Issa

AUTEX Research Journal, Vol. 5, No1, March 2005 © AUTEX

NEW TECHNIQUE FOR OPTIMISING YARN-END PREPARATION ON SPLICER, AND A METHOD FOR RATING THE QUALITY OF YARNEND Khaled Issa, Rudi Grütz‫٭‬ Interdisciplinary Graduate school of Science and Engineering, Tokyo Institute of Technology, R2-51, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan Phone: +81- -45-924-5478; Fax: +81-45-924-5175; E-mail: {[email protected]} ‫٭‬Institut für Textil und Bekleidungswesen, Niederrhein University of Applied Science Webshulstr. 20, 41065, Mönchengladbach, Germany Phone: +49-2161-186710; Fax +49-2161-186713; E-mail:{[email protected]}

Abstract This paper presents a method for improving the yarn-end preparation on a splicer by forming a loop outside the opening tube which assures gentle delivery of the yarn to the opening tube, as well as control of the yarn-end length which will be prepared. Twelve groups of yarns were selected and tested using the new technique and a standard splicer. The new technique for yarn-end preparation showed better results in comparison to the standard splicer, especially for high twisted and plied yarn.

Key words: winding, splicer, opening process, yarn quality

Introduction The conditions for a good splice connection are met if the yarn ends are disentangled down to their individual fibres. The yarn ends are thereby spread apart, so that the individual fibres lie with spaces between each other, and dirt particles, dust, and short fibres are thus easily cleaned off from the yarn ends. Yarn ends prepared in this manner can then be connected by different splicing methods. These include the familiar method of compressed air splicing, as well as those of compressed gas or wet splicing [2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]. Many methods are used in the preparation of yarn ends for splicing. These methods can be grouped into three main types; the mechanical method, the pneu-mechanical method and the pneumatic method [15, 16, 17, 18, 19, 20, 21, 22]. In this work, an effort has been made to optimise the yarn-end preparation process by adding a loop former, in order to form the loop outside the opening tube to prevent the irregular opening and thinning of the yarn ends [1].

Experimental work Materials Twelve representative groups of yarns reflecting the purpose of the study were selected as shown in Table 1: • PE/CO 65/35 Nm 34/1 was used as a standard yarn for comparison. • Four groups of cotton were used; two groups had the same count (Nm 68/1) and different twist factors (881, 916 T/M), while the others have the same count and twist factors (Nm 85/1, 970 T/M) with different spinning processes. • Two groups of high twisted viscose with the same count and twist factor (Nm50/1, 1700 T/M) and different twist direction. • Two groups of high twisted wool with the same count and twist factor (Nm27/1, 1100 T/M) and different twist directions. • Siro spun wool (Nm 64/2, 886 T/M) • Two groups of high twisted polyester, including fine count polyester (Nm 132/1), and PE/PE core yarn (Nm 76/1). http://www.autexrj.org/No1-2005/0132.pdf

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Machine and instruments The opening and splicing tests of the standard and new splicer were carried out on an Autoconer 338 machine. The opening and splicing components and settings were the same, with small differences because of the different constructions and principles. For example, the feeder arm, which is used for overlapping the prepared yarn ends in the splicing nozzle hole, is not found in the new splicer; instead, the loop former which forms the loop outside the preparation nozzle performs the same function, and with this loop former it is possible to adjust the opening length. Table 1. Materials used in the experiments Group 1 Material PE/Co Count Nm 34/1 T/M 570 Twist Z direction Other

2

3 4 Cotton

5

68/1 881 916

85/1 970

Z

Z Prim

6

7

8

Viscose 50/1 1700 Z

S

Z

ELit

9 Wool 27/1 1100 S

10 64/2 886

11 PE 132/1 1200

12 PE/PE 76/1 1000

S

Z

S

Siro

Core yarn

Experimental design and procedures The following procedure was carried out on raw yarn, opening and splicing according to flow chart 1: • The tensile properties of raw yarns were tested on the Statimat M; 100 tensile tests per yarn were carried out for that purpose. • Opening tests on the standard splicer were prepared after optimising the machine settings and opening components to obtain the best opening samples. • The splice tests were carried out after optimising the splice settings and selecting the suitable splice components. • The same procedure was done for the new splicer after many stages of developments, but the splice tests were carried out only in nine groups. No splice tests were made for wool, because we planned to make splice joints without a thermo splice unit, but this could not be done. • The data obtained from opening, splice, and raw yarn tests was collected and analysed.

