Study on Spinning triangles in the common ring spinning and Super draft ring spinning systems

In the paper, one kind of super draft ring spinning frame with four drafting rollers and corresponding three drafting zones were introduced. The yarn qualities spun by the super draft ring spinning frame were analyzed by studying the shape of spinning triangles. Using the high speed camera system OLYMPUS i-speed3 and one kind of transparent front top roller, the spinning triangles were captured, and the geometry size of spinning triangle were measured. Then, according to the theoretical model of fiber tension in the spinning triangle, fiber tension distributions in the spinning triangles were presented by using Matlab software. Using the combed roving of 350 tex as raw material, three kinds of cotton yarns, 27.8 tex (21^S), 18.2 tex (32^S) and 14.6 tex (40^S), were spun in the common ring spinning frame with three different suitable spindle speeds, travelers and twist factors. Using the combed roving of 350 tex and 500 tex as raw material, 14.6 tex cotton yarns were spun in the super draft ring spinning frame with three different drafting ratios at back zone. It is shown that with the increasing of spindle speed, a more asymmetric shape of spinning triangle would be produced, and lead to worsen yarn evenness. With the decreasing of traveler weight, the height and horizontal deviation of the spinning triangle is decreased, and may lead to better yarn evenness and less long hairiness. By taking suitable large yarn twist factors, the comprehensive qualities can be improved. Comparing with the common ring spinning, the spinning triangle is larger in the super draft ring spinning. That is, in the super draft ring spinning, the fibers in the strand in the front roller nip are more dispersed, and not benefit for yarn qualities. Therefore, the compact device was introduced into the super draft ring spinning, and the cotton pure yarns and blend yarns were spun, and the yarn qualities were measured and analyzed.     

Prediction of strength and weavability of blended spun yarns

In this paper, we report on predicting the strength of polyester/viscose spun yarns made on ring, rotor and air-jet spinning systems. A system has been developed to measure the weavability of yarns. Hamburger’s fibre bundle theory is modified to predict the strength of blended yarns from the strengths of single-fibre component yarns. The modified model predicts blended yarn strength more accurately than the original Hamburger’s model emphasizing the importance of yarn structure on blended yarn strength. The weavability of blended yarns is measured on a CTT instrument incorporating a shedding device which addresses the stresses viz., cycle extension, flex abrasion and beat up occur during weaving. The measured weavability compared well with that obtained on a commercial Sulzer Ruti Reutlingen Webtester. Yarn structure and strength and cohesion of fibres affect the strength and weavability of yarns.     

Effect of bio-friendly conditioning agents on jute fibre spinning

From early times, jute fibre has been generally conditioned for easy spinning by adding oil and water in the form of an emulsion. The commonly used oil consists of C₁₂–C₃₁ fractions of mineral oil that sometimes impart different intensities of oily (kerosene) or fishy smell to the end product. In the present work, efforts have been made to find a suitable sustainable substitute of mineral oil based conditioning agent for spinning of jute yarn and for this, three types of vegetable oil (rice bran oil, palmolein oil and castor oil), a silicone emulsion, a mixed enzyme system and glycerine have been used separately or in combinations as conditioning agents for jute fibre before its mechanical processing for making yarn in jute spinning machines. Considering comparable mechanical process performance for spinning of jute fibre (viz., fibre loss as droppings during processing, moisture retention prior to spinning stage and spinning end breakage rate), tensile properties of yarn, and lower yarn hairiness, it may be suggested to use 2.5% castor oil alone, or 2% castor oil in combination with 0.1–0.5% glycerine in the form of oil-in-water emulsion as the most suitable alternatives to conventional mineral oil-based jute conditioning agent to spin ordinary jute yarn.     

Jute yarn as reinforcement for polypropylene based commingled eco-composites: Effect of fibre content and chemical modifications on accelerated ageing and tear properties

Bidirectional PP/jute yarn eco-composites were fabricated via environment friendly commingling technique and its long term durability/life time was monitored as an effect of accelerated solar ageing on its mechanical properties (tensile & flexural). Accelerated solar ageing promoted the thermal oxidation of PP thus resulting in deterioration of its properties, however; MAPP and KMnO₄ treated commingled composites showed much better stability towards thermal oxidation brought about by the solar concentrator, compared to untreated sample and neat polypropylene. This increased resistivity of treated composites (especially MAPP and KMnO₄) towards thermal oxidation brought about by the solar concentrator is due to the increased interfacial adhesion between the matrix and jute yarn owing to chemical modifications. The significance of effective stress transfer between the PP matrix and reinforcing jute yarns is evident from the increased tear resistance of PP/jute yarn commingled composites with increasing fibre content and also with different chemical treatments.     

