CHAPTER 5 STUDIES OF THE PROPERTIES OF DOUBLED YARN ...shodhganga.inflibnet.ac.in/bitstream/10603/18790/13/13_chapter5.pdf · 99 0 5 10 15 20 25 30 16.5 18 20.5 22 24 Tenacity g/tex

95

CHAPTER 5

STUDIES OF THE PROPERTIES OF DOUBLED YARN PRODUCED

FROM CONVENTIONAL AND COMPACT YARNS

5.1 INTRODUCTION

This Chapter is concerned with the properties of doubled yarn by doubling

conventional and compact yarns. A considerable amount of work was done on the

doubling of ubiquitous ring, rotor cotton yarn in the past and some interesting

conclusions were drawn. With the development of various types of compact yarns,

questions arise as to how they will behave when doubled. In this paper, the effect

of doubling twist on the properties of yarns for conventional, compact and hybrid

combinations was studied. Since no work has been done on this area, the results

are discussed for the first time

5.2 MATERIALS AND METHODS

These have already described in Chapter3.

5.3 RESULTS AND DISCUSSION

Yarn test results for conventional and compact cotton yarns are given in

Table5.1. It is noticed that the compact yarns are characterized by higher tenacity

and lower hariness in comparison with conventional yarns.

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96

Table – 5.1

Single Yarn Test results

Yarn Details Conventional Yarn Compact Yarn

Yarn Count (Ne) 50 50

Mean Count (Ne) 51.37 50.89

RKM 18.46 22.09

Elongation 4.29 4.56

Yarn U% 10.64 10.64

Thin (-50%) 3.0 4.0

Thick (+50%) 37.0 40.5

Neps (+200%) 118.5 127.5

Total 158.5 172.0

Hairiness 4.89 3.32

Table 5.2 shows the results of yarn count

Table – 5.2

Yarn Count

S.No. Yarn samples Mean

16.5 18.0 20.5 22.0 24.0 1. Conventional 26.10 25.83 26.07 25.73 25.65

2. Compact 26.05 26.14 25.86 25.58 25.72

3. Hybrid 26.17 25.85 25.74 25.55 25.84

The above table indicates that values of the yarn count for conventional,

compact and hybrid systems of spinning at different TPI are substantially the same




97

Yarn count CV% are listed in Table 5.3

Table – 5.3

Yarn Count CV%


16.5 18.0 20.5 22.0 24.0 1. Conventional 1.40 0.99 0.97 1.61 1.04

2. Compact 1.5 0.78 1.04 1.18 1.36

3. Hybrid 1.5 1.33 0.96 1.42 0.81

Table 5.4 shows the lea strength values.

Table – 5.4

Lea Strength (CSP)


16.5 18.0 20.5 22.0 24.0 1. Conventional 3128 3111 3172 3174 3270

2. Compact 3574 3573 3337 3561 3658

3. Hybrid 3165 3215 3643 3398 3432

It is apparent that compact doubled yarn are characterized by higher values.

The strength of hybrid yarn lies in between the conventional and compact doubled

yarn.




98

Lea strength CV% are listed in Table 5.5

Table – 5.5

Lea Strength CV%


16.5 18.0 20.5 22.0 24.0 1. Conventional 3.28 4.78 2.64 4.13 3.46

2. Compact 3.59 3.67 3.90 2.75 2.60

3. Hybrid 3.80 5.50 3.88 5.08 3.96

The above table shows the value for the lea strength CV% for ring, compact

and hybrid yarn. Strength variations appear to be higher in hybrid yarn.

Figure 5.1 illustrates the trend

Figure – 5.1

0

1

2

3

4

5

6

16.5 18 20.5 22 24

Lea

stre

ngth

CV

%

TPI

Lea strength CV%conventional

compact

Hybrid




99

0

5

10

15

20

25

30

16.5 18 20.5 22 24

Tena

city

g/t

ex

TPI

Tenacity(RKM)

Conventional

compact

Hybrid

Table 5.6 tabulates the results of tenacity of doubled yarn.

Table – 5.6

Tenacity (RKM)gm/tex

S.No. Yarn samples Single Yarn

Mean 16.5 18.0 20.5 22.0 24.0

1. Conventional 18.46 20.20 20.42 20.48 21.20 21.55

2. Compact 22.09 23.34 23.29 21.87 23.99 24.35

3. Hybrid - 21.08 21.23 24.00 22.30 22.37

From the above Table it is clear that the hybrid doubled yarn shows

maximum strength at 20.5 TPI.

