Production of Fine Count Yarns from Some Extra-long Egyptian Cottons on Different Spinning Systems

The current research was carried out to produce fine count yarns from extra-long Egyptian cotton varieties using compact and ring spinning systems.in addition, to compare between compact yarns and ring yarns in terms of their physical and mechanical properties. Three commercial extra-long staple Egyptian cottons Giza92, Giza93 and Giza 96 were used to produce four linear densities of 80, 100, 120 and 140 at 3.6 twist multiplier. Results obtained showed that Giza 92 was surpassed significantly other extra -long staple varieties. It recorded the highest mean values of yarn strength and yarn evenness While, the same variety recorded the lowest mean values of yarn hairiness and imperfections. Compact yarns were much better than yarns spun on the ring spinning in yarn strength, yarn elongation, evenness, yarn imperfections and yarn hairiness. Yarn count 80,s gave higher single yarn strength (20.89cN/tex), yarn elongation (5.03%) and yarn evenness (17.49%) and lower yarn hairiness (2.04) and imperfections than yarn count 140s. Single yarn strength, yarn elongation and yarn evenness were decreased with increasing yarn count. While the number of neps, hairiness, the number of thin and thick places were increased with increasing yarn count. Concerning, the effect of interaction between cotton varieties × yarn counts × spinning systems on yarn quality properties. Yarn count 80s recorded the highest mean values of yarn strength (23.14, 21.1 and 20.2 cN/tex) and yarn evenness (17.72, 16.53 and 16.79%) for varieties Giza92, Giza93 and Giza96, respectively for compact spinning system. Yarn strength at count 80, 100, 120 and 140 correlated negatively and highly significant with micronaire value and maturity ratio.

Investigation Of Fiber Length Change In Different Stages Of Ring Spinning Process

Fiber length is one of the major fiber properties that influence yarn strength, evenness, product handle, product luster, and yarn hairiness. To assure yarn quality, fiber passes through a number of machinery during the spinning process, where it is subjected to various sorts of action that modifies the fiber length. As different process parameters are chosen based on fiber length, fiber length analysis throughout the spinning process will benefit in the adjustment of machine parameters to produce better quality yarn. This study will reveal the chronological change in average fiber length at different stages of the carded ring spinning process, as well as a correlation analysis of length change among different phases, using correlation and regression methods. For five distinct mixing samples, raw cotton, card mat, carded sliver, breaker drawn sliver, finisher drawn sliver, roving, and yarn (pneumafil) were examined at each stage from raw cotton to ring frame. Then, using USTER AFIS PRO, all of the samples were numerically evaluated and statistically analyzed using Microsoft Excel 2016. A positive correlation between fiber length changes at several phases was observed in the experiment, with average fiber length increasing in carding, breaker drawing, finisher drawing, and simplex but decreasing in card mat and ring.

Investigation into four-roller compact spinning with air damper for improving yarn performance

Compact spinning, as a new kind of spinning technology, has gained wide attention because of its great reduction in spinning triangle and yarn hairiness. In order to meet the demand of high-grade clothing, research on further improving the performance of compact spun yarn is the emphasis. Of all the existing compact spinning systems, the four-roller compact spinning with lattice apron is most widely used at present because of its low cost. Therefore, this paper aims to put forward a new kind of device to improve yarn performance for four-roller compact spinning systems. Related experiments have been done to verify the efficiency of the device, and the mechanism is analyzed by computational fluid dynamics. The numerical simulation shows that the device can change the direction of airflow and increase the velocity in the directions of transverse condensing and thickness. It is shown that the air damper is convenient to use and has potential applications in spinning compact yarns with better performance.

Numerical Simulation of Fiber Motion in the Condensing Zone of Lateral Compact Spinning with Pneumatic Groove

Lateral compact spinning with pneumatic groove is a spinning process to gather fibers by common actions of airflow and mechanical forces. Compared with ring spinning, it can more effectively reduce yarn hairiness and enhance yarn strength. However, fiber motion in the agglomeration area is complex. And, it is important to establish a new fiber model to accurately describing the fiber motion. The objectives of this research were to create a new fiber model to simulate the agglomeration process, to analyze yarn properties of the lateral compact spinning with pneumatic groove, and to compare with other spinning yarns through a series of tests. The new fiber model was based on the finite element method implemented in MATLAB and was to show the fiber motion during the agglomeration area. The simulation generated results were close to the real motion of fibers in spinning. In the lateral compact spinning with pneumatic groove, fiber bundle through the agglomeration area can be gathered, and the output of the fiber bundle was nearly to cylinder before yarn twisted. The experiments demonstrated that the lateral compact spinning with pneumatic groove can improve the yarn properties: increase the yarn twist, enhance the yarn strength, and reduce the yarn hairiness.

