2. The Card
It is always considered by the experts that card is the heart of the spinning
mill.
The statement “Well-carded is half-spun” demonstrate the immense
significance of carding for the final result of the spinning operation.
The importance of carding is still greater where new spinning systems are
concerned.
The considerable influence of the card on yarn quality arises from the very
complex series of events in the process itself and also from the pressure
to adopt an extremely high production rate on economic grounds.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 2
4. Taker-in
Flats
Main cylinder
Cleaning unit
Doffer
Detaching Apparatus
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 4
5. The Tasks of the Card
I-Opening to Individual Fibers
Whereas the blowroom opens the raw material only to flocks, The card must open to
the stage of individual fibers. This is essential to enable the elimination of impurities
and performance of the other operation to be achieved.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 5
6. The Tasks of the Card
II-Elimination of Impurities
Elimination of foreign matter occurs mainly in the region of the taker-in. Only a
small part of the contaminants is carried along with the flat stripping or falls out at
other positions.
The degree of cleaning
achieved by the modern
card is very high, in the
range of 80-95%. Thus, the
over-all degree of cleaning
achieved by the blowroom
and the carding together is
as high as 95-99%.
But card sliver still contains
0.05-0.3% foreign matter
normally. Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 6
8. The Tasks of the Card
III-Elimination of dust
In addition to free dust, which can be
directly sucked away as in the
blowroom, the card also removes a
large proportion of the microparticles
that are bound to the fibers.
Significant fiber/metal or fiber/fiber
friction is needed in order to loosen
such particles. Both are available at
the card in considerabe measure: the
card is a good dust-removing machine.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 8
9. The Tasks of the Card
IV-Disentangling of Neps
Whereas the number of neps increases from machine to machine in the
blowroom, The card reduces the remaining number to a small fraction.
It is often falsely assumed that neps are eliminated at the card; in fact, they are
mostly opened out.
Only a certain number of the neps leave the machine unopened via the flat
strippings.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 9
10. The Tasks of the Card
IV-Disentangling of Neps
An improvement in the disentangling of neps is obtained by:
• Closer spacing between the clothings;
• Sharper clothing;
• Optimal (not too low) speeds of the taker-in;
• Low doffer speeds; and
• Lower throughput.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 10
12. The Tasks of the Card
V-Elimination of Short Fibers
Short fibers can only be eliminated if they are pressed into the clothing.
Since that is not possible with metallic clothing only the flats can be considered
in this context.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 12
14. The Tasks of the Card
V-Elimination of Short Fibers
The ability to select short as opposed to long fibers is based on the fact that long
fibers have more contact with the clothing of the main cylinder than the short fibers.
Thus, longer fibers are continually caught and carried along by the main cylinder.
Short fibers, on the other hand, offer less surface to the clothing of the main
cylinder; they therefore stay caught in the flats’ clothing, press into it, and leave the
machine in the flat strippings.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 14
15. The Tasks of the Card
V-Elimination of Short Fibers
The card eliminates 1-2% of flat strippings. Approximately half of the
strippings are made up of short fibers.
The card therefore eliminates fewer than 1% of short fibers. In the
staple diagram, this is hardly noficeable - the inaccuracy of the staple-
measurement procedure is greater than the change in value.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 15
16. The Tasks of the Card
VI-Fiber blending
The card hardly improves long-term blending, since the residence time
of the material in the machine is too short. However, it improves
transverse blending because, apart from the OE-spinner, the card is
the only machine to process individual fibers.
In the formation of the web, and with the repeated rotation of the fibers
on the main cylinder, an intimate fiber-with-fiber mixing is achieved.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 16
17. The Tasks of the Card
VII-Fiber Orientation
The effect of parallelizing is often attributed to the card. This is not completely
justified, since the fibers in the web are not parallel, although they do have, for
the first time, a longitudinal order.
The parallel condition is achieved on main cylinder, but it disappears during the
formation of the web between cylinder and doffer.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 17
19. The Tasks of the Card
VIII-Sliver formation
In order to be able to deposit the fiber material, to transport it, and process it
further, an appropriate intermediate product must be formed.This output
material is called sliver.
