Question

A roving of 2 Ne count is fed to a ringframe set with a mechanical draft of 30. If the length of the drafted strand delivered from the nip of the front rollers is reduced by 3% due to twist then the count (Ne) of the yarn, (rounded off to one decimal place), is \(\underline{\hspace{2cm}}\).

Hint:

To adjust the count of yarn after drafting, use the drafting ratio and apply it to the original count.

Answer 1

Correct Answer: 58

The count of the yarn after drafting is related to the original count and the draft. The formula for count adjustment due to drafting is: \[ Ne_{\text{new}} = Ne_{\text{old}} \times \frac{1}{\text{draft}}. \] Given that the draft is 30, and the yarn is reduced by 3%, the new count \( Ne_{\text{new}} \) is: \[ Ne_{\text{new}} = 2 \times \frac{1}{1 - 0.03} \approx 2.07. \] Thus, the new count of the yarn is \( 2.1 \).