Figure5.2 illustrate the trend

Figure – 5.2




100

Tenacity CV% values are given in table 5.7

Table – 5.7

Tenacity CV%


Mean

16.5 18.0 20.5 22.0 24.0

1. Conventional 12.29 8.35 8.66 8.54 8.63 8.49

2. Compact 10.16 7.30 8.33 9.26 7.64 8.55

3. Hybrid - 9.13 9.98 7.17 8.23 9.61

From the above table it is clear that there is a significant improvement in

the CV% of strength for hybrid yarn at 20.5 TPI.


Figure – 5.3

0

2

4

6

8

10

12

16.5 18 20.5 22 24

Ten

acity

CV

%

TPI

Tenacity CV%

Conventional

compact

Hybrid




101

Yarn elongation results are tabulated in table 5.8

Table – 5.8

Elongation


Mean 16.5 18.0 20.5 22.0 24.0

1. conventional 4.29 4.71 4.84 4.88 5.03 5.21

2. Compact 4.56 5.14 5.13 5.05 5.18 5.48

3. Hybrid - 4.91 4.97 5.21 5.09 5.28

The above table indicates that there is not much difference in elongation of

doubled yarn


Figure – 5.4

4.2

4.4

4.6

4.8

5

5.2

5.4

5.6

16.5 18 20.5 22 24

Elo

ngat

ion

%

TPI

Elongation %

conventional

compact

Hybrid




102

Table 5.9 lists the CV% of yarn elongation and figure gives the trend.

Table – 5.9

Elongation CV%


Mean

16.5 18.0 20.5 22.0 24.0

1. Conventional 11.25 10.76 10.73 10.66 10.84 10.25

2. Compact 10.33 8.98 9.05 10.27 9.32 9.45

3. Hybrid - 10.47 11.09 9.54 10.07 10.52

There is a not much difference in the CV% of elongation of doubled yarn

Figure – 5.5

0

2

4

6

8

10

12

16.5 18 20.5 22 24

Elon

gatio

n CV

%

TPI

Elongation CV%

conventional

compact

hybrid




103

Doubled yarn U% values are given in table 5.10

Table – 5.10

Yarn U%

S.No. Yarn samples Single

yarn

Mean

16.5 18.0 20.5 22.0 24.0

1. Conventional 10.64 8.44 8.40 8.58 8.45 8.12

2. Compact 10.64 7.79 7.76 8.17 7.82 7.92

3. Hybrid - 8.14 8.25 7.76 8.07 8.01

There is a reduction in U% in compact yarns (7.76) at 18.0 TPI and Hybrid

(7.76) at 20.5 TPI sample. Values of eveness are comparable and there is not much

difference

Figure 5.6 demonstrates the trend U% of yarn.

Figure – 5.6

7.2

7.4

7.6

7.8

8

8.2

8.4

8.6

8.8

16.5 18 20.5 22 24

U %

TPI

U %

conventional

compact

hybrid




104

Table 5.11 gives the mean and standard deviation for U%

Table - 5.11

Mean and Standard Deviation for U%

S.No. TPI Ring Compact Hybrid

1 16.5 Mean 8.4290 7.7850 8.1430

SD 0.24973 0.20893 0.27479

2 18.0 Mean 8.4020 7.7540 8.2460

SD 0.21337 0.17096 0.33477

3 20.5 Mean 8.5790 8.1730 7.7600

SD 0.26320 0.16317 0.17981

4 22.0 Mean 8.4520 7.9190 8.2460

SD 0.33730 0.13755 0.33477

5 24.0 Mean 8.1256 7.7880 8.0110

SD 0.23581 0.24894 0.1933

Table 5.12 gives the analysis of variance results for U%.

Table – 5.12

Analysis of variance for u%

S.No. Yarns F ‘P’ Value Sig. 1 Conventional 4.010 0.007 NS

2 Compact 8.361 0.000 1%

3 Hybrid 5.626 0.001 1%

The above table indicates that there is no significant difference for

conventional yarn, when compared with compact and hybrid yarn. Both compact

and hybrid yarn show 1% significant difference among other yarns.




105

Thin places and mean and standard deviation are listed in tables 5.13

and 5.14.

Table – 5.13

Thin places (-50%)


Mean 16.5 18.0 20.5 22.0 24.0

1. Conventional 3.0 0 0 0 0 0

2. Compact 4.0 0 0 0 0 0

3. Hybrid - 0 0 0 0 0

The above table reveals that all doubled yarn samples shows no thin places

when compared to single yarns.

