity for developing a scheme for
classification and measurement techniques. It has been
established that faults having different configurations can be
differentiated on the basis of their configuration [1]. One of
the main objective of the staple fibre spinners is to regulate
the orientation of hundreds of fibres, having varying
properties, into a yarn of required mass uniformity per unit
length of yarn [2]. Therefore, it is high time to address the
measurement limitation of presently prevailing mass variation
concept along the yarn length [3,4]. Further, the yarn consists
of faults which deviate to quite a considerable extent to
intrinsic yarn diameter and length [5-9].
Unevenness has become synonymous with the mass
variation as obtained by the capacitance based measurements.
However, the basis for all fabric related calculations is the
yarn diameter which ultimately translates into the behaviour
as perceived by human eye. Hence it is important to measure
the diametric variation on continuous basis and obtain a
more realistic measure of the yarn diameter. Further, the
commercially used methods visualise the yarn cross-section
in a single projection view only. However, generally the
spun yarns cross-section is non-circular and approximates an
ellipse [10,11]. Hence it is usually desirable to evaluate two
orthogonal diameters of a yarn simultaneously to assess
diameter variations in both directions.
Accordingly, a Diametric Faults system is being developed
by the present authors and the system is capable of (a)
monitoring of yarn faults; (b) measurement of diametric
unevenness of yarn and yarn faults and; (c) classification of
yarn faults on the basis of their configurations [12]. The
Diametric Faults system measures dimensions of faults and
accordingly classifies the yarn faults on the basis of their
lengths and lateral sizes and provides a numerically based
objective and quantitative yarn fault classification system
[12]. The proposed system can generate yarn diameter as
well as cross-sectional area signals and can extract the yarn
faults based on the longitudinal and lateral size. It is further
observed that the dimensional characteristics of thick and
thin faults obtained from diameter and cross-sectional area
signals are identical [12]. However, the applicability of the
area signal is found to be better since the information about
the increase of volume of faulty region of the yarn are more
near to reality. Further, it also provides the yarn cross-
sectional eccentricity, a measure of yarn roundness, as estimated
using Horwitz’s approach [13]. Detailed analysis of the yarn
fault classes related to extra volume add-on, fault length and
frequency/location of faults along the yarn length is also
possible. The classification of faults in terms of cross
sectional size and length is comparable to the commercially
available yarn faults classification systems [12].
Present work reports the applicability of the proposed
system to study the influence of different spinning systems,
yarn fineness and opening & cleaning systems on yarn
characteristics in terms of diametric variation along the yarn
length.
Experimental
As the yarn samples to be spun were meant for yarn
diameter measurement, it was important to choose a material
which is not biased for any effect due to its fibre properties.*Corresponding author: [email protected]
DOI 10.1007/s12221-017-7337-y
Diametric Unevenness Using Diametric Fault System Fibers and Polymers 2017, Vol.18, No.10 2019
Hence, it was decided to use cotton fibre, which inherently
include adequate amount of fibre property variation in
respect to length, fineness etc. For all the yarn samples,
uniform yarn tension of 0.3±0.1 g/tex was used during the
measurement. Yarn cross-sectional eccentricity, e, is derived
using the expression , where a and b are the
length of semi-major and semi-minor axis of ellipse
respectively, and estimated using Horwitz’s approach [13].
Eccentricity indicates the flatness and is considered
as a measure of roundness [14].
Table 1 gives the fibre properties of used cotton. Following
three industrial trails are carried out to establish the
applicability of the Diametric Faults system.
1) Influence of two different spinning systems: Ring and
Compact
2) Influence of two different makes of opening and
carding (O&C) system: O&C1 and O&C2
3) Influence of yarn fineness: 24.6 tex and 14.7 tex on
compact spinning system
The process sequences of samples preparation are given in
Figure 1.
Results and Discussion
All four yarns with the proposed combinations, as described
in Figure 1, were tested on the newly developed Diametric
Faults system and these yarns were also evaluated on
commercially available system for comparison.
Comparison of Compact and Ring Yarn
This study deals with the comparison of ring and compact
yarn of 24.6 tex, produced on both the systems.
Yarn Diameter and Yarn Diametric Unevenness (CVd%)
The results of yarn diameter and diametric unevenness
(CVd%) are given in Table 2(a). It is observed that compact
yarn gives lower diameter as well as lower yarn diametric
unevenness (CVd%) than corresponding ring yarn.
Yarn Cross-sectional Area and Yarn Cross-sectional
Area Unevenness (CVca%)
The yarn cross-sectional area variation curves using cross-
sectional area signal are given in Figures 2 and 3 and the
results are tabulated in Table 2. The results confirm that
mean cross-sectional area of compact yarn is lower than
corresponding ring yarn. Further, it is noticed that the
maximum and minimum range of cross-sectional area in
case of compact yarn is higher than corresponding ring yarn.
It is also depicted from Table 2(b) that cross-sectional area
unevenness (CVca%) value of compact yarn is found to be
lower than corresponding ring yarn. The lower CVca% of
compact yarn can be supported by the lesser number of thick
and thin faults than corresponding ring yarn. But it is
interesting to note that eccentricity value of compact yarn is
a2
b2–( )/a2
1 e2–
Table 1. Properties of the cotton used
Fibre properties Values
Micronair (inch) 4.06
Length (UHML) (mm) 29.34
Strength (gm/tex) 30.68
Trash content (%) 3.67
Total (Neps/gm) 112
Figure 1. Process sequence of sample preparation.
