5 big spinning technologies competition who will be the winner

There are currently five practical and highly regarded spinning methods in the field of cotton spinning, namely traditional ring spinning, rotor spinning, air-jet spinning, vortex spinning and improved ring spinning-compact spinning.

The ring spinning method has a history of more than a century and a half, and the latter four have been developed in recent decades or even in recent years, and are collectively referred to as new spinning methods. Different spinning methods have their own unique features in terms of yield, quality, and yarn structure and characteristics.

I. Comparison of yarn forming mechanism

1.Traditional ring spinning

Ring spinning is a spinning method in which drafting, twisting and winding are performed simultaneously. The roving is drafted to the required sliver of the yarn count in the drafting system, and then added by the ring and traveller. Twisting and winding to form a yarn. Due to the drafting effect, the width of the sliver in the main drafting area is several times the diameter of the yarn being spun. At this time, each fiber is in a free state when it reaches the front jaw line. When these fibers leave the front jaw line, they are twisted together to form a spinning twisted triangle. This spinning twisted triangle area prevents the edge fibers from completely entering the yarn body, part of the edge fibers are separated from the main body to form flying flowers, and more edge fibers are twisted into the yarn body at one end and hairiness is formed at the other end. These fibers not only negatively affect the uniformity, elasticity and other properties of the yarn, but also are extremely detrimental to the strength of the yarn. In addition, the fibers at the outside of the triangular area receive the highest tension during twisting, while the fibers at the center receive the smallest tension. Therefore, the initial tension of these fibers during yarn formation varies, which affects the strength of the yarn. These are the defects caused by the triangle area of traditional ring spinning.

2.Rotor spinning

Rotor spinning, also known as open-end spinning, belongs to the free-end spinning method. The sliver fed directly into the spinner is carded into a single fiber by the carding rollers. The fibers are separated from the surface of the carding rollers through the cotton conveying pipe and enter the spinning cup by the centrifugal force of the carding rollers and the effect of the negative pressure air flow in the spinning cup A complete fiber ring is formed in the agglomeration tank. The fiber ring rotates at a high speed with the spinning cup. Under the action of the spliced yarn, the fiber is continuously formed with the twist and continuous stripping of the fiber bundle.

3.Air-jet spinning

Air-jet spinning is represented by the MJS (MurataJetSpinner) model manufactured by Murata, Japan. The sliver is directly fed into the drafting device, and the drawn sliver enters the nozzle. The two high-speed rotating air streams in opposite directions falsely twist and wrap the sliver. After the sliver is pulled out, the electronic yarn clearer is used to remove defects. After being wound on the package.

4.Vortex spinning

Vortex spinning is a new generation of air-jet spinning technology MVS introduced by Murata after MJS. The spinning principle of vortex spinning is that the sliver is directly fed into the drafting device, and the drawn sliver is output from the front roller jaw and immediately sucked by the negative pressure generated by the vortex in the straight nozzle of the spinner to form a core fiber. When the end of the fiber leaves the front roller, it expands due to the eddy current effect, covers the surface of the hollow spindle, and rotates along the fixed hollow inner wall. With the forward movement of the sliver, the end of the fiber is wound around the core to obtain the yarn. Twist into yarn.

5.Improved ring spinning-compact spinning

Compact spinning is also known as agglomeration spinning. It mainly adds a fiber agglomeration area in front of the ring spinning machine drafting device, and the fiber bundles migrated from the front roller nip line of the drafting device are gathered in a line, which basically eliminates the gap between the front roller and the twisting point. The spinning twisted triangle zone solves the key problems of yarn strength, hairiness and flying flowers in traditional ring spinning, and brings a series of benefits to subsequent processing and product quality. Different machine manufacturers provide a variety of patents for agglomerating these fibers, but the principle is basically the same. They are designed to effectively control the fibers in the sliver, especially the edge fibers and planktonic fibers, through agglomeration. The width of the drafting bead is reduced, thereby substantially eliminating the spinning twist triangle, and producing a new type of high-quality compact ring yarn.

Comparison of yarn structure and shape

Different spinning methods have different yarn formation mechanisms, the arrangement of fibers in the yarn and the tightness of the yarn are also different.

1. The structure of traditional ring spinning yarns

In traditional ring-spun yarns, the fibers are basically arranged in a spiral line. Because of the spinning twisting triangle, the fibers cannot be twisted into the yarn body. Many edges of the fiber are twisted into the yarn body and the other end is exposed in the yarn. Hairiness is formed on the outside of the sliver, so although the ring-spun yarn structure is relatively tight, the surface of the sliver is relatively disordered and the finish is relatively poor.

2.Rotor spinning yarn structure

During the twisting process of the rotor-spun yarn, the fibers in the twisting zone lack active grip and are in a loose state, so the fiber straightness is poor, and the degree of fiber internal and external transfer is low. The structure of the yarn is divided into a yarn core and an outer fiber. The structure of the core is similar to that of a ring-spun yarn, and is relatively tight; the structure of the outer fiber is loose, and it is randomly wrapped around the core. Therefore, compared with the traditional ring yarn, the rotor yarn structure is more fluffy and fuller in appearance.

3.Air-jet spinning yarn structure

Air-jet yarn is a double-structured yarn. One part is almost parallel, non-twisted core fibers, and the other is wrapped fibers that are wrapped around the core yarn. The structure of air-jet yarn is relatively fluffy, and the gap between the fibers is large. The ratio of the wrapped fiber to the core fiber is about 1: 9. The wrapped fiber applies centripetal stress to the core fiber strip, giving the yarn the necessary polymerization force. To withstand external stress.

4.Swirl spinning yarn structure

Vortex yarn is also a double-structured yarn. The core fibers of the sliver are arranged in parallel and have no twist. The end fiber is wrapped around the core fiber and twisted into a yarn by the action of the rotating airflow. But different from air-jet yarn, the outer layer of vortex yarn has a large specific fiber (about 60%), so that the untwisted fiber is almost completely covered, and the surface fiber arrangement is more similar to that of ring-spun yarn.

5.Compact spinning yarn structure

The fiber arrangement in compact spinning yarns is the most neat and clear. In a sense, it may be the ideal fiber arrangement in the yarn. Due to the contraction and polymerization of the air flow, the ends of the fibers are twisted into the yarn, and the yarn structure is the most compact. The appearance of the yarn is smooth and the hairiness is small. The twisted spiral structure of the yarn is clearly visible, and the fiber has almost no internal or external transfer. This is the most significant characteristic of agglomerated spinning. This improvement in yarn structure is achieved through the elimination of spinning twist triangles.