Study on Fiber Overlap and Fiber Extent in Blended Spun · PDF fileStudy on Fiber Overlap and Fiber Extent in ... ring and air-jet spun yarns, whereas spinning-in-coefficient is

Journal of Engineered Fibers and Fabrics 137 http://www.jeffjournal.org Volume 8, Issue 1 – 2013

Study on Fiber Overlap and Fiber Extent in Blended Spun Yarns

Biswa Ranjan Das, PhD, S. M. Ishtiaque, PhD, R. S. Rengasamy, PhD

Indian Institute of Technology Delhi, New Delhi, Delhi INDIA

Correspondence to:

Biswa Ranjan Das email: [email protected]

ABSTRACT This article reports on the analysis of the fiber overlap and fiber extent in ring, rotor, and air-jet spun polyester/viscose blended yarns. The fiber overlap and fiber extent was measured by employing the tracer fiber technique. Statistical analysis was carried out at the 95% significance level with the single tail test to trace out specific trends executed by the spun yarns with any change in their blend proportions. The fiber overlap index and spinning-in-coefficient is correlated with tensile characteristics (static and dynamic) of the spun yarns to explore the most influential structural parameter among them for different applications. This presents study indicates that the prediction of spun yarn performance in post spinning processes is more appropriately modeled based on fiber overlap index over spinning-in-coefficient for ring and air-jet spun yarns, whereas spinning-in-coefficient is more appropriate for rotor spun yarns. For apparel use, spinning-in-coefficient is more appropriate over fiber overlap index for rotor and air-jet yarns to model the spun yarn strength as opposed to fiber overlap index for ring spun yarns. Keywords: blended yarns, fiber extent, fiber overlap, polyester, statistical analysis, viscose. INTRODUCTION The tensile behavior of spun yarns is a function not only of the fiber characteristics such as length, fineness and strength but also of the fiber axial distribution in the yarn. Thus fiber distribution in addition to its physical properties plays a significant role in the determination of the tensile behavior, namely, strength, modulus, elasticity, yield stress, work of rupture and elongation [1]. The axial distribution of the fibers decides its effective spun-in length for contributing to yarn strength. The axial distribution is basically characterized by the mean fiber extent or fiber overlap index. The objective of fiber overlap index (FOI) is to obtain a direct interpretation of total contact length between the fibers, which is earlier indirectly interpreted from fiber extent. As per the finding of

researchers, the fibers in the yarn cross section lie in the form of small bundles or clusters and it was noticed during the examination of the projected cross-sections of the blended spun yarns that the two components are arranged throughout the sections in small groups or clusters consisting of one fiber type [2]. The cohesiveness of the fibrous structure contributes to higher slippage resistance during spun yarn failure, hence enhances the yarn strength [3]. From this angle, the FOI appears to be a better representative than the fiber extent for axial distribution of fibers. The essence of the study of fiber overlap in spun yarns was initially explored by Ishtiaque et al. They observed that for 24s Ne ring, rotor, and air-jet spun viscose yarns, ring yarn showed the highest FOI and fiber extent followed by air-jet and rotor spun yarns [4]. Later Ishtiaque et al studied the effect of carding parameters and draw frame speeds on the fiber overlap of cotton ring spun yarns [5]. The two works reported above are the only studies reported in the literature on fiber overlap in spun yarns and fiber overlap in blended spun yarns. The present work focused on the fiber overlap and fiber extent in polyester/viscose blended yarns made from ring, rotor, and air-jet spinning systems. The effect of change in blend proportion on fiber overlap index and fiber extent is reported. As reported in our earlier communication that the dynamic yarn strength and lowest static strength is highly correlated with weavability over average static yarn strength and is more accurate in predicting the performance of spun yarns in post spinning machines; warping, sizing, weaving and knitting [6]. Also, researchers have experimentally determined that the average static tensile characteristics measured at 500 mm length is more appropriate to simulate the mechanical properties of fabrics [7]; hence, the fiber overlap index and spinning-in-coefficient is correlated with dynamic and static tensile characteristics to explore the more influential structural parameter for modeling spun yarn strength for post spinning


