Quality Evaluation of Ethiopian 100% Cotton Carded Ring Spun Yarn with Respect to USTER Standards

Yarn quality influences both fabric production processes efficiency and export market. One method used to gauge competitiveness of an industry is to study its product quality. The aim of this research work is to evaluate the quality of Ethiopian textile spinning mills’ 100% cotton carded ring spun yarns in terms of its evenness (coefficient of mass variation, CVm), imperfections (thick and thin places, neps), and tensile properties with USTER Statistics 2018. Five spinning mills (B3, A0, A2, A4, and K3) of 15N, 20Ne, 25Ne, 30Ne, 35Ne, and 40Ne nominal yarn counts have been selected for the study. The yarn evenness and imperfections were measured using USTER tester 5 and tensile using a STATIMAT tester. The USTER statistical results showed 20.3Ne (mill B3), 32Ne (mill A4), and 36.2Ne (mill A2) had better overall quality, respectively. It was observed that most selected spinning mills had low evenness, imperfections, yarn strength, and good yarn elongation. Tensile properties of A2 (32.85Ne and 36.2Ne) had fallen under 5% USTER statistics percentile which indicates excellent yarn strength. Generally, from studied mills, it was seen that 61.5% of cotton yarn CVm and thin places falls at above 95% and 15% of yarn tenacity falls at ≤5% of Uster statistical percentile.

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.

Study to relate mini-spun yarn tenacity with cotton fiber strength

There has been great interest in assessing yarn tenacity directly from available cotton fiber property data acquired by various means, including high-volume instrumentation (HVI). The HVI test is a primary and routine measurement providing fiber properties to cotton researchers. Knowledge about yarn tenacity within a cotton cultivar or between cultivars could be useful with regard to understanding the selection of cotton cultivars. This study examined the effect of cotton growth location, crop year, and cultivar on three relationships (fiber strength versus fiber micronaire, yarn tenacity versus fiber micronaire, and fiber strength versus yarn tenacity), and found great variations in the Pearson correlation and the gradients of respective regression lines. Instead of developing linear regression models from HVI fiber properties to predict yarn tenacity, this study applied a simple ratio method (i.e. normalized fiber strength or yarn tenacity against five HVI fiber properties) to relate fiber strength with yarn tenacity. The short fiber index was found to have a greater effect on the correlation between modified yarn tenacity and modified fiber strength than micronaire, yellowness, upper-half mean length, or uniformity index. This result implied the feasibility of utilizing HVI fiber short fiber index and strength data, as a semiquantitative and fast approach, to compare yarn tenacity performance within a cotton cultivar or between cultivars.

Reducing yarn hairiness in ring spinning by an agent-aided system

An agent-aided system (AAS) for improving comprehensive properties of ring spun yarns with the aid of viscosity and surface tension of the agent is reported in this paper. The mechanism of the humidification and friction process of the AAS was investigated, and related experiments were also carried out to verify the mechanism of analysis. The results confirm that the AAS can attach the fiber ends protruding out of a yarn body on the yarn surface and assist in twisting the fiber ends back into the interior of the yarn body, resulting in a significant reduction of the modified ring spun yarn hairiness. Moreover, the yarn hairiness is prominently reduced after the winding process. The experimental results also show that a speed ratio of 1.3 between the rotating speed of the cylinder and the output speed of the yarn leads to the greatest extent of harmful hairiness reduction (34%), which also corresponds to optimal modified yarn tenacity. Meanwhile, the modified ring spun yarns show a tight and smooth appearance, and the yarn evenness has no deterioration. In addition, the AAS is applicable to both cotton and viscose yarns with different yarn counts. Therefore, the AAS can potentially be used to reduce yarn hairiness for ring spun yarns and enhance the quality of ring spun yarns in the textile industry.

Modal–Cotton Fibre Blend Ratio and Ring Frame Parameter Optimisation Through the Taguchi Method

The influence of Modal–cotton (MC) fibre blend ratio and ring frame machine parameters such as front top roller loading and break draft on the blended yarn properties has been studied. Compact MC blended yarn samples of 14.75 tex with three different MC fibre blend ratio has been produced in a LR 6 ring spinning frame fitted with Suessen Compact drafting system. A robust design optimisation to minimise the variations of the output yarn properties such as blended yarn tenacity, yarn unevenness and hairiness caused because of the variations in the material as well as machine setting parameters is achieved through the Taguchi parametric design approach. It is found that the maximum compact MC blended yarn tenacity is 23.76 g/tex, which is influenced very much by MC fibre blend ratio but meagrely by top roller loading and break draft. Similarly, the minimum 9.54 U% and 3.59 hairiness index are achieved with 100:0 and 70:30 MC fibre blend ratio, respectively, at 23-kg top roller loading. Statistical ANOVA analysis is performed on the results and optimum values are obtained within the 95% confidential level through confirmation experiments.

An investigation on the properties of polyester textured yarns produced with different fiber cross-sectional shapes

In this study, the effects of different fiber cross-sectional shapes and yarn linear density values on Partially Oriented Yarn (POY) and textured yarn characteristics have been examined. In experiment, five different cross-sectional shapes, namely round, trilobal, tetra, hexsa and octolobal and two different linear densities have been used and tenacityelongation, crimp and shrinkage tests have been applied to the yarns. As a result, the round and octolobal crosssectional shapes lead to yarn formation with high tenacity and breaking elongation, on the other hand trilobal and hexsa cause low tenacity and breaking elongation. The round cross-section has provided yarn formation with high crimp and low shrinkage, the hexsa and tetra cross-sectional shapes have caused lower crimp and high shrinkage. It was also observed that the increase in the linear density has caused a decrease in yarn tenacity, however this has increased the crimp and shrinkage behaviours of the yarns.