From Fibers to Yarns: Unlocking the Secrets of Common Spinning Technologies

yarns

Different spinning processes exert varying effects on the physical properties and appearance of yarns, and may even result in distinct characteristics of final products. At present, six practical spinning technologies—ring spinning, open‑end spinning, air‑jet spinning, vortex spinning, siro spinning and compact spinning— have attracted considerable attention from textile enterprises. Each boasts unique features in terms of output, quality, yarn structure and properties.

1、ring‑spun spinning

Ring spinning is the most widely used spinning method on the market. It processes drawn sliver or roving through rotating ring travelers. With the bobbin winding faster than the traveler, fibers are twisted into fine yarn, suitable for short‑fiber spinning including carded, combed and blended yarns. Driven by the yarn, the traveler rotates around the ring to add twist, while friction keeps its speed lower for winding. Ring‑spun yarn features conical spiral fiber arrangement with tight interlocking structure, high tenacity, ideal for threads, woven and knitted products.

ring-spun spinning

2、Open-end Spinning

Also known as rotor spinning, open‑end spinning is a free‑end spinning technique. After sliver is carded into single fibers by a combing roller, fibers enter the rotor under centrifugal force and negative‑pressure airflow, forming a fiber ring that twists continuously into yarn. It suits short‑fiber medium‑coarse yarns with clean, even slivers and high twist.

3、Air‑jet Spinning

air-jet spinning

Air‑jet spinning is a non‑free‑end spinning technology. It is an innovative method that twists yarn via high‑speed swirling airflow, represented by Murata’s MJS system from Japan. First, slivers are fed directly into a drafting device. Then the drafted strands enter nozzles, where two counter‑rotating high‑speed airflows false‑twist and wrap them into yarn. Finally, the finished yarn passes through an electronic yarn clearer to remove defects before being wound onto packages.
Air‑jet spinning uses air‑powered twisting. Therefore, it achieves high‑speed spinning without high‑speed rotating parts. Furthermore, compared with ring spinning, it omits roving and winding processes. As a result, factory space is saved. In addition, labor and material consumption per ten thousand spindles are greatly reduced versus ring‑spun yarn. Moreover, air‑jet yarn features a dual‑layer structure. On one hand, core fibers are nearly parallel and twist‑free. On the other hand, wrapping fibers enclose the core from outside. Besides, air‑jet yarn has a relatively bulky structure with large gaps between fibers. Specifically, the ratio of wrapping fibers to core fibers is about 1:9. Meanwhile, wrapping fibers exert centripetal stress on core strands. Hence, the yarn gains sufficient cohesion to bear external force. Additionally, air‑jet yarn has a high friction coefficient. Furthermore, both the yarn and its friction performance show directional features. Meanwhile, it offers better abrasion resistance than ring‑spun yarn, yet a stiffer hand feel. Accordingly, it can produce fabrics with unique styles, such as linen‑like, crepe and wool‑like textiles. Finally, with extra attachments, air‑jet spinning can also produce special yarns, including fancy yarn, core‑spun yarn and blended yarn.

4、Vortex Spinning

Vortex spinning is an innovative spinning method. Instead of high‑speed rotating rotors, it uses stationary vortex spinning tubes. Firstly, slivers are fed directly into the drafting unit. Then, drafted fiber strands exit the front roller nip. Immediately afterward, they are drawn by negative pressure from vortex airflow inside the straight nozzle. This forms core fibers. Next, as fiber ends leave the front roller, they expand under vortex effects. They then cover the surface of the hollow spindle and rotate along its fixed inner wall. Finally, with the forward movement of yarn strands, fiber ends wrap around the core. In this way, the yarn obtains twist and takes shape.
vortex spinning

5、Siro Spinning

siro spinning

Siro spinning works on ring spinning frames. Firstly, two rovings with a fixed spacing are fed into the machine. Then, after drafting, two single fiber strands exit the front rollers. Meanwhile, slight twist is formed on each strand through twist transmission. Later, the two strands merge and receive further twisting. Consequently, a ply‑like yarn is formed and wound onto bobbins. In addition, two spaced strands enter the drafting zone separately. They are drafted individually before being twisted into yarn. If one strand breaks, the other may run alone continuously. Moreover, this single‑strand running occurs under stable spinning tension. As a result, off‑count yarn defects appear. Therefore, to guarantee yarn quality, a siro single‑yarn breaking device is required. Finally, it cuts off the remaining strand once one strand breaks.

6、Compact Spinning

Compact spinning is an advanced spinning technology.It is applied on modified new‑type ring spinning frames.Firstly, a fiber condensation zone is added before the drafting system.Therefore, the spinning triangle between front rollers and twisting point is largely eliminated.Then, fiber strands exit the front roller nip.Afterwards, they pass through a perforated apron over a special‑shaped suction tube.Meanwhile, strands move along the apron surface.Moreover, airflow creates contraction and aggregation effects.Through suction slots of the special‑shaped tube, strands gather and rotate.Gradually, flat ribbon‑like strands turn into cylindrical ones.In addition, all fiber ends are twisted into the yarn core.As a result, compact‑spun yarn features tight structure.Besides, it has smooth appearance and few hairiness.Furthermore, compact‑spun yarn enjoys high tenacity and low hairiness.Finally, it hardly causes fuzzing during weaving processes.