1. Carding – Introduction
“The Card is the heart of the Spinning Mill”
“Well Carded is half spun”
- These proverbs demonstrate the immense significance of carding for final result of the
spinning operation.
- There is a strong relationship between increase in production and reduction in quality: the
higher the performance, the more sensitive becomes the carding operation and the greater the
danger of a negative influence on quality.
- The concept of carding machine is unchanged since 1770.
- Since 1965 production rate has been increased from about 5 Kg/h to about 100 Kg/h, a rate of
increase not matched by any other machine except the draw frame.
Carding – Definition& Classification
Carding is the action of reducing tufts of entangled fibers into a filmy web of individual fibers by
working the tufts between closely spaced surfaces clothed with opposing sharp points.
Machines used to carry out this work are called cards, and we shall consider three types that
are of importance in the processing of cotton, wool and man-made fibers:
1. revolving flat card
2. worsted card
3. woolen card
Before describing the main features and operation of these cards, certain basic principles
common to all three will first be explained.
From the definition, it can be easily reasoned that carding is most effective with very small, well
opened tufts, i.e., containing only a few tens of fibers. Although the opening and cleaning stage
produces tufts on the order of a few milligrams, further opening is required to obtain a uniform
feed of suitably small tufts for carding.
The tasks of the card:
1. Opening to individual fibers, enabling elimination of impurities and performance of
other operations.
2. Elimination of impurities, mainly in the region of the taker-in.
 Very high degree of cleaning (range 90-95%) by modern cards.
 Thus, the overall degree of cleaning achieved by the blow-room and carding room
together as high as 95 -99%.
 Card sliver still contains 0.05-0.03% of foreign matter.
3. Elimination of Dust, which are bound to the fibers.
 Significant fiber/metal and/or fiber/fiber friction is needed in order to loosen such
particles, this are available in carding operation.

2. 4. Disentangling of neps.
 The number of neps increases from machine to machine in the blow-room, the card
reduces the remaining number to a small fraction, they are mostly opened out.
 Improvement in disentangling of neps is obtained by closer spacing between clothing;
sharper clothing; optimal speed of taker-in; low doffer speeds; lower throughput.
5. Elimination of short fibers, this may occur at flats.
 Long fibers have more contact with the clothing of the main cylinder than the short
fibers. Thus longer fibers are continuously caught and carried along the main cylinder,
where the short fibers stay caught in the flats clothing, press into it and leave the
machine in the flat stripping.
 The card eliminates very small percentage of short fibers about 1%.
6. Fiber Blending, mainly transverse blending occurs because the card is the only machine to
process individual fibers.
 In formation the web, and with repeated rotation of the fibers on the main cylinder,
intimate fiber with fiber mixing is achieved.
7. Fiber orientation:
 The card is often attributed the effect of paralyzing. A parallel condition is achieved on
main cylinder, but it disappears during web formation between cylinder and doffer.
8. Sliver formation, for further processing.
 Generally the hank lies between 4 and 5.5 Ktex in the short staple spinning mill.
Elements of Card

3. 1) Pipe ducting for supplying raw material,
2) Chute feed; evenly compress a batt of 500 – 900 Ktex.
3) Transport roller; forwards the material to feed arrangement,
4) Feed arrangement, consists of feed roller and feed plate,
5) Taker-in, opens the material to small flocks, when the material passes to main cylinder, mote
knifes; grid bars and carding segments eliminate a great part of impurities.
6) Grid equipment,
7) Suction duct to carry away the waste.,
8) Main cylinder
9 and 12) Fixed carding segments designed to assist the carding operation.
10) Flats, The main carding operation occurs between flats and cylinder. Flats comprise 80 to
116 individual carding bars combined into a band moving on an endless path. 30 to 46 of flats
are always in action.
11) Cleaning unit, strips fibers, neps and foreign matters from flats,
13) Grid or cover plate
14) The doffer, combine the fibers into a web, because of its substantially lower peripheral
speed relative to the cylinder.
15) Stripping deice, Doffing master, draw the web from the doffer.,
16) Calender rollers
17) Can,
18) Coiler
Carding – Feed types
There are two types of feeding to the cards
1. feeding material in the form of scutcher lap
2. flock feed system (flocks are transported pneumatically)
Salient Features Lap feeding
 linear density of the lap is very good and it is easier to maintain(uniformity)
 the whole installation is very flexible
 deviations in card output will be nil, as laps can be rejected
 autolevellers are not required, hence investment cost and maintenance cost is less
 transportation of lap needs more manual efforts (more labour)
 lap run out is an additional source of fault, as it should be replaced by a new lap
 more good fibre loss during lap change
 more load on the taker-in, as laps are heavily compressed

