Friday, 5 September 2008
FAQ in Cotton Spinning -6
FAQ in Cotton Spinning-6
Q. What type of hooks are there in the card web ?
Answer: Bulk of the fibres in the card web are found to have hooks at their rear ends, and they are termed as trailing hooks.
Q. What type of hooks are removed at the drawframes.
Answer: Hooks are preferentially removed when they are presented in the drafting field in trailing direction.
Q. What is doubling. How does this affect regularity of a sliver.
Answer: Doubling is feeding more slivers together into the drafting zone. It improves the uniformity of sliver.
Q. Why we cannot offer a high draft in one go.
Ans: The resistance offered by the disorderly state often results in a greater unevenness in the drawing material.
Q. What can be the drawbacks of excessive parallelisation.
Ans: Slivers with high parallelisation become soft and their withdrawl from cans at later stages results in excessive creel breakages.
Q. What is roller slip
Ans: Top rollers are no positively driven. They are made to bear against the bottom fluted rollers with a suitable weighting arrangement. The motion transmission to the top roller is through the bulky sheet of fibres. Thus the speed of top roll is not the same as botton roll. This fall in speed of top roller is termed as roller slip.
Q. what will happen due to roller slip
Answer: The roller slip produces characteristic drafting waves or unevenness characeristics.
Q. What is a drafting wave
Answer: The irregular motion of short fibres between pairs of rollers give rise to a wave like formation that is known as drafting wave.
Q. What is the principle applied in roller setting over 44 drafting system.
Front and second pair= effective length + 1/8 "
2nd and Third pair= eL+ 1/8"+1/8"
3rd and Back Pair= eL+1/8"+1/8"+1/8"