Figure 2. Yarn cross-section area profile of 24.6 tex combed compact yarn.
2020 Fibers and Polymers 2017, Vol.18, No.10 V. K. Yadav et al.
found to be lesser than corresponding ring yarn. The obtained
eccentricity value clearly indicates that compact yarn is more
circular than corresponding ring yarn.
The results of diameter profiles of 24.6 tex compact and
corresponding ring yarns of 200 m yarn length are given in
Figures 2 and 3. It is depicted that CVca(m)% and
CVca(mm)% for compact yarn are found to be lower than
corresponding ring yarn. The results of variance-length
given in Table 3 and variance-length curve given in Figure 4
clearly depict that CVca% of compact yarn, at different
reference length, is always lower than corresponding ring
yarn. The lower CVca% of compact yarn can be supported by
the lesser number of thick and thin faults than corresponding
ring yarn.
The results of CVca% at different considered sections of
the yarn are given in Figures 5 and 6. It is further noticed
Figure 3. Yarn cross-section area profile of 24.6 tex combed ring O&C1 yarn.
Table 2. Yarn cross-sectional area and yarn diameter characteristics
(a) Yarn diametric characteristics
SampleIntrinsic yarn Dia
(mm)
Mean Dia
(mm)
Dia standard
deviation (mm)
CV of yarn Dia
CVd%
Max Dia
(mm)
Min Dia
(mm)
24.6 tex Combed Compact 0.206 0.263 0.029 10.95 0.605 0.181
24.6 tex Combed Ring O&C1 0.219 0.291 0.034 11.81 0.541 0.176
24.6 tex Combed Ring O&C2 0.233 0.294 0.033 11.11 0.53 0.192
14.7 tex Combed Compact 0.153 0.194 0.021 11.13 0.386 0.124
(b) Yarn cross-sectional area characteristics
Sample
Intrinsic
cross-section
area (mm2)
Yarn cross-section area Yarn eccentricity, e
Mean
(mm2)
Standard
deviation (mm2)CVca%
Max
(mm2)
Min
(mm2)Mean
Standard
deviation
24.6 tex Combed Compact 0.0332 0.0576 0.0155 26.97 0.9859 0.0217 0.500 0.2295
24.6 tex Combed Ring O&C1 0.0378 0.0718 0.0195 27.13 0.2868 0.0043 0.520 0.2219
24.6 tex Combed Ring O&C2 0.0427 0.0731 0.0185 25.35 0.2684 0.0212 0.508 0.2223
14.7 tex Combed Compact 0.0183 0.0319 0.0081 27.48 0.1437 0.0051 0.506 0.2446
Table 3. Variance-Length analysis based on area signal
Reference
length
(mm)
24.6 tex
Combed
Compact
24.6 tex
Combed
Ring O&C1
24.6 tex
Combed
Ring O&C2
14.7 tex
Combed
Compact
1 31.01 38.30 36.80 34.06
10 20.92 23.98 22.89 22.40
50 11.76 12.18 11.37 11.98
100 9.31 9.46 8.84 9.19
250 6.53 7.14 6.51 6.32
500 5.17 6.10 5.45 5.03
1000 4.18 5.30 4.84 3.99
2000 3.41 4.81 4.35 3.06
3000 3.06 4.60 4.16 2.74
4000 2.84 4.45 3.95 2.49
Note: Variance values are percentage coefficient of variation (CV%).
Diametric Unevenness Using Diametric Fault System Fibers and Polymers 2017, Vol.18, No.10 2021
that mean cross-section area and CVca(mm)% are found to
be lower for compact yarn than corresponding ring yarn.
The compact spinning system, used for present experimental
purposes, condenses the fibre ribbon coming out of drafting
system by means of pneumatic compaction with the help of
a perforated roller. The fibre condensation happens after
drafting but before the yarn twisting by generating aerodynamic
forces. Therefore, the width of the fibre ribbon reaching the
spinning triangle is very small which makes possible that all
the fibres are perfectly caught by the spinning triangle [15].
The fibre ribbon emerging from the nip of the first top roller
get influenced by the aerodynamic forces developed by the
vacuum inside the perforated drum. These forces guide the
fibres to the nip of the second top delivery roller. The drafted
ribbon of fibres finally gets compacted laterally by means of
aerodynamic forces. The above-mentioned process is mainly
responsible for reduction of yarn diameter in comparison to
corresponding ring yarn.
Further, the compacting of the fibre ribbon takes place on
the surface of the perforated metal drum which has a high-
quality surface finish. The coefficient of friction between the
surface of the drum and fibres moving on drum is very low.
Figure 4. Variance-Length (V-L) curve of area signal.
Figure 5. Sections wise profile of 24.6 tex combed compact yarn.
