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Dref-3 friction spun core yarns produced using staple fibre yarn as the core, e.g. Jute core yarn wrapped with cotton fibre, have poorer mechanical properties compared to the core yarn itself. The purpose of this study was to understand the structure of such yarns, that will lead to the optimization of fibre, machine and process variables for production of better quality yarn from the Dref-3/3000 machines.

The Dref spinning trials were conducted following a full factorial design with six variables, all with two operative levels. The Dref-3 friction spun yarn, in which the core is a plied, twisted ring yarn composed of cotton singles and the sheath, formed from the same cotton fibres making the singles, has been examined. The structures have also been studied by using the tracer fibre technique.

It was observed that rather than depending on the plied core yarn, the tensile properties of the Dref-3 yarn are significantly determined by the parameters those affect the constituent single yarn tensile properties, i.e. the amount of twist and its twist direction, yarn linear density and the sheath fibre proportion used during the Dref spinning in making the final yarn. Further, when the twist direction of single yarn, double yarn and the Dref spinning false twisting are in the same direction, the produced core-sheath yarn exhibits better tensile properties.

The understanding of the yarn structure will lead to optimized production of all staple fibre core Dref spun yarns.

The research work may lead to utilization of coarse and harsh untapped natural fibres to the production of value-added textile products.

Though an earlier research has reported the effects of sheath fibre fineness and length on the tensile and bending properties of Dref-3 friction yarn, the present study is the first documented attempt using the tracer fibre technique to understand Dref-3 yarn structure with plied staple fibrous core.

No study was published about the tensile properties of different sections of multicount yarn. Hence there was a need to conduct a detailed section-wise tensile study of fancy multicounty yarn. The purpose of this study is to identify the different sections of the same multicount yarn and test them separately.

Multicount yarn with slubs were prepared on a ring frame with the Amsler Textile Effect System. Different yarn sections from each multicount yarn are identified as fine normal, fine slub, medium normal, medium slub, coarse normal, coarse slub and the changeover sections. These sections are tested for the breaking load and breaking elongation. Broken ends of the yarn sections are also studied, and these broken ends are classified as sharp broken end, tapered broken end and slipped broken end. A study is also conducted on the location of break or the place of break at the changeover sections.

It was found that the twist of yarn at slub sections was lower than the twist at normal sections. In spite of the low yarn twist at slub sections, the breaking load of the yarn was higher at slub sections than at normal sections by 12 to 30 per cent owing to the presence of more number of fibres that share the breaking load. The breaking load at the changeover section (normal to slub and slub to normal) was found to be higher than that at normal section and lower than at slub sections. No significant difference was found between the breaking load of the two changeover sections (normal to slub and slub to normal). The majority of breaks in normal yarn sections were of the tapered broken end type and the majority of breaks in slub yarn sections were slipped broken ends.

Efforts are taken to identify different sections of the same multicount yarn with the help of specially designed square black board and tensile study of these sections are carried out.

Fancy multicount yarn (9.5s Ne) is prepared on a ring frame with an Amsler fancy yarn attachment per the Box-Bhenken design for three variables and at three levels. The ring frame process parameters selected are spindle speed, traveller mass and twist multiplier. Different yarn properties, such as yarn tenacity, breaking elongation, yarn irregularity, yarn hair index, imperfections and thin places -40% are tested. An analysis of the result is done by using statistical software. It is observed that a 9000 rpm spindle speed with a 5 twist multiplier gives maximum yarn tenacity, a 9000 rpm spindle speed with traveller mass of 120 mg gives minimum yarn irregularity and traveller mass of 120 mg with a 4.8 twist multiplier gives minimum yarn imperfections within the experimental zone explored.

This paper aims to study the yarn cross-section shape which is a very important yarn physical parameter and has a dominant effect on the physical structure of the yarn. Four factors affecting the yarn cross section, i.e. twist multiplier, Roving hank, spinning system and doubling technique, were investigated.