Investigation into the effects of yarn structure and yarn count on different types of core-spun yarns

The scope of this research is to study the effect of yarn structure and yarn count on properties of types of core-spun yarns, including elastic core/T400, elastic core/Lycra, dual core, and tri-core yarns. Five types of yarn structures and three yarn counts were produced. Mechanical properties, yarn irregularity, imperfections, and hairiness were measured. Full-factorial analysis and Tukey tests were performed on the test results. It was concluded from factorial analysis that yarn count, yarn structure, and two-way interaction had a significant effect on yarn properties, except for yarn hairiness where the effect of yarn structure and two-way interaction was not significant. A Tukey pairwise comparison was used in this study to specify exactly the subgroups of yarn count and yarn structure that have a significant mean difference. The scanning electron microscopy (SEM) images of the dual-core yarns and tri-core yarns were performed to illustrate the structure of these yarns.

The Effect of Humidified Air on Yarn Properties in a Jet-Ring Spinning System

In this study, the effect of 100% atmospheric relative humidity on yarn properties was investigated using jet-ring nozzles and compared with the yarn properties of yarns produced with air operated jet-ring nozzles under normal conditions. As a humidification system, a pneumatic conditioner, also known as a lubricant, was used in pneumatic systems. This conditioner was connected just before the pneumatic distributor that supplies air to the nozzles. The tube in stage 2 of the conditioner was filled with pure water at room temperature (25 °C ± 2 °C). The air conditioner dose was adjusted to 100% atmospheric relative humidity. The use of humidified air to jet-ring nozzles had a slight positive effect on all yarn properties (yarn hairiness, yarn irregularity, yarn elongation and yarn tenacity). According to the results, it resulted in a 1% to 3% improvement in yarn quality. This study is the first example and an original study in this field, as there is no study using humidified air in existing jet-ring air nozzle studies. It was proven in this study that humidified air results in a slight improvement in yarn properties.

Investigating the effects of some process parameters on the quality of coarse compact yarn produced from carded roving

This project work aimed to investigate the interactive effects of carded roving parameters (i.e., roving hank and twist) and break draft of ring frame on the quality of compact yarn such as evenness, strength and hairiness. However, in this work, compact spun yarns produced from carded roving hanks of 0.70Ne and 0.90Ne while the roving twist per meter inserted at two levels (i.e., 40 and 45) for each of hank. Moreover, the break draft values of ring frame kept at three levels (i.e., 1.15, 1.25 and 1.35) for each type of roving. However, 100% cotton compact yarns of 24Ne and 32Ne produced for this experimental investigation. However, results showed that yarn unevenness (U%) and imperfection index (IPI) values of compact yarn decreased for the finer roving hank (0.90Ne) irrespective of yarn fineness. It was also noticed that low twisted roving improved yarn evenness during coarser yarn (i.e., 24Ne) production. Regarding the count strength product (CSP) value, increasing levels of roving twist deteriorated the CSP results in general. Trend of CSP results also revealed that finer roving produced higher levels of CSP results for comparatively finer yarn production. As far as yarn hairiness is concerned, it was observed that finer roving (0.90Ne) having higher levels of twist reduced yarn hairiness irrespective of yarn fineness without any exception. Finally, it can be said that this study will help the researchers for comprehending the influences of the process parameters during the production of compact yarn from carded roving.

Determination of Optimum Twist Equation for the Long Staple Combed Cotton Ring-Spun Yarn

The aim of this research was to determine the optimum twist equation for ring-spun yarns. The yarn twist can be calculated by different equations. With the research, we tried to find the appropriate equation to determine the yarn twist, which is determined by the values of yarn strength and hairiness. In the research, yarns from long staple combed cotton rovings and of different fineness (10 tex, 11.8 tex, 20 tex and 29.4 tex) were analyzed. The yarn twist was calculated using the equations of Koechlin and Laetsch. The analyzed yarns were produced in the spinning mill on the laboratory ring spinning machine Spinntester. In the second part of the investigation, yarn strength and hairiness were analyzed as a function of yarn twist. The results showed that Laetsch’s equation is suitable for determining the twist for yarns with a fineness of 10 tex, 11.8 tex, 20 tex and 29.4 tex, since, in this case, the calculated number of yarn threads is higher and thus the strength and elongation at break are also higher. The yarn hairiness is higher in analyzed samples for yarns with the twist calculated according to the Koechlin’s equation.