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Journal of Engineered Fibers and Fabrics 87 http://www.jeffjournal.org Volume 7, Issue 1 – 2012

Comparison of Conventional Ring, Mechanical Compact and Pneumatic Compact Yarn Spinning Systems

Sevda Altas1, Hüseyin Kadoğlu2

1Ege University Emel Akın Vocational School, İzmir TURKEY

2Ege University Textile Engineering Department, İzmir TURKEY

Correspondence to:

Sevda Altas email: [email protected] ABSTRACT This research is a comparative study of the physical properties of mechanical compact and conventional spun yarns and fabrics knitted from these yarns. To experiment the relational behavior, mechanical compact and conventional spun cotton yarns were produced in three different yarn linear densities having three twist levels. In order to examine the effect of spinning systems on fabric properties single jersey fabrics were knitted from these yarns. Results showed that, compact spun yarns have less hairiness, higher strength and higher elongation ratio than conventional spun yarns. Also, fabrics produced with compact yarns were found to have less pilling tendency. In the second part of the study, we compared the yarn properties produced with conventional ring, mechanical compact and pneumatic compact spinning systems. Analysis showed that, yarns produced with the pneumatic compact spinning system had the highest strength and the lowest hairiness. Keywords: Mechanical compact spinning, conventional ring spinning, carded cotton, combed cotton, yarn physical properties, fabric physical properties. INTRODUCTION In conventional ring spinning, the zone between the nip line of the delivery rollers and the twisted end of the yarn is called the “spinning triangle”. This is the most critical part of the ring spinning system. In this zone, the fiber assembly doesn’t have any twist. The edge fibers play out from this zone, and make little or no contribution to the yarn tenacity. Furthermore, they lead to yarn hairiness [1]. In compact spinning, the “spinning triangle” is eliminated and almost all fibers are incorporated into the yarn structure under the same tension. This leads

to significant advantages such as increasing yarn tenacity, yarn abrasion resistance and reducing yarn hairiness [2 and 3]. There are different compact spinning systems on the market from different manufacturers. The main difference of these systems is the condensing unit. Most of the pneumatic compacting systems are composed of perforated drums or lattice aprons over the openings of the suction slots. With the air flow, the fibers move sideways and they are consequently condensed. Today, pneumatic compact spinning system is widely used in compact yarn production. However the adaptation of this system to conventional ring spinning machine is very complex and expensive; also this method cause high additional energy consumption during spinning process. Mechanical compact spinning is an important alternative for compact yarn production. The system is cheaper and less complicated than pneumatic compact yarn spinning systems. Furthermore, there is not any additional energy consumption during the spinning process [4]. In this study Rotorcraft mechanical compact spinning system (RoCoS) was used in the production of compact yarns. In RoCoS compact spinning system, the compact yarn is produced by adding positive nip at the end of the drafting unit. The condenser is held against the bottom front drafting roller by means of a magnet. By the help of the “groove” in the ceramic compactor, fibers are brought closer and spinning triangle is eliminated [5 and 6]. The view of the RoCoS mechanical compact spinning and the back view of magnetic compactor are given in Figure 1.


FIGURE1. The view of RoCoS mechanical compact spinning and the back view of the magnetic compactor.

The compacting zone of the compactor is the distance between the two nipping points (A and B). The front top roller and delivery rollers have the same are peripheral speed; therefore fibers are not drafted in this area. A roving guide is attached to the top roller mill shaft. By the help of it, roving is fed into the center of the ceramic compactor. Roving guide movement is critical, during compacting process for the best compact yarn production roving guide should be stopped. However in bulk production to increase the life time of the roller, traversing distance must be reduced. According to previous research, mechanical compact spinning significantly improves yarn tensile properties and reduces its hairiness [7 and 8]. Until now there are many studies about the comparison of the conventional ring and compact yarns properties [9-12]. In the first part of the study, in order to understand how the effect of spinning system varies on yarn linear density and twist coefficient, we produced various compact and conventional spun yarns. In the second part of the study, we compared conventional ring, mechanical compact and pneumatic compact yarn spinning systems.