4. Salient Features flock feeding
 high performance in carding due to high degree of openness of feed web
 labour requirement is less due to no lap transportaion and lap change in cards
 flock feeding is the only solution for high prouduction cards
 linear density of the web fed to the card is not as good as lap
 installation is not flexible
 autoleveller is a must, hence investment cost and maintenance cost is more
CHUTE FEED system:
The fiber mat fed to the carding machine should be of a high degree of uniformity to ensure
consistent opening and carding .This uniformity is achieved using the chute feed system, which
aims at feeding a fiber sheet of a uniform packing density and uniform linear density (weight
per unit length) to the carding machine.
The basic components of the chute feed are:
1- High volume upper trunk
2- Integrated air volume separator
3- Feed roll, electrically coupled to the feed roll of the card
4- Segmented tray to secure clamping
5- Opening roll with pins
6- Closed air circuit with integrated fan
7- Self cleaning air outlet combs.

5. LAP FEED System:
Feed unit & licker-in
It consists lap stand, lap roller, feed plate & feed roller. Lap roller rotates at slow speed and lap
is unwound by the friction of lap roller.
Sheet of cotton now passes over the feed plate and pass under the feed roller which is
heavily weighed to grip the cotton. Lap roller ( 6 inch dia) is driven by feed roller (2.5 inch dia)
and feed roller is driven by doffer, so rate of unwinding of lap, supply of material from feed
roll to licker-in are all kept under control. Feed roller feed the sheet of cotton to the action of
fast revolving Licker-in.
Grooved surface of the licker-in is clothed with saw tooth wire. Lap is now well opened into
very small tufts by the beating action of fast revolving Licker in.
Mote-knives and licker - in under grid
In order to retain the cotton on licker-in and yet permit dirt to be separated from it, the
underside of the licker-in is enclosed by one or two mote knives and licker-in undergrid. To
opened fibre tufts are carried by licker-in against Mote knife and over the under grid.
Mote is a particle of seed, leaf, boll, shale or stem. Due to the resistance of the mote knives,
heavily vegetable impurities known as "Motes and sand” are removed and falls down through
licker-in under casing.
"Mote knives to Taker-in Setting -Upper Knife -0.010 inch Bottom Knife -0.0012 to 0.015 inch”.
Three types of mote knives are available.
a. In the first type the angle and setting with respect to taker-in are fixed.
b. In the second type the angle is fixed while the setting can be altered.
c. In the third type both angle and setting can be altered.

6. The angle of mote knives may range from vertical disposition to about 30 degree to the vertical
but the nearer a knife approaches a tangential position, the greater is the extraction of waste. If
the setting is too close- loss of good cotton may occur, if it is too wide-the mote knife operates
in efficiently.
Licker-in under grid:
The object of the licker-in under grid is to hold the good fibres on the licker-in and to permit the
short fibres, dust, dirt particles to fall down, and collect outside the licker in grid through
spacing of under grid
Licker- in under grid consists number of spaced bar and perforated metal sheet. Setting
between licker-in to grid-5/16" close setting increases the fibre extraction with waste.
Stripping action between licker in and cylinder
In between licker in & cylinder, the direction of the both licker-in and cylinder wires are inclined
in the same direction. This is called point to back arrangement.