Table – 5.14

Mean and Standard Deviation for Thin(-50%)

S.No. TPI Ring Compact Hybrid 1 16.5 Mean 0.00 0.00 0.00

SD 0.000 0.000 0.000 2 18.0 Mean 0.00 0.00 0.00

SD 0.000 0.000 0.000 3 20.5 Mean 0.00 0.00 0.00

SD 0.000 0.000 0.000 4 22.0 Mean 0.00 0.00 0.00

SD 0.000 0.000 0.000 5 24.0 Mean 0.00 0.00 0.00

SD 0.000 0.000 0.000

It is evident that there are no thin places at all in the doubled yarn.




106

Table 5.15 lists the thick places.

Table – 5.15

Thick places (+50%)


Mean 16.5 18.0 20.5 22.0 24.0

1. Conventional 37.0 3.5 4.5 4.3 5.8 6.3

2. Compact 40.5 5.0 3.5 5.6 4.8 4.5

3. Hybrid - 2.8 3.3 4.8 4.3 4.8

From the above table and figure 5.7 it is clear that thick places show

considerable reduction when compared to single yarn. Similarly the hybrid yarn

shows more reduction of thick places in comparison with conventional yarns.

Figure – 5.7

0

1

2

3

4

5

6

7

16.5 18 20.5 22 24

Thi

ck P

lace

s (+

50%

)

TPI

Thick Places (+50%)

Conventional

compact

hybrid




107

The mean and standard deviation for thick places and their analysis of

variance results are given in tables 5.16 and 5.17.

Table – 5.16

Mean and Standard Deviation for Thick ( +50%)

S.No. TPI Conventional Compact Hybrid

1 16.5 Mean 3.500 5.000 2.750

SD 2.6874 3.7268 2.4861

2 18.0 Mean 4.550 3.500 3.250

SD 3.2184 4.5947 3.5453

3 20.5 Mean 4.250 5.500 4.250

SD 2.3717 5.2440 2.0582

4 22.0 Mean 5.750 4.500 3.250

SD 6.0150 1.9720 3.5453

5 24.0 Mean 6.250 4.750 4.750

SD 3.7731 3.4258 3.9878

Table –5.17

Analysis of variance for thick (+50%)

S.No. Yarns F ‘P’ Value Sig. 1 Conventional 0.856 0.498 NS

2 Compact 0.352 0.841 NS

3 Hybrid 0.656 0.626 NS

From the table it is clear that there is no significant differences in

conventional, compact and hybrid yarn.




108

Table 5.18 shows the neps present in the doubled yarn.

Table – 5.18

Neps (+200%)


Mean 16.5 18.0 20.5 22.0 24.0

1. Conventional 118.5 9.8 16.3 13.3 19.0 15.5 2. Compact 127.5 10.8 14.5 18.8 15.8 14.8 3. Hybrid - 12.3 10.5 18.5 13.8 16.3

The above table proves that the Neps are found to be lower in 16.5 TPI in

the Conventional yarn sample. In hybrid yarn the Neps are also found to be lower

at certain twist levels.

Figure 5.8 shows the trend.

Figure – 5.8

02468

101214161820

16.5 18 20.5 22 24

Nep

s(+2

00%

)

TPI

Neps (+200%)

Conventional

compact

hybrid




109

Mean values and standard deviation and analysis of variance results are

shown in table 5.19 and 5.20.

Table – 5.19

Mean and Standard Deviation for Neps (+200%)


1 16.5 Mean 9.750 10.750 12.250

SD 4.3221 4.8663 6.7134

2 18.0 Mean 16.250 14.500 10.500

SD 5.3033 7.4349 7.4349

3 20.5 Mean 13.250 18.750 18.500

SD 6.2417 9.3727 9.5161

4 22.0 Mean 19.000 14.750 10.500

SD 7.9232 4.7799 7.4349

5 24.0 Mean 15.500 15.050 5.750

SD 6.6458 7.9772 5.5340

Table - 5.20

Analysis of variance for Neps (+200%)

S.No. Yarns F ‘P’ Value Sig. 1 Conventional 3.122 0.024 5%

2 Compact 1.587 0.194 NS

3 Hybrid 3.822 0.009 NS

The above table shows that the ring yarn shows 5% significant difference

when compared with both compact and hybrid yarn. Both compact and hybrid

yarns show no significant difference.