2022 Fibers and Polymers 2017, Vol.18, No.10 V. K. Yadav et al.
This facilitates the lateral shifting of the compacted fibre
ribbon. Thus, fibre ribbon structure delivered by the nip of
the delivery roller forms a very small spinning triangle
which makes possible that all the fibres are perfectly
embedded in the fibre ribbon and caught by the spinning
triangle. Because of this pneumatic compaction, it reduces
the yarn cross-sectional area, makes yarn more circular and
improves the CVca% in comparison to the corresponding
ring yarn [15,16].
Classification of Yarn Faults
A comparative study of compact and ring spinning system
is carried out as per the process plan given in Figure 1. The
results of yarn faults, measured on proposed Diametric
Faults system using cross-sectional area and classified on the
basis of volume approach, of 24.5 tex compact and ring yarn
of 200 meter measured length are given in Tables 4 and 5. It
is noticed that compact yarn shows lesser number of total
faults than corresponding ring yarn. It is seen that total
number of thick faults are lesser than thin faults. The
observed trend is valid for both compact and ring yarns at
±35 % and ±50 % sensitivity. The observed difference is due
to the used drafting system which results in improper control
of the fibres during drafting [17]. The positive control of
fibres in the drafting zone as a result of pneumatic compaction,
in the case of compact spinning system, is responsible for
lesser number of thick and thin faults than ring spinning
system.
Yarn faults can occur due to infinite reasons and can be
classified into three broad classes i.e. faults resulting due to
raw material; faults resulting due to process; and faults
produced at yarn spinning system. The raw material and
carding process give rise to the fault from the lower class
whereas the faults in the upper class are due to drawing and
spinning. It has been experienced that with the same cross
sectional size classes, the short length faults in general,
occur more frequently than the longer length faults. Further,
it is known that the process and machine parameters of
preparatory system affects the yarn evenness and may also
have an influence on the frequency of occurrence of thick
and thin faults [17]. It is an established fact that the thin and
thick faults are responsible for yarn unevenness. Extensive
mill experiments have in fact shown that the same factors
which influence the yarn unevenness also influence the level
of faults. These factors are, namely, the short fibre percentage in
cotton mixing; the type of drafting system and draft distribution
of yarn manufacturing system; the quality of fibre opening;
carding and combing process. The generation of thick faults
are due to the presence of unopened fibre clusters in the
sliver, and are therefore, dependent only on the degree of
fibre individualization achieved prior to drafting system and
also drafting irregularities. In general, the effect of carding is
far more pronounced on the number of thick faults than on
the number of thin faults [17].
Characteristics of Yarn Faults
The yarn faults are further characterized in terms of fault
dimensions and different derived index. The Table 6 shows
that the fault length and additional volume occupied by the
all thick faults present on a known measured length of the
yarn is found to be lower for compact yarn than corresponding
ring yarn but total number of thick faults are higher for ring
yarn in comparison to compact yarn. Results of compact
yarn also confirm lower mean cross-sectional area of thick
faults than corresponding ring yarn. Accordingly, it is
noticed that volume add on per fault and volume add on per
Figure 6. Section wise profile of 24.6 tex combed ring O&C1 yarn.
Diametric Unevenness Using Diametric Fault System Fibers and Polymers 2017, Vol.18, No.10 2023
(b) 24.6 tex combed ring O&C1 yarn
Thick total 3 13 21 26 119 39 38 0 0 0 0 0 0 259
% Deviation
in
volume
250 0
259
150 0
100 1 10 11
75 1 6 7 12 26
45 1 7 8 69 28 15 128
30 3 9 14 15 44 3 1 89
20 2 3 5
10 0
5 0
0 0
0 1 2 3 4 8 10 20 40 80 160 320 640
0 0
6
-5 0
-10 0
-20 0
-30 0
-45 1 1 2
-75 1 1 1 3
-100 1 1
Thin total 1 2 1 0 2 0 0 0 0 0 0 0 0 6
Table 4. Distribution of faults at sensitivity of ±35 %
(a) 24.6 tex combed compact yarn
Thick total 1 8 18 16 55 14 14 0 0 0 0 0 0
% Deviation
in
volume
250 0
126
150 0
100 1 1 1 3
75 1 1 1 7 10
45 1 4 3 21 10 6 45
30 8 13 12 32 2 1 68
20 0
10 0
5 0
0 0
0 1 2 3 4 8 10 20 40 80 160 320 640
0 0
0
-5 0
-10 0
-20 0
-30 0
-45 0
-75 0
-100 0
Thin total 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2024 Fibers and Polymers 2017, Vol.18, No.10 V. K. Yadav et al.
