Ring spinning, open-end spinning, siro spinning, compact spinning... can you distinguish it clearly?

2021/04/09

What are their names?

Where are they applied?

What is the difference between their production processes?

And the difference between the machinery and raw materials used to make them

This article will interpret the differences between common yarns in all aspects


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Ring spinning, open-end spinning, siro spinning, compact spinning... can you distinguish it clearly?

 

1. Ring spinning

 

Ring spinning is the most commonly used spinning method on the market. Ring spinning means that the sliver or roving fiber sliver after being drafted is introduced by the ring traveler rotating, the bobbin winding speed is faster than the traveler, and the cotton yarn is twisted into spun yarn.

 Ring spinning 

It is widely used in spinning engineering of various short fibers. Such as carding, combing and blending, the traveller is driven by the bobbin through the yarn to rotate around the ring for twisting. At the same time, the friction of the ring makes the rotation speed slightly lower than that of the bobbin to be wound. The spinning speed is high, and the shape of the ring-spun yarn is a conical spiral with most fibers transferred inside and outside, which makes the fibers entangle and connect inside and outside the yarn. The yarn has a compact structure and high strength. It is suitable for thread making, weaving and knitting, etc. Various products.

 various short fibers

1.1 Ring spinning (combing) process:

Clear cotton - carding - pre-drawing - sliver and winding - combing - drawing - roving - spinning - winding

 

1.2 Ring spinning (carding) process:

Clear cotton--carding--drawing--roving--spinning--winding

 

2. Air spinning

 

2.1 Working principle of open-end spinning

 Working principle of open-end spinning

Air spinning does not use spindles, and mainly relies on multiple components such as opening rollers, rotors, and false twisting devices. The opening roller is used to grab and card the fed sliver fiber, and the centrifugal force generated by its high-speed rotation can throw the grabbed fiber out. The rotor is a small metal cup. Its rotation speed is more than 10 times higher than that of the opening roller. The resulting centrifugal effect expels the air in the cup to the outside; according to the principle of fluid pressure, the cotton fiber enters the air flow cup. , And form a fiber stream, which moves continuously along the inner wall of the cup. At this time, there is a yarn end outside the cup, which draws out the fibers on the inner wall of the cup and connects them, plus the drilling effect produced by the high-speed rotation of the yarn tail with the cup, it is like "feeding" the cotton fiber while adding yarn. Thread kneading connects the yarn with the fibers on the inner wall of the cup, and draws the yarn under the spinning tension of the bobbin to continuously output the yarn to complete the process of air spinning.

 

2.2 Features of open-end spinning

 

Open-end spinning has the advantages of high speed, large yarn roll, wide adaptability, simple structure and no need of spindles, steel rings, and travellers, which can double the yield of spun yarn.

 

2.3 The difference between open-end spinning and ring spinning:

 

Open-end spinning and ring spinning are a new type of spinning technology, and the other is an old-fashioned spinning technology. Open-end spinning is air spinning, while ring spinning is mechanical spinning, which is twisted by spindles, steel bells, and travellers, and drafted by rollers. In air spinning, the fibers are transported by air flow, and one end is held and twisted.

 

Generally speaking, ring-spun yarn has less hairiness, higher strength and better quality. The air-jet spinning process is short, the raw material is short, the yarn wool, the count and the twist are not high, and the price is low.

 

In terms of yarn structure, ring spinning is relatively compact, while air spinning is relatively fluffy and has a rough style. It is suitable for denim fabrics, and air spinning is generally thicker.

 

3. Air-jet spinning

3.1 Working principle of Air-jet spinning

Working principle of Air-jet spinning 

Air-jet spinning is a new type of spinning method that uses high-speed rotating airflow to twist the yarn into yarn. Air-jet spinning adopts cotton sliver feeding, four-roller double short apron super drafting, and twisted yarn by a fixed nozzle. After the yarn is drawn out, it is wound onto the bobbin through the yarn clearer, and is directly wound into a package yarn.

 

Air-jet spinning can spin 30-7.4tex (20-80 British counts) yarn, which is suitable for pure spinning and blending of chemical fiber and cotton. Due to the special yarn forming mechanism of air-jet spinning, the structure and performance of air-jet yarn are obviously different from ring-spun yarn, and its products have unique styles.

Air-jet spinning

3.2 The characteristics of air-jet spinning and its products

 

3.2.1 High spinning speed

 

Air-jet spinning adopts air twisting and no high-speed rotating parts (such as travellers in ring spinning) to achieve high-speed spinning. The spinning speed can reach 120-300 m/min, and the output of each head is equivalent to that of each ring spinning. 10-15 times.

 

3.2.2 Short technological process

 

Compared with ring spinning, air-jet spinning has less roving and bobbin two processes, saving about 30% of the plant area. Compared with ring spinning, 90 people are employed for 10,000 spindles, a reduction of about 60%. The material consumption of the machine is about 30% lower than that of ring spinning, and the usual maintenance costs and workload are also reduced.