In extreme cases, card sliver has a hank from 3 ktex (new spinning processes)
to 6 ktex. Generally, the hank lies between 4 and 5.5 ktex in the spinning mills.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 19
20. The Tasks of the Card
Autolevelling system
In order to be improve the quality of the sliver autolevelling system may be
used The autolevelling system provides lower mass variation in sliver.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 20
22. Operation Principle of the card
In modern installations, raw material is supplied via pipe ducting
(1) into the feed chute (2) of the card. An evenly compressed
web of about 500-900 ktex (g/m) is formed in the chute. (video)
1
2
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 22
23. Operation Principle of the card
A transport roller (3) passes material to the feed arrangement
(4). This consists of a feed roller and a feeder plate designed to
push the sheet of fiber slowly into the operating range of the
taker-in (5) while maintaining optimal clamping (video).
3
5
4
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 23
24. Operation Principle of the card
The portion of the sheet projecting from the feed roller must be
combed through and opened to flocks by the taker-in. These
flocks are passed over grid equipment (6) and transferred to the
main cylinder (8).
8
8
6
7
6
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 24
25. Operation Principle of the card
In moving past mote knives, grids, carding segments (6), etc., the
material loses the greater part of its impurities. Suction ducts (7)
carry away the waste. The flocks themselves are carried along
with the main cylinder to the flats (10) and are opened up to
individual fibers between these two devices in the actual carding
process.
10
6 7
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 25
26. Operation Principle of the card
The flats (10) consist of 80-116 individual carding bars combined
into a band moving on an endless path. Some 30-46 of the flats
are located in the carding position relative to the main cylinder;
the rest are on the return run. During this return, a cleaning unit
(11) strips fibers, neps, and foreign matter from the bars.
10
11
11
10
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 26
28. Operation Principle of the card
Fixed carding bars (9) and (12) are designed to assist the
operation of the card. The underside of the main cylinder is
enclosed by grids or cover plates.
12
9
9 12
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 28
29. Operation Principle of the card
After the carding operation been completed, the main cylinder
carries along the fibers that are loose and lie parallel without
hooks. However, in this condition, the fibers do not form a
transportable intermediate product. An additional cylinder, the
doffer (14), is required for this purpose. The doffer combines the
fibers into a web because of its substantially lower peripheral
speed relative to the main cylinder.
14
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 29
30. Operation Principle of the card
A stripping device (15) draws the web from the doffer. After
calendar rolls (16) have compressed the sliver to some extent,
the coiler (18) deposits it in cans (17). The working rollers,
cylinders, and flats are provided with a clothing that becomes
worn during fiber-processing, and these parts must be reground
at regular intervals and even replaced from time to time (video).
18
18
15 15 17
17
16 16
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 30
31. The Operating Regions of the Card
Feed of Material
In modern spinning installations, the card is the first machine to
deliver a cohesive intermediate product.
The product is expected to be very even and as far as possible free
of faults.
Irregularities in the sliver can be traced through into the yarn, at
least in the spinning of carded yarns; they diminish yarn quality.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 31
32. The Operating Regions of
the Card
The feed to the card must be very
even.
It is a minor problem where lap feed is
used since each lap checked for
accuracy of count.
However, in Flock-feed system, the
batts in the individual feed chutes of
all cards must be equally thick, evenly
distributed and must be of equal
density to achieve even feeding.
Also finely opened is required in
Flock-feed system due to greater
material throughput.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 32
33. The Operating Regions of the Card
Lap/Flock-feeding
Advantages of lap feeding :
1. Ease in the maintenance of constant lap thickness,
2. The blends can be allocated to individual machines, but in flock feeds only to
machine groups.
Disadvantages:
1. Greater manual effort in
transport and lap change;
2. More clean waste and faults
caused by lap-changing and
by correcting of faulty
changes;
3. An additional burden on the
taker-in because scutcher
laps are heavily compressed.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 33
34. The Operating Regions of the Card
The Taker-in
This is a cast roller with a diameter usually around 250 mm. A
sawtooth clothing is applied to it. Beneath the taker-in, there is an
enclosure of grid elements or carding segments.