(d) 14.7 tex combed compact yarn
Thick total 1 3 14 17 87 38 29 0 0 0 0 0 0
% Deviation
in
volume
250 0
189
150 2 2
100 1 1 2
75 1 9 8 18
45 1 5 9 46 24 17 102
30 1 2 8 8 38 4 1 62
20 1 2 3
10 0
5 0
0 0
0 1 2 3 4 8 10 20 40 80 160 320 640
0 0
1
-5 0
-10 0
-20 0
-30 0
-45 0
-75 1 1
-100 0
Thin total 0 1 0 0 0 0 0 0 0 0 0 0 0 1
Table 4. Continued
(c) 24.6 tex combed ring O&C2
Thick total 3 13 23 25 71 40 18 0 0 0 0 0 0 193
% Deviation
in
volume
250 0
193
150 0
100 1 3 3 7
75 1 1 2 4 6 2 16
45 3 2 6 6 38 26 13 94
30 9 16 16 27 5 73
20 1 1 1 3
10 0
5 0
0 0
0 1 2 3 4 8 10 20 40 80 160 320 640 1288
0 0
-5 0
-10 0
-20 0
-30 0
-45 0
-75 0
-100 0
Thin total 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Diametric Unevenness Using Diametric Fault System Fibers and Polymers 2017, Vol.18, No.10 2025
unit length are found to be lower for compact yarn than
corresponding ring yarn for both ±35 % and ±50 % sensitivity
levels. But mean thick fault length of compact yarn is higher
than ring yarn at ±50 % sensitivity level and is lower at
±35 % sensitivity level than corresponding ring yarn.
The results of dimensional characteristics of thick and thin
faults of different lengths belonging to a specific volume
size (volume percentage increase) at ±35 % sensitivity level
of four yarns under study are reported in Tables 7 and 8. It is
depicted that volume add-on per fault, volume add-on per
Table 5. Distribution of faults at sensitivity of ±50 %
(a) 24.6 tex combed compact yarn
% Deviation
in
volume
250 0
14
150 1 1
100 1 1
75 1 4 1 6
45 1 1 3 1 6
30 0
20 0
10 0
5 0
0 0
0 1 2 3 4 8 10 20 40 80 160 320 640
0 0
0
-5 0
-10 0
-20 0
-30 0
-45 0
-75 0
-100 0
24.6 tex Combed Ring O&C1
% Deviation
in
volume
250 0
50
150 0
100 3 4 1 8
75 1 9 3 13
45 1 2 3 6 15 1 28
30 1 1
20 0
10 0
5 0
0 0
0 1 2 3 4 8 10 20 40 80 160 320 640
0 0
0
-5 0
-10 0
-20 0
-30 0
-45 0
-75 0
-100 0
2026 Fibers and Polymers 2017, Vol.18, No.10 V. K. Yadav et al.
unit length and mean fault length at different level of volume
percentage increase are found to be lower for compact yarn
than corresponding ring yarn. However, cross-sectional area
CV% does not show any specific trend. A similar exercise
was also carried out for thin faults and results are given in
Table 9. It is noticed that at ±50 % sensitivity level both the
yarns do not show thin faults in the yarns but at ±35 %
sensitivity level only O&C1 ring yarn shows thin faults.
Table 5. Continued
(b) 24.6 tex Combed Ring O&C2
% Deviation
in volume
250 0
32
150 0
100 1 2 1 1 5
75 2 3 5
45 1 6 1 3 9 20
30 1 1 2
20 0
10 0
5 0
0 0
0 1 2 3 4 8 10 20 40 80 160 320 640 1288
0 0
-5 0
-10 0
-20 0
-30 0
-45 0
-75 0
-100 0
(c) 14.7 tex Combed Compact Yarn
% Deviation
in volume
250 0
33
150 1 1
100 1 1
75 7 1 1 9
45 1 3 4 12 2 22
30 0
20 0
10 0
5 0
0 0
0 1 2 3 4 8 10 20 40 80 160 320 640
0 0
0
-5 0
-10 0
-20 0
-30 0
-45 0
-75 0
-100 0
Diametric Unevenness Using Diametric Fault System Fibers and Polymers 2017, Vol.18, No.10 2027
Yarn Characteristics of Different Makes of Opening and
Carding Systems
In the proposed study, an attempt has been made to study
the influence of different type of spinning preparatory
systems i.e. opening and carding systems on yarn characteristics.
Finally, 24.6 tex ring yarn was produced using two different
opening and carding (O&C) systems as illustrated in Figure 1.
Yarn Diameter and Yarn Diametric Unevenness (CVd%)
The results of yarn diameter and yarn diametric CVd(mm)%
of 24.5 tex yarn are given in Table 2 and it is observed that
mean diameter of O&C1 yarn is found to be lower than
corresponding O&C2 yarn. The intrinsic yarn diameter also
follows the same trend. Further, it is noticed that the
maximum and minimum range of yarn diameter is higher for
O&C1 than corresponding O&C2 yarn. But it is interesting
to note from Table 2 that diametric unevenness (CVd%)
value of O&C2 yarn is found to be lower than corresponding
O&C1 yarn.