 

3.2.3 Good quality and distinctive products

 

The comprehensive evaluation of air-jet yarn quality is good, except that the yarn strength is 5-20% lower than that of ring spinning, other quality indicators are better than ring spinning. The physical properties of air-jet yarn, such as even CV value, coarse details and yarn defects, are better than ring-spun yarn. The hairiness over 3mm is less than that of ring-spun yarn. Although the yarn strength is lower, the unevenness of strength is lower than that of ring-spun yarn. It is suitable for the weaving of new looms such as rapier looms and air jet looms, and can increase the production efficiency of the looms by more than 2%.

 

In addition to the quality of air-jet spinning is similar to that of ring-spun yarn, it also has its uniqueness. Air-jet yarn has a large friction coefficient, the yarn has directionality, and its friction performance is also directional. The wear resistance is better than ring-spun yarn, but the hand feel is harder.

With some additional devices in air-jet spinning, some special types of yarns can be developed, such as fancy yarns, core-spun yarns, and mixed yarns.

 

3.2.4 Wide adaptation of varieties

 

Air-jet yarn can be used as knitting products as well as woven products, with a wide variety of adaptability. More applications are: knitted T-shirt products, the fabric surface is even and plump, no skew, less streaks, less streak defects, anti-pilling, cool and breathable, and strong three-dimensional effect; bedding, using air-jet yarn to dry well and stiff The characteristics of this product can get even cloth surface, thick hand feeling, crisp and good air permeability; leisure products, such as: double-sided casual wear, sportswear, etc.

 

According to the characteristics of air-jet yarn, products with unique styles can also be developed. For example, the stiffness and roughness of the air-jet fabric can be used to process it into linen-like fabrics, crepe fabrics, and wool-like products.

 

4. Vortex spinning

4.1 The working principle of vortex spinning

 

Vortex spinning is a new type of spinning method that uses a fixed vortex spinning tube instead of a high-speed rotating spinning cup for spinning. In a sense, vortex spinning is the true air spinning. The fiber sliver is fed by the cotton roller, and is opened by the licker roller to form a single fiber. With the effect of air flow, it is fed into the vortex tube at a high speed from the cotton conveying pipe. The vortex tube is composed of a core tube and an outer tube. There are three tangential air inlets on the outer pipe, and the lower end is connected with a blower. The blower continuously draws air from the pipe, and the outside air enters the vortex tube along the air inlet to produce a vortex-like airflow. When the rotating upward airflow reaches the core tube, it merges with the fibers entering the cotton conveying pipe and forms a condensed fiber ring along the inner wall of the vortex tube, which rotates stably around the axis of the vortex tube and twists the fibers into yarn. The yarn is continuously drawn from the yarn guide hole by the lead roller to be wound into a bobbin. The main feature of vortex spinning is the elimination of high-speed spinning spinning components. The use of air-jet twisting eliminates the problem of inertia and bearing load caused by high-speed twisting components (such as the rotor of air-jet spinning), and the problem of increased spinning tension due to the balloon formed by spinning (such as Ring spinning).

 

4.2 Features of vortex spinning

4.2.1 Advantages of vortex spinning, fast speed and high output

The spinning speed of the vortex spinning machine is 100~200m/min, and the practical speed is generally 100~160m/min. Domestic vortex spinning machines are used to spin 6-12 British count yarns, with a spinning speed of 100-140m/min and a unit yield of 600-800 (kg/thousands·h), which is equivalent to 4 to 5 times that of ring yarn; Spinning 40 metric count acrylic yarn, using 10 sets (192 heads/set) PF-1 vortex spinning machine, with an output of 400kg/h. It is equivalent to the output of 20 (4000 heads) BD-200 air-jet spinning machines and the output of 16 320 spindles of 40 ring spinning machines. The output of a vortex spinning head is equivalent to the output of 2.08 air spinning heads or 8.5 ring spindles. Because vortex spinning relies on vortex twisting, the spinning speed can continue to increase if research and improvement continue.

 

4.2.2 Short process flow and high production rate

Vortex spinning is directly spun from fiber sliver into cheese, so like other new types of spinning, the two processes of roving and winding can be omitted. Due to the low end breakage rate of vortex spinning, the loss of back-spatter is small, and the finished rate is as high as 99%.

 

4.2.3 It is suitable for spinning and is suitable for making pile products

Vortex spinning can spin yarns with fiber lengths of 38~60mm, pure and blended yarns for cotton and chemical fibers. The yarn structure is relatively bulky, so its dyeability, slurry absorption and air permeability are better, and the yarn has better pilling resistance and abrasion resistance. The yarn count range is limited to medium and low count yarns, which is suitable for pile products. For example, 38mm long chemical fibers (acrylic, chlorinated, viscose, etc.) are spun into 6-12 British yarns and knitted into fleece, trousers, scarves, cushions, sofas, furniture cloths and small table cloths. product.

