CARDING by Khare

Khare up to 15pages, and Merill

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CARDING by Khare

The importance of Carding machine in spinning can be judged from the proverb “well

carded is half spun”, and also that ‘card is the heart of spinning”. The process of carding is

the heart of entire spinning operation. It is said that “To card well is to spin well”.

Subsequent to blowroom cleaning operation, the carding is the only major stage for cleaning

operation.

A carding machine fulfils the following objectives:

1. It thoroughly opens the tiny lumps, flocks, or fiber tufts to the individual state.

The tiny lumps, locks or are separated to a state of single fibre. In further attenuation or

thinning out process subsequent to carding, the fibres are required to be drafted where it is

important to have these fibres pulled individually rather than in clusters.

2. It removes impurities including short fibres. Blowroom never aims at complete

opening of the tufts to a single fibre state. The smaller clusters still remain un tackled and

possibly retain some entrapped trash. Most of the heavy trash is extracted in blowroom,

however some finer impurities are still present. Surprisingly enough, the cleaning action of

the card adjusts itself to the varying trash contents in the lap fed. However, even the cleaning

action of the card is never the complete one. The trash content in the delivered product –

‘silver’- of the card may, therefore be negligible but when the same in the final yarn it may

be quite significant and noticeable with naked eyes. In this context the concept of tandem

carding can be really appreciated. The short fibres are removed between cylinder and flats

(brushed out), and under the cylinder (drop outs).

The trash or the waste falls down through the grid bars, and are collected by waste

extraction unit. Short fibres are collected by the flats fitted above the cylinder. Flats are

narrow (about 1.5” wide) cast iron pieces spread along the width of the card. The cleaning

achieved by the card is 80-95%. Thus both blow-room and card achieve a cleaning of about

90-95%.

3. It removes the dust present in the material. Two important areas are where cotton is fed

(the licker-in) called the ‘motes’. It is heavy and lik beater seed but fine; and the carding

surface (between the cylinder and the flats) mixed with short fibres.

4. It helps in removal of neps.

Neps are entanglement of fibres that can not be opened. The removal of neps takes

place between flats and cylinder of a card machine. Although it is assumed that neps are

eliminated by the card but they are mostly opened. The neps increases with the passage of

material in each of the machines of blow-room line. The card action is to remove the neps

and is still capable to produce them. Neps, as defined, are the tiny highly entangled and knot-

like structures of fibres, generally not bigger than pin head and are difficult to remove. The

excessive high percentage of short and immature fibres leds to high nep generation. The

impurities of vegetable origin are present in the cotton, these fibres wrap around them, thus

producing neps. In ginning and blowroom, the rolling of fibres substantially increases the

neps.


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With the best mechanical condition of card, Nep level can be significantly reduced.

The card is never able to remove all the neps. The left over appear in the final yarn as ugly

specs in white cloth, or unevenly dyed spots in coloured fabrics. The combing process

remove the neps very effectively. The opened neps in carding are hereby the same in the

number as generated in blowroom.

5. Carding helps in blending of fibres.

In carding the fibres are opened upto individual state. Also these fibres are repeatedly

rotated on cylinder leading to very intimate fibre mixing.

6. It helps in fiber mixing.

The fibres after the doffer are in web form. The stretch applied while coverting this web

into sliver orient the fibres along the sliver axis.

7. Conversion of lap into a loose rope like structure called ‘silver’ is also the object of

carding. Sliver is a continous, untwisted strand of fiber, about 1” in diameter.

1.0 Objects:

The object of carding can be briefly summarized as follows:

1. Individualisation or fibre to fibre separation.

2. Continuation of the cleaning process.

3. Removal of neps and short fibres.

4. Conversion of lap into silver.

2.0 Passage of Material Through A Carding Machine:

In carding machine lap is fed between a feed plate ( ) and the feed roller ( ). Feed

roller is metallic, fluted and around 2.25” diameter. These present the lap to the licker-in or

taker-in ( ). It is about 9” in diameter, has saw tooth wire fitted, and revolves around 900

rpm. Due to very high speed when compared to the feed roller, and more numbers of saw

tooth on the licker-in (about 30,000-40,000), it reduces the fibre tuft size to a great extent.

Mote knife ( ), that are fitted below liker-in, are extended throughout the width of carding

machine. They are knives as bars with about 3” thick. Next to it is licker-in under casing.