EXPERIMENTAL Yarn Samples Production In the experimental part of the study 100 % carded cotton and 100 % combed cotton rovings having Ne 1.04 and 45 T/m were collected from one spinning mill. Carded and combed rovings used in the study were produced from (ait olmak) one type of cotton (Ege St.1) raw material. By this way we could compare the physical properties of mechanical compact spun carded and conventional spun combed yarns. The fiber properties measured with High Volume Instrument (HVI) test machine were given in Table I. The first part of the study was carried out in Ege University’s Textile & Apparel Research and Application Centre while the second part of the study was carried out at one of the textile mill in Turkey. For this reason the spinning particulars of two set of experimental yarns could not be the same as can be seen in Table II for the first part of the study and Table III for the second part of the study. In the first part of the study, during mechanical compact and conventional yarn spinning, the same rovings and the same spindles were used in order to eliminate any possible effect of roving and spindle on yarn quality properties. Yarn linear densities were chosen as; 29.5/1 tex (Ne 20/1), 19.6/1 tex (Ne 30/1) and 14.7/1 tex (Ne 40/1). For each yarn count, three twist coefficients were chosen as;

αtex

= 103 (αe = 3.4),

αtex

= 115 (αe = 3.8)

αtex

= 127 (αe = 4.2).

In the second part of the study, we compared conventional ring, mechanical compact and pneumatic compact yarn spinning systems. Rieter K44 pneumatic compact spinning system was used in the production of pneumatic compact yarns. We used 100 % combed rovings which were used in the first part of the study. Yarn linear densities were chosen as; 13.1/1 tex (Ne 45/1), 9.5/1 tex (Ne 62/1) and 7.8/1 tex (Ne 75/1) having the same twist coefficients as; α

tex=120 (αe = 4.0).


TABLE I. Raw Material Physical Properties.

Measured fiber properties Carded cotton

Combed cotton

Fiber fineness, micronaire 4.30 4.35

Fiber strength, gr/tex 37.00 39.02

2.5 % span length, mm 28.43 29.57

Uniformity, % 85.40 86.62

Short fiber percentage, % 6.83 5.75

Elongation at break, % 4.40 4.82

TABLE II. Spinning particulars for conventional ring and mechanical compact yarn spinning systems.

Technological/machine set parameters Yarn linear density

29.5/1 tex 19.6/1 tex 14.76/1 tex

Ring yarn type Conventional /

Mechanical Compact Conventional /

Mechanical CompactConventional /

Mechanical Compact

Theoretical twist coefficient (αtex

) 103 115 127 103 115 127 103 115 127

Theoretical twists (turns/m) 602 667 735 735 818 902 838 947 1044 Spindle speed (rpm) 10.000 10.000 10.000

Ring diameter (mm) 42 42 42 Traveller type (ISO No) 80 45 35.5 Traveller design and finishing treatment SFB 2.8 pm dr Saphir SFB 2.8 pm dr Saphir SFB 2.8 rl dr Saphir

Cradle spacer thickness (mm) 3.75 3.25 2.75

TABLE III. Spinning particulars for conventional ring, mechanical compact and pneumatic compact yarn spinning systems.

Technological/machine set parameters Yarn linear density

13.1/1 tex 9.5/1 tex 7.8/1 tex

Compacting system Ring / RoCoS /

Rieter K44 Ring / RoCoS /

Rieter K44 Ring / RoCoS /

Rieter K44

Theoretical twist coefficient (αtex

) 121 121 121

Theoretical twists (turns/m) 1056 1239 1363

Spindle speed (rpm) 18.500 17.000 16.000

Ring diameter (mm) 42 42 42

Traveller type (ISO No) 25 25 23.6

Traveller design and finishing treatment c1 el udr Safir c1 el udr Safir c1 el udr Safir

Cradle spacer thickness (mm) 2.75 2.75 2.75

Yarn evenness, faults, hairiness and diameter properties were tested using an Uster® Tester 5 (UT5). We tested each type of yarn 10 times with 400 m/min test speed. Yarn tenacity and elongation properties were tested with a Tensojet. We tested each type of yarn 25 times with 200 m/min test speed. For a comprehensive examination of yarn hairiness, the average hairiness of yarns was also measured with a Keisokki Laserspot Hairiness Diameter Tester. This instrument measures hairiness and yarn diameter at the same time using a laser beam. The instrument counts the number of hairs in

different length classes including 1 mm, 2 mm, 3, mm and calculates the hairiness index. In this study, we tested each type of yarn 5 times with a 50 m/min test speed and evaluated the hairiness index results. All tests were performed after the yarns were kept in standard atmospheric conditions for 24 hours (65±5 % relative humidity, 20±2ºC). In the analysis of test results, Factorial ANOVA and Multiple ANOVA (LSD) methods were used with SPPS statistical pocket program at 0.05 significance level.