7. Stripping action is made possible due to the following reasons:
• Point to back arrangement of the wires facilitates stripping of fibres from the licker-in
by the cylinder.
• The surface speed of the cylinder is twice that of licker-in.
• The close setting of 0.007 inch from licker-in wire to cylinder helps to transfer the fibre
effectively.
• Air current close to the cylinder helps the transfer of fibres, from licker in to cylinder.
Carding - Feeding and opening zone
 The journey of fibers through the carding process being with feeding a uniform fiber
batt prepared by the chute feed system and supplied to the carding machine using feed
roller.
 The weight of the fiber batt may typically range from 400 to 1000 g/m(Ktex). This
weight approximately corresponds to a number of fibers in the mat cross section in the
range from 2 to 6 millions of fibers depending on fiber fineness.
 The task before the carding process is to intensively open and draft this large mass
down to about 3 to 5 g/m (the sliver count); or to reduce the number of fibers down to
approximately 40,000 fibers in the card sliver cross section. This intense reduction is
mainly achieved in the zone between the feed roll and the taker-in (or licker-in).
 The purpose of the taker-in is to pluck finely opened flocks out of the feed batt, to lead
them over the dirt eliminating parts like mote knives, combing segment and waste
plates, and then to deliver the fibres to the main cylinder.
 The feeding rate is normally slow to allow exposition of small portion of the fiber batt to
the action of the high speed licker in (typically, 25 cm diameter, 700 – 1200 rpm for
cotton and 400 – 600 rpm for man-made fibers). In high production cards the rotational
speed ranges from 700-1400.
 The treatment for opening and cleaning imparted by Taker-in is very intensive, but
unfortunately not very gentle. Remember that around 60% of the fibres fed to the main
cylinder is in the form of individual fibres. The circumferential speed of Taker-in is
around 13 to 15 m/sec and the draft is more than 1000.
 It clearly shows that fibre gets deteriorated at this opening point. Only the degree of
deterioration can be controlled by adjusting the following:
 the thickness of the batt
 the degree of openness of the rawmaterial
 the degree of orientation of the fibres
 the aggressiveness of the clothing
 the distance between the devices
 the rotational velocity of the taker-in the material throughput.

8.  The taker-in being clothed with saw-tooth wire removes the fiber tufts from the input
fiber mat. The centrifugal force caused by the high rotational speed of the licker-in
throws the heavy trash particles, and seed coats fragments out at the mote knives with
the assistance of air draft. The taker-in removes about half of all trashes held in the
cotton.
 The feeding direction of the fiber batt can also impact the opening performance. In
general, there are two types of feed: counter direction, and unidirectional (as shown in
figure.)
Rieter has devloped a "unidirectional feed system" where the two feed devices(feed roller and
feed plate are oppositely arranged when compared with the conventional system. i.e. the
cylinder is located below and the plate is pressed against the cylinder by spring force.
Owing to the direction of feed roller, the fibre batt runs downwards without diversion directly
into the teeth of the taker-in(licker-in) which results in gentle fibre treatment. This helps to
reduce faults in the yarn.
According to Rieter, the unidirectional arrangement allows better adjustment to the distance
between the fiber nipping point and the combing point, and gentler action on the fibers (less
fiber deflection).
In one of the modern carding machines, such as Trutzschler DK760, Single taker-in system,
some innovative design features were introduced to insure efficient opening, minimum fiber
damage and minimum waste of good fibers.
The setting of deflector blades can be adjusted from outside to control the amount of waste
and trash removal. The distance between the fiber nipping point and the combing point
(typically 0.4-0.5mm) plays a vital role in determining the opening performance of the licker-in.

9. Trutzschler DK760
Another innovation of the opening zone is the so-called WEBFEED system introduced by
Trutzschler, which consists of three taker in cylinders of the same diameter (175 mm).
In this system, the fiber batt is guided by pressing the batt against the feed roll in 10 small,
independent sections of 100 mm width using the so-called “Sensofeed” feed-plate system.
1 A Special clothing of feed roll prevents lap formation
2 Spring loaded feed table
3 Spring loaded measuring lever
4 Spring elements
5 First roll of WEBFEED

10. The deflection of all springs elements are processed to become one average signal which is
used as actual value of short wave leveling system. As an additional function, the integral feed
tray SENSOFEED comprises material feed monitoring. Metal particles of thick places in the web
are detected in an immediate stop of the card.
The WEBFEED system consists of three opening and cleaning rolls in series arrangements. The
tufts are opened in a gentle way and to a higher degree than is in case with conventional licker-
ins. Transferring an even and fine web to the cylinder results in a higher carding efficiency at
the main working points (between cylinder and flats/carding segments). The card can be run at
higher cylinder speeds, with finer clothing and tighter adjustments.