 

4.2.4 Simple operation and convenient connection

Vortex spinning adopts a vortex tube to form yarn. Because the vortex tube is stationary and has no high-speed rotating parts, the joint is very convenient and simple, and there is no need to clean after the end is broken, which improves the working environment. There are no special requirements for spinning equipment and temperature and humidity. Because the vortex spinning has no high-speed rotating parts, there is no high-speed bearing lubrication problem, low loss, low noise, and convenient maintenance.

 

4.3 The production practice shows that there are some limitations in the development of vortex spinning.

 

a. The range of suitable raw materials for vortex spinning is limited to short chemical fibers and medium-length fibers. Due to the quality of the yarns, the competitiveness in the field of fine-gauge yarns is not strong.

 

b. The yarn structure of vortex spinning is relatively slack, and the uniformity of long segments is good, but the strength is low and unstable, which limits its development to the field of fine-gauge yarn.

 

c. Although vortex spinning uses air vortex to replace the rotor of air spinning, it overcomes the problem of wear caused by the high-speed rotation of the air spinning rotor and the problem of excessive bearing load, but it still cannot solve the problem of vortex at the free end of the yarn. The yarn arm formed when the tube rotates at a high speed causes the problem of large centrifugal force and tension. Therefore, it is impossible to make a breakthrough in its spinning speed.

 

d. The yarn formed by vortex spinning is too short due to poor fiber straightness and too short agglomeration process, which makes the structure of the yarn looser and the yarn strength is low. Therefore, its products have limitations and are only suitable for chemical fiber raw materials and spinning coarse gauges. Knitting yarn or thick pile yarn and other products that do not require high strength, or spinning core-spun yarn with filament as the core. Nevertheless, vortex spinning, which also feeds cotton sliver directly into yarn, has the conditions and possibility to realize a fully automated continuous production line. Because the roving frame, spinning frame and automatic winder are eliminated, the floor space, labor and investment are reduced, so it has its unique advantages. In the field of knitting yarn, it will further replace ring-spun yarn and air-flow yarn. Therefore, it is necessary to continue to research and improve, overcome its disadvantages and limitations, and make it a new spinning method with characteristics.

 

5. Siro Spinning

5.1 The working principle of Sirospun

 

It is also called for twin-twist spinning, which is called A and B yarn in China. Recently, it was officially designated as Siro spinning. Siro spinning is to feed two rovings with a certain distance on the spinning frame. After being drafted, the front roller outputs the two single-yarn slivers. Due to the transmission of twist, the single-yarn slivers have a small amount of The twist is further twisted into a twisted yarn similar to a ply after splicing, which is wound on the bobbin.

The working principle of Sirospun

The initial design purpose of Siro spinning is to be used in wool spinning. It is characterized by less hairiness, high strength, and good abrasion resistance. It can achieve the effect of single yarn weaving and realize the lightness and thinness of wool fabric. Although Siro spinning has made great improvements compared with similar conventional yarns in many aspects, there is still a long way to go before weaving wool spinning single yarns without sizing. Afterwards, wool spinning often gave up this method, and instead used this method in blended spinning such as T/C, C.V.C, etc.

ring-spun yarn

Because it can produce the twist effect of the yarn after dyeing, it feels good, so it is popular. Recently, it has improved the hairiness problem, such as spinning some fibers that are prone to hairiness, such as rayon, modal, Tencel, soybean fiber, and even cotton. They are all produced by this method. The grade of raw materials used in Siro yarn can be lower than that of conventional ring-spun yarn, and its fabric has less hairiness than conventional ring-spun yarn fabric, soft hand feeling, abrasion resistance and good air permeability.

 

5.2 Siro Spinning Broken End Treatment

 

Because Siro spinning feeds two strands with a certain distance into the spinning drafting zone, they are drafted separately and then twisted to form a yarn. The two strands may run into a single yarn after one strand breaks and the other strand runs. In the case of stable spinning tension, the yarn will not be threaded, resulting in wrong yarn count. In order to ensure the spinning quality, it is necessary to install a Siro spinning single yarn interrupting device. After one strand breaks, the interrupting device can beat the other single yarn. Off.

 

6. Compact spinning

 

6.1 The working principle of compact spinning

The new ring spinning frame

Compact spinning is a new spinning technology for spinning on an improved new ring spinning frame. The spinning mechanism is mainly: a fiber aggregation zone is added before the traction device of the ring spinning frame, which basically eliminates the spinning triangle area between the front roller and the twisting point. After the fiber strands are output from the front opening of the front roller, they first pass through the mesh apron of the special-shaped suction tube. The strands move on the mesh apron. Due to the contraction and polymerization of the airflow, the strands are gathered through the suction groove of the special-shaped tube. Turning, it gradually turns from a flat ribbon to a cylinder, and the ends of the fibers are twisted into the yarn, so the yarn is very tight, and the yarn has a smooth appearance and less hairiness. The compact yarn has higher strength and less hairiness. The phenomenon of sanding is the least likely to occur during the knitting process.

