Comparison between Conventional Ring and Compact Spinning of some Egyptian Cotton Varieties

INTRODUCTION

Quality and quality management are the key words used in our time; cost and quality are the most important factors for any company. The raw material cost in a spinning mill reaches up to 60% of the production cost (Staler, 1995 and 2000). Krause and Soliman (1991) and   Basal and Oxenham, (2006) show the possibility to use a compact spinning to improve the quality of the yarns produced from short staple cotton fibers in order to get use of the improvement in the compact yarn properties.

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 (Kampen, 2000 and Cheng and Yu, 2003).

Krifa and Ethridge (2003) and Cheng and Yu (2003) reported that compact spun yarn strength and elongation at break point are higher by about (15% and 20%), respectively. Furthermore, the yarn hairiness becomes (70%) less, and the coefficient of variation of the yarn was lower by (15%) than that for the equivalent ring spun yarn.

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 Jayavarthanavelu (2006) and Basal and Oxenham (2006) found that high tenacity values of compact yarns can be attributed to the higher rate and amplitude of fiber migration in these yarns compared to those in conventional ring yarns.

The yarns spun on the compact spinning system are characterized by higher tenacity, higher elongation at break, smaller mass irregularity measured at short segments, and significantly lower hairiness than those spun on the conventional ring spinning frame. For the long staple Egyptian cotton varieties, the breaking force or single yarn strength of the compact yarn was 17.63% higher than the conventional ring spun yarn (El-Sayed and Sanad, 2007).

In conventional ring spinning, 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 (Ömeroğlu and Ülkü, 2007).

The reconstructed structure of the ring yarn and the compact yarn segments were compared, and compact yarn presented different structural characteristics, where there are more regular fibers within yarns, and the arrangement of fibers in the cross-section presented a periphery-dense and core-uniform packing. All these findings provide evidence for better understanding of the relatively higher strength and less hairiness of compact yarns (Wu et al., 2009).

The compact spinning yarns have the following advantages when compared to the ring spinning yarns: higher strength and elongation at break, somewhat equivalent or higher yarn unevenness, and a significantly lower number of yarn faults such as thin, thick places and neps, as well as lower hairiness (Sanad et al., 2011). 

The compact yarns have lower hairiness than conventional ring yarns because of the elimination of spinning triangle in spinning system.  The compact spinning system slightly increases the evenness and imperfection values of yarns. However, as the yarn becomes finer these effects gradually disappear (Altas and Kadoğlu, 2012).

Iqbal (2018) reported that compact yarns are claimed to be stronger and less hairy dye to the improved fiber binding, and have better yarn elongation and yarn irregularity values compared with conventional ring yarn.

The goal of this work is to make best use of compact spinning taking the advantage of compact yarn structure in processing of combed compact yarns instead of combed ring yarn. A comparative study of the physical and mechanical properties of yarn produced from the three Egyptian cotton varieties on the two spinning systems is studied.

MATERIALS AND METHODS

In this study used three commercial Egyptian cotton varieties (Giza 94, Giza 92 and Giza 86) long staple belong combed roving during 2019 season. The fiber properties measured with the Uster® HVI 900 testing instrument in accordance with ASTM (1991). D5867-05, were given in Table (1).

Chosen produce three yarn count (Ne 80’s, Ne100’s and Ne 120’s) count yarns spun at twist multipliers 4.0. The yarns were produced in both compact and conventional ring spinning. A standard spinning preparation and modern machinery in the experimental spinning mill, Cotton Research Institute, were used to produce conventional and compact carded yarns under comparable technological conditions on the RST1 Marzoli ring and compact spinning fitted with (Olfil System) on one frame, as shown in Figure (1).

After the spinning trials, the physical properties of each yarn sample were measured according to ASTM (1991). D-2256-80, D-1425-81 and the measurement results of conventional ring yarns and compact yarns were compared to each other. Yarn evenness (CV%), hairiness and imperfections values were measured on Uster Tester 3 (the measurement length was 400 m/bobbin). Yarn tenacity (cN/Tex) and elongation at break (%) were measured on a Statimat ME with 120 breaks per sample.

All tests were performed after the yarns were kept in standard atmospheric conditions for 24 hours (65±2 % relative humidity, 20±2ºC).

In the analysis of test results, factorial ANOVA and multiple ANOVA (L.S.D.) methods were designed as analysis of variance experiment with three replications at 0.05 significance level.

Table (1). Fiber properties of the commercial Egyptian cotton varieties during 2019 season

  U.H.M.L.: upper half means length.

Figure (1).Yarn formation in conventional and compact ring spinning. Artzt, (2000)

RESULTS AND DISCUSSION

Evaluation of yarn properties

According to the experimental results of yarn properties, compact yarns were better quality than conventional yarns due to elimination of fiber fly in compact yarn spinning system. The main effects of spinning system, cotton varieties and yarn count on yarn properties as in Table (2), have been analyzed also the interaction effects of spinning system and cotton varieties (S x V), spinning system and yarn count (S x C), cotton varieties and yarn count (V x C) and also spinning system, cotton varieties and yarn count (S x V x C) as in Tables (3 and 4). 

Presented results in Table (2) showed that spinning systems, cotton varieties and yarn count besides their first and second order interactions had significant effects on all the studied traits as follows.

Based on the analysis results following conclusions can be drawn:

Yarn tenacity and elongation ratio results:

The results presented for tenacity measurement of conventional and compact spun yarns, according to statistical analysis showed that the effect of spinning system has significant effect on all cotton varieties for lea count strength product (LCSP), single yarn strength (cN/tex) and elongation ratio as shown in Tables (2 and 3). The tenacity and elongation values of combed compact yarns are significantly higher than combed conventional ring yarns.

The interactions between spinning system and cotton varieties (S x V) are shown in Figure (2) and Table (3). The results indicate that Giza 92 had the highest tenacity followed by Giza 94, and Giza 86, respectively. Also the interaction between spinning system and yarn count (S x C) are shown in Figure (2) and Table (3) is effect statistically significant on both combed yarn tenacity and elongation ratio. The tenacity and elongation values of conventional and compact spun yarns increase as the yarn becomes coarser.

Table (3) and Figure (2) compares the results of yarn strength obtained on the yarn count (Ne 80’s, Ne 100’s, and Ne 120’s) both combed compact yarns and combed conventional ring yarns from the cotton varieties. The results showed that the yarn strength decreased with the increase of the yarn count, and that the most decrease in yarn strength with increasing yarn count recorded for Giza 94, variety and the lowest variety in decrease in the yarn strength was the Giza 86.

Table (2). Effect of spinning system (S), cotton variety (V), yarn count (C) and their interactions on yarn properties during 2019 season

LCSP: lea count strength product – U%: percent mean deviation – C.V. %: coefficient of variation.

*  Significant difference at 0.05 level of probability.

Means within each column with the same letters are not significant difference at 0.05 level of probability.

Table (3). The first order interactions spinning system x cotton variety (S x V), spinning system x yarn count (S x C) and cotton varieties x yarn count (V x C) for yarn properties during 2019 season

LCSP: lea count strength product – U%: percent mean deviation – C.V. %: coefficient of variation.

Means within each column with the same letters are not significant difference at 0.05 level of probability.

Table (4). Effect of spinning system (S), cotton variety (V) and yarn count (C) interactions on yarn properties during 2019 season

LCSP: lea count strength product – U%: percent mean deviation – C.V. %: coefficient of variation.