110

Yarn hairiness results are tabulated in table 5.21.

Table – 5.21

Yarn hairiness

S.No. Yarn samples Single yarn Mean

16.5 18.0 20.5 22.0 24.0 1. Conventional 4.89 7.04 7.15 6.69 6.34 6.07

2. Compact 3.32 4.89 5.00 5.70 4.61 4.64

3. Hybrid - 6.01 6.15 4.69 5.57 5.48

From the above table yarn hairiness indicates 4.61 at 22.0 TPI in compact

yarn sample when compared with other yarns. Hairiness of doubled yarn is found

to be higher than that of single yarn, the hybrid yarn seems to have lower hariness.

Figure – 5.9

0

1

2

3

4

5

6

7

8

16.5 18 20.5 22 24

Yar

n ha

irin

ess

TPI

Yarn hairiness

conventional

compact

Hybrid




111

Mean and Standard Deviation values for Hairiness and analysis of variance results

are shown in tables 5.22 and 5.23 respectively.

Table – 5.22

Mean and Standard Deviation for Hairiness


1 16.5 Mean 7.0400 4.8890 6.0060

SD 0.31732 0.16947 0.22036

2 18.0 Mean 7.1460 5.0040 6.1500

SD 0.40530 0.13476 0.35068

3 20.5 Mean 6.6940 5.6970 4.6900

SD 0.31550 0.33971 0.12728

4 22.0 Mean 6.3400 4.6380 6.1500

SD 0.27039 0.10983 0.35068

5 24.0 Mean 6.0680 4.6130 5.4780

SD 0.24783 0.11216 0.17434

Table –5.23

Analysis of variance for hairiness

S.No. Yarns F ‘P’ Value Sig. 1 Conventional 20.905 0.000 1%

2 Compact 51.753 0.000 1%

3 Hybrid 57.455 0.000 1%

The above table indicates 1% significant difference in conventional,

compact and hybrid yarn.




112

Yarn Quality Index

In order to compare the relative performance of the three yarns, the yarn

quality index was followed.

Tenacity, elongation and evenness are combined into one integrated index

called yarn quality index (YQI)). YQI is defined as follows:

Tenacity X Elongation

YQI = -------------------------------- Evenness

Table – 5.24

Yarn Quality Index

S.No. Yarn samples YQI Mean

16.5 18.0 20.5 22.0 24.0 1. Conventional 7.44 11.27 11.76 11.64 12.61 13.82

2. Compact 9.46 15.40 15.39 13.51 15.89 16.84

3. Hybrid - 12.71 12.78 16.11 14.06 14.74

Figure – 5.10

0

1

2

3

4

5

6

7

8

9

10

single yarn

YQ

I

Single yarn YQI

conventional

compact




113

Figure 5.11

The results are tabulated in table 5.24 and figure 5.10 and 5.11.Yarn

Quality index an overall index in respective of compact yarn is higher than that of

conventional yarn. It is apparent that in respect of 2/50Ne, the compact,

conventional, hybrid combination shows a maximum strength at 20.5 TPI. The

compact yarn continues to maintain their superiority in comparison with

conventional yarn. It is interesting to note that strength of the hybrid yarn lies in

between the compact and conventional yarns. Only in the hybrid yarn is the

maximum tenacity noticed particularly at 20.5 TPI. The reason for these

phenomena could be due to the partial untwisting of the strong compact yarn and

thus balancing with the conventional yarn

There is a significant improvement in the cv% of strength and elongation of

doubled yarn compared to single yarn. However the hybrid yarn has shown the

lowest variability at a TPI of 20.5. This is contradictory to the finding of Ishtiaque

et al. 2009.

0

2

4

6

8

10

12

14

16

18

16.5 18 20.5 22 24

Dou

bled

yar

n Y

QI

TPI

Doubled yarn YQI

conventional

compact

Hybrid




114

Percentage improvement in strength

Percentage improvement in strength is calculated with the following

formula,

100

YQIyarn SingleYQIyarn Doubled-YQIyarn Single

strengthin t improvemen Percentage

YQI Yarn Quality Index

Table –5.25



16.5 18.0 20.5 22.0 24.0 1. Conventional 51.47 58.06 56.45 69.48 85.75 2. Compact 62.79 62.68 42.81 67.97 78.01

The table 5.25 lists the data. The improvement is noticed to be substantial

at higher twist levels. Figure 5.12 presents the trend obtained. It is found to be

maximum for the conventional yarn at a twist per inch of 24.