Optimum drafting conditions of bamboo charcoal-modified fiber blended yarn obtained by drafting behavior analysis

In this work, the effect of optimum drafting condition on the drafting behavior and yarn quality of the bamboo charcoal-modified fiber blended spun yarns were studied. We measured the drafting force and drafting force variance, CV% of the bamboo charcoal-modified Polyester/Cotton (BCP/C) blended roving and bamboo charcoal-modified Rayon/Cotton (BCR/C) blended roving to examine the influence of the roller gauge and drafting ratio on drafting behavior and yarn quality. We understand that the drafting force of the bamboo charcoal-modified fiber blended roving follow the same trend as that for the regular P/C and R/C blend roving. However, the drafting force presents some difference in characteristics between these bamboo charcoal-modified fiber blended rovings. To correlate the drafting force variation, CV% and the bamboo charcoal-modified fiber blended spun yarn properties, we evaluated the yarn quality and investigate the yarn quality index in conjunction with the break drafting ratio. Therefore, in this work, we can obtain the best optimum drafting conditions for bamboo charcoal-modified fiber blended spun yarns; for the 19.7 tex of BCP70/C30 blend spun yarn was under the roller gauge of 54 mm at the draft ratio of 1.3, whereas, for the 19.7 tex of BCR40/C60 blend spun yarn was under the roller gauge of 54 mm at the draft ratio of 1.2.     

Spinning performance and antibacterial activity of SeaCell® active/cotton blended rotor yarns

Microorganisms can lead to functional, hygienic and aesthetic (e.g. deterioration, staining) problems on textile products. Natural fibers especially cotton are more easily affected by microorganisms. Blending of cotton fibers with antimicrobial fibers can enhance the protective properties of products against microorganisms. Demand of antimicrobial performance from the products changes depending on the application area. Therefore determination of suitable antimicrobial fiber quantity for the desired application is important. In this study the spinning performance of SeaCell Active/cotton blended open end rotor yarns and antibacterial activities of fabrics produced by these blended yarns were investigated. Five different cotton/SeaCell Active blended slivers with SeaCell Active content from 3 % up to 53 % were prepared on drawframe machine and all slivers were spun into yarns on open end rotor spinning machine at a yarn count of 20 tex with α_Tt=3827 twist coefficient. The effects of rotor speed, opening roller speed, rotor, opening roller and navel type on the quality parameters of SeaCell Active/cotton blended yarns were investigated. Tensile properties, hairiness, unevenness and IPI values of the yarns were reported. All types of cotton/SeaCell Active blended yarns were knitted on a circular knitting machine. Antibacterial activity of the fabrics was analyzed quantitatively. Antibacterial tests showed that good antibacterial activity can be achieved after several washings even with 3 % of SeaCell Active fibers in fabrics.     

Leveraging the Antibacterial Properties of Knitted Fabrics by Admixture of Polyester-Silver Nanocomposite Fibres

Leveraging the antibacterial properties of polyester-cotton knitted fabrics has been attempted in this research by admixture of small proportion of polyester-silver nanocomposite fibres. Polyester-cotton (50:50) yarns were spun by mixing 10, 20 and 30 % (wt.%) polyester-silver nanocomposite fibres with normal polyester fibres so that overall proportion of polyester fibre becomes 50 %. The proportion of cotton fibre was constant (50 %) in all the yarns. Three parameters, namely blend proportion (wt.%) of nanocomposite fibres, yarn count and knitting machine gauge were varied, each at three levels, for producing 27 knitted fabrics. Polyester-cotton knitted fabrics prepared from polyester-silver nanocomposite fibres showed equally good antibacterial activity (65-99 %) against both S. aureus and E. coli bacteria. Antibacterial properties were enhanced with the increase in the proportion of polyester-silver nanocomposite fibres, yarn coarseness and increased compactness of knitted fabrics. Yarn count and blend proportion of nanocomposite fibre were found to have very dominant influence in determining the antibacterial properties of knitted fabrics.     