Fabric Samples Production Ring and compact yarns were knitted with 48-gauge, 12-inch diameter Mesdan 294 E laboratory knitting machine with 225 turn/min production speed. The pilling properties were measured with a Martindale Abrasion and Pilling Tester by 2000 revolutions. The pilling tendencies due to friction of 6 different fabric surfaces were determined according to the ISO 12947-1 standard. Later we used an SDL Atlas Automated 3D Pilling and Fuzz Grading test machine to assess pilling grade values. The bursting strength measurements of 5 different type of fabric were determined according to ISO 13938-2 (7.3 cm2 area; 30.5 mm diameter) with James Heal Truburst® test device. All tests were performed after the fabrics were kept in standard atmospheric conditions for 24 hours (65±5 % relative humidity, 20±2ºC). RESULTS AND DISCUSSION Evaluating the Yarn Properties According to experimental results of yarn linear densities, compact yarns were found to be coarser than conventional yarns due to elimination of fiber fly in compact yarn spinning system. We analyzed the main effects which are yarn linear density, twist coefficient and spinning system on yarn properties. We also analyzed the interaction effects of spinning system versus yarn linear density and spinning system versus twist coefficient. Figures 2-7 shows the main effect plots on both carded and combed yarns. The effect of spinning system is shown as X1 and X4. The effect of yarn linear density is shown as X2 and X5. The effect of twist coefficient is shown as X3 and X6. M represents the mean value for each observed yarn property. In the graphics R represents the ring spinning system and C represents the compact yarn spinning system. According to the statistical analysis the effect of yarn linear density is significant on all observed yarn properties. As the yarn linear density increase evenness, the number of thin place, the number of thick place and neps values increase, hairiness, diameter, tenacity and elongation values decrease.

In carded yarns, increase of twist coefficient increases the evenness, tenacity and elongation values and decreases hairiness (Uster and Keisokki) and diameter values significantly. On the other hand, we couldn’t observe any significant relation between twist coefficient and the number of thin place, the number of thick place and neps values. In the combed yarns, the increase of twist coefficient increase tenacity and elongation and decreases the number of thick place, neps, Uster hairiness and diameter values significantly. On the other hand, we couldn’t observe any significant relation between twist coefficient and Keisokki hairiness, evenness and the number of thin place values. Due to having different measuring principles, the effect of twist coefficient on Uster and Keisokki hairiness results are not similar in all type of yarns observed in this study. Table IV represents the Factorial ANOVA statistical results of the yarn properties. F value represents whether a significant difference among treatment means or interactions exists. Significance (Sig.) value represents the homogeneity of variances, if it is less than 0.05 than we can say that the effect is statistically significant.

FIGURE 2. The main effect plots for yarn evenness.

FIGURE 3. The main effect plots for yarn hairiness (uster).


FIGURE 4. The main effect plots for yarn hairiness (keisokki).

FIGURE 5. The main effect plots for yarn diameter.

FIGURE 6. The main effect plots for yarn tenacity.

FIGURE 7. The main effect plots for yarn elongation.

TABLE IV. The F and significance values of factorial ANOVA analysis for conventional ring and mechanical compact spun yarns.

Compared pairs

Spinning system

Spinning system* Yarn linear density

Spinning system* Twist coefficient

Carded cotton Combed cotton Carded cotton Combed cottonCarded cotton

Combed cotton

F Sig. F Sig. F Sig. F Sig. F Sig. F Sig.

CV (%) 260.40 .000* 44.54 .000* 22.39 .000* 28.78 .000* 0.57 .562 0.915 .403

Thin place (-%50) 16.54 .000* 2.70 .102 3.19 .043* 5.13 .007* 0.006 .994 0.736 .481

Thick place(+%50) 94.34 .000* 4.44 .036* 5.78 .004* 18.94 .000* 0.20 .811 1.01 .364

Neps (+%200) 40.35 .000* 36.87 .000* 53.67 .000* 58.12 .000* 2.74 .067 6.18 .003*

Hairiness (Uster) 1428.3 .000* 4055.2 .000* 7.11 .001* 25.66 .000* 1.01 .366 15.19 .000*

Hairiness (Keisokki) 629.0 .000* 259.58 .000* 4.70 .045* 8.62 .010* 1.47 .284 0.39 .689

Diameter (mm) 1392.7 .000* 2255.9 .000* 31.86 .000* 63.55 .000* 2.61 .076 13.63 .000*

Tenacity (cN/tex) 329.35 000* 219.92 .000* 12.02 .000* 7.44 .001* 0.79 .454 1.16 .317

Elongation (%) 133.94 .000* 137.32 .000* 6.14 .000* 10.82 .000* 0.36 .693 1.55 .217

* Statistically significant.