process and apparel end use performance respectively. EXPERIMENTAL Sample Preparation Viscose fibers of 1.5 denier and 44 mm length and polyester fiber 1.4 denier and 44 mm length were spun to produce polyester/viscose blended yarns of different proportions (0/100, 33/67, 50/50, 67/33, 100/0) on ring, rotor, and air-jet spinning systems. The nominal count of yarns spun in ring, rotor, and air-jet spinning system was 22 Ne. The spinning parameters employed for each yarn were those that are considered appropriate by commercial spinners, based on their experience with each of the spinning systems. The twist multipliers (TM in cotton system) for ring, rotor, and air-jet spun yarns were 2.8, 4.2, and 4.2 respectively. The tracer fibers were mixed before the opening operation in the blow-room in such a proportion so as to have an average of 6 tracers of different colors in a yarn cross-section. The six different colors selected for tracer fiber preparation were red, green, orange, violet, black and blue. The preliminary experiments carried out before utilization of these tracer colors confirmed that these tracer colors were well visible and contrasting to each other, when the yarns were immersed it in benzyl alcohol solution and observed under a projection microscope. The mix ratio of tracer fibers for representing different blend proportion was decided as per the blend ratio of polyester/viscose blended yarns; for example for 67/33 polyester/viscose blended yarns, a 4:2 ratio of polyester tracer: viscose tracer was maintained. Hook and Fiber Extent The classical tracer fiber technique was employed to determine fiber extent, fiber overlap Index, different types of hooks and hook extent [8]. To visualize the tracer fibers, the yarn was passed through a glass trough containing benzyl alcohol solution as optical diluent. The visible tracer fibers were observed under a projection microscope with a magnification of 100. To study these yarn structural parameters, 400 different tracer fibers were observed for each yarn. The fiber extent is a measurement of the projected length of the fiber along the yarn axis. The types of hooks, hook extent and number of hooks were also measured with the fiber extent measurement. The types of hook (classified as leading, trailing and double hook in respect of direction of their delivery from the machine) and hook extent were studied. After measuring the mean fiber extent of each yarn corresponding to different spinning systems, the

spinning-in-coefficient (KF) of the different yarns was calculated using the following equation [9].

L

L

L

n

L

FK

n

i

i

01 (1)

where, Li is the individual fiber extent, L0; arithmetic mean of the projected length of individual fibers along the axis of the yarn, n; numbers of observations, and L; the fiber length. Fiber Overlap Index (FOI) The fiber overlap index (FOI) is the ratio of the total projected overlap length of ‘n’ simultaneously overlapping tracer fiber along the yarn axis to the total fiber extent of those ‘n’ overlapping tracer fibers (Figure 1). The total extent of overlapping fibers is the multiplication of the number of overlapping fibers observed and the average fiber extent in the yarn. Hence, mathematically FOI can be explained as follows [10]:

lengthfibreaveragen

LLLFOI

nn

i i

1

222

(2)

F1

Fn

F2F3

F4

Ln

L4

L3

L2

L1

FIGURE 1. Schematic view of evaluation of fiber overlap index in spun yarns (more than two fibers simultaneously overlapping).

Figure 1 represent the ideal fiber overlapping case, the dark black line (names F1,F2,F3,F4…..Fn ) are projection of individual tracer fiber along the strand axis and start adding the total length as soon as first two fibers start overlapping. The value of FOI from the above mentioned formula can range from 0 to 1. A total of 200 yarn cross sections were considered for the fiber overlap index study.


Tensile Testing The tensile properties of yarns were measured on an INSTRON 4301 Tensile Tester at a standard gauge length of 500 mm and 180 mm/min extension rate. For each yarn, 100 tests were carried out. The dynamic testing of yarns was carried out using a CTT (Constant Tension Transport) instrument from Lawson-Hemphill Inc., at a constant transport speed of 40 m/min with the test module of CTT-DET. The tension was initially set at zero and was gradually increased in steps of 50 cN till the yarn breaks. The yarn tension was gradually decreased from this maximum tension level in steps of 5 cN to trace out the maximum tension level at which the yarn can successfully run for 200 m without any break and this tension is treated as the dynamic tensile load. The yarn elongation % observed at this tension is considered as the dynamic elongation %. The elongation % recorded in the dynamic tensile tester is the ratio of the speeds of front and back rollers multiplied by 100. Statistical Analysis The prediction of the population behavior from the sample behavior involves a probability factor, which is statistically called the significance level. The significance intervals comprising the population mean is as follows.

