& lt2> Siro spinning is to feed two slivers with a certain distance into the spinning drafting area, and draw and twist them into yarn respectively. One strand of yarn breaks, and the other strand breaks away from the single yarn, resulting in wrong yarn when the spinning tension is stable. In order to ensure the spinning quality, Siro spinning needs to install a single yarn breaking device. After one yarn is broken, another single yarn can be broken.
The development company under the New Zealand Wool Research Institute is one of the first authorized directors of Siro spinning technology, which can produce single combed wool yarn and directly weave it into warp yarn without sizing or any post-finishing. It is always the goal of combed wool spinning industry to directly weave single-ply yarn without double-ply or protective coating. Siro spinning yarn significantly improves production efficiency and provides opportunities for wool to develop new products. The basis of this technology is a pair of additional rollers, which are installed on the drafting cradle of spinning frame together with a simple clamp. These patented rollers have a special groove surface, which changes the way in which fibers are twisted into draft yarns, without any influence on the routine operation. It can also be compatible with automatic doffing device. At first glance, the finished yarn is no different from the conventional yarn, but the wear test clearly shows its excellent quality. This process ensures that the fiber is firmly locked in the yarn structure and makes the yarn smoother, thus resisting the continuous friction and wear on the loom. However, single yarn weaving should not only consider product quality, but also consider production efficiency. First of all, the whole production process is greatly shortened because twisting and corresponding treatment are omitted.
Secondly, compared with the conventional yarn, the production of the same number of fabrics, because Siro spinning only needs to provide half the length of yarn, thus significantly improving the spinning productivity, and because the spinning count is twice that of the conventional yarn, the broken end rate is also significantly reduced. In the experimental stage of the single-yarn weaving plan, factories in Italy, Australia and New Zealand each installed a spinning frame to produce commercial batches of yarns, and then woven them into a series of fabrics. All reports reflect that the efficiency of spinning and weaving is satisfactory. There is no obvious difference in strength, elongation and uniformity between Sirospun and traditional two-ply yarn. After spinning, Sirospun will automatically undergo high-pressure sterilization, setting, winding, cleaning and splicing just like ordinary single yarn. Using Siro spinning technology to spin strands can save the process of doubling and twisting two strands and reduce the production cost. It feeds two rovings in parallel on the ring spinning machine, draws and outputs them in the front roller, and then twists the two rovings into yarn. The Indian Institute of Textile Science and Technology studied the technological parameters of Siro spinning with polyester-wool blending ratio of 55/45, and compared them with single yarn and double yarn with the same yarn count. In the carding and spinning process system, the blending ratio of 3d polyester and 22.5μm wool is 55/45, and the blending ratio of 2.2d polyester and 20μm wool is 55/45 to spin Nm20 Siro yarn. Five different whisker spacings and 75. The CV value, yarn defects, hairiness, single yarn strength and elongation at break, wear resistance and compression coefficient of yarns were compared. At the same time, it is compared with single yarn and double yarn with the same yarn count. The experimental results show that the properties of polyester-wool blended Siro yarn can be optimized by selecting process parameters. When the whisker spacing is 10mm, the CV value and abrasion resistance of the yarn are better, but the details will increase with the increase of the spacing. When the whisker spacing is 12mm, the strength and elongation at break are the largest. Yarn hairiness changes with the number of yarns. When the spacing increases to 10 mm, the long and short hairiness tends to decrease, and the sliver spacing has no effect on the compression coefficient of yarns. Generally, the greater the twist coefficient, the uneven yarn evenness, the lower the hairiness and compression coefficient, and the better the strength and wear resistance. Except CV value, yarn defects and elongation at break, other properties of Siro yarn are better than single yarn or double yarn with the same yarn count. In the structure of Siro spinning yarn, both the yarn and the single yarn have a certain twist, in fact, it is twisted twice in the process of yarn formation. Single strand and yarn have the effect of twisting in the same direction, which makes the yarn smooth in appearance, less hairiness and good wear resistance. Although it is single yarn, it has the function of strand, which can partially replace strand, reduce working procedures, reduce costs and increase economic benefits of enterprises. Compared with ordinary ring spinning, Siro spinning greatly reduces hairiness, which provides good conditions for weaving in the next process.
Because of feeding two rovings, the hanging spindles on the spinning frame need to be doubled, and the fixed weight of each roving is half lighter than that of the traditional single-yarn roving with the same spinning count. In addition, Siro spinning must have a cutting device. In the process of spinning, if one fiber bundle breaks, the other fiber bundle must be cut off in time, otherwise it will cause yarn defects. There are many articles on the size of roving spacing in Siro spinning, and the author thinks that roving spacing does have a great influence on spinning quality. BR> relationship, but it cannot have a fixed value. Why? Because the determination of roving spacing is also restricted by raw material conditions. Assuming that the roving spacing is set to 14 mm, if your raw material strength is poor, or if you have too many tops and the equipment is in poor condition, it will easily lead to uneven evenness and increased broken ends. On the contrary, if the opening is properly narrowed, the yarn evenness and the number of broken ends will be improved. On the contrary, after setting the roving spacing, the physical indexes of raw materials must be controlled to meet the spinning requirements. Siro spinning is generally equipped with interrupters, which are designed according to the roving spacing. When the yarn spacing becomes smaller, the yarn breakage may not be detected by the interrupter (no yarn breakage signal), so another fiber bundle cannot be interrupted, resulting in yarn defects of single yarn running.
