Application Of Siro Spinning In Denim

siro spinning

With the influx of denim clothing into the market, it has gradually been loved by people for its free, spontaneous, unrestrained and sexy clothing characteristics. Now with the improvement of people’s living standard and the change of people’s consumption concept, denim pursues more comfortable, more personalized and more fashionable products. Denim yarn is also being transferred from airflow spinning to ring spinning, bamboo yarn, fancy yarn and new fiber yarn. Thus the application and promotion of new spinning technology is conducive to denim fashion and fashionable. This paper mainly introduces the yarn formation principle and structural characteristics of selvage spinning, the process optimization of selvage spinning in the spinning process, the main varieties of selvage spinning yarn for denim and its application in denim.

Modern and New Spinning Technologies

The Principles of Siro Spinning

Siro spinning was initially used in pure spinning and blending of wool and wool-type chemical fiber, and in recent years, cyclo-spinning has been widely used in cotton spinning process. Siro spinning cotton spinning equipment transformation is relatively simple, it only needs to ring spinning spinning machine roving frame slightly modified, add more than double the hanging spindle, and then use a certain interval of the double trumpet can be. The spinning principle is as follows: in the ring spinning spinning machine two roving at the same time through a double horn, fed into the same drafting area, because the mouth of the horn has a certain interval, so that the drafting area of the two whiskers to maintain the separation of the state of the two whiskers, after drafting whiskers from the front of the rollers after the output of a certain length of the merger, by the same ingot twisting, the formation of similar to the structure of the double-stranded yarn.

Structural Features and Advantages of Siro Spun Yarn

Due to the different process of Siro

spinning, compared with other denim yarns: air-flow spinning yarn, ordinary ring-spun yarn and strand, and compact spinning yarn, it has its following characteristics and advantages:

  • The hairiness of CYLOSPUN yarn is less than that of ordinary ring-spun yarn, especially the long hairiness of more than 3m is well improved. Because the selvage spinning yarn in the twisting, two whiskers for each other as the center twisted into a selvage yarn, twisting triangle becomes narrow. At the same time, during the winding process, the hair feathers sticking out of the main body of the selvage are rolled inside the yarn and are well gripped. In this way, since the hairs are rolled into the yarn by the two rovings, there is no significant increase in hairiness when going through the winding process as in other spinning methods. Because of less hairiness of the finished yarn, it has greater advantages in the process of sizing, dyeing, weaving and burnishing, etc. The woven denim has clear texture, good abrasion resistance and good anti-pilling and pilling performance.
  • Because of Sailor spinning adopts two roving drafting at the same time, so it has more obvious effect on improving the yarn stem. At the same time, due to the twisting of two whiskers, the yarn strength is stronger than that of single yarn.
  • Generally speaking, the whiskers after drafting are twisted in the same direction and synchronously, so that the yarn has a special structure, and the fibers on the surface of CYLOSPUN yarn are neatly arranged, and the yarn structure is compact. Compared with airflow spinning yarn which is loose on the outside and tight on the inside, the fabric surface of siro spinning yarn is softer than that of airflow spinning yarn. Compared with ordinary ring-spun yarn, which is tighter on the outside and looser on the inside, the surface of cloth made from selor spinning yarn is stiffer than ring-spun yarn. Denim woven with siro yarn has a soft handfeel between airflow yarn and ring spun yarn, with moderate drape and stiffness, and is more slippery.
siro spinning

Optimizing Siro Spinning Processes for Denim

The spinning count of the yarn for denim is relatively low, so the process parameters should be optimized in the spinning process, so that the quality of the finished yarn can meet the requirements, and the spinning life is good to do.