nSZxnSZx // (3)

where; x is the sample mean, Z; standard normal variate, S; sample standard deviation, n; number of samples and μ; population mean. The significance interval for 95 % level is as follows.

nSxnSx /96.1/96.1 (4)

This infers that there is 95% chances that the population mean will occur between

nSx /96.1 and nSx /96.1 . When

comparison has to be drawn between two populations parameter based on the mean values of the sample parameters, hypothesis testing is followed. The details of the hypothesis testing is as follows (for sample strength, n > 30). Ho: null hypothesis: there is no difference between the sample means.

H1: alternate hypothesis: 21 xx

where 1x , 2x are sample means. The calculated Z

statistics is defined as follows [11].

2

22

1

21

21

n

S

n

S

xxZ

(5)

where, S1, S2 are sample standard deviations and n1, n2 are number of samples. The calculated Z value is used to compare with the Z value obtained from the statistical table to draw the inference. If the calculated Z value is higher than the Z value obtained from the table, then the null hypothesis will be rejected and alternate hypothesis will be accepted. The statistical analysis here is carried out at 95% significance level for single tail test, so the Z value obtained from the table is constant for all the analysis (Z=1.67). The calculated Z value for various experiments is compared with 1.67 to draw the conclusion about the specific trend followed by the polyester/viscose blended yarns with change in the constituent proportions. RESULTS AND DISCUSSIONS Fiber Extent The air-jet spun blended yarns displayed the highest value of fiber extent followed by ring and rotor spun yarns (Table I). The drawn slivers fed to the air-jet spinning machine had a very good degree of fiber orientation, as three drawing passages were made, and the orientation was further improved during drafting on air-jet machine. The fiber consolidation of air-jet spun yarns is based on the twisting and untwisting mechanism. The false twist is inserted by the first air-jet at low pressure and untwists at the higher pressure second air-jet and this twisting-untwisting mechanism makes the cross-section of structure with approximately 80 % of the fibers remaining in the core and 20 % contributing to the wrapper fibers. The core fibers remain straight and parallel to the yarn axis and follow a small wavy path. No fiber buckling or hook formation takes place in the drafting zone of the air-jet spinner. There is evidence of lower values of hook % and its extent in air-jet spun yarns as shown in Table II, Table III and Table IV. All these factors contribute to the highest value of fiber extent and thus spinning-in-coefficient of air-jet spun yarns.


TABLE I. Spinning-in-coefficient and mean fiber extent of polyester/viscose blended ring, rotor and air-jet yarns.

MFE-mean fiber extent, SIC-spinning-in-coefficient, P-polyester, V- viscose, Values in the parenthesis indicate the CV%.

TABLE II. Hook % and hook extent (mm) of polyester/viscose blended ring spun yarns.

P-polyester, V-viscose, A-average

TABLE III. Hook % and hook extent (mm) of polyester/viscose blended rotor spun yarns.

TABLE IV. Hook % and hook extent (mm) of polyester/viscose blended air-jet spun yarns.

The fiber extent value was found to be lowest for all rotor spun yarns. First, this is because of the lower fiber orientation of the drawn slivers in comparison to roving fed to rotor spinning. Second, there are some known technological limitations of rotor spinning that lead to the formation of hooks and fiber buckling [12, 13], as evident from Table II, Table III and Table IV. Third, the fiber consolidation mechanism in rotor spinning orients the fibers with higher inclination. Fourth, the fiber breakage during opening and the inherent mechanism of wrapper fiber formation during yarn formation. These four factors