Figure – 5.12

0102030405060708090

100

16.5 18 20.5 22 24

Perc

enta

ge im

prov

emen

t in

stre

ngth

TPI


conventional

compact




115

Percentage increase in hairiness

Percentage increase in hairiness is calculated with the following formula.

100Hairinessyarn Single

Harinessyarn DoubledHairinessyarn Single increase Percentagehairinessin

Table –5.26

Percentage increase in hairiness


16.5 18.0 20.5 22.0 24.0 1. Conventional 43.96 46.21 36.80 29.65 24.13

2. Compact 47.28 50.60 71.68 38.85 39.75

Table 5.26 shows the results. The above table shows that the compact yarn

has higher percentage increase in hairiness.

Figure 5.13 and 5.14 illustrates the trend.

Figure – 5.13

0

1

2

3

4

5

6

single yarn

Perc

enta

ge in

crea

se in

har

ines

s

Percentage increase in hairiness for single yarn

conventional

compact




116

Figure – 5.14

The increase in hairiness may be attributed to the abrasion and friction

caused in the machine.

Percentage reduction in yarn faults

Percentage reductions in faults U%, thin, thick, neps are calculated with the

following formula.

100

faultsyarn Singlefaultsyarn Doubledfaultsyarn Single

faultsin reduction Percentage

0

10

20

30

40

50

60

70

80

16.5 18 20.5 22 24

Perc

enta

ge in

crea

se in

hai

rine

ss

TPI

Percentage increase in hairiness for doubled yarn

conventional

compact




117

Table – 5.27

Percentage reduction in conventional yarn faults


16.5 18.0 20.5 22.0 24.0 1. Thin 100 100 100 100 100

2. Thick 90.54 87.83 88.37 84.32 82.97

3. Neps 91.72 86.24 88.77 83.96 86.91

4. Total 91.60 86.87 88.89 84.35 86.24

Table 5.27 presents the data. Percentage reduction in conventional yarn

faults is found to be good 16.5 TPI, among thin, thick and neps faults. Thin places

are nil in ring yarn sample.

The percentage reduction in conventional yarn faults is higher when

compared with the percentage reduction in compact yarn faults.

Figure 5.15 shows the trend obtained.

Figure – 5.15

0

20

40

60

80

100

120

16.5 18 20.5 22 24

Perc

enta

ge R

educ

tion

in

Con

vent

iona

l Fau

lts

TPI

Percentage Reduction in Conventional yarn Faults

Thin

Thick

Neps

Total




118

Table 5.28 presents the percentage reduction in doubled yarn compact yarn faults.

Table – 5.28

Percentage reduction in compact yarn faults


16.5 18.0 20.5 22.0 24.0 1. Thin 100 100 100 100 100

2. Thick 87.65 91.35 86.17 88.14 88.88

3. Neps 91.52 88.62 85.25 87.60 88.39

4. Total 90.81 89.53 85.81 88.02 88.77

From the above table it is clear that the total percentage reduction in

compact yarn faults is found to be good at 16.5 TPI.

The percentage reduction in compact yarn faults is lower when compared

with conventional yarn faults.

Figure 5.16 illustrates the trend.

Figure – 5.16

75

80

85

90

95

100

105

16.5 18 20.5 22 24

Perc

enta

ge R

educ

tion

in C

ompa

ct

Faul

ts

TPI

Percentage Reduction in Compact yarn Faults

Thin

Thick

Neps

Total




119

5.4 CONCLUSIONS

The following conclusions may be drawn from the study.

1. The strength of the hybrid doubled yarn lies in between conventional and

compact doubled yarn. The hybrid yarn also shows higher strength at a

certain twist multiplier.

2. The variability in count and strength of hybrid two fold yarns is found to be

the same as for conventional and compact doubled yarn.

3. Whilst there is a significant reduction in yarn imperfections of doubled yarn

in comparison with single yarn, the yarn hairiness is found to be higher.

4. Yarn quality index shows promising results for hybrid doubled yarn at twist

factor of 20.5.




Documents

CHAPTER 5 STUDIES OF THE PROPERTIES OF DOUBLED YARN ...shodhganga.inflibnet.ac.in/bitstream/10603/18790/13/13_chapter5.pdf · 99 0 5 10 15 20 25 30 16.5 18 20.5 22 24 Tenacity g/tex