Flow chart 1. Experimental procedures

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Development stages on the new splicer The principle of the new splicer is based on aspiring the yarn ends into the preparation nozzles in such a way as to prevent the yarn ends from forming a loop inside the opening tube. The loop former is constructed as a rotary vane that can be moved in a defined way. The first design of the new splicer was as shown in Figure 1, in which the driving pins of the rotary vane sweep over retaining pins that are secured above and below the splicer prism. The loop former also includes a drive configuration for rotating the rotary vane into various functional positions. The functional positions of the rotary vane include: • a first functional position (starting position) for placing a yarn end section with the free yarn end into the splicer, as shown in Figure 1; • a second functional position (yarn tensing position) for adjusting the optimal yarn section length, as shown in Figure 2; • A third functional position (adjustment position), located between the first and second position, for preparing the yarn end section in the preparation nozzle. In this position, the yarn ends are positioned approximately in the middle above the mouth of the preparation nozzles, which enables satisfactory preparation of the yarn ends by the air stream applied in the preparation nozzles, as shown in Figure 3.

Figure 1. The first phase in yarn end preparation on the new splicer

It was noted that during the first experiments conducted using this construction, the results of the opening samples were not good. This was due to several factors: • The yarn end was subjected to the suction action of the opening nozzle during the initial stage of the splicing operation and just before the cutting stage. This means that the preparation of the yarn end starts between the yarn tensing position (II) and the yarn adjusting position (III), i.e. during the back movement of the rotary vane. This leads to an angular movement of the yarn end in the inner surface of the opening tube (dancing) during the opening operation, and consequently opening badly. • In addition to that, the design of the retaining pins did not consolidate a perfect control of the yarn end during the opening operation, which naturally caused bad opening. For these reasons, different steps of developments were applied on the design of the loop builder, as follows: • The design of the retaining pins were modified as shown in Figure 4, to enable more control of the yarn ends during the opening operation. • Additional yarn controller pins were added above the opening tube to prevent ’dancing’ of the yarn http://www.autexrj.org/No1-2005/0132.pdf

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ends in the opening tube during the return movement of the rotary vane, by which the yarn ends seem to be fixed during air aspiration in the opening tubes. By using these controller pins, a good opening sample was obtained. The first design of this controller pin is shown in Figure 5, then it was modified to another one as shown in Figure 6.

Figure 2. The second phase in yarn end preparation on the new splicer

Figure 3. The third phase in yarn end preparation on the new splicer

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Figure 4. First development of the new splicer with a new design of retaining pin

Figure 5. Second development of the new splicer with the controller pin

Results and discussion Opening results System of estimating the opening appearance grade While developing the opening process for the standard splicer by applying the new principle, it became necessary to define the quality of the opening ends in order to objectively compare the http://www.autexrj.org/No1-2005/0132.pdf

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opening operation of the existence splicer with another operation, or with the newly developed technique of the new splicer. For that reason, an opening appearance grade system (OAGS) was established as a standard for judging the quality of the opened ends.

Figure 6. Third development of the new splicer with the modified controller pin

Out of 2400 opening samples of 12 different groups examined on the standard splicer, the criterion was established to grade the quality of the opening ends. Establishing and developing these criterions was carried out in twostages: First stage: Four criteria were listed: length, untwist, shape, and thinning of the opening zone. These criteria were established to grade the opening ends of the yarn as good (2:1), average (0), or poor (1:-2), as shown in Table 2. The disadvantages arising from this system were as follows: • The shape of the opening zone depends mainly on the type of yarns. For example, cotton yarns acquire a tapered shape, while wool and synthetic yarns acquire a cylindrical shape. Therefore, it was inappropriate to take one shape as the reference standard for all types of yarns. • The thin-out of the opening zone depends on the intensity of the air pressure in the opening tube, and the slippage between air and fibres depends on the types of yarn. • In addition, there was no clear difference between the (-2) and (-1) grade, or between the (2) and (1) grade, and the distinction depended on the experience of each judge. Table 2. The first established criteria for judging the appearance of the opening zone