The fibres with the due to centrifugal force are hit against the undercasing. It helps in falling

of the trash from the gaps between the undercasing. The fribres after a few revolutions

around the licker-in get transferred to the cylinder ( ). Cylinder is huge size, about 50.75”

diameter, and fitted with flexible wires (around the size of fine comb). Back plate fitted just

above and between licker-in and cylinder help in transfer of fibres onto the cylinder. Over the

cylinder, flats ( ) are fitted. Flats are T-shaped are metallic strips of about 1.5” width, has

flexible pin type teeth, are around 80-116 in numbers, and joined together with a chain. They

move very slowly (3-4”/min), and in opposite direction to the cylinder. They help in

performing carding action, and extraction of short fibres and neps. At any point of time, there

are about 42 flats that are working with the cylinder. Undercasing and/or grid bars are fitted

below the cylinder for extraction of impurities. Dust and flies are removed by air suction.the

calculation of number of teeth of cylinder to the fibres shows that theoretically each fiber is

presented to about more than 10 wires, and thus make it to individual state.


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The fibres are then transferred to doffer ( ) that is about 27” in diameter. It has saw tooth

and runs at a slower speed. The fibres thus get condensed. Doffer comb ( ) is fitted next to

doffer. It is thin steel blade moving up and down with about 1000 oscillation/ minute. This

causes the striping the fibres from doffer in web form. These fibres are then passed through a

number of calendar rollers and finally through trumpet ( ). The trumpet converts the web in

sliver (a rope like structure) form. This sliver is collected in cans that may be 24” to 42”. A card

in case of cotton produces about 4% waste. The sliver hank is normally between 0.1s to 0.15s.

different card clothing are shown below


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3.0

Line diagram of a Carding machine (d) shown on top, and Draw frame (e) is just above


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3.0 Important region in carding:

3.1 Feed Plate:

Fig 3. Page no. 8

It is also known as feed dish plate because it is in the form of rectangular dish. It is

unwound very slowly at the rate of 25-28 cms/min. Feed plate has a slight curved shape

called nose plateau at the end which gives greater gripping action over the lap. This gives a

wedge shape space.

Fig 5(b). Page no. 9

It helps to provide the progressive action of the licker-in wire points. Fibres are fed to

licker-in at 30 cms/min, while the licker-in runs at a 320 m/min. Fibres is likely to put a

considerable strain on them. Wedge shape space helps licker-in wire points gradually

penetrate into the lap fringe. Longer length of the straight face of the nose would provide a

longer distance between the point A and B.

3.2 Feed Roller:

The feed roller has flutes giving adequate grip on the lap fringe under the roller. In early

systems, the feed rollers were weighted by the dead hanging weights. The feed rollers

should exert uniform pressure on the lap fringe. It is checked by putting through a piece of

paper which is uniformly gripped across the width.

When the card is stopped for setting, it is usually customary to take

roller down. The teeth on the change pinion and plate wheel also be checked occasionally

for any damage to the teeth, otherwise the drive to feed roller is not smooth and continuous.

This will invariably uneven feed. In this case the lap will be plucked, due to sudden speed of

feed roller. It endangers licker wire and fibres.

3.3 Licker –IN:

It is a shell roller with a diameter of 9” having uniform spirally cut

grooves of 6-8 per inch along the length of licker- in and accommodates the base of licker-in

saw tooth wire. During wire mounting on licker-I, one wire is started from end Ato the other


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extreme and beyond B. There are extremely 30,000 to 40,000 fine saw tooth type of wire

points.

Different classes of cottons can be verified by:

1. Changing its speed

2. Number of teeth per inch

3. Angle of rake.

Fig No 9(a)

Fig No 9(c)

Wires of minimum 3 teeth/inch. For coarser and trashy cotton wires of 6 teeth/

inch are used. For long and fine cottons very low licker-in speeds from 350 r.p.m to 420

r.p.m. For very dirty short staple cotton higher speeds beyond 760 r.p.m are in use.

When the licker-in speed is required to be increased, it is necessary to keep the

ratio of their surface speeds (cylinder: licker-in) around 2 to 2.1.With higher licker-in

speeds, there are more number of points passing through the lap fringe and

consequently, the opening action of the licker-in wire points are more powerful.