Based on the analysis results following conclusions can be drawn: Yarn Evenness Results The experimental results of conventional and compact spun yarns evenness are given in Figure 8. According to statistical analysis, the effect of

spinning system is statistically significant on both carded and combed yarn evenness as shown in Table IV. Carded compact yarns have higher evenness values than carded conventional ring yarns. The interaction effect of spinning system and yarn linear density is


statistically significant. The difference between the evenness values of conventional and compact spun carded yarns increases as the yarn becomes coarser. Combed compact yarns have higher evenness values than combed conventional ring yarns. The interaction effect of spinning system and yarn linear density is statistically significant. While at 29.5 tex and 19.6 tex combed compact yarns have higher evenness than conventional ring yarns, at 14.7 tex conventional ring yarns have higher evenness values than combed compact yarns. The reason behind the higher irregularity of the compact yarns can be explained by the use of front bottom roller in mechanical compact spinning system (Figure 1). Rollers cause irregularities in the drafted strand since there is an incomplete control of the motion of each individual fiber or fiber group especially for coarser yarns. Similar result is obtained with previous study about mechanical compact spinning [8]. In both carded and combed yarns the interaction effect of spinning system and twist coefficient on yarn evenness isn’t statistically significant. Yarn Imperfection Results In carded yarns, the effect of spinning system is statistically significant on the number of thin places, the number thick places and neps values (Table IV). Carded compact yarns have higher thin place, thick place and neps values than carded conventional ring yarns. The interaction effect of spinning system and yarn linear density is statistically significant. The difference between the number of thin places, the number of thick places and neps value of compact and conventional spun carded yarns increases as the yarn becomes coarser.

FIGURE 8. The evenness of compact and conventional spun yarns.

In combed yarns the effect of spinning system is statistically significant on the number of thick places and neps values (Table IV). Combed compact yarns have higher thick place and neps values than combed conventional ring yarns. The interaction effect of spinning system and yarn linear density is statistically significant. While at 29.5 tex and 19.6 tex combed compact yarns have higher number of thick places and neps, at 14.7 tex conventional combed ring yarns have higher number of thick places than compact yarns. This result can be explained with the weak control of fibers in coarse yarn due to the increased number of fibers in the yarn cross section. The interaction effect of spinning system and twist coefficient is only statistically significant on neps values of combed yarn. However the effect is irregular and the trend is unclear to accept the presence of any meaningful relation. Yarn Hairiness Results The Uster and Keisokki hairiness test results of conventional and compact spun yarns are given in Figure 9 and Figure 10 respectively. According to statistical analysis, the effect of spinning system is statistically significant on both carded and combed yarn hairiness as shown in Table IV. Carded and combed compact yarns have lower hairiness (Uster and Keisokki) than carded and combed conventional ring yarns. This could be explained by the elimination of spinning triangle in compact yarn spinning system. With both Uster and Keisokki hairiness test result, the interaction effect of spinning system and yarn linear density is statistically significant on carded and combed yarn hairiness (Table IV). However the effect is irregular varying yarn linear density and the trend is unclear to accept the presence of any meaningful relation. The interaction effect of spinning system and twist coefficient is only statistically significant on Uster hairiness values of combed yarn. The differences between compact combed and conventional combed yarn hairiness values increases as the yarn twist coefficient decreases. This shows that the advantage of the compact spinning system on combed yarn hairiness property is more noticeable at lower twist levels.


FIGURE 9. The hairiness (uster) results of compact and conventional spun yarns.