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Secondstage: for these reasons, the opening criteria were revised to be based only on the length and untwist of the opening zone, as shown in Table 3. Three categories of lengths were defined: 1— short length, ‘the opening length up to 5mm’. 2— average length, ‘from 5 to 10 mm’. 3— optimum length, ‘more than mm’. The untwist of the opening zone fell into one of the following categories: 1— Zero untwist, ‘no opening of yarn end’. 2— Partial overturn, ‘there is excess opening of the yarn end, which makes it overturn in the other direction’. 3— Complete overturn, ‘the end is completely twisted in the other direction, and there is a wrapped end or there are neps at the end of the opening zone’. 4— Partial untwist, ‘the yarn end is partially opened’. 5— Optimum untwist, ‘the yarn end is completely opened and all fibres are parallel’. Table 3. The criteria developed for judging the appearance of opening zone Opening appearance grade

Opening criteria

Length of opening zone Untwist of opening zone

zero

poor

average

Up to 5 mm

Up to 10 mm

Partially overturn

Complete overturn

Partially untwist

optimum Equal to, or more than 15 mm Optimum untwist

Analysing the optical judgment data Establishing a standard for judging the appearance of the yarn-end opening was just a guide for the judges and an objective tool for comparing between two different systems, or even between different splicers in the same machine. However, the data obtained from the judgment system should be analysed statistically in order to be sure that, even with the same guide being used by all judges, there was some kind of correlation between them; in other words, to measure the agreement between them, and to be sure that this agreement is significant and is not based on chance. For that reason, a 2 system for measuring the correlation between judges was devised using the chi-square (X ) technique [24]. 2

The X technique depends mainly on comparing the values measured with the expected values. Table 2 4 shows an example of the X method for PE/CO. Table 5 summaries the results of correlation between judges by paired comparison. There was agreement between pairs of judges, while the disagreement between them as a group was significant, as shown in Table 6. This could be related to any of several factors: • The minimum available number of experts for making optical judgements; the data was judged by only four experts, for which reason it was difficult to obtain a significant agreement with this number. 2 • There were a number of differences inside the groups affected in the final X value. • As in any new system, further training is required for the judges, and further improvement in the system may be needed. Optical judgment results The results of optical judgments (in percentage) for the standard splicer are summarised in Figures 7 and 8. PE/CO has the maximum percentage for optimum opening length, followed by cotton groups, viscous, and polyester respectively, as shown in Figure 7. Wool groups give the lowest optimum opening length, while they are superior for medium length and display the best optimum untwisting, as shown in Figure 8. The addition of polyester to cotton improves the properties of cotton yarn; for example, the effective length increased, and a better fibre orientation was obtained, which makes the untwist of the yarn easy. The surface friction of wool fibres prevents proper pre-opening of the fibres at the yarn splice, but it seems that higher pneumatic pressure may be helpful mainly in opening the fibre http://www.autexrj.org/No1-2005/0132.pdf

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strand. This may be the reason for the superiority of wool yarns for the medium opened length and the best optimum untwisting. 2

Table 4. The X analyses for the judging data obtained on the standard splicer for PE/CO Short length

Medium Length

Optimum length

∑ Ci

Observed

0.0

41.0

159.0

200.0

Expected

0.3

37.8

162.0

O2/E

0.0

44.5

156.1

PE/CO Nm 34/1

Judge 1

200.6

d

-0.4

Status

No difference

No difference

No difference

Observed

0.0

20.0

180.0

Expected

0.3

37.8

162.0

O2/E

0.0

10.6

200.0

Status

No difference

No difference

Observed

0.0

65.0

Significant difference 135.0

Expected

0.3

37.8

162.0

O2/E

0.0

111.9

112.5

Judge 2

2

∑O /E

200.0 210.6

d

Judge 3

200.0 224.4

d Status

No difference

Observed

1.0

Significant difference 25.0

Expected

0.3

37.8

162.0

O2/E

4.0

16.6

186.9

No difference

No difference

No difference

1.0

151.0

648.0

Judge 4

No difference 174.0

200.0 207.5

d Status ∑Ri

2

800.0

843.1

2

Chi- square X = (∑∑O /E - ∑∑Ri) = 43.047 Measured chi-square at (' df = (r-1) (k-1) = (3-1) (4-1) = 6", α = (0.05)) = 12.59 There are significant disagreements between the judges on the function of opening length where