Momentum with which the points plunge into lap fringe is also very high. This, though

leads to very effective opening action, is likely to cause certain damage to the fibres.

Lower licker-in speeds are used for longer staple fibres. The longer fibres are also

comparatively cleaner and more delicate necessitating a milder treatment in licker-in

zone.

Angle of inclination of licker-in wire teeth also has profound effect on their action

on the fibres. The forward rake wire is generally used for coarser mixings treatment is

little harsher.


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Fig No 10(a), Page No 13

The perpendicular or 90° rake is mostly used for finer varieties of cotton. Treatment is

milder. The negative rake wire, is exclusively used for the synthetics. As there are no

impurities in term of trash, leaf-bits etc. The purpose of licker-in action is just to open

the fibre tufts.

Fig. No. 10(b), Page No. 14

Fig No. 10 page no 14

3.3.1 Types of licker-wires:

6 STL licker-in wires is a standard type for most of the cottons of 16mm

to 35 mm (5/8” to 1.3/8”) staple. There are (4.5 teeth/inch). The angle between

the leading edge of the tooth and its base is 73°.

4 STL wire is of 28 mm-38 mm. The number of points are reduced to 3.5

teeth per inch. The wires are perpendicular rake.

Fig No. 11, Page No. 15

5 SIL wire is used for fibre length of 38 mm. For synthetics there are 3

teeth/ inch and the wire has negative rake of 6° - 8°. With generally 6 to 8 starts,

there may be 18- 36 teeth/ sq. inch.

Because of saw tooth construction, the licker-in metallic wire is perhaps

the strongest amongst the other metallic clothing’s used on a card. There is

greater friction between the wires and the fibres.

3.4 Mote Knives:

There are rectangular knife edged bars, approximately 3” in width and

extend themselves the whole length of licker-in. These knives are usually in pair

and are fitted beneath the licker-in, in between feed plate and under casting. The

mote knives have a bevel shape and can be adjusted to get the desired closeness

from licker-in wire surface.


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Fig No. 12, Page No. 15

1.The first or top knife is at a distance of 0.010” from the licker-in wire points.

2.The second or the bottom knife is at a distance of 0.015”.

Half of the waste present in the lap is extracted at mote knives, a correct setting of

these knives can make their action very effective. As a safety some mills put an

additional third bracket at the centre, to give an extra support.

The mote knives derived there name because they removes motes. The motes are

the vegetable impurities, such as cotton stalks, leaves seed particles etc.

3.5 Licker-in undercasing:

It is a screen partly covered with perforated sheet and, at the front, with 2

to 3 space bars. The undercasing is made of 3 parts- nose, grid – section and perforated

screen. The nose is the flat smooth strip rounded at the front. The nose is mainly

responsible to guide the air currents generated by the licker-in around its surface and

keeps them close. According to aerodynamic principle, the lint being lighter, tries to

remain close to the licker-in surface, while the trash being heavier remains in the outer

air currents. At optimum level, licker-in droppings contain about 30% of lint and 70% of

trash.

Next is the grid section which acts as an opening for the little finer trash.

The opening in between the grid bars varies from 3/16” to 5/16”. The shape of bars is

available in 2 types (A & B) (Fig ……….). The total distance from the nose to the last

grid bar varies from 2.5” to 2.75”.

Fig.

The perforated section –‘Screen’ is mainly provided to remove much finer dust

in the alp fringe. The pore size is 1/32 to 3/32”. The total length is 5.5” to 8’. Wider

spacing between mote knives and undercasing (P1) is more opportunity for trash to fall

down and consequently this type of undercasing will be more useful for short staple

trashy cottons. The longer undercasing providing a smaller gap (P2) act as a lint saver.

Cylinder, the undercasing is set at 34/1000”.


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3.6 Back Plate:

The sheet extends from the licker-in cover to a point where the flats begin their

working on the cylinder. The upper and lower settings are obtained through 2

adjusting screws A & B respectively.

The lower edge of the black plate controls the air currents generated by the

revolving cylinder. These air currents try to rush into cylinder-flat zone where the

main carding action takes place. The control of air currents reduces any back

pressure at licker-in undercasing nose, resulting in less loss at licker-in zone.

