Question

The main reason for generation of hairy yarn in the twisting zone of ring frame is

• A. rear end of fibre is not gripped
• B. both the ends of fibre are not gripped
• C. leading end of the fibre is not gripped
• D. both the ends of fibre are gripped

Hint:

To reduce hairiness, modern "compact spinning" systems use pneumatic suction to condense the fiber strand, ensuring all leading ends are tucked in before twisting occurs.

Answer 1

The Correct Option is C

Concept: Yarn hairiness refers to the presence of fiber ends or loops protruding from the main body of the yarn. In ring spinning, hairiness is primarily generated at the "spinning triangle" situated between the delivery rollers and the first point of twist.

Step 1: Dynamics at the Delivery Roller.
As the fiber strand leaves the nip of the front delivery rollers, it spreads out to form a triangle. Ideally, all fibers should be twisted into the yarn core. However, individual fibers behave differently based on their position.

Step 2: Mechanism of Hairiness.
The leading end of the fibre (the front end moving toward the yarn) is the most critical. If the leading end is not immediately caught by the twisting yarn and tucked into the core, it stays outside. Centrifugal forces and the geometry of the spinning triangle then cause this un-gripped end to protrude, creating a "hair." While the trailing (rear) end can also cause hairiness, the failure to grip the leading end is the primary culprit in the twisting zone.