A study on siro-jet spinning system

Nowadays, there is ever increasing interests regarding with the nozzle usage in spinning systems and also winding process. In this study, an air nozzle was attached on to the sirospun spinning system and the system was called as siro-jet. Sirospun is a spinning system combining spinning and doubling in one operation and a yarn like a two fold is produced. The principle of the siro-jet system is based on the placement of the nozzle at the exit of drafting unit on sirospun spinning system and pressurized air was fed into the nozzle by the compressor during the spinning. In literature, air nozzle application in this manner is not common and hence the system is very less known. For that reason, siro-jet and siropun yarns were produced with different fibre types, material qualities and yarn counts, and the properties of the yarns were compared. At the end of the study, it was determined that siro-jet spinning system truly improves the yarn hairiness in comparison to sirospun spinning system. Even, the siro-jet yarns are less hairy after winding process. Interestingly, hairiness results of siro-jet and sirospun yarns produced with short, non-uniform fibres showed that siro-jet spinning system allows working with low cost raw materials while maintaining yarn quality. Therefore, siro-jet can be considered as an innovative spinning system regarding with less hairy yarn production opportunity.     

The mechanism and/or prediction of the breaking elongation of polyester/viscose blended open-end rotor spun yarns

In this study, an analysis on the breaking elongation mechanism of the polyester/viscose blended open-end rotor spun yarns has been carried out. In addition, a back propagation multi layer perceptron (MLP) network and a mixture process crossed regression model with two mixture components (polyester and viscose blend ratios) and two process variables (yarn count and rotor speed) are developed to predict the breaking elongation of polyester/viscose blended open-end rotor spun yarns. Seven different blend ratios of polyester/viscose slivers are produced and these slivers are manufactured with four different rotor speed and four different yarn counts in rotor spinning machine. In conclusion, ANN and statistical model both have given satisfactory predictions; however, the predictions of ANN gave relatively more reliable results than those of statistical models. Since the prediction capacity of statistical models is also obtained as satisfactory, it can also be used for breaking elongation (%) prediction of yarns because of its simplicity and non-complex structure. In addition, it is also found in this study that yarn count, rotor speed and breaking elongation of polyester-viscose fibers and the blend ratios of these fibers in the yarn have major effects on yarn breaking elongation.     

Evaluation of flax accessions for high value textile end uses

Due to recent changes in EC subsidies for flax cultivation it has been difficult to grow short fibre flax profitably in the UK. The Texflax project aimed to demonstrate that high quality flax fibre can be produced and processed on short fibre cotton spinning systems. Initially 92 flax accessions were cultivated on test sites in the UK over three growing seasons to explore the range of fibre diameter found in fibre flax. The efficacy of applying a translocating herbicide at different stages of plant maturity for optimum fine fibre production was explored. A range of factors indicated that application at the midpoint of flowering stage is favourable for the desiccation of flax and onset of retting. Fibre was caustic extracted using a laboratory method developed at De Montfort University, and fibre evaluated in terms of diameter, length, consistency and cleanliness. At the end of the project five accessions from the original 92 were chosen as producing optimal quality fibre suitable for high value textile end uses. Improved agronomy and subsequent processing enabled yarns with a 50:50 cotton:flax blend to be spun at 26 N m yarn count, the normal blend ratio for this count being 70:30. The yarn properties show an improvement when compared to standard products and finer quality fabrics have been prepared using the yarns.     

黄麻与棉转杯混纺纱的纺制

本文对黄麻／棉混纺纱的生产工艺作了初步的探索，利用经过脱胶后的精细化黄麻纤维，通过对纺纱加工工艺与设备的选择、调整，纺制成了黄麻／棉55／45的转杯混纺纱.结果表明，黄麻纤维在脱胶精细化处理后，是可以加工成应用领域更广泛的产品的.     

Compression properties of weft knitted fabrics consisting of shrinkable and non-shrinkable acrylic fibers

High-bulk worsted yarns with different shrinkable and non-shrinkable acrylic fibers blend ratios are produced and then single jersey weft knitted fabrics with three different structures and loop lengths are constructed. The physical properties of produced yarns and compression properties of produced fabrics at eight pressure values (50, 100, 200, 500, 1000, 1500 and 2000 g/cm²) were measured using a conventional fabric thickness tester. Then, weft-knitted fabric compression behavior was analyzed using a two parameters model. It is found that at 40% shrinkable fibre blending ratio the maximum yarn bulk, shrinkage, abrasion resistance and minimum yarn strength are obtained. It is also shown that high-bulk acrylic yarn has the highest elongation at 20% shrinkable fibre blend ratio. The statistical regression analysis revealed that the compression behavior of acrylic weft-knitted fabrics is highly closed to two parameter model proposed for woven fabrics. It is also shown that for weft-knitted structure, there is an incompressible layer (V′) which resists against high compression load. Acrylic weft-knitted fabrics with knit-tuck structure exhibit higher compression rigidity and lower softness than the plain and knitmiss structures. In addition, at 20% shrinkable fibre blend ratio, the high-bulk acrylic weft-knitted fabrics are highly compressible.     