The setting of upper edge (forward the flats) acts as a seal to limit the air

currents. If this setting is too wide, the cotton is blown out between the flats.

Therefore, the setting also controls the amount of flat strip. The lower and upper

edge controls the appearance of card web delivered. Too wide a setting lead to

cloudy (whitish) web due to ineffective carding action.

3.7 Cylinder:

Carding is to reduce the entangled mass of fibres into a fibre to fibre state of separation

– the filmy web- by working them between the two closely spaced and relatively

moving surfaces clothed with opposite sharp wire points. A carding action is obtained

when cylinder wires and flat wires work point to point.

Fig.

The action between licker-in and cylinder is more of stripping nature. There is no true

carding action between cylinder and doffer. There is condensation of fibres on wire points. The

real carding, is between only cylinder and flats. The main cylinder is 50” in diameter is called

‘heart’ of carding.

3.7.1 Wire Points:

Flexible wire was used for clothing both for cylinder and the doffer. The flexible

wire clothing is constructed by inserting a fixed length of flexible wire into backing material or

‘foundation’. The wire of a certain length is bent in the form of a staple having a square base or

‘crown’ and 2 legs. The legs of the wires are passed through holes previously pierced in the

foundation and then are bent at a point to form ‘knee’. The formation of the knee is brought

about by bending the legs over a bar before full crown is forced through the foundation.

Overall height of the wire is 9.52 mm(0.375”), whereas the total length of wire is 22.19

mm(0.875”).

A typical cylinder wire fillet has 8 staple in a row and approximately 60 rows per inch

along the length.

3.7.2 Foundation for flexible wires:


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In early days, leather was used as the foundation material. It is still used in woolen

carding. However, it lacks in elasticity. The most popular foundation material is made by

bonding cotton and linen fabrics by rubber solution. They are not only rigid and strong but also

are comparatively cheaper.

The standard ‘CWC’ foundation has 3 plies-

a) Cotton face cloth

b) Linen warp & woolen weft cloth at centre

c) Cotton backed cloth.

3.7.3 Setting pattern of crown in flexible wire clothing:

In setting the wire crowns, different designs like plain, rib, twill or sateen used. There are

approx. 50 to 80 rows of crowns per inch along the length of wire clothing. Most

commonly used sets are rib of cylinder and twill for doffer.

Fig No 42 Page no 25

The effectiveness of the clothing is influenced by:

a) Type of wire used and its gauge.

b) The angle at which the teeth are inserted into the foundation.

c) Angle formed at knee.

d) Relative height of knee and point above foundation.

e) Density of wire points.

f) Sharpness of wire points.

A steel wire of round cross section is very popular. A finer gauge and higher

number of points are used for longer and finer cottons.

3.7.4 Carding action and carding angle:

Fibres are carded between the cylinder and flats. With PQRS as the wire, the drag

F (component F. Sin B) will displace the point C, so that there will be a lifting-up of point

S in relation to base of foundation. The point S will be brought closer to the flat wires

leading to risk of contact between 2 wires.

In actual practice, the foundation being quite resilient. The flexing of wires take

place only in the lower region. Hence, the effect of the component F.Cos B is more

pronounced than that of F.Sin B. To get more opening power, smaller carding angles (B)

are chosen. & increases the power of penetration.

3.7.5 Count of card clothing:-

a) First count the number of crowns/ inch across the width of the fillet (say 4)

b) Calculate the crowns per nogg (say 3 in case of rib set)

c) Count the number of noggs or repeat in 1” along the length of fillet( say 25)

(a) X (b) X (c) = 4 X 3 X 25= 300 crowns per sq. inch.

Since each crown has 2 points,

Wire points/sq. inch = 300 X 2= 600 ---(A)


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Using the equation – (A)

Count of clothing – points/ sq. inch÷ 5 ---(B)

The expression (A) will give

The count of clothing as { 600/5 = 120°}

3.7.6 Metallic wire clothing:

Increasing card production was due to the introduction of metallic wire.

This thin portion is stamped or punched so as to leave a thin serrated strip called

‘saw tooth wire’. It is also termed very frequently as ‘rigid’ wire, an apt

designation. This is because the tooth formed is very solid, strong and sturdy. The

teeth are usually subjected to hardening treatment (This involves both controlled

heating followed by cooling) enabling retention of the sharpness of wire points for

longer duration. The base or the rib portion, however, is specially tempered to

retain the flexibility, so that it conforms well to the periphery of the cylinder.

