There are 2 types of yarn spinning techniques commonly used in cotton spinning.
- ring yarn
- open-end thread
1. Ring Yarn Production
Ring yarn is produced from long fibers of cotton. Ring yarn is divided into two as carded and combed. The difference between the two yarns is due to the combing process. The combing process is to subject the raw material (cotton) feeding the machine to an intense combing process with the help of the combs in the machine and thus to separate the short fibers of the cotton. Depending on the cotton used and the machine settings, 5%-25% fiber can be evaluated differently by removing it from the raw material.
The difference of combed yarn from carded yarn is that it is produced using longer fibers obtained after the combing process..In this way, much finer yarn counts can be produced. This yarn, which is produced in high quality, has an extremely flat structure, is softer and has high absorbency; It is used in the production of shirts, underwear, women's clothes and high quality bed linen.
With the rise in living standards in recent years, the quality of sleep has been increased along with softness and naturalness, thanks to carded and ring yarns, which have also been used in the home textile industry. In addition, while increasing the quality in industrial uses (Hotel, Restaurant and Hospital textiles), it extended the service life and provided advantages for businesses by preserving its first day's flat appearance until the last use.
Carded and combed yarn are of higher quality than open-end yarn.It has a softer and flatter texture and higher absorbency compared to open-end yarn, as integrity can be achieved with less twist count during the production phase. In addition, the rate of deformation, which is called pilling or lice, is very low in the fabrics produced with these yarns, which are also very strong. However, it should be noted that the cost of these yarns is higher than that of open-end yarn.
2. Open-End Yarn Production
Open-End spinning system is a completely different production technique compared to ring yarn. Unlike ring yarn, it is produced from short fibers of cotton. A rotor rotating at a very high speed is fed with cotton roving prepared using short fibers. Thanks to the centrifugal force, the wick spreads and adheres to the rotor surface. Open-end yarn is produced by continuously pulling a yarn extended into the rotor. This yarn, which is produced by evaluating even the shortest fibers of cotton, is very economical. In order to ensure integrity, the number of twists must be higher than the ring system. This causes it to have a harder structure.
DIFFERENCES BETWEEN OPEN-END YARN AND RING YARN
1-Production speed in Open-End spinning is higher than in Ring spinning systems. This is a factor that reduces costs while increasing production.
2-In Open-End spinning, the process steps are shorter than in Ring spinning. This is one of the cost-reducing factors.
3-The yarn produced in the Open-End system is more voluminous, more elastic, more absorbent and less hairy than Ring yarn. Handle is also good if not too high twist. A good absorbency feature ensures a high percentage of sizing and brighter tones.
4-The properties of the yarn produced in the Open-End system are less variable than the Ring yarn. Fineness, unevenness, durability etc. vary less throughout the yarn.
5-Due to the process, the cross section of Open-End yarns must have an average of 70-100 fibers. This is why Open-End yarns cannot be produced in fine counts as Ring yarns (requires 50-70 fibers in the cross section).
For example, although Ne40 yarn can be made theoretically in the Open-End system, in practice Ne30 yarn cannot be exceeded.
6-A technological disadvantage of open-end spinning is the helical fibers formed on the yarn surface. When the spun yarn is fed into the rotor cavity, some of the fibers are wound on the surface of the yarn in the twist direction. We can use this feature to separate Open-End yarns from Ring yarns. When we try to untwist the yarn with our two thumbs in the opposite direction of the twist, we can notice that the Ring yarns are untwisted and the fibers come out, but on the surface of Open-End yarns, the helical fibers mentioned above do not allow the yarn to untwist and we see that the yarn remains twisted.
Magnified images of Ring and Open-End Yarns are seen above.
A-Short fiber ring yarn,
B-Long fiber ring yarn
C-Short fiber open-end yarn,
D-Long fiber open-end yarn
7-The strength of Open-End yarns is 15-20% lower than Ring yarns. Strength can be increased by increasing the twist more. But this causes the attitude to harden.
8-Open-End yarns are mostly short fiber yarns.
9-Open-End yarns are generally used in the production of many products that do not require very high strength. Its usage area is expanding day by day. Technologically, Open-End yarns can be used as weft and warp yarns in weaving. It is more uniform, less thin, elastic and has higher abrasion resistance, which is advantageous for use in warp compared to ring yarns. Due to the good absorbency, they are also sized well. As a weft yarn, its uniformity and friction resistance provide advantages for Open-End yarns. Open-End yarns can also be used in the production of knitted fabrics. Due to the voluminous nature of Open-End yarns, it is extremely suitable to be produced as hand and machine yarn. However, the low strength of Open-End yarns shows itself as a negative effect.