lead to the lowest fiber extent values of rotor spun yarns. The results indicate that the ring spun yarns display fiber extent values between the air-jet and rotor spun yarns. The better opening operation with a good degree of fiber drafting in the ring frame is the reason for the good degree of fiber extent of ring spun yarns. The fiber extent of yarns is a resultant effect of preparatory process, drafting force, and fiber properties. The preparatory processes influence the degree of fiber opening of the material. Better opening at the blow room and card leads to incidence of more straight fibers in the yarn. The ease of fiber opening is dependent on the cohesiveness of the fibers. The cohesiveness of the viscose and polyester fibers is indirectly assessed by measuring the roving strength. The tenacity values of polyester and viscose rovings were measured at 500 mm gauge length and 180 mm/min straining rate and found to be 0.29 cN/tex and 0.55 cN/tex respectively. Because of the lower cohesiveness of polyester fiber compared to viscose fiber, the polyester fibers are opened to a higher extent during the blow room and carding operations, leading to higher percentage of straight fibers. Viscose fibers having higher cohesiveness, compact the fiber bundles during material processing, which is prohibitive to ease of fiber opening and leads to many incidence of hooks and lower straight fibers. In ring spinning during drafting, fibers become straight due to the relative difference in the speed of leading and trailing ends of fibers caused by the drafting force acting on the fibers and these straightened fibers are held in this state and not allowed to relax in the yarn immediately due to insertion of twist after drafting. The higher cohesiveness of viscose fibers creates higher drafting force, which straightens trailing hooks. The polyester fibers having higher bending rigidity compared to the viscose fibers, offer higher resistance to bending during fiber folding and hook generation. The crimp removal during the spinning process additionally supports a higher straightening of fibers. The crimp % of polyester and viscose grey and dyed fibers were tested on a Vibrotex and found to

be 13.69 & 2.61 and 9.67, and 9.60 respectively. This indicated that there is significant difference in the crimp % of polyester grey and dyed fibers. The change in crimp % of viscose fibers after dyeing is negligible. The decrease in the crimp % of polyester fibers after dyeing indicates that there may be further straightening of the residual crimp, hence a good chance for an increase in the fiber extent. The combination of the all the factors; back process, drafting force, fiber properties and crimp removal during spinning decide the fiber extent of polyester/viscose blended yarns. Back process, fiber properties and expected change in crimp % favors the higher fiber extent of polyester fibers, but drafting force favors viscose fibers to have higher fiber extent. The resultant of the favoring factors decides the mean fiber extent of the blend with change in their blend proportion. Statistical analysis carried out on the mean fiber extent dataset mentioned in Table I at 95% significance level infer that, there is no change in the mean fiber extent values with increase in the viscose content. The statistical inference of effect of increase in the viscose content on mean fiber extent is expressed in Table V. It can be seen that the effect of an increase in the viscose content on mean fiber extent is similar for all three spun yarn technologies. The mean fiber extent of the polyester component is higher than the mean fiber extent of the viscose component of 67/33 polyester/viscose and 50/50 polyester/viscose blended yarns, with decrease in the level of difference as indicated by the Z statistic and no difference between mean fiber extent of polyester and viscose component in 33/67 polyester/viscose blended yarn at 95% significance level. This clearly indicates that the increase in the drafting force with the increase in the viscose component increases its mean fiber extent. As the mean value of fiber extent of the blend is calculated considering individual components of fiber extent with their respective proportion, the difference between the individual components of mean fiber extent is averaged out and makes no difference in the mean fiber extent value of different blends.


TABLE V. Statistical inference of mean fiber extent of polyester/viscose blended yarns.

Fiber Overlap Index (FOI) The air-jet blended yarns displayed the highest value of fiber overlap index followed by the ring and rotor spun yarns (Table VI). This is due to a very good degree of orientation of fibers in the sliver fed to the air-jet spinner and the high fiber length exploitation as indicated by the highest value of SIC and lowest percentage of different types of hooks and their extent (Table I, Table II, Table III and Table IV). TABLE VI. Fiber overlap index of ring, rotor and air-jet spun payns.

Blend % Fiber Overlap Index (FOI)

ring rotor air-jet 100%

P 0.541 (41.7)

0.44 (38.7)

0.65 (25.4)

67/33 P/V

0.529 (43.5)

0.38 (36.9)

0.59 (27.6)

50/50 P/V

0.522 (42.8)

0.42 (41.8)

0.60 (26.9)

33/67 P/V

0.531 (40.9)

0.41 (40.6)

0.62 (28.4)

100% V

0.498 (44.6)

0.40 (39.3)

0.63 (30.1)