In past researches, the yarn cross-sectional area was calculated by considering any one yarn radius giving the approximate yarn cross-sectional area by assuming the yarn as a circular one.

In this study, a testing instrument is fabricated as shown in Plates 1 and 2 for yarn cross-section measurement and a novel method for calculating the correct yarn cross-sectional area of the yarn was developed.

In the past, no such studies have been conducted on the yarn cross-section studies because of the various limitations of the yarn cross-section measuring or testing instruments.

The use and importance of mélange yarn in apparel sector is increasing day by day. With the gradual increase in market share, achieving the desired quality level of mélange yarn remains a challenge for yarn manufacturing industry. The purpose of this paper is to investigate the effect of raw material (dyed fiber percentage in the mixing), important spinning process variable (yarn twist multiplier) and productivity (spindle rpm of ring frame) on properties of cotton mélange spun yarn.

Box and Behnken Design of experiment has been used to investigate the important yarn quality parameters like evenness, imperfection, hairiness, breaking strength and breaking elongation of blow room blended cotton mélange yarn. The quadratic regression model is used to derive the statistical inferences about sensitivity of the yarn quality parameters to the different process variables. The response surfaces are constructed for depicting the geometric representation of yarn quality parameters plotted as a function of process variables.

The study shows that shade depth and spindle speed have significant effects on the mélange yarn unevenness and imperfections. Mélange yarn strength and hairiness are significantly affected by shade depth and yarn twist multiplier (TM). Yarn elongation at break is only influenced by the spindle speed. A darker shade is responsible for higher yarn unevenness, imperfection, hairiness and lower yarn strength. A higher spindle speed is also liable for deterioration of yarn quality.

Many spinning industries are planning to convert their existing spindles from normal gray yarn production to mélange yarn manufacturing. The outcome of this study will lead to achieve better mélange yarn quality and productivity by the industry.

Research on mélange yarn is itself scant. This study is exclusively conducted to analyze the individual and interactive effect of various process parameters on the mélange yarn quality.

The traditional Japanese cotton-crepe fabric chijimi has been used for summer clothing for over a century because of its good skin comfort. The high extensibility of this fabric relies on the high-twist cotton yarns used in the weft direction. The purpose of this paper is to show the effect of environmental humidity on the extensibility of highly twisted cotton yarns to help in choosing weft yarn suitable for woven fabric.

Four highly twisted cotton yarns are examined under 10-90 percent RH and in 25°C water. Cyclic tensile tests are performed to obtain the tensile energy, resilience, extensibility at maximum applied load (EM), and residual strain.

Comparing the same yarn-count samples Y1 and Y2, the EM of Y2 (2,200 T/m) is larger than that of Y1 (1,000 T/m) under all RH conditions, and the difference increases at humidity over 60 percent RH. For fabric crepe samples woven by Y1 (warp) and Y2 (weft), the extensibility (EM-1) in the weft direction is in the range 16-26 percent, which is equivalent to that of outer-knitted fabrics. The extensibility and recovery of chijimi is largely dominated by the twist of weft yarns, which is also influenced by changes in relative humidity.

The skin comfort of Takashima chijimi has been of interest, but the high extensibility of this cotton fabric has not been given much attention. The results of this study show that yarn twist is key to controlling extensibility in high-humidity environments.