FIGURE 10. The hairiness (Keisokki) results of compact and conventional spun yarns. Yarn Diameter Results The diameter measurement results of conventional and compact spun yarns are given in Figure 11. According to statistical analysis, the effect of spinning system is statistically significant on both carded and combed yarn diameter as shown in Table IV. The diameter values of carded and combed compact yarns are lower than the carded and combed conventional ring yarns. Due to elimination of spinning triangle in compact spinning, the migration of fibers in compact yarns is deeper and as a result of this compact yarns diameter is smaller than conventional spun yarns [8 and 13]. The interaction effect of spinning system and yarn linear density is statistically significant on both carded and combed yarns diameter. The difference between the diameter values of conventional ring and compact yarn increases as the yarn becomes coarser.

FIGURE 11. The diameter results of compact and conventional spun yarns.

The interaction effect of spinning system and twist coefficient is statistically significant on combed yarn diameter. The difference between the diameter values of conventional and compact spun combed yarns decreases as the twist coefficient increases. Yarn Tenacity and Elongation Ratio Results The tenacity measurement results of conventional and compact spun yarns are given in Figure 12. According to statistical analysis, the effect of spinning system is statistically significant on both carded and combed yarn tenacity and elongation properties as shown in Table IV. The tenacity and elongation values of carded and combed compact yarns are significantly higher than carded and combed conventional ring yarns. The diameter values of compact yarns were smaller than those of conventional ring yarns. In other words the density of these yarns was higher. The higher density would also infer higher fiber to fiber interaction and thus higher strength [8 and 13]. The interaction effect of spinning system and yarn linear density is statistically significant on both carded and combed yarn tenacity and elongation ratio. The difference between the tenacity and elongation values of conventional and compact spun yarns decreases as the yarn becomes coarser. For both carded and combed yarns, the interaction effect of spinning system and twist coefficient isn’t statistically significant on yarn tenacity and elongation ratio.


Evaluating the Knitted Fabric Properties Table V shows the thickness and the weight per unit area of fabrics knitted with conventional and compact yarns. The weight per unit area of fabrics knitted with compact yarns is higher than the fabrics knitted with conventional ring yarns. The difference in the weight per unit area of the fabrics is due to the difference between the yarn liner densities of conventional ring and compact spun yarns. However we couldn’t observe any significant difference between the thicknesses of the knitted fabrics.

FIGURE 12. The tenacity results of compact and conventional spun yarns.

TABLE V. The thickness and weight per unit area of fabrics knitted with conventional ring and mechanical compact spun yarns.

FIGURE 13. The main effect plots for fabric bursting strength.

FIGURE 14. The main effect plots for fabric pilling grade.

Fabric property

Yarn linear

density (tex)

Twist coefficient (αe)

3.4 3.8 4.2

Weight per unit

area (gr/m²)

%CV Thickness

(mm) %CV

Weight per unit

area (gr/m²)

%CV Thickness

(mm) %CV

Weight per unit

area (gr/m²)

%CV Thickness

(mm) %CV

Fabrics knitted with carded ring yarn

29.5/1 140 4.38 0.73 0.01 149 4.91 0.75 0.02 146 7.93 0.77 0.02

19.6/1 94 5.85 0.69 0.03 95 0.38 0.72 0.02 102 2.09 0.75 0.02

14.7/1 62 1.13 0.57 0.02 66 1.30 0.68 0.01 69 2.98 0.73 0.03

Fabrics knitted with carded compact yarn

29.5/1 151 1.90 0.72 0.01 157 2.00 0.73 0.02 164 2.58 0.78 0.02 19.6/1 100 3.07 0.69 0.02 103 1.72 0.74 0.02 111 1.72 0.79 0.02

14.7/1 66 0.99 0.62 0.03 72 0.99 0.69 0.04 81 0.50 0.73 0.03

Fabrics knitted with combed ring yarn

29.5/1 148 1.30 0.70 0.05 153 2.83 0.76 0.02 153 2.64 0.77 0.02

19.6/1 98 7.64 0.69 0.03 96 1.96 0.67 0.02 103 3.05 0.73 0.02

14.7/1 70 4.42 0.62 0.04 69 0.38 0.67 0.02 70 2.28 0.70 0.02

Fabrics knitted with combed compact yarn

29.5/1 152 1.40 0.70 0.03 163 1.26 0.74 0.03 163 1.61 0.77 0.03 19.6/1 92 2.07 0.66 0.02 99 5.55 0.73 0.03 110 1.30 0.78 0.02

