Question

In Comber preparatory, as the Pre-Comb draft increases, the Noil % will

• A. First increase and then decrease
• B. First decrease and then increase
• C. Decrease
• D. Increase

Hint:

Higher pre-comb draft reduces fibre control and generally increases noil percentage in combing.

Answer 1

The Correct Option is D

Concept: In comber preparatory (lap preparation or draw frame stage before combing), the pre-comb draft plays an important role in fibre arrangement and control. Draft determines how much the fibre strand is attenuated before entering the combing process. When draft increases beyond the optimal limit, fibre control becomes weaker, leading to more short fibre separation during combing, thereby increasing the noil percentage.

Step 1: Understand pre-comb draft effect.
Pre-comb draft controls fibre alignment and cohesion before combing. \[ \text{Higher draft} \Rightarrow \text{Lower fibre cohesion} \]

Step 2: Relate draft with fibre loss.
When fibre cohesion reduces:
• Short fibres are more easily removed
• Fibre control at nippers becomes weaker \[ \text{Result: Noil \% increases} \]

Step 3: Check trend behavior.
As pre-comb draft increases continuously: \[ \text{Noil \% increases progressively} \]

Step 4: Final answer selection.
Thus, \[ \boxed{\text{Increase}} \] So, \[ \boxed{\text{Option (D) is correct.}} \]