Chi- square X2 measured the degree of agreement between the judges for the different criterion The calculated value of X2is compared with the measured

X 2 = ∑i =1 ∑ j =1 r

value from the table.

k

Oij

k

∑ Ri is the column summation of the observed values

2

Eij

i =1 k

−N

∑ Cj is the raw summation of the observed values

If X2 calculated < X2measured, there will be agreement between judges, and vice verse

j =1

N is the total summation of all the observed values

d measured the significant differences inside the groups (it is the adjusted standard of the residual for the ij cell)

N=

∑ ∑ r

k

i =1

j =1

Rij = ∑i =1 ∑ j =1 Oij Chir

k

Expected value E for each cell

Table 5. The results of correlation by paired comparisons J1 J1 J2 J3 J4

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J2 87%

J3 85% 81%

8

J4 81% 95% 74%

E

ij

= Ri * Cj

N

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Table 6. The X results for all groups Material PE/CO

2

Calculated X

2

Measured X

Status

43.047

12.59

No correlations

Cotton Nm 68/1 881 T/M

48.2

12.59

No correlations

Cotton Nm 68/1 916 T/M

37.7

12.59

No correlations

104.56

12.59

No correlations

Cotton Nm 85/1 Elite Cotton Nm 85/1 Prim z

53.36

12.59

No correlations

Viscose Nm 50/1 1700T/M (z)

125.10

12.59

No correlations

Viscose Nm 50/1 1700T/M (s)

46.64

12.59

No correlations

Wool Nm 27/1 1100T/M (z)

25.04

12.59

No correlations

Wool Nm 27/1 1100T/M (s)

41.01

12.59

No correlations

Wool Nm 64/2 Siro

36.36

12.59

No correlations

Polyester Nm 132/1

151.96

12.59

No correlations

PE/PE core yarn

84.82

12.59

No correlations

Another factor that explains the best opening results of wool and viscose yarns could be the use of an opening tube with a saw-tooth head. During air swirling in the tube the yarn swirls and contacts thishead; this contact simulates the action of beater of opening machines, and this leads to good opening of the yarn end, especially of the rounded fibres. Comparing these results with those obtained from using the new principle, as shown in Figures 9 and 10, it can be noted that there is a significant increase in the opening length and untwist degree for the cotton groups. Only one group (cotton Nm 85/1 Prim) shows a low untwist degree. The reason for this could be the greater intensity of the air pressure in the opening tube, which causes more opening of the yarn ends than the optimum, an increase in the opening length, and the chance of overturn of the yarn ends, causing nip at the top of the opening zone. The significant increase in the degree of untwisting of high twisted viscose, wool, and polyester are remarkable the short opening length of viscose and wool, and an increase in the optimum opening length of polyester. The superiority of viscose, wool, and polyester groups for untwisting degree is related to the application of the new principle of forming the loop outside the opening tube, which guaranteed the opening of the yarn ends first. By using the new principle, the untwist and length of opening are affected by the stiffness of yarn and its ability to bend. As the yield in bending of polyester occurred more easily, so it becomes easier to build the loop and the longer open length. On the other hand, viscose and wool fibres are stiffer and show less yield in bending, so that there is a resistance of loop formation which causes less opening length [23]. Comparisons between the two systems of opening As seen in Figures 11 and 12, it can be stated that there are many advantages of using the new system for f opening the yarn end over the old system: • There are significantly better opening results (length and untwist) for all groups under this experiment, especially for high twisted yarn. • These better opening results were obtained with less costly opening parameters; using less air pressure, less time duration, and less costly opening components, compared to the running system: for example using a normal opening tube (z or s) instead of an opening tube with a sawtooth head, which is more costly and requires a special production process. • It is possible to control the length of the opened yarn end with the new system, by changing the rotation movement of the loop former. • The new splicer is more complicated in construction when compared to the old one because it contains an additional loop former, which means that it is more costly. Nevertheless, in the long run it may be more advantageous to use this new system, when comparing this increase in cost with the better opening results obtained in high twisted yarns, and with the future modification of the new splicer which can be used generally for all yarns.

