Carding
* Carding is defined as the reduction of entangled mass of fibres to filmy web by working them between two closely spaced relatively moving surfaced closed with sharp points.
* Carding is called the Heart of Spinning.
Card Settings
What is card setting and why is it important? Mention some important settings in carding machine.
Setting means maintaining the right tolerance of space between two working organs of the machine such as between taker-in and cylinders, cylinder and flats, cylinder to doffer etc.(Setting is the distance between two working organs)
Incorrect setting affect working efficiency of the machine and quality of processed material. Therefore card settings are very important and crucial for the process
Some of the important settings for cotton are as follows:-
Feed plate –taker-in =10-12 thou
Taker-in-cylinder =7 thou
Flat – cylinder =10 – 12 thou
Cylinder-doffer =4 -5 thou
Setting depends upon type of fiber (cotton, synthetic) and its dimension (length, fineness) and production rate.
Setting is increased between feed plate and taker-in, if fiber length is increased.
Setting between flats and cylinder is reduced for finer fibers.
Settings are increased between feed plate-takers and flat-cylinder for polyester and acrylic fibers compared to cotton.
XXXXXXXXXXX
Coiler mechanism of carding machine
Sliver is stored in cans in a particular mechanism which is called sliver coiling.
Objects of coiling:
i ) To lay the condensed sliver delivered by the calendar rollers in an orderly manner in a cylindrical can.
ii) To pull out sliver from the can for the next process without entanglement or stretching.
The coiler gets its drive from the bottom calendar roller shaft through a gear (H) which drives the vertical shaft 3 through level gears G) and (F). At the top of the vertical shaft there are two more level gears (I) and (J) through which coiler calendar rollers get motion.
A tube wheel (7) is driven by the fear D. An inclined coiler tube (6) collects the sliver from the nip of the coiler calendar rollers. The lower end of the coiler tube is provided with an exit for the sliver at a point near its periphery so that the sliver is laid in circular coil into the can.
The can is positioned on the bottom plate through reduction gearing from the bottom of the vertical shaft at a slow speed.
Figure (1-bottom calendar roller, 2-Top calendar roller, 3-vertical shaft, 4-coiler trumpet, 5-coiler calendar roller, 6- coiler tube,l 7- gear on coiler tube, 8-drive to the can plate, 9 –can, 10-canplate gear.
Laying down of sliver
Cycloidal deposition of sliver has proved to be most advantageous method of filling a can. In this process, two shifting movements of deposition point are carried out simultaneously. AS the coiler plate and the can both are rotating, the delivered sliver continuously deposits in the can on a circle but the deposition point of the circle is constantly shifting, so a helical arrangement of the circle is produced within the can.
Objectives of Carding machine
Opening individual fibres.
Elimination of dust.
Elimination of remaining impurities.
Detangling of neps.
Elimination of short fibres.
Fibre blending.
Fibre orientation.
Producing a uniform & continuous card sliver.
Objects of Draw Frame
* To straighten the crimped & hooked fibres the carded sliver.
* To do the parallelization of the fibres along the sliver axis.
* To improve the short, medium & long term unevenness of the sliver by doubling.
* To produce a more uniform sliver of definite wt/unit length.
* Mixing/Blending.
Tasks/Functions of Draw Frame
Drawing:
A process in short staple spinning in which the slivers are blended, doubled, leveled & drafted by passing the slivers through a series of pairs of rollers, each pair moving faster than the previous one is known as drawing process.
Doubling:
The process of combing two or more slivers, rovings or yarns into one. This term is not restricted to the combination of two units. Example: 2:1, 4:1, 8:1 etc.
Drafting:
The action of reducing the thickness or linear density of the feed material
( Sliver, lap, slubbings, roving) by drawing is known as drafting.
Creeling:
The operation of replacing the cans of feed material at the back of the sliver to the old is known as creeling.
Doffing:
The operation of removing the full delivery cans from the front of the machine replacing by empty can is known as doffing.
Elements of Drafting arrangements
1. Bottom roller.
2. Top roller.
3. Top roller pressure.
Speed Frame
Simplex or Speed Frame or Roving Frame is an intermediate process in which fibers are converted into low twist lea called roving.
The sliver which is taken from draw frame is thicker so it is not suitable for manufacturing of yarn. Its purpose is to prepare input package for next process. This package is to prepare on a small compact package called bobbins.
Objects/ Functions of Speed Frame
Attenuation of drawn sliver to form roving of required count by drafting.
Insert small amount of twist to give required strength of roving.
Wind the twisted roving on to the bobbin.
Build the roving in bobbin such a form which will facilitate handling, withdrawing & transfer to the next process.
Operations Involved in Simplex Machine
1. Creeling
2. Drafting
3. Twisting
4. Winding
5. Building
6. Doffing
PARTS OF SIMPLEX &THEIR FUNCTIONS
* Bottom steel fluted rollers
* Top rollers
* Aprons
* Pressure arm
* Cradle assembly
* Flyer
* Condenser
* Top & bottom cleaners
* Bobbin Rail
Ring Frame
Ring spinning is a method of spinning fibres, such as cotton, flax or wool, to make a yarn.
In ring spinning, the roving is first attenuated by using drawing rollers, then spun and wound around a rotating spindle which in its turn is contained within an independently rotating ring flyer.
Task and Operation involved in ring frame
1. Creeling:
Roving is arranged on the top of the ring frame by the creel on the both side of the machine. Creel helps to move the roving bobbin freely and hold such that, roving fed to the drafting zone on tension.
2. Drafting:
Drafting reduce the wt/unit length of roving. Roving comes out from the roving bobbin are passed through the drafting zone.
3. Twisting:
Spiral turns are imparted along the fibre axis. It increases yarn strength. The traveller which helps to insert twisting on the yarn, gets drive directly from spindle.
4. Winding:
After twisting, The yarns are wound on a suitable package for storage, transportation & processing for the next process.
5. Building:
For proper size & shape of the package, the bobbins are lifted gradually. The resultant bobbins are conical shaped full bobbin.
6. Doffing:
After required length of yarn is wound on the package, the m/c is stopped for replacement of the full bobbin by an empty package.
Operating diagram of Ring frame machine:
1-Roving bobbin
2-Leading part
3-Holders
4-Guide rails
5-Drafting arrangements
6-Collection of waste
7-Thread guide
8-Spindle
9-Traveller
10-Ring