The polyester/viscose blended rotor spun yarn displays the lowest value of FOI. This is due to the poor fiber orientation value of the drawn slivers fed to the rotor spinning machine and the lower fiber length exploitation in rotor yarns as indicated by the lower value of SIC and incidence of maximum percentage of different types of hooks and their extent. The fiber orientation further deteriorates during fiber transport, deposition and peeling off during rotor spinning. Furthermore, the fibers are deposited in the rotor groove in layers, where the starting point of each consecutive layer is displaced a little bit from each other [14]. The individualization of the fibers in the rotor groove and back doubling effect leads to small size bundle or cluster formation during yarn formation. The small size clusters will have lower overlapping of fibers across the yarn body. So these factors are responsible for poor FOI of rotor spun yarns. The ring spun blended yarns displayed a higher value of FOI than rotor spun yarns. The higher FOI value of ring spun yarns is due to feeding of more parallel and straight fibers to the ring frame in the form of roving. Furthermore, the overall fiber-length exploitation is also greater for ring yarn than rotor spun yarn, as evident from SIC and hook % and their extent values. There are chances of better fiber orientation and straightening during the ring frame drafting operation, as opposed to deterioration of fiber orientation in the rotor spinning system due to its inherent mechanism. The above all favored factors contribute to the higher FOI of polyester/viscose blended ring spun yarns. The FOI value of polyester/viscose ring spun yarn reduces with the increase in viscose fiber content of the blends except for the 33/67 polyester/viscose yarn. The FOI in the yarn is decided by the influence of SIC, cohesiveness of fiber bundles and number of fibers in the yarn cross-section. Higher value of SIC increases the FOI. Higher cohesiveness of fiber bundles apply more resistances to the sliding of fibers relative to each other, thus enhancing FOI [8]. More fibers in the yarn cross-section increase the specific surface area. Higher specific surface area indicates more surface contact between the fibers, hence higher resistance to fiber sliding relative to each other. The resultant effect of all the above mentioned three factors decides the FOI. As can be seen from Table I the increase of the viscose content in polyester/viscose blended yarns does not influence the SIC value, hence the resultant


effect of fiber cohesiveness and number of fibers in yarn cross-section decide the FOI. The number of fibers in the yarn cross-section decreases with an increase in viscose content, which is due to higher denier and density of viscose fibers (1.5 and 1.50 g/cm3) compared to polyester fibers (1.4 and 1.38 g/cm3). However, the statistical analysis carried out on the FOI values mentioned in Table VII infer that the difference between the FOI values of 100 % polyester and 100 % viscose and 33/67 polyester/viscose and 100 % viscose ring spun yarns are statistically significant at the 95 % level . The statistical inference of the effect of an increase in the viscose content on the fiber overlap index is expressed in Table VI. The higher value of FOI of 100 % polyester and 33/67 polyester/viscose yarns compared to 100 % viscose yarn is due to dominating effect of number of fibers in the yarn cross-section over the cohesiveness of fiber bundles. The number s of fibers in the yarn cross-section of 100 % polyester and 33/67 polyester/viscose are higher than the 100 % viscose yarn by 14.18 % and 8.62 % respectively. The increase in viscose content up to 67 % of polyester/viscose blended yarn does not indicate any difference in the FOI value is due to the counter balance between the effect of cohesiveness of fibers and number of fibers in the yarn cross-section. Statistical analysis carried out on the FOI dataset of rotor spun yarns infers that the FOI value first decreases with the increase in the viscose content up to 33 % and then increases for the viscose content of 50 % and afterward remain constant with the increase in the viscose content. The decrease in FOI value with the increase in the viscose content up to 33 % and further increase with increase in the viscose content up to 50 % could be due to a domination effect of the cohesiveness of carded slivers over the number of fibers in the yarn cross-section and vice versa. The observation of constant FOI value from viscose content of 50 % to 100 % may be due to the balancing effect of cohesiveness of carded slivers and number of fibers in yarn cross-section. Statistical analysis carried out on the FOI dataset of air-jet spun yarns at 95 % significance level infers that a difference exists between 100 % polyester and 67/33 polyester/viscose blended yarn. The higher FOI value of 100 % polyester yarn compared to polyester/viscose 67/33 blended yarn and no difference between the other blends could be due to the similar reason, as applicable for the ring spun blended yarns.