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Short

Medium

Long

90%

Length of opening zone %

80% 70% 60% 50% 40% 30% 20% 10%

PE /C

O

co tto n

65 /3 5

(2 ) co tto n co (3 tto ) n ( co Pr tto im n ) (E lit -e zh Vi ) sc os e (z Vi ) sc os e (s ) W oo l( z) W oo l( s) W oo l( Si ro ) P PE ol ye /P st E er (c or e ya rn )

0%

Figure 7. The length of opening zone of the different groups on the standard splicer

Zero

Partially

Optimum

Partially overturn

complete overturn

Untwist of opening zone %

80% 70% 60% 50% 40% 30% 20% 10%

(E lit -e zh ) Vi sc os e (z ) Vi sc os e (s ) W oo l( z) W oo l( s) W oo l( Si ro ) Po ly PE es /P te E r (c or e ya rn )

(P rim )

(3 )

co tto n

co tto n

co tto n

(2 )

co tto n

PE

/C

O

65 /3 5

0%

Figure 8. The untwist of opening zone of the different groups on the standard splicer

Splicing results There are three ways of specifying breakage or resistance to breakage in yarn and splices by tenacity, elongation, and energy necessary or work of rupture. Tenacity gives a measure of the resistance to steady force. It will thus be the correct quantity to consider when a splice joint is subject to a steady pull. Breaking elongation gives a measure of the resistance of the splice joint to elongation, and is thus important when a splice is subjected to steady state force for a period. Work of rupture is the appropriate quantity to consider when sudden shocks are liable to cause breakage, such as for example during weaving & knitting. When comparing different types of splice joints to see which is http://www.autexrj.org/No1-2005/0132.pdf

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least likely to break, it is important to consider the conditions under which breakage could occur, and then decide which quantity is appropriate to consider. In this research, the relation between tenacity and elongation of the splice joint and parent yarn has been studied and reported. Short

Medium

Long

100%

Length of opening zone %

90% 80% 70% 60% 50% 40% 30% 20% 10%

co tto n

PE /C

O

65 /3 5

(2 ) co tto n co (3 ) tto n (P co ri m tto ) n (E lit -e zh Vi ) sc os e (z Vi ) sc os e (s ) W oo l( z) W oo l( s) W oo l( Si ro ) Po PE lye /P st E er (c or e ya rn )

0%

Figure 9. The length of opening zone of the different groups on the new splicer

Zero

Partially

Optimum

Partially overturn

complete overturn

Untwist of opening zone %

90% 80% 70% 60% 50% 40% 30% 20% 10%

Po ly es /P te E r (c or e ya rn )

Si ro )

z)

s)

PE

W oo l(

W oo l(

W oo l(

(E lit -e zh ) Vi sc os e (z ) Vi sc os e (s )

co tto n

co tto n

(P rim )

(3 )

(2 )

co tto n

co tto n

PE

/C

O

65 /3 5

0%

Figure 10. The untwist of opening zone of the different groups on the new splicer

Relation between yarn and splice tenacity Figures 13to 16 show the relationship between tenacity of yarn and splices. Figure 13 shows the relation between the average tenacity of yarn and splices. The tenacity of the splice joint produced by

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the standard splicer varies from 79% to 99% of the average yarn tenacity, and for some groups exceeds the average tenacity of the ’wool siro 102%’ yarn. For the new splicer, the average tenacity of the splicing joint increased for all groups, with increased advantage for polyester and viscose groups. The good opening of viscose groups in the two splicers gives better tenacity with less coefficient of variation. New splicer

STD splicer

100%

optimum opening length %

90% 80% 70% 60% 50% 40% 30% 20% 10%

(E lit -e zh ) Vi sc os e (z ) Vi sc os e (s ) W oo l( z) W oo l( s) W oo l( Si ro ) Po ly PE es /P te r E (c or e ya rn )

(P rim )

(3 )

co tto n

co tto n

co tto n

PE

/C

O

co tto n

(2 )

65 /3 5

0%

Figure 11. Relation between optimum opening length of the standard and new splicer

New splicer

STD splicer

90% optimum opening length %

80% 70% 60% 50% 40% 30% 20% 10%

ya rn )

st er /P E

(c or e

)

Po lye PE

W oo

l(

Si ro

s) l(

z)

W oo

l( W oo

(s )

