The difference between ring spinning, air spinning, air jet spinning and vortex spinning
May 31, 2024
1.Ring spinning
Ring spinning refers to the process of drawing a fiber strip from a sliver or roving through a ring wire ring. The winding speed of the bobbin is faster than that of the wire ring, and the cotton yarn is twisted into fine yarn. For example, in carded, combed and blended spinning, the wire ring is driven by the bobbin through the yarn strip to rotate around the steel collar for twisting. At the same time, the friction of the steel collar makes its speed slightly lower than that of the bobbin and is wound. Ring spinning is the most widely used and most common spinning method on the market.
2. Open-End spinning:
Open-end spinning does not use spindles, but mainly relies on multiple components such as combing rollers, spinning cups, and false twist devices. The combing roller is used to grab and comb the fed cotton sliver fibers. The centrifugal force generated by its high-speed rotation can throw out the grabbed fibers. The rotation speed of the spinning cup (a small metal cup) is more than 10 times higher than that of the combing roller. The resulting centrifugal effect discharges the air in the cup outward; according to the principle of fluid pressure, the cotton fibers enter the airflow cup and form a fiber flow, which moves continuously along the inner wall of the cup. At this time, there is a yarn head outside the cup, which leads the fibers on the inner wall of the cup out and connects them. In addition, the drilling effect generated by the high-speed rotation of the cup with the yarn tail is like "feeding" cotton fibers while adding yarn rubbing to connect the yarn with the fibers on the inner wall of the cup. It is stretched under the winding tension of the yarn tube, and the yarn is continuously output to complete the process of open-end spinning.
Characteristics of open-end spinning
Air-jet spinning has the advantages of high speed, large yarn roll, wide adaptability, simple structure and no need for spindles, steel collars or wire rings, which can double the output of fine yarn.
3.Vortex spinning
Vortex spinning is a new spinning method that uses a fixed vortex spinning tube to replace the high-speed rotating spinning cup for spinning. In a sense, vortex spinning is the real air-jet spinning. The fiber strips are fed by the cotton feeding roller, opened into single fibers by the licker-in roller, and fed into the vortex tube at high speed from the cotton conveying pipeline by the action of the air flow. The vortex tube consists of a core tube and an outer tube. There are three tangential air inlets on the outer tube, and the lower end is connected to the blower. The blower continuously extracts air from the tube, and the outside air enters the vortex tube along the air inlet, generating a vortex-shaped airflow. When the rotating upward airflow reaches the core tube, it merges with the fibers entering the cotton conveying pipeline, forming a condensed fiber ring along the inner wall of the vortex tube, stably around the axis of the vortex tube, rotating at high speed, and twisting the fibers into yarn. The yarn is continuously drawn out from the yarn guide hole by the lead-out roller and wound into a bobbin.
Advantages of vortex spinning: fast speed and high output
The spinning speed of vortex spinning machine is 100~200m/min, and the practical speed is generally 100~160m/min. Domestically, vortex spinning machine is used to spin 6~12 British yarn, the spinning speed is 100~140m/min, and the single yield is 600~800 (kg/thousand spindles·h), which is equivalent to 4~5 times that of ring yarn; such as spinning 40 public acrylic yarn, using 10 sets (192 heads/set) PF-1 vortex spinning machines, the output reaches 400kg/h. It is equivalent to the output of 20 sets (4000 heads) BD-200 air-spinning machines, and the output of 40 ring spinning machines with 16320 spindles. The output of one vortex spinning head is equivalent to the output of 2.08 air-spinning heads or 8.5 ring spindles. Since vortex spinning relies on vortex twisting, if research and improvement continue, the spinning speed can continue to increase.
Short process flow and high yield
Vortex spinning is to spin fiber strips directly into cone yarn, so like other new spinning methods, it can save the two processes of roving and winding. Since the breakage rate of vortex spinning is very low, the return loss is small, and the yield is as high as more than 99%.
Strong spinning adaptability and suitable for making fleece products
Vortex spinning can spin fibers with a length of 38~60mm, and is suitable for pure and blended yarns of cotton and chemical fibers. The yarn structure is relatively bulky, so its dyeability, slurry absorption and air permeability are relatively good, and the yarn's anti-pilling and wear resistance are also relatively good. The yarn count range is limited to medium and low count yarns, which are suitable for making fleece products. For example, 38mm long chemical fibers (acrylic, chloroprene, viscose, etc.) are spun into 6~12 count yarns, which are woven into fleece clothes, fleece pants, scarves, cushions, sofa fabrics, furniture fabrics and small tablecloths and other knitted fleece products.