Yarn Cross-section Area and Yarn Cross-sectional
Unevenness (CVca%)
The yarn cross-section area signal variation curves of both
the yarns are shown in Figures 3 and 7 and the results are
tabulated in Table 2. It is observed that mean cross-section
area of O&C1 yarn is found to be lower than corresponding
O&C2 yarn and intrinsic cross-section area also follows the
same trend. Further, it is noticed that maximum and
minimum range of yarn cross-section area is little lower for
O&C2 yarn than corresponding O&C1 yarn. As depicted in
Table 2 the cross-section area unevenness (CVca%) and
eccentricity value of O&C2 yarn are found to be lower than
the corresponding O&C1 yarn. The obtained eccentricity
value clearly indicates that O&C2 yarn is having more
circular cross-section than corresponding O&C1 yarn at
99 % confidence level. The confidence interval for the
difference in the mean at 99 % confidence level is found out
to be 0.0122-0.0127 and actual difference of 0.012 in the
Table 6. Volume characteristics of faults based on cross-section area signal
Yarn typeFault
class
Mean CS
area
(mm2)
Max CS
area
(mm2)
Min CS
area
(mm2)
Vol
addon
(mm3)
Total
length
(mm)
No. of
faults
Vol addon
per fault
(mm3)
Vol addon per
unit length
(mm3)
Mean fault
length
(mm)
Sensitivity Level ±35 %
24.6 tex
Combed
Compact
Thick 0.053 0.068 0.03 31.87 746.55 126 0.253 0.043 5.93
Thin 0 0 0 0 0.00 0 0 0 0
Total 0.053 0.068 0.03 31.87 746.55 126 0.25 0.04 5.93
24.6 tex
Combed
Ring O&C1
Thick 0.07 0.174 0.051 102.35 1713.81 259 0.395 0.06 6.62
Thin 0.067 0.093 0.052 -0.49 17.78 6 -0.082 -0.028 2.96
Total 0.070 0.174 0.051 101.86 1731.58 265 0.38 0.06 6.53
24.6 tex
Combed
Ring O&C2
Thick 0.066 0.093 0.027 68.34 1181.05 193 0.354 0.058 6.12
Thin 0 0 0 0 0.00 0 0 0 0
Total 0.066 0.093 0.027 68.34 1181.05 193 0.35 0.06 6.12
14.7 tex
Combed
Compact
Thick 0.033 0.054 0.021 34.07 1325.23 189 0.18 0.026 7.01
Thin 0.03 0.03 0.03 -0.02 1.98 1 -0.02 -0.01 1.98
Total 0.033 0.054 0.021 34.05 1327.20 190 0.18 0.03 6.99
Sensitivity Level ±50 %
24.6 tex
Combed
Compact
Thick 0.058 0.072 0.038 7.46 89.86 14 0.533 0.083 6.42
Thin 0 0 0 0 0.00 0 0 0 0
Total 0.058 0.072 0.038 7.46 89.86 14 0.53 0.08 6.42
24.6 tex
Combed
Ring O&C1
Thick 0.072 0.175 0.048 26.2 292.80 50 0.524 0.089 5.86
Thin 0 0 0 0 0.00 0 0 0 0
Total 0.072 0.175 0.048 26.2 292.80 50 0.52 0.09 5.86
24.6 tex
Combed
Ring O&C2
Thick 0.072 0.096 0.051 11.67 138.75 32 0.365 0.084 4.34
Thin 0 0 0 0 0.00 0 0 0 0
Total 0.072 0.096 0.051 11.67 138.75 32 0.36 0.08 4.34
14.7 tex
Combed
Compact
Thick 0.03 0.047 0.02 7.36 193.55 33 0.223 0.038 5.87
Thin 0 0 0 0 0.00 0 0 0 0
Total 0.030 0.047 0.02 7.36 193.55 33 0.22 0.04 5.87
2028 Fibers and Polymers 2017, Vol.18, No.10 V. K. Yadav et al.
mean is outside this confidence interval.
The results of area profile of O&C1 and O&C2 yarns are
given in Figures 3 and 7. It is observed that the value of
CVca(m)% and CVca(mm)% of O&C2 yarns are lower than
Table 7. Dimensional characteristics of thick faults based on fault sizes at sensitivity of +35 %
Vol %
Inc
Mean CS
area
(mm2)
SD
(mm2)
CS area
(CV%)
Max CS area
(mm2)
Min CS
area
(mm2)
Vol addon
(mm3)
Total
length (mm)
No. of
faults
Vol addon
per fault
Vol addon
per unit
length
Mean fault
length
(mm)
24.6 tex Combed Compact
5 0 0.00 0
10 0 0.00 0
20 0 0.00 0
30 0 0.00 0
45 0.0566 0.0096 16.94 0.0678 0.0398 9.65 314.52 68 0.1418 0.0307 4.63
75 0.0536 0.0069 12.79 0.0615 0.0400 13.69 314.03 45 0.3041 0.0436 6.98
100 0.0492 0.0126 25.72 0.0648 0.0301 6.59 97.27 10 0.6590 0.0678 9.73
150 0.0481 0.0109 22.61 0.0625 0.0374 1.92 20.74 3 0.6407 0.0927 6.91
250 0 0.00 0
24.6 tex Combed Ring O&C1
5 0 0.00 0
10 0 0.00 0
20 0 0.00 0
30 0.0617 0.0029 04.77 0.0641 0.0585 00.42 14.81 5 0.0833 0.0281 02.96
45 0.0684 0.0094 13.80 0.0958 0.0591 15.65 410.80 89 0.1759 0.0381 04.62
75 0.0820 0.0232 28.28 0.1299 0.0510 50.66 908.50 128 0.3958 0.0558 07.10
100 0.0615 0.0069 11.13 0.0696 0.0530 20.90 252.80 26 0.8040 0.0827 09.72
150 0.0718 0.0163 22.64 0.0891 0.0548 14.72 126.89 11 1.3383 0.1160 11.54
250 0 0.00 0
24.6 tex Combed Ring O&C2
5 0 0.00 0
10 0 0.00 0
20 0 0.00 0
30 0.0531 0.0061 11.53 0.0578 0.0429 0.34 12.34 3 0.1138 0.0276 04.11
45 0.0613 0.0123 20.15 0.0833 0.0341 12.27 318.47 73 0.1681 0.0385 04.36
75 0.0665 0.0103 15.47 0.0900 0.0574 37.84 660.14 94 0.4026 0.0573 07.02