(z ) Vi

sc os e

)

sc os e

Vi

(E lit

-e zh

ri m (P

co tto n

co tto n

co tto n

(3

)

)

) (2

co tto n

PE /C

O

65 /3 5

0%

Figure 12. Relation between optimum opening untwist of the standard and new splicer

For wool groups, which also had good opening, the average splice tenacity by using a thermo-splice unit in the standard splicer reached 87% of the average yarn tenacity. However, trying to splice wool http://www.autexrj.org/No1-2005/0132.pdf

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yarn in the new splicer without a thermo-splice unit did not work even with better opening, which was related to the specific characteristics of wool fibres (stiffness, roughness, scales etc.) which makes splicing wool yarn with an air jet splicer and without a thermo unit more difficult. This also explains the better tenacity obtained from a wool splicing joint using a thermo-splicer. Because the yarn in the splicing prism is subjected to hot air, causes the fibres to felt together more, and consequently a strong splice joint can be obtained. Nevertheless, this strong joint has disadvantages that may affect dye ability and light reflection. In addition, the higher coefficient of friction of wool and polyester fibres [25] generates more inter-fibre friction, and thus cohesive yarn. This explains the better splice tenacity of wool and polyester compared to cotton. For cotton groups there is no special trend; this is due to the more intensive air in the opening tube, which causes unreliable opening. With near-identical or even better splice tenacity obtained by using the new splicer, there is significantly less variation in tenacity, especially for viscose and polyester, which means a more reliable splice joint. Relation between yarn and splice elongation Figures 17to 20 shows the relation between elongations of yarn and splices. The results showed that the highest elongation for both yarn and splice is for wool groups, viscose, and polyester respectively, and cotton groups showed the lowest elongation. The elongation of the yarn is affected by the fibre specifications. The wool fibre’s breaking elongation varies from 30% to 42% compared to cotton fibre’s 5% to 7% [26]. In addition, the crimp of the wool and synthetic fibres is highly elastic, so that when a force is applied on the yarn it causes some actual elongation of its actual length. The minimum elongation obtained by using the new splicer increased, with a significant decrease in the coefficient of variation and standard deviation. Nonetheless it can be seen that the wool groups gave the highest variation of 40%-60%, as well as the highest standard deviation. The reason for this could be the friction between wool fibres, which depends mainly on the direction in which it is pulled. The resistance is greater when it is pulled against the scales than when it is pulled with them; this is known as the directional friction effect (DFE), which means that the individual fibres will show prefrictional movement in one direction and will continually entangle themselves with the remaining fibres. This process of felting of wool leads to various coefficients of friction, and consequently extension variation along the yarn length. Yarn

STD splicer

New splicer

50 45 40 Tenacity (cN/tex)

35 30 25 20 15 10 5

(E lit -e zh Vi ) sc os e (z ) Vi sc os e (s ) W oo l( z) W oo l( s) W oo l( Si ro ) Po PE ly es /P te E r (c or e ya rn )

co tto n

co tto n

(P rim )

(3 )

(2 )

co tto n

co tto n

PE

/C

O

65 /3 5

0

Figure 13. Relation between average tenacity of yarn and splice

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Yarn

STD splicer

New splicer

45

Minimum tenacity (cN/tex)

40 35 30 25 20 15 10 5

(E lit -e zh ) Vi sc os e (z ) Vi sc os e (s ) W oo l( z) W oo l( s) W oo l( Si ro ) Po ly PE es /P te E r (c or e ya rn )

(P rim )

(3 )

co tto n

co tto n

co tto n

PE

/C

O

co tto n

(2 )

65 /3 5

0

Figure 14. Relation between minimum tenacity of yarn and splice

Yarn

STD splicer

New splicer

30

CV % of tenacity

25 20 15 10 5

) co tto n co (3 tto ) n (P co ri m tto n ) (E lit -e zh Vi ) sc os e (z Vi ) sc os e (s ) W oo l( z) W oo l( s) W oo l( Si ro ) Po PE l y /P es E te (c r or e ya rn )