11. Gradual opening with three rolls protects the fibers. The critical point between feed roll and
licker-in, the fibers must be suddenly accelerated. The first WEBFEED roll runs at a clearly lower
speed than be the only licker-in roll of conventional cards.This saves delicate fibers.
When processing cotton, the first roll is equipped with short pins. These pins gently pluck the
tufts from the clamping point of the integral feed tray SENSOFEED. The second and the third
clothing rolls open the tufts further and form a web.
Another advantage of using the needle roll is its life is about 10 times as long as traditional
metallic wire licker-in. The clothing of the second and third roll is made of special steel. They
have the same life as cylinder clothing.
Carding – Carding zone
 Fibers that are opened and cleaned by licker-in system are transferred to the main
cylinder by stripping action.
 Fibers are stripped by the cylinder from the licker-in are transferred to the carding
zone, which is the area between the main cylinder and the flats.
 In order to remove fibers from the licker-in by the main cylinder, the surface speed of
the main cylinder should be higher than that of the licker-in.
 A typical value of the surface speed of the licker in may range from 700 m/min to 950
m/min. The surface speed of the cylinder may range from 1000 m/min to 2400 m/min.
(at diameter is 1290 mm, and 260 to 600 rpm.). Thus the draft is ranging from 1.5 to 2.5.
 In the cylinder/flat area, cotton tufts are subjected to carding action. In principle, a
carding action is accomplished when the wire of the two surfaces are inclined in

12. opposite directions and the direction and the rates of motion are such that one surface
passes the other, point against point.
 The flats are wired clothed bars rotating at a very slow speed (typically 8 – 20 cm/min)
against the high speed cylinder.
They are usually set very close to the main cylinder. The setting between the flats and main
cylinder is determined by a number of factors some of which are mechanical-related and others
are material related.
 Mechanical related factors include the bearing condition, the shape and dimensions of
the wires.
 Material related factors include fiber length, fiber fineness and fiber to fiber friction.
The setting is very critical in relation to the formation of the fiber neps.
Carding section (Conventional Carding)
This section includes the following topics:
1. Carding action between cylinder and flat
2. Heel and Toe arrangement.
3. Arch and concentric bends.
4. Flexible bend.
5. Front plate.
6. Back plate
7. Cylinder under casing
1. Carding action between cylinder and flat.
Purpose of the cylinder and flats are :
i)To card the fibres which means to open the cotton, even to the separation of one fibre
from all the others (fibre to fibre separation)
ii) To separate short fibres, dust and dirt and collect outside the cylinder under casing through
spacing of the under grid.
The wire points of flat oppose the direction of the cylinder wire point, i.e. point vs point wire
system is placed between cylinder and Flat. Flat slowly moves at the rate of 2.5 inches/min and
rotates in the same direction of cylinder, because of these reasons, carding action takes place
between cylinder end flats which means fibre to fibre separation is achieved.
The flats gets full charge of cotton as the flats come in to position over the cylinder.

13. INTERCHANGE OF FIBRES:
The fibres protruding from the charges in the flats are hooked by the cylinder wires in their
passage and may be carried forward out of that flat region. Similarly, fibres hooked by the
cylinder wires, if they protrude can again be gripped by the flat wires and removed from the
cylinder, and this interchange can take place over the top portion of the card where the flats
are situated.
2. Heel and Toe arrangement
The wire surface of the flat is not parallel to that of the cylinder.
Wire point setting between cylinder and flat is wider where the cotton enter and closed where
the cotton leave.
This arrangement is called as heel and toe arrangement. Object of heel and toe arrangement is
to achieve gradual carding action at each flats.
Necessity: When the cotton is carried forward from one flat to another, the air current,
centrifugal force, elasticity of fibre causes the fibre to raise from the surface of cylinder. These
raised fibres would be rather severely dealt with if they were dragged into the narrow setting
between cylinder and flats. This suddenness action is avoided by heel & toe arrangement.
3. Cylinder arch and concentric bends
On each side of the main cylinder, a strong cast iron cylinder arch is fixed. Cylinder arches
support the flats. On cylinder arch, front concentric bend, back concentric bend and flexible
bend are assembled with cylinder grinding and Front plate encloses the space between
flat and doffer. Back plate is filed on back concentric bend. This encloses the space
between flat and licker in.

14. 4. Flexible bend
On each side of the cylinder, a strong cast iron cylinder arch is fixed. On cylinder arch, front
concentric bend, back concentric bend and flexible bend are mounted.
Flexible bend supports the flats. Flexible bend is used to adjust and correct the setting between
flat and cylinder. Flexible bend is provided one on each side of the card.
This bend is not flexible but their curvature can be altered, to correct the cylinder to flat setting.
The repeated grinding of the cylinder wire points need accurate adjustment to set the flat as
close as 0.010.
To get wider setting between cylinder and flats, the lacking screw should be released first and
then by operating the circular nut the regulating screw is raised.
The flexible bend will also be raised, carrying the flate away from the cylinder. This will result in
a wider setting between the flats and cylinder.
When the correct setting is obtained, locking screw is fully tightened so that the position of
flexible bend will be fixed till next adjustment.
5. Front plate or percentage plate
What will happen if front plate setting is adjusted and how will you control the % of flat waste?
On each side of the cylinder, a strong cast iron cylinder arch is fixed. On cylinder arch, front
concentric bend, back concentric bend, flexible bend are mounted.
Front concetric bend supports 3 pieces of front plate
i) Top percentage plate setting: Upper edge-10 thou to 60 Thou( 10 Thou means 0.010 inch)
and Lower edge-32 Thou.
The object of this setting is to control flat strips waste.