100 0.0726 0.0112 15.42 0.0895 0.0572 9.75 117.51 16 0.6093 0.0830 07.34
150 0.0751 0.0104 13.86 0.0926 0.0637 8.14 72.58 7 1.1630 0.1122 10.37
250 0 0.00 0
14.7 tex Combed Compact
5 0 0.00 0
10 0 0.00 0
20 0 0.00 0
30 0.0383 0.0022 05.64 0.0400 0.0359 00.15 11.85 3 0.0508 0.0129 03.95
45 0.0360 0.0028 07.88 0.0417 0.0288 05.53 320.94 62 0.0892 0.0172 05.18
75 0.0290 0.0057 19.54 0.0376 0.0221 18.67 757.41 102 0.1831 0.0247 07.43
100 0.0383 0.0075 19.58 0.0470 0.0286 06.82 185.16 18 0.3788 0.0368 10.29
150 0.0288 0.0092 31.99 0.0408 0.0210 00.93 21.23 2 0.4630 0.0436 10.62
250 0.0272 0 00.09 0.0273 0.0272 01.97 28.64 2 0.9833 0.0687 14.32
Diametric Unevenness Using Diametric Fault System Fibers and Polymers 2017, Vol.18, No.10 2029
corresponding O&C1 yarn. This can be supported from the
results of variance-length and variance-length curves given
in Table 3 and Figure 4 respectively because CVca% of
O&C2 yarn is found to be lower at different reference length
in comparison to corresponding O&C1 yarn. Yarn cross-
section area signal variation curves of different sections of
yarn of defined segment are shown in Figures 6 and 8. It is
noticed that mean cross-section area and CVca(mm)% are
found to be lower for O&C2 yarn than the corresponding
O&C1 yarn.
The observed trend can be supported with the following
explanation. The primary objective of the preparatory
process is to open, clean, and parallelize the fibres with
minimal fibre breakage and entanglement to improve the
quality of yarn [18,19]. Accordingly, the machines are
sequenced to carry out the gradual fibre opening. The type of
machines and the sequence used in O&C2 system are
responsible for gentle and progressive opening to achieve
the required degree of fibre opening in few steps in
comparison to O&C1. The highest possible opening or the
lowest possible tuft weight is achieved by gradually
increasing the wire point density and peripheral speeds of
opening rollers in few steps to avoid unnecessary stress on
the fibres [18,19]. The inbuilt provision of face changing of
cotton sheet which is passing through series of opening
rollers under unclamped condition further enhance fibre
opening.
The quality of carding process is decided by the available
area of the main cylinder. The revolving flats with an
optimum number of flats are indispensable for cleaning, nep
removal and short fibre separation. The revolving flats
require a well-prepared fibre web. Higher pre-opening area
and increased post-carding area available in O&C2 system
ensures intensive carding with cleaner sliver and a higher
fibre individualization in the sliver, thereby leading to better
quality potential of the machine.
Classification of Yarn Faults
In the proposed study 24.5 tex yarn was produced by using
two different makes of opening and carding systems (O&C1
and O&C2) as illustrated in Figure 1 and the results are
shown in Tables 4 and 5. It is depicted that total number of
faults in the yarn made with O&C1 are higher than yarn
from O&C2 and trend is valid for both ±35 % and ±50 %
sensitivity levels.
Characteristics of Yarn Faults
The detailed analysis of thick and thin faults of 200 meter
yarn length based on cross-sectional area signal at two
different sensitivity levels is given in Tables 4 and 5. The
volumetric characteristics of yarn faults are given in Table 6.
It is noticed that O&C2 yarn show lower number of thick
faults and total length occupied by thick faults than
corresponding O&C1 yarn. Accordingly, the volume add-on
and mean cross-sectional area of thick faults are lower for
O&C2 yarn than O&C1 yarn. It is further observed that
volume add-on per fault, mean fault length and volume add-
on per unit length for O&C2 are lower than corresponding
O&C1 yarn and trends are valid for both ±35 % and ±50 %
sensitivity levels. The results of the dimensional characteristics
of thick and thin faults of different lengths belonging to a
specific volume size (volume percentage increase) at ±35 %
Table 8. Dimensional characteristics of thin faults based on fault sizes at sensitivity of -35 %
Vol %
decrease
Mean CS
area
(mm2)
SD
(mm2)
CS area
(CV%)
Max CS
area (mm2)
Min CS
area
(mm2)
Vol addon
(mm3)
Total
length
(mm)
No. of
faults
Vol addon
per fault
Vol addon
per unit
length
Mean fault
length
(mm)