Simple operation and convenient jointing
Vortex spinning uses vortex tubes to form yarn. Since the vortex tube is stationary and has no high-speed rotating parts, the joint is very convenient and simple. There is no need to clean after the end is broken, which improves the working environment. There are no special requirements for the pre-spinning equipment and temperature and humidity. Since vortex spinning has no high-speed rotating parts, there is no problem of high-speed bearing lubrication, less wear and tear, low noise, and easy maintenance.
Production practice shows that there are also some limiting factors in the development of vortex spinning.
a. The range of raw materials suitable for vortex spinning is limited to short chemical fibers and medium and long fibers. Due to the quality of the yarn, its competitiveness in the field of fine yarn is not strong.
b. The yarn structure of vortex spinning is relatively loose, and the long segment has good uniformity, but the strength is low and unstable, which limits its development into the field of fine yarn.
c. Although vortex spinning uses air vortex to replace the rotor of air spinning, it overcomes the wear problem and excessive bearing load caused by the high-speed rotation of the rotor of air spinning, but it still cannot solve the problem of yarn arms formed by the free-end yarn tail when it rotates at high speed in the vortex tube, which leads to greater centrifugal force and tension. Therefore, its spinning speed cannot make a breakthrough.
d. Due to the poor fiber straightness and the short coagulation process, the yarn structure of vortex spinning is loose and the yarn strength is low. Therefore, its products are also limited. It is only suitable for chemical fiber raw materials and spinning of coarse knitting yarn or thick pile yarn, which do not require high strength, or spinning core-spun yarn with filament as the yarn core. Despite this, vortex spinning, which also feeds cotton strips to directly form yarn, has the conditions and possibility to realize the production of fully automated continuous production lines. Since the roving frame, spinning frame and automatic winding machine are eliminated, the floor space, labor and investment are reduced, so it has its unique advantages and will further replace ring yarn and air-spun yarn in the field of knitting yarn. Therefore, it is necessary to continue research and improvement to overcome its disadvantages and limitations and make it a new type of spinning method with unique characteristics.
3.Air-jet spinning
Air-jet spinning is a new spinning method that uses high-speed rotating airflow to twist the yarn into yarn. Air-jet spinning uses cotton sliver feeding, four-roller double short rubber ring super-large drafting, and twisting into yarn through a fixed nozzle. After the yarn is drawn out, it is wound onto the yarn tube through a yarn clearer and directly wound into a package yarn. Due to the special spinning mechanism of air-jet spinning, the structure and performance of air-jet yarn are significantly different from those of ring yarn, and its products have a unique style.
Characteristics of air-jet spinning and its products:
a. High spinning speed. Air-jet spinning uses air twisting and no high-speed rotating parts (such as steel wire rings in ring spinning), which realizes high-speed spinning. The spinning speed can reach 120-300 meters/minute, and the output per head is equivalent to 10-15 times that of ring spinning per spindle.
b. Short process flow. Air-jet spinning has two fewer processes, roving and package, than ring spinning, saving about 30% of plant area. Compared with ring spinning, 90 workers are needed for 10,000 spindles, which is about 60% less. The machine material consumption is about 30% lower than that of ring spinning, and the maintenance cost and maintenance workload are also reduced.
c. Good product quality and unique. The comprehensive evaluation of the quality of air-jet yarn is good. Except that the yarn strength is 5-20% lower than that of ring spinning, other quality indicators are better than those of ring spinning. The physical properties of air-jet yarn, such as CV value of yarn evenness, coarse and fine details and yarn defects, are better than those of ring yarn. The hairiness above 3mm is less than that of ring yarn. Although the yarn strength is lower, the strength unevenness is lower than that of ring yarn. It is suitable for weaving of new looms such as rapier looms and air-jet looms, and can increase the production efficiency of looms by more than 2%.
In addition to being similar to ring yarn, the quality of air-jet spinning is also unique. The friction coefficient of air-jet yarn is large, the yarn is directional, and its friction performance is also directional. The wear resistance is better than that of ring yarn, but the hand feel is harder.
By adding some devices to jet spinning, some special yarns can be developed, such as fancy yarn, core-spun yarn, mixed yarn, etc.
d. Wide variety of applications. Jet yarn can be used to make both knitted products and woven products, and has a wide variety of applications. The more common applications include: knitted T-shirt products, with a smooth and plump surface, no skew, few stripes, few stripe defects, anti-pilling, cool and breathable, and a strong three-dimensional sense; bedding, using the characteristics of good and stiff stripes of jet yarn, can obtain a smooth surface, thick feel, crisp and good breathability; leisure products, such as: double-sided leisure wear, sportswear, etc.
Based on the characteristics of jet yarn, unique style products can also be developed. For example, by using the stiffness and roughness of jet fabrics, they can be processed into imitation linen fabrics, crepe fabrics, imitation wool products, etc.