With the development of science and technology and the progress of society, the requirements of humans on textiles are constantly increasing, so the requirements for yarn quality have also raised higher standards. The development of human spinning technology has experienced a long process. The emergence of ring spinning methods has advanced the spinning technology to a new stage. However, due to the limitation of the spinning mechanism, the spinning speed of ring spinning It is difficult to further increase the production volume significantly, and there are still many unreasonable aspects in the process of ring spinning. Therefore, it has become one of the people's efforts to develop new spinning principles, study new spinning methods to improve spinning output, quality and develop new yarn varieties.

The development of new spinning technology has never stopped. Since the 1950s, rotor spinning, air-jet spinning, electrostatic spinning, friction spinning, parallel spinning, eddy current, which have a completely different spinning mechanism from ring spinning, have emerged. New spinning technologies such as spinning and self-twisting. In recent years, air-jet vortex spinning (MVS) has emerged. The emergence of these new spinning methods and technologies has broken through the traditional spinning mechanism, making it possible to increase the spinning speed and increase the package. The labor productivity has been greatly improved, and the variety of colors has been greatly increased, thus effectively promoting the development of spinning technology.

Various types of spinning methods

Different new spinning methods have different spinning mechanism and yarn forming mechanism (mainly twisting characteristics), and their yarn forming structure, yarn forming performance and further application are also quite different. It can be divided into two major categories: new non-ring twisting spinning technology (free end spinning method, non-free end spinning method) and new spinning method based on ring spinning (spindle twisting).

For non-free end spinning, such as air-jet spinning, self-twist spinning, etc., the fiber strands are completely continuous during the spinning process. Therefore, the feeding of the fiber is usually completed by a roller drawing device similar to ring spinning. The roller has a strong control of the fiber during the drawing process, so that the fiber arrangement is more straight and parallel. Yarn quality provides a guarantee. In addition, in the non-free end spinning, when the fiber is twisted, both ends are mechanically controlled, so that the tightness of the formed yarn is high, and the fiber is straightened and parallel during the forming process.

For free-end spinning, such as rotor spinning, friction spinning, electrostatic spinning, etc., because the fiber is formed by true twisting, it is necessary to ensure that a break point (free end) is generated during the fiber transportation process. To meet the requirements of true twisting. The continuous fiber bundle is usually broken before twisting, usually in its axial direction. Carding rollers are often used to decompose the fibers to ensure the separation of the fibers to form the free end. The free-end spinning method has a greater influence on the yarn strength.

For the new spinning technology based on ring twisting, the yarn spinning mechanism of ring spinning is used. By changing the spinning machine mechanism, feeding method and strengthening the control of the fiber in the triangle area, the ring spinning technology is optimized to make the yarn The performance is greatly improved, or the yarn is given a new structure, so that the fabric has a new style. This type of spinning technology mainly includes compact spinning, covering spinning, core-spun spinning, siro spinning, sirofil spinning, solo spinning, low torque spinning, agglomerated spinning, etc.

Different methods have different characteristics

Different spinning methods have different spinning mechanisms and different spinner structures, as well as different fiber suitability and different yarn forming structures and properties.

Rotor spinning: Generally speaking, the rotor yarn is divided into three layers: the central area is relatively tight; the outer layer is loose; the surface is also wrapped with some entangled fibers. In addition to a few typical helical shapes, most of the fiber shapes in rotor yarns are in complex shapes such as hook, roll, and twist.

The determination of the suitable fiber for rotor spinning mainly considers the fiber length. The fiber length should be suitable for the rotor diameter. When the length is appropriate, the spinnable fibers include cotton, wool, silk, hemp, chemical fiber and blended fiber. All kinds of recycled flowers, scraps, and even waste textile materials can be used, but if the fibers are too short, the cooperation between the fibers is poor, and the quality of the yarn will be reduced.

Air-jet spinning: Air-jet yarn is a typical wrapping structure, that is, the center is a core fiber with no or less twist, and the surface is wrapped (bundled) fiber. This structure and spinning process require a certain length of fiber, so spinning T / C, pure polyester, etc. have always been suitable raw materials for spinning, and cannot spin pure cotton. In recent years, various cotton-type cellulose fibers have been Widely used in air-jet spinning, it has become its most suitable fiber, such as viscose, modal, etc. The main reason is that in addition to the appropriate length, these fibers are generally soft and finished, which just improves the defects of the air-jet yarn and its products. Cellulose fiber represented by viscose has become the most suitable fiber for air-jet spinning.