24.6 tex Combed Ring O&C1
-5 0 0.00 0
-10 0 0.00 0
-20 0 0.00 0
-30 0 0.00 0
-45 0.0634 0.0010 01.50 0.0641 0.0623 -0.13 6.42 2 -0.0638 -0.0199 3.21
-75 0.0847 0.0146 17.22 0.0935 0.0679 -0.15 5.43 3 -0.0500 -0.0276 1.81
-100 0.0522 0.0001 00.21 0.0523 0.0521 -0.22 5.93 1 -0.2224 -0.0375 5.93
14.7 tex Combed Compact
-5 0 0.00 0
-10 0 0.00 0
-20 0 0.00 0
-30 0 0.00 0
-45 0 0.00 0
-75 0.0297 0 0 0.0297 0.0297 -0.02 1.98 1 -0.0237 -0.012 1.98
-100 0 0.00 0
2030 Fibers and Polymers 2017, Vol.18, No.10 V. K. Yadav et al.
sensitivity level of yarns are reported in Tables 7, 8 and 9. It
is observed that at ±50 % sensitivity levels, both the yarns do
not show any thin fault in the yarn, but at ±35 % sensitivity
level only ring O&C1 shows thin faults.
Table 9. Dimensional characteristics of thick faults based on fault sizes at sensitivity of ±50 %
Vol % Inc
Mean CS
area
(mm2)
SD
(mm2)
CS area
(CV%)
Max CS
area
(mm2)
Min CS
area
(mm2)
Vol addon
(mm3)
Total
length
(mm)
No. of
faults
Vol addon
per fault
Vol addon
per unit
length
Mean fault
length
(mm)
24.6 tex Combed Compact
5 0 0.00 0
10 0 0.00 0
20 0 0.00 0
30 0 0.00 0
45 0 0.00 0
75 0.056 0.0035 6.17 0.0613 0.0501 1.77 32.59 6 0.2954 0.0544 5.43
100 0.0598 0.0068 11.3 0.0718 0.0479 2.87 40.98 6 0.4787 0.0701 6.83
150 0.0376 - 0.34 0.0378 0.0375 0.59 5.43 1 0.588 0.1083 5.43
250 0.0711 - 0.28 0.0713 0.0708 2.22 10.86 1 2.2209 0.2045 10.86
24.6 tex Combed Ring O&C1
5 0 0.00 0
10 0 0.00 0
20 0 0.00 0
30 0 0.00 0
45 0.072 - - 0.072 0.072 0.08 1.98 1 0.0836 0.0423 1.98
75 0.072 0.0165 22.96 0.1021 0.0565 9.52 136.28 28 0.3399 0.0698 4.87
100 0.0628 0.0065 10.34 0.0694 0.0545 7.87 84.93 13 0.6054 0.0927 6.53
150 0.0559 0.007 12.48 0.0659 0.0478 8.73 69.62 8 1.0907 0.1253 8.7
250 0 0.00 0
24.6 tex Combed Ring O&C2
5 0 0.00 0
10 0 0.00 0
20 0 0.00 0
30 0 0.00 0
45 0.0513 0.0008 1.56 0.0522 0.0508 0.33 6.91 2 0.1649 0.0477 3.46
75 0.0698 0.0110 15.71 0.0789 0.0528 4.99 73.57 20 0.2495 0.0678 3.68
100 0.0830 0.0098 11.84 0.0891 0.0685 2.22 23.21 5 0.4436 0.0956 4.64
150 0.0815 0.0104 12.77 0.0959 0.0640 4.14 35.06 5 0.8288 0.1182 7.01
250 0 0.00 0
14.7 tex Combed Compact
5 0 0.00 0
10 0 0.00 0
20 0 0.00 0
30 0 0.00 0
45 0 0.00 0
75 0.0320 0.0071 22.05 0.0427 0.0222 3.29 112.08 22 0.1495 0.0293 5.09
100 0.0275 0.0086 31.15 0.0470 0.0213 2.42 058.26 9 0.2687 0.0415 6.47
150 0.0256 - 00.84 0.0259 0.0253 0.70 010.37 1 0.7047 0.068 10.37
250 0.0272 - 00.09 0.0273 0.0272 0.95 012.84 1 0.9538 0.0743 12.84
Diametric Unevenness Using Diametric Fault System Fibers and Polymers 2017, Vol.18, No.10 2031
Comparative Study of Different Yarn Fineness
The proposed study deals with the comparison of two
yarns of different fineness i.e. 24.5 tex and 14.7 tex made on
compact spinning system.
Yarn Diameter and Yarn Diametric Unevenness (CVd%)
The results of yarn diameter and CVd(mm)% given in
Table 2 shows that the maximum and minimum range of
yarn in case of 24.5 tex yarn is higher than corresponding
14.7 tex yarn. It is also depicted from Table 2 that diametric
unevenness (CVd%) value of 14.7 tex is higher than 24.5 tex
yarn.
Yarn Cross-section Area and Yarn Cross-section Area
Unevenness (CVca%)
The results of mean yarn cross-section area and yarn
cross-section area unevenness are given in Table 2. It is
observed that mean cross-section area of 24.5 tex compact
yarn is higher than corresponding 14.7 tex compact yarn.