(2

co tto n

PE /C

O

65 /3 5

0

Figure 15. Relation between CV% of tenacity of yarn and splice

Relation between degree of opening and splice appearance The degree of the yarn end’s opening affected both the tensile properties of the splice and its appearance. Figure 21 shows the different shapes of the opening zone and its effect on the shape of the splice joint. From this, we can conclude that good opening degree, of length and untwist is the only way to get a good appearance of the splice. Otherwise, short lengths without untwist or even with excess untwist leads to bad appearance of the splice, as shown. Furthermore, as the length of the opening zone becomes shorter with better untwist degree, the http://www.autexrj.org/No1-2005/0132.pdf

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appearance of the splice joint is much better than in the longer one than with this shorter length, if the tensile properties of the splice joint are good or the same compared to the longer length. Thus, optimising the opening process for producing shorter lengths will be essential, which is clear from the results obtained regarding the new splice especially for viscose.

Yarn

STD splicer

New splicer

Standard deviation of tenacity

5 4.5 4 3.5 3 2.5 2 1.5 1 0.5

PE /C

O

co tto n

65 /3 5

(2 ) co tto n co (3 tto ) n (P co ri m tto n ) (E lit -e zh Vi ) sc os e (z Vi ) sc os e (s ) W oo l( z) W oo l( s) W oo l( Si ro ) P PE ol y /P es E te (c r or e ya rn )

0

Figure 16. Relation between standard deviation of tenacity of yarn and splice

Yarn

STD splicer

New splicer

18 16 Average elongation %

14 12 10 8 6 4 2

(E lit -e zh ) Vi sc os e (z ) Vi sc os e (s ) W oo l( z) W oo l( s) W oo l( Si ro ) Po ly PE es /P te E r (c or e ya rn )

(P rim )

(3 )

co tto n

co tto n

co tto n

(2 )

co tto n

PE

/C

O

65 /3 5

0

Figure 17. Relation between average elongation of yarn and splice

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Yarn

STD splicer

New splicer

14 Minimum elongation %

12 10 8 6 4 2

(2 ) co tto n co (3 ) tto n (P co ri m tto ) n (E lit -e zh Vi ) sc os e (z Vi ) sc os e (s ) W oo l( z) W oo l( s) W oo l( Si ro ) P ol PE ye /P st E er (c or e ya rn )

PE /C

O

co tto n

65 /3 5

0

Figure 18. Relation between minimum elongation of yarn and splice

Yarn

STD splicer

New splicer

70

CV % of elongation

60 50 40 30 20 10

(2 ) co tto n co (3 ) tto n (P co ri m tto ) n (E lit -e zh Vi ) sc os e (z Vi ) sc os e (s ) W oo l( z) W oo l( s) W oo l( Si ro ) Po PE lye /P st E er (c or e ya rn )

co tto n

PE /C

O

65 /3 5

0

Figure 19. Relation between CV% of elongation of yarn and splice

Conclusion and future recommendations We have demonstrated a method for optimising the opening process on the splicer by which a loop former is added to form the loop outside the opening tube in order to prevent irregular opening and thinning of the yarn ends. The opening and splicing results obtained by using this principle were better than the results on the standard splicer.

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Yarn

STD splicer

New splicer

Standard deviation of elongation

8 7 6 5 4 3 2 1

(E lit -e zh ) Vi sc os e (z ) Vi sc os e (s ) W oo l( z) W oo l( s) W oo l( Si ro ) Po ly PE es /P te E r (c or e ya rn )

co tto n

co tto n

(P rim )

(3 )

(2 )

co tto n

co tto n

PE

/C

O

65 /3 5

0

Figure 20. Relation between standard deviation of elongation of yarn and splice

Better opening results were obtained by using the new splicer, especially for high twisted and plied yarns. The degree of untwisting in the viscose groups was nearly doubled. An increase from 9% to 70% is recorded for wool and polyester. The tensile results showed that the average tenacity and elongation increased for all groups. There are significant correlations between the optical appearance of the opening and splice. With optimum opening, good splice appearance was obtained. An Opening Appearance Grade System (OAGS) of the splicer was established to rate the quality of the opening of the yarn end according to its appearance, and allows it to be objectively compared with other or new samples on the basis of the opening technique developed. The statistical test showed that there are some correlations between pairs of judges, while the relationship within the group is insignificant. Further modifications on the statistical techniques are required, and using Automatic Visual Inspection (AVI) for rating the opened end may yield better results.