The purpose of the taker-in is;
1. to pluck finely opened flocks out of the feed batt,
2. to lead them over the dirt-eliminating parts under the roller,
3. to deliver them to the main cylinder.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 34
37. The Operating Regions of the Card
a,b,c : Grid elements, 1- Feed plate, 2- Feed roller
3- Taker-in roller, 4- Main cylinder
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 37
38. The Operating Regions of the Card
The adjustments on taker-in are,
1. the thickness of the batt;
2. the degree of openness of the raw material in the feed stock;
3. the degree of orientation of the fiber in the feed stock;
4. the aggressiveness of the clothing;
5. the distance between the devices;
6. the rotational velocity of the taker-in; and
7. the material throughput.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 38
39. The Operating Regions of the Card
Main cylinder
The cylinder is usually manufactured from cast iron but is now
sometimes made of steel.
Most cylinders have a diameter of 1280 - 1300 mm and rotate at
speeds between 250 and 500 (or up to 600) r/min.
It is essential that the speed can be changed, i.e. exactly adapted to
the requirements according to the raw material, spinning process
etc., because the cylinder speed has some influence on yarn
quality.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 39
41. The Operating Regions of the Card
Beneath the cylinder, and fully enclosing it, is a grid made of sheet
metal provided with transverse slots. This is designed to remove
impurities and maintain constant air-flow conditions.
Flats creates a large surface area by its clothing strips. Long fibers
have more contact with the clothing of main cylinder than the short
fibers. Therefore the long fibers are carried along but the short
fibers’ edges are caught by the flat strippings and leave the
machine. The elimination is carried out by filling the clothing and the
flats then past by a cleaning device.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 41
42. The Operating Regions of the Card
The Doffer
The cylinder is followed by the doffer, which is designed to take the
individual fibers from the cylinder and condense them to a web. The
doffer is mostly formed as a cast-iron drum with a diameter of about
600-707 mm. It is fitted with metallic clothing and runs at speeds of
about 300 m/min.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 42
43. The Operating Regions of the Card
The Detaching Apparatus
In the last-mentioned system, either two counter-rotating belts carry the
web into the centre (a) or a circulating band carries the web to one side of
the card (b).
It is advantageous if these sliver formers can be so manipulated that web
sections can be taken out for checking of neps.
(a) Prof.Dr. A.Kirecci - TE 211 Yarn Man. I (b) 43
45. The Operating Regions of the Card
Crushing Rollers (Web Crushing)
Between the detaching roller (1) and the transverse sliver
condenser belt (3), some manufacturers include two smooth steel
rollers (2) arranged one above the other.
They can run without loading, in which case they serve simply as
guide rollers, or they can be loaded with a pressure of about 15
N/cm and are thus converted into crushing rollers.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 45
46. The Operating Regions of the Card
Crushing Rollers (Web Crushing)
Where cotton with a medium-to-high dirt content is being processed,
additional cleaning can be carried out here by squashing the foreign
particles.
The fragments fall away immediately afterwards or in the subsequent
machines.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 46
47. The Operating Regions of the Card
Coiling into cans
The material should be coiled into cans for the transport purposes.
This can be achieved automatically by having one spare free can
ready at anytime.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 47
48. The Operating Regions of the Card
Clothing
Of all the individual components of the card, the clothing has the
greatest influence on quality and productivity.
Mills now have to make a difficult choice between hundreds of
available clothing types, a choice of the utmost importance.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 48
49. Selection criteria are;
1. type and design of card;
2. rotational speed of the cylinder;
3. production rate;
4. material throughput;
5. raw-material type (natural or synthetic fibers);
6. fiber characteristics (mainly fineness, length, bulk, and dirt content);
7. over-all quality requirements; and
8. price of the clothing.
Prof.Dr. A.Kirecci - TE 211 Yarn Man. I 49
