APPARATUS: Carding machine
THEORY: There are four main objective of carding:
- fibre to fibre opening
- parallelization of fibre
- sliver formation
- removing trash,
- fibre fragments,
- very short fibre and nepscarding machine consist of following parts :lap roller, feed plate ,feed roller ,taker inn ,carding plate ,main cylinder ,stationary flats ,revolving flats ,brush roll ,doffing rollers ,stripping roller, crushing roller, trumpet, calendring roller, coiler.
WORKING PRINCIPLE: The main objective of taker inn is cleaning,for increasing cleaning intensity we can increase number of rollers but maximum we can use 3 rollers, there is also a grid bar arrangement. The profile of taker inn is coarse than profile of main cylinder and doffer.
In main carding zone there is a main cylinder whose speed and circumfernce is greater than taker inn. Above main cylinder there is a revolving flats arrangement.There is total 80 flats in which 30 are in working condition, distance between flats and cylinder is equal to staple length.lever is also present there to move cylinder upward and downward.
Flats are used to produce combing effect and to remove short fibres because short fibres stick on the profile of flats and when these flats move upward there is a brushing rollers which remove short fibres from flats.doffers are placed in stripping zone doffers are used to collect material from main cylinder and transport it forward.crushing rollers are used to crush seed coat present in web.trumpet is used to give funnel shape to the web(sliver).
FLOW OF MATERIAL: We feed sheet of cotton to feed plate it goes forward to the feed roller, behind feed roller taker inn is present then material goes to the main cylinder.In this step fibre to fibre opening and blending occurs because diameter of taker inn is small as compare to the size of main cylinder,when sheet come from taker inn to main cylinder it is not completely filled to move it forward to doffer then second sheet come from taker inn which spreads on main cylinder than blending of first and second layer occur and ratio is depend upon us.
Flats present above the main cylinder provide combing effect and the objective of parallelization of fibre is also acheive in this process. Doffer collects the material from main cyider and transport it to the striping roller and it is also called web collecting roller,stripping roller forward material to the crushing roller then material goes to the trumpet, trumpet gives circular sape to the web and then calendring rollers stabilize web by compressing it hence sliver is formed then coiler passed the sliver to the cane by the help of guiding rollers/
RESULT: In the end of carding the result which was acheived is carded/