Air-jet vortex spinning: Air-jet vortex spinning is to complete decomposition, condensation, stripping, twisting and other functions by air flow, and has obvious characteristics of free-end spinning. The formation of the free end of the tail is the basis for yarn formation. The air-jet vortex yarn is composed of part of the core fiber and the outer layer of twisted fiber. The outer layer of fiber has obvious spiral twisting characteristics, which is different from the wrapping characteristics of air-jet package spinning.

The fiber of air-jet vortex spinning is more twisted, and it can spin short fibers such as pure cotton, but practice has proved that the effect of spinning pure cotton is still not as good as that of spinning chemical fiber and its blending. The latest research shows that the optimal fiber length of air-jet vortex spinning is about 32mm.

Friction spinning: Due to the fact that there is a large angle of change in the direction of friction spinning, the fiber straightening is greatly affected. Therefore, the shape of the fiber in the yarn is more disordered, folded and rolled Irregular fibers with entanglement and hooks account for 70% to 80% of the yarn, and less than 10% of the fibers have no defects at the head and end of the spiral. Friction spinning has a wide range of suitable fibers, and the fiber length is between 10mm and 150mm, which can be cotton, wool, silk, hemp, chemical fiber, etc. It is the spinning method with the largest suitable spinning length range.

Self-twisted spinning: Self-twisted yarn is double-stranded, and it can be used for weaving only after adding twist on the twister or double-twisting machine to self-twisted yarn; the twist unevenness of self-twisted yarn is not The uniformity rate is 3% ~ 4%, the strength is 15% ~ 20% lower, the strength unevenness rate is 2% ~ 3%, and the elongation at break is also high. Suitable fibers need a certain length, generally wool (above 60mm), medium-length chemical fiber (above 65 ~ 76mm), expanded acrylic (above 80mm).

Vortex spinning (traditional): It is worth pointing out that traditional vortex spinning and air jet vortex spinning are two different spinning methods, which are completely free-end spinning. The fibers of the vortex yarn are very disordered, and there are a large number of closed surface fibers, which is why it is suitable for raising fabrics. Limited by the diameter of the vortex tube (14mm ~ 16mm), vortex spinning can only spin cotton fibers, including cotton, chemical fiber, etc., and some short (velvet) fibers, acrylic fibers (pile fabrics), etc. have good results.

New technology has obvious advantages

The new spinning technology based on ring twisting utilizes the spinning mechanism of ring spinning. By changing the spinning machine mechanism, feeding method and strengthening the control of the fiber in the triangle area, the ring spinning technology is optimized to greatly improve the yarn performance. Improve, or give the yarn a new structure, so that the fabric has a new style. This type of spinning technology mainly includes compact spinning, covering spinning, core-spun spinning, siro spinning, sirofil spinning, solo spinning, low-torque spinning, agglomerated spinning, etc.

In compact spinning, a control element is added to the front roller or near the front roller, which strengthens the control of the fibers and makes the bars tightly arranged, greatly reducing the width of the bars in the twisting triangle area of the traditional spinning machine, or reducing Small or eliminated twisting triangle area is conducive to reliably twist the fiber in the sliver into the sliver, thereby greatly reducing hairiness, and at the same time, the suction air is also conducive to the fiber once again during twisting and winding Straightening opportunities, thereby eliminating yarn hairiness and improving yarn strength.

Siro spinning is to feed two rovings into the drafting mechanism of the spinning frame at a certain distance, and at the same time is drawn. After coming out of the front roller holding point, two fiber whiskers with a certain distance are formed. It is gathered by twisting, twisted into strands, and then wound onto the bobbin through the yarn guide hook and the traveler to become Siro yarn.

Sirofil spinning is developed from Siro spinning, that is, in Siro spinning, a filament is used to replace one of the rovings, and the distance between the two is greater than the distance between the two rovings of Siro spinning. The breaking strength of Sirofil yarn is greater than that of staple fiber ply yarn and Siro yarn, the elongation at break is greater than that of single yarn, and the hairiness is less. Replacing a single yarn with chemical fiber filaments can both reduce costs and increase the yarn number.

Solo spinning is a split roller or plastic clip with a lot of grooves on the surface under the front roller of the spinning frame. The groove or plastic clip is used to divide the whiskers output by the front roller into many narrow strips. Due to the transmission of twist, these narrow The strip has a small amount of twist, and after being merged and twisted, a solo yarn similar to a multi-strand (cable yarn) is formed, so the solo spinning is also called cable spinning.

The advancement of textile fiber raw materials and spinning technology has improved the output and quality of textiles. The development of new yarns should combine the application of new fiber materials and its new spinning technology in order to develop products with excellent characteristics that are welcomed by the market.