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Analysis of the Breaking Characteristics of Twisted Yarns
Abstract and Figures
In many cases single yarns do not fulfill the requirements necessary for the production of certain types of textiles. At the same time, they do not have most of the characteristics that are important for textile production with outstanding quality parameters. Therefore, the twisting process is employed to produce twisted yarns which can be used to produce fabrics for various applications. The breaking properties of twisted yarn depend on the strength of the component yarns, the number of strands, the twisting amount, the friction forces between the yarns, as well as on the twisting method used. The use of known parameters of twisted yarns determines the relations defining their breaking force. The breaking force is here defined as a function of the breaking forces of the component yarns, the number of yarns twisted in the yarn, and their angle to the twisted yarn axis. In addition, based on experimental results and the theorethical equations, real mathematical relations were established which can serve to project the breaking forces of ring and rotor twisted yarns obtained by the method of double layer twisting. This will simplify and improve the technical preparation of the weaving process. twisted yarn type. Special attention was given to the projecting of the breaking forces of twisted ring spun yarns, twisted rotor spun yarns and twisted yarns made of one rotor spun and one ring spun yarn. By combining one ring spun and one ro-tor spun yarn, an attempt was made to take advantage of the positive properties of two component yarns.
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... Yarns with linear masses ranging from 20 tex to 50 tex were produced on the ring spinning frame. The thicker yarns used in the research were obtained by joining and twisting finer yarns on a laboratory double-twisting machine [26]. ...
Warping is a crucial process that connects two main stages of production: yarn manufacturing and fabric creation. Two interrelated parameters affect the efficiency of this technological process: warping speed and the ability to swiftly detect the yarn breaks caused by various defects. The faster a break is detected and the warping machine stopped, the higher the machine’s working speed can be. Since the beginning of such devices, various types of yarn break detectors have been proposed, primarily based on different mechanical solutions. To enhance the break detection process, a solution involving the use of an accelerometer to measure yarn vibrations and thereby detect whether the moving yarn has broken is proposed. Based on the detection of a threshold value of 22 m/s², the warping machine could be stopped within 2.752 to 2.808 ms, which is 50 times faster than in the traditional mechanical detectors under investigation. Furthermore, through a precise analysis of yarn vibration patterns, it became possible to determine the distance from the sensor at which the break occurred. This analysis was conducted using the proprietary MRSCEK coefficient, which aggregates data obtained from six standard coefficients: mean, root mean square, standard deviation, crest factor, energy, and kurtosis. This information could potentially lead to the development of automated systems for removing breaks without human intervention in the future. Research efforts focused on analyzing the vibration signals received from yarns made with different linear densities. The results showed that such a system could effectively replace commonly used mechanical yarn break detectors and operate much faster.
... The use of twisted yarn for the weft generally gave the best results in terms of the breaking characteristics of the fabrics when tensioning in the diagonal direction. Single yarn (50 tex), whose linear density corresponds to the twisted yarn (25 x 2 tex) has a higher breaking elongation compared to the twisted yarn, but even in this case, the breaking elongation of the fabric in the weft direction with twisted yarn applied is generally the highest, other things being equal parameters, which is the result of the good characteristics of twisted yarns [12]. ...
Deformations of woven materials occur in the process of forming fabrics into more complex textile structures, as well as during the exploitation of finished products. Several factors influence the deformation properties of textile materials. The key factors are the properties of the yarn used, the construction of the fabric and the density of the warp and weft threads. The anisotropic properties of woven materials impose the need to analyze the deformation in the direction of the warp and in the direction of the weft of fabric. In addition, the research includes the analysis of the deformation of woven materials at an angle of 45 ° in relation to the direction of the warp. The results of the research showed that increasing the density of the weft threads leads to an improvement in the characteristics at the limit of yielding and breaking in the direction of the weft and at an angle of 45 °. Based on the obtained results, dependencies were proposed that can be used to predict the deformation of woven textile materials in a plain weave using tensile force in the direction of the warp, in the direction of the weft and at an angle of 45 °.
When the yarn, which is the main raw material of the textile industry, is produced as a single ply, some of its physical properties may be limited. In addition, in parallel with the changing and developing final product properties, extra physical properties are required from single ply yarns. As a result, folding and twisting processes have become a method used to improve the physical properties of the yarn. The most used twisting method today is the two-for-one twisting method. Although little known, the Hamel twist (elasto-twist) method is another method that is being used. In this study, Ne 70/2 yarn with five different twist values was produced in the Hamel twist system. Uster, CV, thick place, thin place, neps, strength and hairiness values of the produced yarn samples were determined and the obtained data were evaluated. The findings showed that the quality parameters examined under the effect of twisting improved on all sample groups and that the twist level had a significant effect on the quality parameters in this system.
The effects of ply and single twists on tensile, hairiness and abrasion resistance properties of two-ply yarns with three different yam counts were investigated. Tensile test results showed that the effect of ply twist on breaking strength properties of ply yarns was similar to the effect of the twist on the breaking strength of single yarns. Increases in single twist caused decreases in the strength of ply yarns. Increases in both single and ply twists caused increases in the breaking elongation of ply yarns. Single and ply twists affected the hairiness properties of ply yarns and hairiness values decreased as twist levels increased. Ply twist was more effective on hairiness properties than single twist. Abrasion resistance increased both in fine and coarse yarns as ply twist increased. Any important effect of single twist was not observed on abrasion resistance in fine ply yarn while abrasion resistance increased in coarse yams in the case of low single twist level.
Bursting strength, pilling and abrasion properties of knitted fabrics, which were produced from six different direct two-ply yarns, were researched. The yarns were spun from two different raw materials by using three different spinning systems. Bursting strength values of knitted fabrics, which were produced from both Suessen compact siro and Pinter compact siro yarns, were considerably higher than the ones produced from conventional Siro-spun yarns. However, the differences between bursting strength values were not found statistically significant. Pilling test results showed that fabric samples knitted from two-ply compact yarns had lower pilling tendency than the ones which were knitted from conventional Siro-spun yarns. Abrasion resistance of fabric samples knitted from compact sirospun yarns was higher in terms of both cycle of first yarn breakage and percentage weight loss. However, the most important differences between yarns of different spinning systems were obtained in tests which concerned weight loss. According to this, statistically significant differences were obtained between fabric samples which were knitted with conventional sirospun yarns of 20.5µm wool fibres and with two-ply compact spinning systems after 15000 abrasion cycles.
In the twisting process yarn was exposed to various influences that caused various tensions in various sectors. All that influenced the resulting tension with which yarn was twisted onto the bobbin. Yarn tensions were defined under various twisting conditions. Afterwards, poly-cyclic mechanicalproperties of these yarns were examined. Fastness of twisted yarns to poly-cyclic extensions was examined by the method of repeated extensions to the constant elongation, on INSTRON-tester. Elongation of 4 %, corresponding to the warp elongation on the loom, was taken. As experimental material, worsted wool yarn spun from T-63 wool fibres was chosen.
An analysis of models (presented in available world literature) for the twist of multi-folded threads consisting of two component fibre streams (doubled thread, doubled yarn) is discussed. The possibility of forecasting the twist value of the component streams for an accepted twist value of the multi-folded thread is considered. 2003
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