When mounted on it. Unlike licker-in wire, the wires on cylinder and doffer are

simply put on their plain or bare surface. Hence, both the teeth and the foundation

like licker-in wire form the integral part of the saw tooth wire.

3.7.7 Metallic wires on cylinder & doffer:

The metallic wires on both cylinder and doffer are much finer. The

cylinder wires are smaller & have more ppi height. The angle of the leading edge

in case of cylinder wires, it is called as ‘carding angle’. Cylinder has to initiate

and complete the carding action, the doffer is merely used as the carrier. The

smaller wires on cylinder give the required degree of fineness to the work done

by it. The larger no. of points per inch on cylinder wire gives the density to effect

the fibre to fibre separation.

The broader base (thickness of rib) of the wire provides a firm seating. A

narrower carding angle could have been more suitable in cylinder.

3.7.8 Types of wires:

a) 201 for cylinder: It is used for man made fibres.

b) 301 for cylinder: It is used for fine and medium counts.

c) 408 for cylinder: It is used for processing of low grade cottons, surgical

cottons, waste cottons etc.

d) TROS for cylinder: Low density of wires is specially developed for breaker in

Tandem carding.

e) PA.4 for doffer: It is paired with No. 201

f) GP1 & GP2 for doffer: It is universally used for all types. Point density on

GP1 is higher than GP2. GP1 is used for finer count and GP2 is used for medium

and course counts.

g) 8360 for doffer: The wire angle is 65°. It provides positive and efficient

transfer of fibres.

h) 8400 for doffer: It is used for fine cottons.


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The choice of the wire, will depend upon the manufacturing conditions. Some of

factors are as follows:

a) Type of material to be processed.

b) Staple length, micronaire or denier of the fibres.

c) Type of card- conventional, converted to high projection or original HP card.

d) Cylinder speeds.

e) Production rates.

f) End use- carded or combed.

(A) Card clothing recommended

Sr

.

N

o.

Type Staple Micronaire

of deniar

Licker

-in

Cylinder Doffer

1 Short staple

dirty cotton

24 mm &

below

3.2 & over 6 STL 212 8360

2 Short staple

lower trash

24 mm &

below

3.2 & over 6 STL 212 8360

3 Medium staple

cotton

Up to 30mm 3.5-3.8 6 STL 212 or

312

8360

4 Long staple

cotton

30 mm- 35

mm

3.0- 33 5 STL 312 8400

5 Synthetics Up to 40 mm 1.2 den. 5 STL 212 8400

6 Synthetics Up to 50 mm 1.5 to 2.0

den.

5 STL 212 8360

7 Synthetics Up to 40 mm Above 2.0

den.

5 STL 505 8360

8 Blends ----- ---- 5 STL 212 8360

(B) Wire Particulars

Sr.

No.

Height in

mm

Angle Rib

thickness

in mm

Teeth

inch1

Point inch

2

1 2.8 75° 0.8 14.1 448

2 2.8 75° 0.8 20.1 635

3 2.8 66° 0.8 19.5 620

4 2.8 80° 0.8 8.4 267

5 2.8 80° 0.6 20.0 780

6 4.0 66° 0.9 12.7 358

7 4.0 60° 0.9 14.1 398


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(C) Wire Particulars:

No. Rib Thickness Height Angle Teeth/ inch

1 0.038” 0.125” 71° 14

2 0.035” 0.125” 78° 20

3 0.031” 0.160” 55° 10

4 0.033” 0.197” 65° 14

5 0.038” 0.197” 65° 12.5

3.7.9 Flexible v/s Metallic card clothing:

Sr

No.

Flexible card clothing Metallic card clothing

1 Wires are separately inserted into

foundation material. Wire points (teeth)

and foundation both is flexible. Feature

of clothing is bent wire knee. Flexible

wire gets displaced.

It has saw tooth. Teeth are

formed integrally with the

foundation rib. Its structure is

solid and sturdy. No danger of

displacement of wire points.

2 Any carding angle cannot be chosen.

There are some limited carding angles.

Any carding angle can be

chosen.

3 There is a fiber accumulation. The wire

points being clogged after a short

interval. A frequent stripping action is

required.