This paper introduces the principle of Siro spinning technology, the realization method on cotton spinning frame, the spinning technology of Siro spinning pure cotton combed yarn, blended yarn and polyester-viscose composite yarn, and compares and analyzes the quality of Siro spinning and ring spinning. It is considered that the yarn hairiness, evenness and strength of Siro yarn are better than ring spun yarn, but the details are not as good as ring spun yarn.
The traditional ring spinning yarn has many hairiness, which not only affects the surface smoothness of the yarn itself and the utilization coefficient of fiber strength, but also affects the smooth processing of the next process. On the other hand, with the development of weaving technology, shuttleless looms require higher and higher yarn quality, and the hairiness problem is more prominent. In order to reduce yarn hairiness, measures can be taken in raw material selection, process optimization, equipment selection and operation management. At the same time, new spinning technologies can be applied, such as compact spinning technology and blowing and twisting device of winder. In addition, Siro spinning technology can also reduce yarn hairiness. The spinning principle was invented by CSIRO in Australia from 1975 to 1976. The original purpose is to reduce the hairiness of wool yarn. 1978, the international wool bureau put this scientific research achievement into practice, 1980, and formally recommended it to all countries in the world. Siro spinning is mainly used for pure spinning or blending of wool, wool polyester and acrylic fiber, and can also be used on cotton spinning frames. Siro spinning technology is very simple to implement in actual production, and the ring spinning frame can be slightly modified. The reformed spinning frame can not only spin siro yarn, but also restore to the original ordinary ring spinning frame at any time and conveniently according to the needs.
1 Siro spinning method:
Siro yarn can be used for weaving or knitting, and its process is to feed two rovings at a certain distance in parallel to the same drafting area of the spinning machine for drafting, and then twist and wind them on the same spindle. Specifically, the following aspects need to be reformed: (1) refitting roving frame, doubling roving hanging spindles, and refitting supporting spindles and hanging spindles is more convenient; (2) The transverse bell mouth in the original drafting mechanism is changed into binocular form; (3) the yarn guide traversing device is fixed at the central position or moves transversely in a small range; (4) Add a broken end self-stop device, which is used to prevent single yarn spinning, that is, when one roving is broken, in order to avoid yarn defects with long details, the other roving must be interrupted in time.
In recent years, the cotton spinning industry has also begun to refer to this spinning method. Generally, the yarns spun in cotton mills are mostly natural yarns. As long as the number of brackets of the car stopper is reduced, the expensive automatic stop device with broken ends can be omitted.
2 Siro spinning practice
2. 1 pure cotton combed products
CJ 14.5 tex siro yarn was spun by two different spinning processes on the modified spinning frame.
See table 1 4.5tex for the comparison between Siro spinning CJ 14.5 tex and ring spinning CJ 14.5 tex.
From the table 1, it can be seen that the evenness CV value, single yarn breaking strength and breaking elongation of Siro yarn are better than those of ring yarn, but there are many details. The evenness, detail, slub, Dan Qiang, elongation and other indexes of Siro yarn spun by Scheme 1 are better than those of Scheme 2, and the comprehensive performance is the best. According to Huste Bulletin 200 1, the evenness, slub and nep of Scheme I are all equivalent to 5% ~ 25%, and the details are equivalent to 25% ~ 50%.
2.2 Mixed products
Under the same conditions, T/CJ 65/T/CJ 65/3513.1tex siro yarn and ordinary ring spun yarn were spun. Siro spinning process is as follows: roving count is 330tex, draft multiple (front× back) is 39.6×1.25 times, and twist is 34.5 twist/m; The rotating speed of front roller of spinning frame is 229 r/min, and the rotating speed of spindle is 17278 r/min. The yarn quality comparison is shown in Table 2.
Compared with ring-spun yarn with the same fineness, Siro yarn has high Dan Qiang, small CV value of 100 meter weight, less hairiness, basically the same evenness, more details and the same number of slubs and neps.
2.3 composite yarn
When two kinds of roving are fed with different raw materials, the spun yarn is composite yarn, also called AB yarn. T/R55/45 18.5 tex composite yarn was spun by Siro spinning technology. The spinning process is as follows: polyester roving basis weight 3.9g/ 10m, viscose roving basis weight 3.2g/ 10m, spinning twist coefficient 3 14, roller gauge 19mm×. The yarn quality is: evenness CV 13.46%%, details 5 /km, slubs 46 /km, neps 59 /km, unit strength 23.3 CN/tex, unit strength CV value 5.72%, elongation at break 10.86% and elongation at break CV5.09%%.
It can be seen that the quality index of Sirospun composite yarn is ideal.
3 Conclusion
The quality of Siro yarn is better, especially the yarn hairiness, evenness and strength index are better than ring spun yarn, which can meet the requirements of weaving and knitting yarns. The disadvantage of Siro yarn is that there are too many details, mainly because the meeting point of two yarns output from the front jaw fluctuates up and down during spinning, which causes the twist size of one yarn to change from the meeting point to the front jaw, and too many details are caused by small twist and big draft error. At the same time, Siro spinning requires large spinning draft and small roving weight, which affects economic benefits and needs further improvement.