14.7/1 68 1.35 0.65 0.01 76 3.34 0.75 0.02 81 6.54 0.75 0.01


Figure 13 and Figure 14 show the main effect plots of fabric bursting strength and pilling grade respectively. The effect of spinning system is shown as X1 and X4. The effect of yarn linear density is shown as X2 and X5. The effect of twist coefficient is shown as X3 and X6. M represents the mean value for each observed fabric property. In the graphics R represents the ring spinning system and C represents the compact yarn spinning system. For the fabrics knitted with carded yarns, the effect of yarn linear density is statistically significant on the pilling grade and bursting strength properties according to the statistical analysis. The pilling grade and bursting strength values of the fabrics increase as the yarn becomes coarser. For the fabrics knitted with combed yarns, the effect of yarn linear density is statistically significant on the bursting strength property. The bursting strength values of the fabrics increase as the yarn becomes coarser. On the other hand, we couldn’t observe any significant relation between combed yarn linear density and pilling grade of the fabrics. In both carded and combed yarns, the effect of twist coefficient on pilling grade and bursting strength properties of fabrics isn’t statistically significant. As it can be seen in Table VI, fabric produced from compact yarn has significantly higher bursting strength than fabric produced from conventional

ring yarn. The bursting strength results of fabrics produced with compact and conventional spun yarns are shown in Figure 15. The yarn tenacity contributes the bursting strength of the fabrics. The increase of yarn tenacity increases the bursting strength property of fabrics. The difference between the bursting strength values of fabrics knitted with conventional ring and compact yarns are less noticeable than the difference between the tenacity values of these yarns. The difference between bursting strength results of the fabrics produced with compact and conventional spun yarns doesn’t change according to yarn linear density and twist coefficient used in the knitting. The pilling results of the fabrics knitted conventional and compact spun yarns are shown in Figure 16. Fabrics produced from compact yarns significantly have higher pilling grade than the fabrics produced from conventional ring yarns. Pilling tendency of fabrics is affected by the yarn hairiness. The fabrics knitted with compact yarns have better pilling performance compared to the fabric knitted from conventional ring yarns. The interaction effect of spinning system and yarn linear density effect is significant on fabric pilling grade. However we couldn’t find linear correlation of the interaction effect of spinning system and yarn linear density.

TABLE VI. The F and significance values of factorial ANOVA analysis for knitted fabrics with conventional ring and mechanical compact spun yarns.

Compared pairs

Spinning system Spinning system*Yarn linear

density Spinning system*Twist

coefficient

Carded cotton Combed cotton Carded cotton Combed cotton Carded cotton Combed cotton

F Sig. F Sig. F Sig. F Sig. F Sig. F Sig.

Bursting strength (kPa) 24.92 .001* 13.94 .006* 0.92 .434 1.52 .275 0.04 .956 0.51 .617

Pilling grade 104.04 .000* 12.36 .008* 11.08 .005* 2.39 .153 2.52 .142 1.09 .380



FIGURE 15. The fabric bursting strength of compact and conventional spun yarns.

FIGURE 16. The fabric pilling grade results of compact and conventional spun yarns.

The Comparison of Conventional Combed and Compact Carded Yarns and Fabrics Produced with Them Table VII shows the statistical analysis for conventional combed and compact carded yarns. Compact spun carded yarn has significantly higher evenness, the number of thin places, the number of thick places and neps values than conventional spun combed yarn. Carded cotton has higher short fiber ratio than combed cotton. Due to the incomplete control of the short fibers in compact yarn spinning system carded compact yarn has higher evenness and imperfection values than conventional combed yarn. However, due to elimination of spinning triangle, compact spun carded yarn has lower hairiness, diameter and similar tenacity and elongation values with conventional combed yarn.

TABLE VII. The F and significance values of factorial ANOVA analysis for conventional combed and compact carded yarns.

Compared pairs Spinning system

Spinning system* Yarn linear density

Spinning system* Twist coefficient

F Sig. F Sig. F Sig.

CV (%) 6327.6 .000* 15.60 .000* 1.10 .334

Thin place (-%50) 248.06 .000* 106.02 .000* 0.55 .578

Thick place(+%50) 1528.5 .000* 231.36 .000* 0.77 .465

Neps (+%200) 1026.7 .000* 110.97 .000* 8.20 .000*

Hairiness (Uster) 759.2 .000* 6.97 .001* 2.96 .054

Diameter (mm) 148.3 .000* 7.85 .001* 2.36 .097

Tenacity (cN/tex) 0.70 .404 9.57 .000* 6.36 .003*

Elongation (%) 0.11 .732 3.54 .033* 0.69 .501



TABLE VIII. The F and significance values of factorial ANOVA analysis fabrics produced with conventional combed and compact carded yarns.