  • To reasonably select the roving quantitative and twist coefficient. Sailor spinning using two roving feed, roving ration to be light design, which helps to reduce the fibers in the spun yarn drafting process shift deviation, improve the yarn stem. When spinning denim yarns below 12 counts, the roving weight adopted by our company is 6.5g/10m. At the same time, in order to ensure the normal spinning of spinning yarn, the roving twist coefficient should be small, which is conducive to drafting. However, if the twist factor is too small, the spinning process will easily break the roving, resulting in long and young yarns and wrong count yarns. Our company adopts 123 as the twist factor of roving.
  • The specification of siro Spinning flapper should be preferred. The specification of double bell is mainly determined by the hole diameter and hole distance. The hole distance of bell is the distance between two roving feeds, which affects the yarn hairiness and yarn breakage. When the hole spacing is small, the yarn breakage is less, but the structural characteristics of Sailor spinning are not obvious, and the improvement of yarn hairiness is not big. Large hole distance is favorable to improve the yarn hairiness, but the yarn breakage will increase if it is too large. After continuous comparative tests, our company chose $2.5×4.5 flare to spin low-count denim yarn. The spun yarn has less hairiness and the life of the spinning machine is guaranteed to be normal.
  • The spinning process can be used to improve the life and yarn details by increasing the twist rate and weight of the wire ring appropriately.
  • The winding process should adjust the parameters of the twister to ensure the normal quality of the joints. At the same time to set up a good electric cleaning process, the single roving spun into a long young yarn and wrong branch yarn defects, to be effectively removed.
Siro Spinning1

Varieties and Applications of Siro Spun Yarn in Denim

Due to its unique yarn structure and good fabric effect, the application of CYLOSPUN technology in denim yarn is becoming more and more widespread. Now in the market, the main use of the selvage spinning technology to spin: selvage core yarn, selvage bamboo yarn, selvage combed yarn, low-twist yarn and so on denim yarns.

  • Spandex core yarn has good elasticity performance, mainly used for weaving stretch denim, weaving cloth wrinkle resistance performance is good, with a certain degree of non-iron sex. So elastic denim has always been a large series of varieties of denim. But the core yarn into the yarn strength is relatively low, the strength of uneven rate is high, easy to cause the weaving process more breakage. Moreover, the core yarn is prone to spandex core exposure, empty sheath and other yarn defects during the spinning process. However, spinning core yarns with the Cyclo-spinning technology can keep the core filament in the center of the two whiskers, with good covering effect. Siro Core Yarn, with the common advantages of Siro and Core Yarn, is an upgraded product of ordinary Core Yarn.
  • Siro Slub Yarn, due to the neat arrangement of yarn fibers, less hairiness. This makes the bamboo knots on the surface of the cloth more clear, concave and convex, and the sense of three-dimensionality is stronger.
  • With the improvement of consumers’ requirements for wearing comfort of denim clothing, the application of combed yarn in denim has become more and more widespread in recent years. Especially with cotton Sailor combed yarn for warp weaving out of denim, because of the yarn hair feathers less, less cotton impurities, with similar characteristics of the strand, so that the surface of the cloth is smooth, clear texture, feel soft, smooth. It greatly improves the grade of denim and forms a new series of high-grade denim.
  • Under normal circumstances, the twisting degree of the selvage spinning yarn is on the high side of the design, but in order to pursue the ultimate softness of the denim fabric, the selvage spinning yarn adopts the low twist design to realize. Low twist makes the fibers inside and outside the yarn transfer less and arrange in a more orderly way, so as to achieve the ideal fabric effect. However, the low twist makes the yarn strength decrease and the hairiness increase accordingly, so the raw material should be selected firstly to ensure the strength of the yarn. At the same time, spinning and winding should be done at a correspondingly low speed to ensure the hairiness of the finished yarn.
  • Under the same normal condition, the twisting direction of the spinning spinning yarn adopts “2” twist, but the strands are usually “S” twist, in order to give full play to the characteristics of the strands, the spinning yarn can also be produced with “S” twist. In order to fully utilize the characteristics of the type of strands, Sailor spinning can also be produced with “S” twist. At present, “S” twisted selvage yarns are seldom used in denim, but are used in special knitting yarns.
Spinning triangle for different spinning systems


Siro Spinning is a new spinning process, relative to the traditional ring spinning, the equipment modification is simple, but to correspondingly increase the investment in the former spinning equipment to ensure the supply balance. It is through the mechanical winding to realize the reduction of yarn hairiness, due to the use of double roving feeding into the drafting area, so it is relatively suitable for spinning medium and low count yarns, not suitable for spinning high count yarns. CYLOW SPINNING should improve the operation level and strengthen the management in order to spin into yarn with good quality and high value-added products.