Structural analysis of finer cotton yarns produced by conventional and modified ring spinning system

Yarn structure plays an important role in determining the properties of spun yarns. Recently, a modified spinning technique has been developed for producing a low torque and soft handle singles yarn by modifying the fiber arrangement in a yarn. Comparative studies revealed that the finer modified yarns possess significantly higher strength and lower hairiness over the conventional yarns of the same twist level, implying a different structure of finer modified yarn. Thus this paper aims to quantitatively study the structures of the finer conventional and modified cotton yarn (80 Ne) produced at the same twist level. Various measuring techniques, namely the Scanning Electron Microscope (SEM), cross section technique and tracer fiber technique, are adopted to analyze their structural characteristics, including fiber configuration, fiber spatial orientation angle, fiber packing density, yarn surface appearance, and fiber migration behavior. Results showed that finer modified yarns exhibit a smoother surface and much more compact structure with less hairiness. The fibers in the finer modified yarn have a complicated fiber path with relatively lower fiber radial position, larger migration frequency and magnitudes. In addition, it was noted that 73% of fibers in the finer conventional yarn follow concentric conical helix, which is contrary to those in the coarser conventional yarn. The analyses conducted in this paper provide deep insights into the mechanism of modified spinning technique and evidential explanations on the difference of properties between the finer conventional and modified yarns.     

Predicting the unevenness of polyester/viscose blended open-end rotor spun yarns using artificial neural network and statistical models

In this study, an artificial neural network (ANN) and a statistical model are developed to predict the unevenness of polyester/viscose blended open-end rotor spun yarns. Seven different blend ratios of polyester/viscose slivers are produced and these slivers are manufactured with four different rotor speed and four different yarn counts in rotor spinning machine. A back propagation multi layer perceptron (MLP) network and a mixture process crossed regression model (simplex lattice design) with two mixture components (polyester and viscose blend ratios) and two process variables (yarn count and rotor speed) are developed to predict the unevenness of polyester/viscose blended open-end rotor spun yarns. Both ANN and simplex lattice design have given satisfactory predictions, however, the predictions of statistical models gave more reliable results than ANN.     

混纺麻纱特征的实用图像表征技术——I.截面图像生成与特征指标

混纺织物的纤维组成和混纺比早在成纱时就已确定,其预先判定极为必要。本文探讨图像技术测量麻/涤混纺纱混合比的快速算法及其实用指标。该表征从麻/涤纱的有效切片、纱线截面摄像、图像小波分析去噪开始,到采用形态滤波法,解决图像局部灰度不均匀;使用分水岭法,分开粘连纤维和减少无效分割,实现图像的采集和预处理。实验结果证明,切片采样和小波除噪可达清晰采像要求;图像预处理可有效提高图像质量和分析精度。由此对纤维截面几何特征分析,得出主要特征参数为纤维当量截面积、异形系数和中腔纹。并依此参数及其组合完成对苎麻和涤纶纤维的自动识别,准确率达99.5%.     

Comparative study on the effect of blend ratio on tensile properties of ring and rotor cotton-polyester blended yarns using concept of the hybrid effect

Study on the characteristics of blended ring and rotor spun yarns is a topic of major interest to the researchers. The overall properties of these blended yarns are affected by the relative proportion, properties of the components and their interactions. The main focus of this work is on comparing and analyzing effects of blend ratio on tensile properties of the yarns produced in different spinning systems using concept of hybrid effects that has not received enough attention from researchers. Various blends of cotton-polyester ring and rotor spun yarns were prepared. Tensile properties of the samples were examined as well. Interactions between cotton and polyester fibers was evaluated through predicting strength and elongation at break of the yarns using simple rule of mixtures (ROM) and hybrid model. Experimental results showed that, the effect of different blend ratios on tensile properties of the samples is different. In comparison with 100 % cotton yarn, promotion in braking strength of the ring and rotor spun samples occurred after increasing fraction of the polyester fiber to 50 and 66.5 % respectively. The prominent finding of the present work is that the trend of change in tensile properties of different yarns versus blend ratio is predictable via hybrid model and migration behavior of the constituent fibers. Coefficients representing the intensity of the interaction and migration index of the fibers were calculated and all results were discussed based on these calculated factors.     

