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.
Answer:
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"

FAQ in cotton spinning-5

FAQ in Cotton Spinning-5

Question: What is the function of calender rollers.
Answer: The function of calender rollers primarily is:
a. To draw the web away from the doffer at a uniform rate as fast as it is stripped.
b. It exerts sufficient pressure on the sliver in order to reduce the bulkiness of this sliver.

Question: How diameter of trumpet hole varies with the thickness of the sliver.
Answer:

Diameter of hole in inches= constant x sqrt (grains/yard of sliver)

constant= 0.022

Question : How does the setting to the following pair of card points affect the quality of sliver produced.
Answer:
Taker in to cylinder: wider settings: creates neps and licker-in gets covered with fibres.
Back Plate to cylinder: wider setting causes fly to blow between flats.
Flats to cylinder: Closer settings gives better quality.
Front Plate to cylinder: closer setting-> reduces the weight of flat strip. wider setting-> results in heavier flat strips.
Doffer to cylinder: wider settings-> creates more neps as fibres go round the cylinder unnecessarily more times.
Feed plate to Licker in : wider settings-> lap is plucked without sufficient opening. So web quality is reduced.

Question: What are different types of carding wastes and their constituents
Answer: Licker- in waste-> short fibres, trash.
Flat Strips-> cotton fibres (short)
Stripping waste ( on cylinder and doffer wire)-> short fibres and trash

Question: Why flexible wire clothing is preferred over metallic wire clothing for running long fibres.
Answer: It is observed that flexible fillet has a more gentle carding action and gives lesser damage to good fibres.

Question: Why draw frame is needed
Answer: The fibres in a card web lie haphazardly criss cross to the web. Besides, fibres have either one or both end bent into the form of hooks. These haphazard fibres are required to be straightened and parallelised to the possible extent, also evenness and regularity of sliver is improved.

Process Control in Cotton Mixing

Process Control in Cotton Mixing

These two lectures answer the following questions:

1. How can I decide about cotton mixing for denim.

2. How can I decide about cotton mixing for making knitted fabric.

3. What is information required for an optimum cotton mixing.

4. What is an ideal cotton mix.

5. What are the steps to create an optimum cotton mix.

6. What are the four components of yarn quality. How each of these is affected by fiber quality.

7. What values of yarn quality parameters can be obtained from a cotton mix of particular fiber attribute.

8. For some pre specified values of yarn characteristics, what are the average values of fibre attributes that we should in cotton mix.

9. What are the various problems due to cotton mixing vairations, case study of fabric barre.

The answers to the above questions will be found here.

FAQ in cotton spinning-4

FAQs in Cotton Spinning
Q. Discuss about the feed rolls used in opening machine with given headings.
(i) Definition, (ii) Construction, (iii) Fundamental, and, (iv) Types of feeding
Q. Define the beater in opening machine.
Q. What are the objects of beater?
Q. Express the drafts and their calculation. What is the difference between the actual draft and mechanical draft?
Q. What are the objects of carding? How are these objects fulfilled
Q. What is meant by card clothing? With a neat sketch show the parts of a card clothing.
Q. What is meant by neps in carding?
Q. Mention and briefly explain the factors in judging the quality of carding.
Q. What are the effects of doubling
Q. Explain about the function of drawing rolls used in drawing frame.
Q. What is meant by cotton combing?
Q. What are the objects of combing? Explain briefly how these objects are fulfilled.
Q. List the various yarn characteristics improved by combing.

Please see the answers to these questions here