Compared pairs Spinning system

Spinning system*Yarn linear density

Spinning system*Twist coefficient

F Sig. F Sig. F Sig.

Bursting strength (kPa) 23.00 .001* 6.59 .020* 0.34 .719 23.00 .001* 6.59 .020* 0.34 .719

Pilling grade 7.82 .023* 1.08 .384 0.43 .659 7.82 .023* 1.08 .384 0.43 .659

* Statistically significant. Table VIII shows the statistical analysis for fabrics knitted with conventional combed and compact carded yarns. Although carded compact and conventional combed yarn has similar tenacity values, fabric produced with compact carded yarns has lower bursting strength than fabric produced with conventional combed yarns. This can be explained by non-uniform fiber arrangement in carded cotton raw material. Fabric produced with compact carded yarn has better pilling properties because carded compact yarn has less hairiness than conventional combed yarns. The Comparison of Yarn Properties Produced with Conventional Ring, Mechanical Compact and Pneumatic Compact Yarn Spinning Systems In this part of the study, we compared the properties of yarns produced with conventional ring, mechanical compact and pneumatic compact spinning systems. Table IX shows the multiple comparison of conventional ring, mechanical compact and pneumatic compact yarn spinning systems. According to statistical analysis results, pneumatic compact spun yarn has the least evenness, the number

of thin place, the number of thick place, hairiness, diameter and the highest tenacity and elongation values. Conventional spun yarn has the highest neps value compared to mechanical and pneumatic compact spun yarns. There isn’t any statistically significant difference between the neps values of pneumatic and mechanical compact spun yarns. Conventional ring yarn has the highest thin place, neps, hairiness, diameter and the lowest tenacity and elongation values. Pneumatic compact spun yarn has lowest number of thick place value compared to conventional ring and mechanical compact spun yarn. There isn’t any statistical significant between the number of thick places between conventional ring and mechanical compact spun yarns. While the pneumatic compacting system uses vacuum effect in the compacting zone, mechanical compacting system uses the magnetic force. The force applied to fibers in pneumatic compact spinning system is stronger than mechanical compact spinning system. As a result of this pneumatic compact spun yarn has less evenness, fewer imperfections, lower hairiness and has higher tenacity and elongation values compared to mechanical compact spun yarn.


TABLE IX. The multiple comparisons (LSD) of conventional ring, mechanical compact and pneumatic compact yarn spinning systems.

Yarn property Compared pairs Mean Difference Significance

CV (%)

Conventional Ring Mechanical Compact .1760 .192 Pneumatic Compact 1.5353 .000*

Mechanical Compact Conventional Ring -.1760 .192 Pneumatic Compact 1.3593 .000*

Pneumatic Compact Conventional Ring -1.5353 .000* Mechanical Compact -1.3593 .000*

Thin place (-%50)

Conventional Ring Mechanical Compact 54.000 .001* Pneumatic Compact 136.833 .000*

Mechanical Compact Conventional Ring -54.000 .001* Pneumatic Compact 82.833 .000*


Thick place (+%50)

Conventional Ring Mechanical Compact 10.666 .372 Pneumatic Compact 101.333 .000*

Mechanical Compact Conventional Ring -10.666 .372 Pneumatic Compact 90.666 .000*


Neps (+%200)


Mechanical Compact Conventional Ring -65.166 .000* Pneumatic Compact 21.166 .072

Pneumatic Compact Conventional Ring -86.333 .000* Mechanical Compact -21.166 .072

Hairiness (Uster)


Mechanical Compact Conventional Ring -1.770 .000* Pneumatic Compact .1787 .008*

Pneumatic Compact Conventional Ring -1.949 .000* Mechanical Compact -.1787 .008*

Hairiness (Keisokki)


Mechanical Compact Conventional Ring -12.740 .000* Pneumatic Compact 1.326 .000*


Diameter (mm)