The effects that spinning technology and spinning parameters have on the color strength (K/S), strength, and breaking elongation of post dyed and mercerized yarns are investigated in this study. The emphasis of the study is on the selection of long stable Egyptian cotton varieties, namely Giza 80, Giza 86, and extra long stable Giza 92. The cotton samples are spun by using compact, ring, and open end spinning technologies. For the purpose of this study, different yarn counts and twist multipliers are used. The mechanical properties, such as the tensile strength and breaking elongation of the produced yarn are investigated and compared before and after the mercerization treatment (slack and tension), followed by a reactive dyeing process. All of the samples are prepared for dyeing after mercerization. The dyeing performance in terms of the K/S is studied. When the results are examined, it is found that the samples that have undergone (bleaching + slack mercerization + reactive dyeing) generally have higher K/S values than samples that have undergone (bleaching + tension mercerization + reactive dyeing) and (bleaching + non-mercerization + reactive dyeing) respectively. Open-end spun yarns have a higher K/S compared to the compact and ring spun yarns with the lowest count yarn and twist level. The strength percentages are higher for compact, then ring and finally open-end spun yarns respectively with tension mercerization. There is no noticeable difference in the elongation% for all of the treatment processes. The authors have used quality engineering reproducibility and repeatability (R&R) tools to guarantee the repeatability and reproducibility of the results in this research paper.

Spinning triangle is a critical region in the spinning process of staple yarn, which geometry influences the distribution of fiber tension and determines the qualities of yarn directly. Therefore, the purpose of this paper is to investigate the fiber tension distribution at the twist point.

First, one theoretical model of fiber tension distributions at the twist point is given according to the motion law of fibers in the spinning triangle. Then, one calculation method of fiber tension at the twist point is given by two steps. First, the initial tension of each fiber at the front nip line caused by the yarn load should be calculated according to the models obtained based on the principle of minimum potential energy. Second, the fiber tensions at the twist point can be calculated using the obtained model in this paper. Finally, as an application of the proposed method, spinning triangles of a modified ring spinning system with a pair of offset device which can change the horizontal offset of the twist point to the symmetric axis of nip line of the spinning triangle continuously are studied. The fiber tension distributions are simulated numerically.

It is shown that the fiber tension distributions at the twist point can be determined by fiber feeding into and out the spinning triangle speed, the initial tension of each fiber at the front nip line, fiber tensile Young’s modulus and cross-sectional area, the number of fibers at spinning triangle and the individual fiber angle with the center fiber. The spinning experiment shows that taking appropriate right or left offset of the spinning triangle can help to improve the spun yarn qualities.

In this paper, the fiber tension distribution at the twist point is investigated. One theoretical model of fiber tension distributions at the twist point is given according to the motion law of fibers in the spinning triangle first. Then, one calculation method of fiber tension at the twist point has been given under the assumption that the initial tension of each fiber at the front nip line is caused by the yarn load.

The purpose of this review paper is to define the dominating factors (such as fiber, yarn, fabric structure, sewing thread, sewing needle and machine parameters) that affect the seam damages and causing defects. It also describes the various explanations of sewing defects in garment production and critically analyzes them for optimum selection of parameters and speeds for minimizing such faults. Hence, the knowledge of various factors which affect the sewing damages/defects will be helpful for garment manufacturers/researchers to know influence of the parameters and control the quality of producing seam.

This section is not applicable for a review paper.

Sewing damages such as needle cut and other sewing damages/defects are studied mostly in woven fabric. There are very few studies conducted on knitted fabric sewing damages/defects. The sewing damage problems do not have single solution that is capable of removing these damages in fabric. All the determined and affecting parameters related to fiber, yarn, fabric construction, sewing thread and sewing machine must be examined to design appropriate remedial measurement related to machine design, fabric parameters and sewing thread. This could help in minimizing or eliminating the needle cut and other sewing damage problems.

It is an original review work and is helpful for garment manufacturers/researchers to reduce the defects and be able to produce good quality seam.

The fine gauge plain weft knitted fabrics knitted from cotton Sirospun¹ yarns are more durable and suitable for summer wear. It was found that they have considerable bursting strength, superior abrasion resistance, superior pilling resistance, greater air resistance, cooler hand‐feel and greater thermal conductivity than the fabrics knitted from two‐fold yarns. The plain weft knitted fabric composed of coarser Sirospun¹ yarn is also better in terms of hand‐feel measured by KES instruments.