TABLE VII. Statistical inference on fiber overlap index of polyester/viscose blended ring, rotor and air-jet spun yarns.

Blend %

Ring Rotor Air-jet

Z value I

Z value I

Z value I

100% P

67/33 P/V 0.74 IS 5.45 S 5.30 S

50/50 P/V 0.44 IS 3.63 S 0.89 IS

33/67 P/V 0.58 IS 0.83 IS 1.66 IS

100% V 2.13 S 0.86 IS 0.76 IS 100% P vs

100%V 2.72 S 3.43 S 1.61 IS

I-inference

Correlation with Tensile Characteristics The values of dynamic strength and breaking elongation are shown in Table VIII. The calculated correlation coefficients of fiber overlap index and spinning-in-coefficient with dynamic yarn strengths are 0.75, 0.23, and 0.54 and 0.52, 0.35, and 0.13 for ring, rotor and air-jet spun yarns respectively. The calculated correlation coefficients of fiber overlap index and spinning-in-coefficients with dynamic breaking elongations are 0.90, 0.26, and 0.29 and 0.50, 0.22, and 0.13 for ring, rotor and air-jet spun yarns respectively. The correlation coefficients indicate that the fiber overlap index is highly correlated with dynamic tensile characteristics over the spinning-in-coefficients, except for the dynamic strength of rotor spun blended yarns. TABLE VIII. Dynamic–tensile strength and breaking elongation of spun yarns.

The values of lowest static strength and its corresponding elongation are shown in Table IX. The calculated correlation coefficients of fiber overlap index and spinning-in-coefficient with lowest static strengths are 0.94, 0.61, and 0.45 and 0.77, 0.64, and 0.13 for ring, rotor and air-jet spun yarns respectively.


The calculated correlation coefficients of fiber overlap index and spinning-in-coefficients with breaking elongations associated with lowest static strengths are 0.21, 0.66, and 0.52 and 0.08, 0.73, and 0.09 for ring, rotor and air-jet spun yarns respectively. The correlation coefficients also indicate that the fiber overlap index is highly correlated with lowest static strengths and their corresponding elongations over the spinning-in-coefficients, except for the lowest static strength and its corresponding elongation of rotor spun blended yarns. TABLE IX. Lowest static tenacity and corresponding breaking elongation of yarns.

The values of average static strength and elongation are shown in Table X. The calculated correlation coefficients of fiber overlap index and spinning-in-coefficient with average static yarn strengths are 0.89, 0.48, and 0.03 and 0.52, 0.56, and 0.18 for ring, rotor and air-jet spun yarns respectively. The calculated correlation coefficients of fiber overlap index and spinning-in-coefficients with average static breaking elongations are 0.85, 0.23, and 0.13 and 0.32, 0.27, and 0.45 for ring, rotor and air-jet spun yarns respectively. The correlation coefficients indicate that the spinning-in-coefficient is highly correlated with average static tensile characteristics over the spinning-in-coefficients for rotor and air-jet spun yarns, whereas fiber overlap index is highly correlated with ring spun yarns. TABLE X. Static tensile strengths and breaking elongation of spun yarns.

The fiber overlap index is highly correlated with dynamic and lowest static tensile characteristics over spinning-in-coefficient for ring and air-jet spun yarns; hence it is more appropriate to exploit in the modeling of the spun yarn tensile characteristics for predicting the performance of yarns in post spinning processes, whereas spinning-in-coefficient is more appropriate for rotor spun yarns. The spinning-in-coefficient is highly correlated with average static tensile characteristics over fiber overlap index for rotor and air-jet spun yarns, so it is more appropriate to exploit in the modeling of tensile properties for predicting the performance of yarns in apparel use as opposed to fiber overlap index for ring spun yarns. CONCLUSION The air-jet spun yarn displayed the highest value of fiber overlap index and fiber extent followed by ring and rotor spun yarns. The difference between the FOI values of 100 % polyester and 100 % viscose and 33/67 polyester/viscose and 100 % viscose ring spun yarns are significant. The FOI values of rotor spun yarns first decrease with the increase in the viscose content up to 33 % and then increase for the viscose content of 50 % and afterward remain constant with the increase in the viscose content. There is a difference between FOI value of 100 % polyester and 67/33 polyester/viscose blended air-jet spun yarns. There is no effect of change in blend proportion on the fiber extent of polyester/viscose blended ring, rotor, and air-jet spun yarns.