Further, it is noticed that maximum and minimum range of
yarn cross-section area in case of 24.5 tex yarn is higher than
corresponding 14.7 tex yarn. It is also depicted from Table 2
that yarn cross-section area unevenness (CVca%) value of 14.7
tex is higher than 24.5 tex yarn.
The yarn cross-section area variation curves of 200 meter
length of 24.5 tex and 14.7 tex scanned yarns shown in
Figures 2 and 9 respectively and Table 2 shows that the
CVca(m)% and CVca(mm)% of 14.7 tex yarn are higher than
the corresponding 24.6 tex yarn. The yarn variance length
and corresponding variance curves of both the yarn fineness
Figure 7. Yarn cross-section area profile of 24.6 tex combed ring O&C2 yarn.
Figure 8. Section wise profile of 24.6 tex combed ring O&C2 yarn.
2032 Fibers and Polymers 2017, Vol.18, No.10 V. K. Yadav et al.
are given in Table 3 and Figure 4, respectively and confirms
that CVca% of 14.7 tex yarn is always higher than corresponding
24.6 tex yarn. The higher CVca% of 14.7 tex yarn can be
supported by the higher number of thick and thin faults in
case of 14.7 tex yarn than corresponding 24.6 tex yarn.
It is interesting to note that eccentricity value of 14.7 tex
compact yarn is found to be higher than 24.5 tex compact
yarn. It confirms that 24.5 tex yarn is more circular than
14.7 tex yarn. The observed trend can be explained on the
basis of yarn packing density. It is an established fact that
yarn packing density of finer count is higher than coarse
count. However, due to the presence of relatively less
number of fibres in the yarn cross-section, cross-section
shape deviates from circularity. The results of CVca% at
different considered sections of the yarns are given in
Figures 5 and 10. It is observed that mean cross-section area
is found to be higher for 24.6 tex yarn. However, CVca(mm)%
is higher for 14.5 tex yarn.
Classification of Yarn Faults
In the proposed study yarn of two different fineness i.e.
24.5 tex and 14.7 tex were produced on compact spinning
system as per the sequence of flow given in Figure 1. The
results of Diametric Faults system of 24.5 tex and 14.7 tex
yarns using cross-sectional area signal are given in the Table
4 and 5. It is noticed that 14.7 tex yarn shows higher number
of total faults than 24.5 tex yarn and trend is valid at both the
sensitivity levels.
Characteristics of Yarn Faults
The characterization of yarn faults in terms of fault
dimensions and index are tabulated in Table 6. The study of
Figure 9. Yarn cross-section area profile of 14.7 tex combed compact yarn.
Figure 10. Section wise profile of 14.7 tex combed compact yarn.
Diametric Unevenness Using Diametric Fault System Fibers and Polymers 2017, Vol.18, No.10 2033
thick faults shows that at ±35 % sensitivity level, the total
number of thick faults, volume add-on and total length
occupied by thick faults are higher for 14.7 tex yarn but
mean cross-sectional area of thick faults are lesser than 24.5
tex yarn. Accordingly, it is noticed that volume add-on per
fault and volume add-on per unit length are lower but mean
fault length is higher for 14.7 tex yarn than 24.5 tex yarn.
But the study of thick faults at ±50 % sensitivity shows that
for14.7 tex yarn, volume add-on per fault, volume add-on
per unit length and mean fault length are found to be lower
than corresponding 24.5 tex yarn.
The results of dimensional characteristics of thick and thin
faults of different lengths belonging to a specific volume
size (volume percentage increase) at ±35 % sensitivity level
are reported in Tables 7, 8 and 9 respectively. It is depicted
that volume add-on per fault, volume add-on per unit length
and mean fault length at different level of volume percentage
increase are found to be lower for 14.7 tex yarn than
corresponding 24.5 tex yarn. However, cross-sectional area
CV% does not show any specific trend.
Conclusion
The Diametric Faults system provides the classification of
faults based on their geometric dimensions and presents
flexibility to the user to choose the boundary limits for fault
classification. It is observed that total number of faults, yarn
diameter and cross-sectional area and their respective CV%,
total length of faults, volume add-on on faults, volume add-
on per fault, volume add-on per mm and mean fault length
of compact yarn were found to be lower than corresponding
ring yarn.
The comparative study of two different opening and
carding systems gives lower total number of faults, total
length of faults, volume add-on on faults, volume add-on per
fault, volume add-on per mm and mean fault length in case
of O&C2 system in comparison to corresponding O&C1
system. The yarn diameter and mean cross-section area of
O&C2 were found to be higher than O&C1 but yarn
diameter and mean cross-section area CVca% of O&C2 were
found to be lower than corresponding O&C1. Further, it is
observed that finer yarn give lower yarn diameter, cross-
section area, volume add-on per fault, volume add-on per
mm in comparison to coarser yarn. However, yarn diameter
and mean cross-section area CV%, total number of faults
and total length of faults are found to be higher for finer
yarn. The total volume add-on and mean fault length of finer
yarn was found to be higher for finer yarn at ±35 %
sensitivity but lower at ±50 % sensitivity level.
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