Acknowledgements This research was supported by the Schlafhorst Company. The authors sincerely thank the winding process team for their support and their helpful discussion

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Criteria

Appearance

Opening Optimum length Splice

Opening Short length Splice

Opening Optimum untwist Splice

Opening Excessive untwist Splice

Opening Irregular shape Splice

Figure 21. Relation between degree of opening and splice appearance

References 1. Khaled Issa, Rudi Grutz, ‘Investigation to optimise opening process for high twisted and plied yarn’, Master thesis, Institut für Textil und Bekleidungswesen, Niederrhein University of Applied Science, Monchengladbach, Germany 1999 2. Gebald G., The splicing technology in automatic winding, W. Schlafhorst AG & CO. http://www.autexrj.org/No1-2005/0132.pdf

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Blumbenberger str. 143-145 D-41061 Mönchengladbach, Schlafhorst documentation No.5 3. Gebald G, Remarkable quality improvements by the Autoconer splicer, The results of 10 years practical experience, W. Schlafhorst AG & CO. Blumbenberger str. 143-145 D-41061 Mönchengladbach, The customer day 84, The future of spinning 4. Garnsworth R.K, ‘Yarn splicing-the different systems and how they work’, Australasian textiles. 1984; 4: No.5, pp 13-16 5. Rohner J., and Gebald G., The theory and practice of splicing, W. Schlafhorst AG & CO. Blumbenberger str. 143-145 D-41061 Mönchengladbach, Schlafhorst documentation No.9 6. Isamu Matsui; Spliced joint of spun yarn and method for producing the same, USP 4, 240, 247 12/1980 57/22 7. Hiroshi Mima, Methods and apparatus for splicing spun yarns, USP 4, 263, 775 4/1981 57/22 8. Hiroshi Mima, Splicing method for spun yarns, USP 4, 445, 317 5/1984 57/22 9. Hidetoshi Kimura, Pneumatic yarn splicing method and apparatus, USP 4, 481, 761 11/1984 57/22 10. Hiroshi Mima, Apparatus for splicing spun yarns, USP 4, 433, 534 2/1984 57/22 11. Carlos P. Isern, Method and apparatus for splicing textile yarns, USP 4, 813, 220 3/1989 57/22 12. Carlos P. Isern, Method for connecting two yarn ends to one another and connection obtained by this method, USP 5, 277, 018 1/1994 57/22 13. Heinz Zumfeld et al, Automotive splicer for splicing ends of spun yarn and a method for splicing spun yarns, USP 4, 738, 093 4/1988 57/263 14. Peter Artzt, Yarn splicing device for the knot-free piecing of yarns and process for the preparation of yarn ends, USP 5, 175, 983 1/1993 57/22 15. Joachim Rohner,.....et al., Make-ready unit for making a thread end ready, USP 4, 565, 058 1/1986 57/22 16. Yoshihiro Nishimura, Device for untwisting the end of yarn in yarn splicing apparatus, USP 4, 676, 055 1/1987 57/22 17. Rudolf Luz, Method and apparatus for preparing yarn ends for splicing, USP 4, 528, 808 7/1985 57/22 18. Ivica Romic, Preparation device for making a thread end ready for splicing, USP 4, 492, 076 1/1985 57/22 19. Koji Deno, Yarn end untwisting device for a pneumatic yarn splicing device, USP 4, 494, 366 1/1985 57/22 20. Ernst B. Völlm, Method and apparatus for preparing and splicing yarn ends, USP 4, 497, 165 2/1985 57/22 21. Hiroshi Mima, Method of preventing irregular untwisting of yarn ends in splicing spun yarns, USP 4, 494, 368 1/1985 57/22 22. Isamu Matsui,....et.al., Yarn untwisting device in splicing apparatus, USP 4, 936, 084 6/1990 57/22 23. Morton, W.E., and Hearle, J.W.S, Physical properties of textile fibres, The Textile Institute 1993, pp. 419-421 24. Sidney Siegal, N. John Castellan, Jr., Non parametric statistics for the behavioral Science, 8 pp. 190-198 25. Morton, W.E., and Hearle, J.W.S, Physical properties of textile fibres, The Textile Institute 1993, pp. 410-412 26. Morton, W.E., and Hearle, J.W.S, Physical properties of textile fibres, The Textile Institute 1993, pp. 281-286

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