SRI LAKSHME ENGINEERING
OVERVIEW ABOUT OPENEND SPINNING MACHINES
Introduction :
Rotor Spinning is a more recent method of yarn formation compared to Ring Spinning. This is a form of open-end spinning where the twist is introduced into the yarn without the need for package rotation. Allowing for higher twisting speeds with a relatively low power cost.
Ring vs. Open-end Spinning
| Ring Spinning | Open-end Spinning |
| Bobbin rotates constantly for insertion of twist | Spool does not need to be rotated to insert twist |
| Cannot handle spools of bigger size | Much larger spools can be wound |
| Can spin finer yarns | 3-5 times faster than ring spinning |
| Uniform and strong yarn | Uniform but flexible yarn with better dyeability |
| Combed yarns (finer) | Carded yarns (coarser) |
| Yarns for varied applications | Yarns for heavier fabrics such as denim, towels, and poplins |
| Stronger | 20% more twisted but 15-20% weaker as the yarn is coarser |
| Suitable for all staple fibers | Not suitable for man-made staple fiber spinning except rayon as the fibre finish clogs the rotor |
In rotor spinning a continuous supply of fibers is delivered from delivery rollers off a drafting system or from an opening unit.
The fibers are sucked down a delivery tube and deposited in the groove of the rotor as a continuous ring of fiber. The fiber layer is stripped off the rotor groove and the resultant yarn wound onto a package. The twist in the yarn being determined by the ratio of the rotational speed of the rotor and the linear speed of the yarn.
Sliver is fed into the machine and combed and individualized by the opening roller. The fibers are then deposited into the rotor where air current and centrifugal force deposits them along the groove of the rotor where they are evenly distributed. The fibers are twisted together by the spinning action of the rotor, and the yarn is continuously drawn from the center of the rotor. The resultant yarn is cleared of any defects and wound onto packages.
BENEFITS
The production rates of rotor spinning are 6-8 times higher than that of ring spinning and as the machines are fed directly by sliver and yarn is wound onto packages ready for use in fabric formation the yarn is a lot cheaper to produce.
Rotor spun yarns are more even, somewhat weaker and have a harsher feel than ring spun yarns. Rotor spun yarns are mainly produced in the medium count (30 Ne, 20 tex) to coarse count (10 Ne, 60 tex) range. End uses include denim, towels, blankets socks, t-shirts, shirts, and pants.
| Figure 2 : Block diagram of Process Flow in Open end spinning. |
| a device for drafting the fibrous mass into individual fibres, | |
| a means of transporting the fibres to the yarn end, | |
| a device for collecting the separated fibres onto the yarn end in a manner that enables the correct yarn count to be obtained, | |
| a device for rotating the yarn end to insert twist into the collected fibres, and | |
| a means of winding the yarn on to the package. |
LATEST TRENDS IN OPEN-END SPINNING
Open-end spinning produces a different type of yarn to ring frame spinning. Open-end yarns tend to be more uniform, lower in strength, more extensible, bulkier, more abrasion resistant and more absorbent.
Rotor spun yarn is more economical than ring spun yarn by virtue of its higher production rate and the condensed process involved in making the yarn.
Usage of Manmade fiber like RECYCLED Hosiery material gives competitive advantage like,
1. Increases productivity.
2. Less waste in production process.
3. Waste cloth recycling process opens a new area in Spinning.
4. Less contamination in material increases productivity in OE mill.
5. Dyeing Process is completely Avoided in Recycled Cotton Yarn.
6. For Looms, raw material cost is reduced by 20%.
7. All Colors are available, results in Zero Dyeing cost.
8. Increases Benefits, Increases demand for COLOUR Yarn.