Question

In the twisting zone, if the rear end of the fiber is not in the nip of the delivery rollers of the ringframe, the fiber will be under no control, which causes \(\underline{\hspace{2cm}}\)

• A. Hairiness
• B. Nep
• C. Thick place
• D. Nap

Hint:

Think of a spinning figure skater. When they pull their arms in, they spin faster. When they extend their arms out, the arms fly outwards due to centrifugal force. An uncontrolled fiber end acts like the skater's extended arm, flying outwards and creating hairiness.

Answer 1

The Correct Option is A

Step 1: Understand the scenario. The question describes a situation in the twisting zone of a ring frame. A fiber's front end is held by the delivery rollers, but its rear end is free because it's shorter than the drafting distance. This free, trailing end is not under tension or control. 
 

Step 2: Analyze the effect of the rotating yarn. As the yarn balloon rotates at high speed to insert twist, this uncontrolled, trailing fiber end is subject to centrifugal force. 
 

Step 3: Determine the outcome. The centrifugal force will throw the trailing end of the fiber outwards, away from the body of the yarn. This protruding fiber end becomes part of the yarn's "hairy" surface. This phenomenon is a primary cause of yarn hairiness, especially from shorter fibers in the blend. 

Conclusion: An uncontrolled fiber end in the twisting zone is thrown outwards by rotation, causing yarn hairiness.