15. The flats are stripped when they have left the cylinder area by an oscillating comb, and the
strips hang at the front of the card like a curtain, being connected together along their lengths
by some fibres which bridge from one strip to another.
Top % plate setting is very important because it control the thickness and weight of the flat
strip.
If this setting is too close - the flow of air over the top edge and between flat is so fast and flats
are effectively stripped and flat waste in the flat is transferred to the cylinder again which
causes poor web buy results in lighter flat strips.
If the setting wider - flow of air round the top edge is reduced but, cotton is now moved from
cylinder Wires to flats, bridging them with them with good cotton, i.e. good material is lost as
flat strip waste.
The best setting is that strip should barely hold together by bridging fibres as they are stripped
at the front of the card. Middle plate provides access to the cylinder wire for sripping and
grinding.
6. Back plate
Back plate is fixed on back concentric bend. This plate encloses the space between flats and
licker in. The object of the back plate is to hold the fibres on cylinder wire and to prevent
undesirable air current.
Setting: Upper edge- 0.010" and Lower edge -0.012"
Wider setting causes cloudy web due to uneven distribution of fibre across the cylinder because
of the uncontrolled air current.
7. Cylinder under casing
The objects of cylinder under casing are: i) To hold the good fibres on the cylinder ii) To permit
the short fibres, dust, dirt particles to fall down and collect outside the cylinder grid through
spacing of under casing. Settings: Back - 0.012“; Middle - 0.032“; Front: 0.064“.
This setting influences air current and production of fly. Wider setting causes loss of fibres. The
setting is wider at front because, here the cotton first makes contact with under casing.

16.  The main cylinder is the central element of the card. It has a diameter of approximately
1.3 m and a working width of one meter. This results in a clothing area more than 4 m2
.
The carding surface of the cylinder is made up of more than 10.000 m of clothing wire
with approximately 6 million single points.
 By shifting the WEBFEED unit and the doffer below the cylinder, more room has been
made for the functions of pre-carding and post-carding.
 In the pre-carding and in the post-carding area of the cylinder, 10 special elements of
the MULTI WEBCLEAN system can be mounted in the most different combinations. The
first and the last elements are fixed. For the remaining 8 positions the following
elements can be flexibly used, depending on the task.

17.  The cleaning element consists of a mote knife with a hood under permanent suction. It
is used for separating dirt particles, seed coat fragments and dust particles.
 Carding element consists of two clothing strips with one support (twin top). A number
of different clothing types and point populations are available depending upon the
installation and the raw material.
Carding - The Doffing & Delivery Zone
 Fibers that are coming out of the carding zone form a very thin web. The weight of the
web is determined by extend of carding (flats/cylinder settings, the relative carding
speed, and the type of cloth on both cylinder and the flats).
 The web is extracted from the main cylinder by another cylinder called a doffer (700 mm
diameter and up to 96 rpm).
 The substantial reduction of the surface speed of the doffer as compared to that the
cylinder results in a condensation effect.
 The fiber web is stripped from the doffer using a stripper roller. It is then passed
through a pair of squeeze or crush rolls before it is finally accumulated widthwise into a
fiber stand form. The calendar rolls compress the fiber strand to provide better integrity
and stable flo of material.
 The fiber strand (the card sliver) proceeds upward over guide pulleys to enter the coiler
system. This consists of a trumpet guide and a second pair of calendar rolls that delivers
the carded sliver through a revolving tube into the card sliver can.
 The sliver WEBSPEED forms the web to a sliver and guides it to the measuring funnel. In
order to allow an optical assessment of the web quality or to take samples, the sliver
former can be opened by pushing a button.

18.  A NEPTCONTROL permanently counts the number of neps, trash particles and seed coat
fragments and reports it to the machine control. The data are evaluated and displayed
on the screen.
Carding – Flat revolving Card(Schematic diagram)