The purpose of compact spinning is to make the fibers as parallel and close as possible before the yarn is twisted. This is an important criterion for high-quality compact spinning yarns. Making the fibers as parallel and consistent as possible before twisting is a prerequisite for its advantages.

 

6.2 Advantages and disadvantages of compact spinning

6.2.1 Advantages

 

a. Before twisting, the single fibers in the yarn are fully straightened, parallel to each other, and arranged tightly, so at the jaws of the twisting roller (also called the twist-stop roller, because it has the effect of preventing the transmission of twist), the yarn The diameter of the sliver becomes very small, so the "twisting triangle" is basically eliminated. Because the single fiber is fully straight and parallel before twisting, and there is no hairiness extending from the main body of the yarn, the resulting yarn has very little hairiness, especially above 3 mm. Hairiness is minimal.

 

b. In the spun yarn, each single fiber is twisted in a straight and parallel state. When the single yarn is tensioned, the force of each single fiber is basically the same, so the compact spinning strength is higher than that of the traditional single yarn. Moreover, because the single fibers in the compact yarn are closely arranged, the cohesive force between each other is large, which also helps to improve the strength of the yarn.

 

c. In the compact spinning process, the yarn sliver is assembled after the drafting specified by the process is completed, so the index of unevenness is not greatly improved, but it has a finishing effect on the yarn in the gathering area. And when twisting at the nip of the twisting roller, the transfer of the inner and outer layers of the fiber is not as strong as the traditional technology, so the compact yarn has uneven, thick and detailed indicators than traditional yarns.

 

d. Due to the above-mentioned characteristics of compact yarn, it provides very good conditions for the next process. The compact yarn has less hairiness, so it reduces the pressure of sizing and singeing processes, and greatly reduces the use of compact yarn in the weft of the shuttleless loom. The resistance of weft insertion is improved, and the efficiency of the loom is improved.

 

e. Because compact yarn fibers are closely arranged and have a small diameter compared with traditional yarns of the same number, the densely woven fabric with the same warp and weft has good air permeability, and the cloth surface is flat and smooth. It is an ideal yarn for high-end textiles. .

 

6.2.2 Disadvantages

 

a. The high cost of compact spinning equipment increases the equipment investment of spinning mills.

b. Except for the great improvement in the hairiness index, the other indexes of yarn such as evenness, thickness and detail have not improved much.

 

6.3 Comparison of Siro spinning, compact spinning and compact Siro spinning

Comparison of Siro spinning, compact spinning and compact Siro spinning

a. Siro spinning is a spinning method that spins yarns similar to the strand structure on the traditional ring spinning frame. Siro spinning technology was first applied to wool spinning, and then gradually applied to cotton spinning. Siro spinning uses two rovings to be fed from the bell mouth. The two rovings are still separated in the front and rear drafting zones. They are combined after a certain length from the front jaws, and are twisted by the same spindle to form a double Siro yarn with structural characteristics of strands. Siro spinning's simultaneous twisting in the same direction makes its yarn have a special structure. Siro spinning has neatly arranged fibers on the surface, tight yarn structure, less hairiness, and good anti-pilling. Compared with stranded fabrics, Siro textiles have a softer and smoother touch. Siro spinning can be used for woven fabrics and knitted fabrics, and can also be used for high-count and high-density fabrics instead of strands.

 

b. Compact spinning technology is a new type of ring spinning technology based on traditional ring spinning. Simply put, it is a spinning technology that densifies the fiber output after the spinning frame is drafted, that is, by adding a suction device before twisting the strands, and through the control of negative pressure, the loose fibers are gathered and entangled, and the fibers are under control. The area is fully straightened, and the twisting triangle area on the traditional spinning machine is reduced, so that the fiber can be twisted in a parallel and tight state. Because the fibers in the sliver are uniformly stressed and tightly entangled, the yarn structure and quality are comprehensively improved, and the hairiness, strength, evenness, abrasion resistance, and the appearance of the yarn have been significantly improved.

 

c. Compact Siro spinning is a combined process spinning method that combines compact spinning and Siro spinning. The yarn spun by this technology combines the excellent characteristics and quality of the two spinning methods, and is comparable to traditional ring spinning. Compared with single yarn and siro yarn, compact siro yarn has less hairiness, higher strength, and has the effect of siro spinning. It is an ideal raw material for spinning high-end fabrics and has a good development prospect.

 

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