Here is the working principle and structure of the rotor-spinning machine.
Spinning technology today cannot exist without open-end rotor spinning. Quick recognition and equal exploitation of its numerous advantages have been made, both from an economic and textile standpoint.
Read and learn how the rotor-spinning machine works.
How Does the Rotor-spinning Machine Work?
The goal of the rotor spinning machine is to produce centrifugal force within the rotor by operating it at a high speed.
- The opening roller first drafts and opens the input sliver. To the rotor, where the fiber strand is subjected to twist insertion, the fibers are delivered via a tube.
- The output yarn is then wound into “cheese” or “cone” packages of the necessary size after twisting. The input sliver may be drawn or carded. A drawn sliver is typically employed. A feed roller that works in tandem with a spring-loaded feed pedal pulls the sliver through a condenser. The location of the fiber bundles entering the opening roller is determined by the nip point between the feed roller and feed pedal.
- In its cross-section, a sliver may contain more than 20,000 fibers. Accordingly, a yarn with a cross-sectional area of 100 fibers will need a 200-draft total.
- As compared to ring spinning, this draft is significantly greater. In order to draft a rotor, an opening roller (mechanical draft) is used to first open the input sliver. This is followed by an air stream (air draft).
- The opening roller combs out the fibers’ leading ends as it rotates quickly. The separated garbage is gathered in the center chamber and can be taken out from there. A transport tube draws in the fiber from the opening roller, which is then deposited into the rotor’s inner grooved surface.
- The transport tube has been tapered to create an accelerating air stream that straightens the fibers. These two processes generate enough draft to reduce the 20,000 fibers that enter the opening roll to a small number of fibers (2–10 fibers) at the transport tube’s exit.
- Mechanical twisting is used to achieve consolidation in rotor spinning. The torque that causes the yarn to twist is applied by the rotor’s rotation.
- The ratio of the rotor speed (rpm) to the take-up speed (meters/min) determines the amount of twists (turns per meter). The rotor produces a turn of twist with each rotation. The drafting and twisting processes are entirely distinct from the winding process during rotor spinning.
Operations of Rotor Spinning Machine
The rotor spinning machine is unlike any other machine in the short staple spinning mill in the range of tasks it has to perform, namely all the basic operations:
- Sliver feed: Through a feed roller, feed table, and opening roller that rotates quickly, a card or draw frame sliver is fed.
- Sliver opening: The individual fibers from the sliver clamped between the feed table and feed roller are combed out by the opening roller’s rotating teeth. The fibers are fed to the fiber channel after leaving the rotating opening roller.
- Fiber transport to the rotor: The fibers disengage from the opening roller and move through the fiber channel to the inside of the rotor via centrifugal forces and a vacuum in the rotor housing at a predetermined point.
- Fiber collection in the rotor groove: The fibers move from the conical rotor wall toward the rotor groove due to centrifugal forces in the quickly rotating rotor, where they are gathered to form a fiber ring.
- Yarn formation: When a spun yarn end exits the draw-off nozzle and enters the rotor groove, the rotor’s rotation outside the nozzle imparts a twist to the yarn, which then continues inside the rotor. The nozzle, which serves as a twist retention component, helps the yarn end rotate around its axis while it continuously twists the fibers deposited in the rotor groove.
- Yarn take-off, winding: The delivery shaft, pressure roller, draw-off tube, and nozzle continuously remove the yarn that has been formed in the rotor, winding it onto a cross-wound package. Several sensors monitor the quality of the yarn and the movement of the yarn between takeoff and the package. If any pre-selected values are exceeded, the sensors start the yarn-clearing process.
Applications of Rotor Yarns
End products made with open-end yarns exhibit a variety of characteristics. When uniformity and a smoother surface are essential for fabrics, these yarns can be used to good effect.
In pile fabrics, clothing, household, industrial, and technical applications, open-end yarns are utilized. Heavyweight satin and poplins, corduroy, velveteen, rainwear, drills, printed fabrics, curtains, window blinds, upholstery, cleaning cloths, dress goods, underwear, rugs, carpets, blankets, terry towels, and diapers are just a few examples of the uses for these materials.
Conclusion: How Rotor Spinning Machine Works?
The draw frame supply’s fibers are divided into separate supplies on an opening roller, carried away by an air stream, guided through a fiber guide channel, and fed to the rotor. The fibers lay down and create a ring inside the housing of the rotating rotor.
The fibers are drawn from this rotating ring in a direction that is roughly perpendicular to the fiber ring’s plane. As the fibers leave the fiber ring plane, the rotation of the rotor causes twists in the fibers. This causes the fibers to become more tightly packed together, i.e., to form a yarn.
What is the Peel Off Point in Rotor Spinning?
The point where the fibers leave the rotor surface is called the “peeling point” and is identified as Point “P.” The peeling point advances in the same direction as the rotation of the rotor, shown by Arrow “a.” The number of turns per inch of twist inserted into the yarn determines how quickly this point advances.
What Are the Disadvantages of Rotor Spinning?
The main disadvantage is that rotor-spun yarns are not as strong as ring-spun yarns, and the maximum tenacity of rotor-spun yarns is at least 10–30%, and in some cases even up to 40%, lower than that of ring-spun yarns.
What is the Mechanism of Yarn Formation in Rotor Spinning?
When a spun yarn end exits the draw-off nozzle and enters the rotor groove, the rotor’s rotation outside the nozzle imparts a twist to the yarn, which then continues inside the rotor.