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

FAQ in cotton Spinning-3

FAQ in cotton spinning-3

Q: What are condensers, what is their role ?
Answer: These are perforated cage rollers. They supply a current of air at a high velocity, convey the cotton uniformly from stage to stage and incidently, perform a bit of cleaning by carrying away the floating dust, impurities and short fibres to a separate collection centre.

Q. What is difference between the conventional and the modern blow room lines.
Answer: Modern blowroom lines have more opening points and fewer beating points.

Q. What is the object of carding.
Answer: The objects of carding are three:
1. To open out thoroughly the tiny lumps so that every fibre becomes individualised and the cotton is no more in an entangled state.
2. To remove all impurities, neps, short fibres etc. which have escaped the blowroom action.
3. To prepare the well cleaned material into a compact sliver form and lay into containers for subsequent processes.

Q. Name the three major regions where cleaning takes place.
Answer: Taker-in and flats.

Q. What are the constituents of flat strips.
Answer: The flat strips are mostly short fibres with some of the impurities like kitty leaf bits etc.

Q. Why speed of licker-in is kept less for longer staples.
Answer: Longer fibres are held for longer time by the bite of the feed roller after the licker-in starts working on them. As a result more teeth act on the fringe of the fibres and there is every chance of fibres getting damaged.

Q. What is back plate. What is its function.
Answer: This ia a curved plate covering the cylinder just above the licker-in and its main function is to keep the fibre bunches delivered by licker-in, remain on the cylinder wire till they are taken by the flats. This also helps to prevent the development of undesirable air currents.

Q. What is front plate. What are its purposes. Why it is called percentage plate.
Answer: This is a plate similar to back plate and is fitted at the front just above the front door. This has a three fold purpose namely:
1. To keep the cylinder surface covered in order to prevent the fibres from flying off.
2. To keep all other material away from cylinder.
3. To provide the opening for stripping and grinding the cylinder.

It is known in America as 'percentage plate' as its adjustment helps to regulate the quantity of flat strips.