The fiber overlap index and spinning-in-coefficient are highly correlated with dynamic and lowest static tensile characteristics for ring and air-jet and rotor spun yarns respectively. The spinning-in-coefficient and fiber overlap index are highly correlated with average static tensile characteristics for rotor and air-jet and ring spun yarns respectively. Modeling of ring and rotor spun yarn tensile characteristics for post spinning process and apparel end use performance is more appropriately based on fiber overlap index and spinning-in-coefficient respectively.

REFERENCES

[1] Radhakrishnaiah, P.; Huang, G.; Rupture Behavior of Spun Yarns Representing Ring, Rotor, Air-Jet and Friction Spinning Systems, Available online at: http://www.cottoninc.com/1997ForumPresentations/RuptureBehavioronSpunYarns.


[2] Xu, B.; Ma, X.; Radial Distribution of Fibres in Compact-Spun Flax-Cotton Blended Yarns, Fibres and Textiles in Eastern Europe 2010, 18: 24-27.

[3] Ghosh, A.; Ishtiaque, S. M.; Rengasamy, R. S.; Analysis of Spun Yarn Failure. Part I: Tensile Failure of Yarns as a Function of Structure and Testing Parameters, Textile Research Journal 2005, 75: 731-740.

[4] Ishtiaque, S. M.; Salhotra, K. R.; Kumar, A.; Analysis of Spinning Process using the Taguchi Method. Part II: Effect of Spinning Process Variables on Fibre Extent and Fibre Overlap in Ring, Rotor and Air-jet Yarns, Journal of the Textile Institute 2006, 97: 285-293.

[5] Ishtiaque, S. M.; Mukhopadhyay, A.; Kumar, A.; Impact of carding parameters and draw frame speed on fibre axial distribution in ring-spun yarn, Indian Journal of Fiber and Textile Research 2009, 34 : 231-238.

[6] Das, B. R.; Ishtiaque, S. M.; Rengasamy, R. S.; Study on the Static and Dynamic Strengths and Weavability of Spun Yarns, Fibers and Polymers (in press).

[7] Realff, M L.; Seo, M.; Boyce, M. C.; Schwartz, P.; Backer, S.; Mechanical Properties of Fabrics Woven from Yarns Produced by Different Spinning Technologies: Yarn Failure as a Function of Gauge Length, Textile Research Journal 1991, 61: 517-530.

[8] Morton, W. E.; Yen, K.C.; The arrangement of fibres in Fibro yarns, Journal of Textile Institute 1952, 43: T60-T66.

[9] Kasparek, J.; Determination of Fibre Orientation in Sliver and Yarns in Open-End Spinning, Textile Month1974, 10: 52-55.

[10] Kumar, A.; Effect of Drafts at different Stages of Spinning Process on Fibre Orientation and Yarn Properties, PhD Thesis, Indian Institute of Technology, New Delhi, India, 2004.

[11] Booth, J. E.; Principle of Textile Testing, 3rd edition, Chemical Publishing, New York, 1969.

[12] Klein, W.; A Practical guide to Opening and Carding”, Manual of Textile Technology, Short-Staple Spinning Series, Vol. 2, The Textile Institute, Manchester, England, 1987.

[13] Klein, W.; The Technology of Short-staple Spinning, Manual of Textile Technology, Short-Staple Spinning Series, Vol. 1, The Textile Institute, Manchester, England, 1987.

[14] Chattopadhyay, R.; Fibre Breakage in Rotor Spinning During Opening by Combing Roller, PhD Thesis, Indian Institute of Technology, New Delhi, India, 1983.

AUTHORS’ ADDRESSES Biswa Ranjan Das, PhD S. M. Ishtiaque, PhD R. S. Rengasamy, PhD Indian Institute of Technology Delhi Hauz Khas New Delhi, Delhi 110016 INDIA

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Study on Fiber Overlap and Fiber Extent in Blended Spun · PDF fileStudy on Fiber Overlap and Fiber Extent in ... ring and air-jet spun yarns, whereas spinning-in-coefficient is