Question

Two cotton fibre varieties A and B having linear density of 3.2 and 4 (microgram/inch) respectively are tested on air flow instrument. The highest flow rate is obtained in case of

• A. Fibre A with maturity ratio 0.9
• B. Fibre B with maturity ratio 0.9
• C. Fibre A with maturity ratio 1.0
• D. Fibre B with maturity ratio 1.0

Hint:

In air flow testing, higher fibre fineness gives lower flow, while coarser and mature fibres give higher flow readings.

Answer 1

The Correct Option is D

Step 1: Principle of air flow instrument.
Air flow instruments measure fibre fineness indirectly by allowing air to pass through a compressed fibre plug. Coarser and more mature fibres create larger inter-fibre spaces, allowing higher air flow.
Step 2: Effect of linear density.
Fibre B has a higher linear density (4 microgram/inch) compared to Fibre A (3.2 microgram/inch), making Fibre B coarser. Coarser fibres permit greater air flow.
Step 3: Effect of maturity ratio.
A higher maturity ratio (1.0) indicates thicker cell walls and better fibre development, which increases the effective fibre diameter and air permeability.
Step 4: Combined effect.
The combination of higher linear density and higher maturity produces the maximum air flow.
Step 5: Conclusion.
Hence, the highest flow rate is obtained for Fibre B with maturity ratio 1.0.