The effect of spinning parameters on mechanical and physical properties of core-spun yarns produced by the three-strand modified method (TSMM)

The effect of spinning parameters on core-spun yarns properties manufactured using three-strand modified method (TSMM) was analyzed. Of the various spinning parameters, strand spacing, yarn linear density and yarn twist have a crucial effect on core-spun yarn properties. To achieve the objectives of this research, general physical properties of core-spun yarns together with existing standards were thoroughly studied. First of all, the strand spacing and yarn linear density were optimized. Afterwards, the effects of variation of yarn twist and sheath roving linear density on core-spun yarns properties were investigated. Finally, the physical and mechanical properties of TSMM yarns were compared with those of siro and conventional ring core-spun yarns counterparts. It was found that, the best strand spacing and yarn linear density to produce core-spun yarns are 8 mm and 45 tex, respectively. Results showed that, tenacity of TSMM yarns increases up to a certain twist level beyond which it reduces. The result confirmed that 45 tex yarns produced by three rovings of the same count are superior with regards to tenacity and hairiness. The optimized yarns produced by three-strand modified method enjoy superior physical and mechanical properties in comparison to the ring and siro core-spun yarns.     

Study on the packing density of structurally modified ring spun yarn

Fibres being the structural unit of a yarn, its nature, composition and arrangement can influence structure and properties. The performance of yarn changes with arrangement of its constituent fibres. Arrangement of fibres in a yarn being system specific, different spinning system results different arrangement of fibres causing variation in product performance. A change in the arrangement of fibres in an already formed yarn can be brought about by suitable physical and/or chemical treatment. A treatment to remove a component is expected to cause changes in final arrangement of fibres in a yarn. In the present study, polyester/PVA blended yarn was modified through dissolution of the later component. The resultant change in structural arrangement on dissolution was assessed by the change in radial packing distribution of fibres. Migration index, helped in identifying the location that was influenced more in the redistribution. In the parent yarn, PVA had a preferential tendency to predominate near the core. On dissolution of PVA, creation of open space was expected and collapsing of the structure led to a possible rearrangement of fibres and reduction in diameter of yarn. Fibre denier, blend ratio and twist factor were also found to influence packing density both in parent and modified yarn. Unlike published reports, interestingly, an increase in fibre packing density was observed on dissolution of PVA. Average packing density in parent yarn was found to lie at a yarn radius between 0.07 mm to 0.09 mm while for the modified yarn it was between 0.05 mm to 0.07 mm.     

Physical and chemical properties of flax fibres from stand-retted crops desiccated at different stages of maturity

Dessication of flax at the mid-point of flowering, followed by stand-retting and high-speed decortication, yielded finer, stronger fibres with lower acid-insoluble lignin content and lighter colour than desiccation at later timings of two weeks after mid-flower and six weeks after mid-flower. Although fibres from all desiccation timings could be carded and blended with wool for spinning on woollen or worsted spinning systems, only the fine fibre from the earliest desiccated flax was suitable for carding, drawing, blending with cotton and spinning on cotton-processing systems.It was concluded that the lower lignin content at mid-flower allowed more complete retting of fibre bundles to give a higher yield of fine elementary fibres. This cotton-compatible fibre was produced at a competitive cost compared with cotton. It is suggested that further optimisation of desiccation timing may permit increased yields of cotton-compatible fibre.     

Study on the static and dynamic strengths and weavability of spun yarns

This study reports on the analysis of tenacity and breaking elongation of ring-, rotor- and air-jet-polyester/viscose spun yarns measured using static- and dynamic tensile testers. The weavability, a measure of performance of these yarns in post spinning operations is quantified. The yarn diameters and helix angles of fibres in these yarns are measured in order to analyze the effect of types of spun yarn and blend proportion on yarn elongations. The dynamic tenacity is highly correlated with the weavability than the average static tenacity measured at 500 mm gauge length. The minimum static tenacity obtained from 100 tests has high correlation with the dynamic tenacity. The present study indicates that it is appropriate to evaluate the performance of spun yarns in winding, warping and weaving based on the dynamic yarn tenacity measured while running a 200 m length of yarn in a constant tension transport tester or the minimum static yarn tenacity obtained using any conventional constant rate extension (CRE) tensile testers corresponding to a total test length of 50 m.