Conventional Ring Mechanical Compact .0235 .000* Pneumatic Compact .0299 .000*

Mechanical Compact Conventional Ring -.0235 .000* Pneumatic Compact .0064 .000*

Pneumatic Compact Conventional Ring -.0299 .000* Mechanical Compact -.0064 .000*

Tenacity (cN/tex)

Conventional Ring Mechanical Compact -4.033 .000* Pneumatic Compact -6.320 .000*

Mechanical Compact Conventional Ring 4.033 .000* Pneumatic Compact -2.286 .000*

Pneumatic Compact Conventional Ring 6.320 .000* Mechanical Compact 2.286 .000*

Elongation (%)

Conventional Ring Mechanical Compact -.2733 .004* Pneumatic Compact -.6067 .000*

Mechanical Compact Conventional Ring .2733 .004* Pneumatic Compact -.3333 .001*

Pneumatic Compact Conventional Ring .6067 .000* Mechanical Compact .3333 .001*



CONCLUSION In the first part of the study, we compared the properties of yarns produced with conventional ring and mechanical compact yarn spinning systems. Compact yarns were found to have lower hairiness than conventional ring yarns. The reason behind the lower hairiness in compact spun yarn is the elimination of spinning triangle in spinning system. Compact yarns were found to have smaller diameter and better tensile properties than conventional ring yarns. As the yarn diameter decreases the fiber to fiber interaction increases and this leads to higher yarn tenacity and elongation ratio. The mechanical compact spinning system slightly increases the evenness and imperfection values of yarns. However, as the yarn becomes finer these effects gradually disappear. The superior properties of compact yarns are seen clearly on the fabric quality. Fabrics knitted with compact yarns were found to have better pilling properties and higher bursting strength than fabrics knitted with conventional ring yarns. Compact spun carded yarn was to found to have lower hairiness and similar tensile properties compared to conventional combed yarn; however it has significantly higher evenness, number of thin places, number of thick places and neps values. If the evenness property of carded compact yarn can be improved, it will have a potential for improving quality and profitability of cotton yarn manufacturing. Fabrics knitted with compact carded yarns were found to have better pilling properties than fabrics knitted with conventional combed yarns. Although carded compact and conventional combed yarns were found to have similar tenacity values, fabrics knitted with compact carded yarns had lower bursting strength than fabrics produced with conventional combed yarns. This can be explained by non-uniform fiber arrangement in carded cotton raw material. In the second part of the study we compared the properties of yarns produced with conventional ring, mechanical compact and pneumatic compact yarn spinning systems.

Pneumatic compact spun yarns were found to have better yarn properties than mechanical compact spun yarn. They had less evenness, less imperfections, lower hairiness, higher tenacity and higher elongation values. The reason behind unsatisfactory test results could be the weak compacting power of mechanical compacting system. There are different compact spinning systems on the market from different manufacturers. In this study we compared only the most commonly used pneumatic compact spinning system. A further study about the comparison of mechanical compact spinning with other pneumatic compacting systems should be a valuable contribution to the decision-makers in the short-staple spinning industry. REFERENCES [1] S. Ömeroğlu, and S. Ülkü, An Investigation

about Tensile Strength, Pilling and Abrasion Properties of Woven Fabrics Made from Conventional and Compact Ring-Spun Yarns, Fibers & Textiles in Eastern Europe, 2007, 15(1), p. 39-42.

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[3] Cheng, K.P.S. Yu, C., A Study of Compact Spun Yarns, Textile Research Journal, 2003, No 4, p. 345-349.

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[9] Dash, J.,R., Ishtiaque, S.,M., and Alagirusamy, R., Properties and Processibility of Compact Yarns, Indian Journal of Fiber & Textile Research, 2002, Vol. 27 (4), pp. 362-368.

[10] Jackowski, T., Cyniak, D, and Czekalski, J., Compact Cotton Yarn, Fibers & Textiles in Eastern Europe, 2004, Vol. 12(4), pp. 22-26.

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[12] Mavruz, S. ve Oğulata, R. T., Statistical Investigation of Properties of Ring and ompact Yarns and Knitted Fabrics Made of These Kinds of Yarns, Tekstil ve Konfeksiyon, 2008, Vol. 3, pp. 197-205.

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AUTHORS’ ADDRESSES Sevda Altas Ege University Emel Akın Vocational School İzmir, Bornova 35500 TURKEY Hüseyin Kadoğlu Ege University Textile Engineering Department İzmir, Bornova 35500 TURKEY

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