The holding power of these

wires is very low and no

accumulation of fibers. About

3% of fibers which go as

stripping waste can be saved.

4 No. of points per unit area is not so high. It gives a high no. of points per

unit area.

5 In a converted card, no separate

foundation wire is required for mounting

of flexible wire.

In this foundation wire is not

so necessary.

6 It often gets dull after a short interval of

2-4 weeks.

It loose there sharpness after 8

to 11 months.

7 The mending of flexible wire is

comparatively easy. It can be easily

changed.

The process of replacement is

time consuming.

3.8 Flats:

It is primarily a cast iron of ‘T’ sharp cross section. There are 105 to 110

flats, each about 35 mm (1”- 3/8”) with only 45-50 flats at any time. There are

two distinct portion on any flat- (a) a working surface. With wire -(b) and bearing

surface specially shaped to have a concave face. Concave face of bearing ends to

provide a support (seating) to the flats. The flat is never correctly balanced. The

curvature of the bend changes when the flats lowered after each cylinder grinding.

The back end of the bearing surface is slightly raised. This tilts the

working surface of the flats in such a way that fiber enters each cylinder flat-zone,

through a wider gap(A). As the fiber move through each flat, the distance between

flat wires and cylinder becomes narrow (B). Thus, if the front end is set at 0.254


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Settings of different parts in carding

Part 1 Part II Setting in

inches

Setting in cm

feed roller

Detail of Parts

Name Size Speed in

r.p.m

Surface speed With longer

cotton fibre

effect of

speed


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COTTON CARDING

Card

It is the instrument for disentangling and arranging the fibers of cotton, wool, flax, etc.

Carding:

It is the final stage of cleansing, wherein the minutest impurities foreign to the material

and all immature fiber, leaf and broken seed ought to be removed.

Objects of carding:

To thoroughly understand the work involved in carding, it is necessary to consider the

arrangement of the cotton fibers in a picker lap.

First, cotton is still in small locks or tufts of variable size and irregularly arranged. Second, some

dirt still remains. Third, they are many fibers which are shorter than the average for the cotton

being handled. Short fibers are relative term depending entirely on the cotton being used.

The objects of carding are:

1. To open the cotton more completely, even to individual fibers.

2. To clean the cotton further by removing dirt, neps and short fiber.

3. To produce a sliver.

The operation continuous the work of opening and cleaning.

Important points of cleaning are:

1. Where the cotton is fed (at the licker-in).

2. Where the cotton is brushed between the carding surfaces (between the cylinder and

flats).

The dirt removed at the licker-in is called motes and is the heavy type much like beater seed but

finer. If a reasonable quantity of dirt is removed, there will be some fiber lost also.

The dirt removed at the flats is mixed with short fibers. It lowers the value of short fibers

but that cannot be helped.

Other type of cleaning, that of removing short fibers at two places first, between cylinder

and the flats and second, drop out under the cylinder at the screen.

Short fibers removed and the dirt that comes out with them are called flat strips.

The third object of carding is the ‘silver’ which is a continuous, untwisted strand of cotton

fibres. The common silver is 1 inch in diameter.

Foundation:

The backing material for clothing is called the Foundation. It is a series of fabrics

held together by some type of adhesive, making a sufficient thickness to hold and support


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the wire of the clothing. Early days, Leather was used considerably for foundation, but

today there are few places where leather is used for foundation in cotton Industry.

Fabric foundation has displaced leather. It displaced leather for 2 reasons:

1. It can be made with a controlled uniformity.

2. It can be made at a lower cost.

A somewhat heavier foundation is used for clothing the cylinder and doffer.Rubber

facing is used for cotton, the purpose is to produce a more sensitive control for supporting

the wire.

Wire:

The wire used in card clothing is hardened, tempered steel ranging in diameter from

.009” to .017”. The wire is bent into staple, forced through the foundation and each point is bent

to the desired angle.

Types of clothing:

There are two general types of clothing:

1. Sheets (including flats): Sheet clothing is that made up with a piece of foundation

six inches in one direction and as long as card is wide in the other direction. Except

for border of one half an inch to one inch, all around, this sheet is set with wire.

2. Fillets: fillets are continuous strips of foundations, 1 ½ inches or 2 wide, entirely set

with wire. Fillets are applied in a spiral around the card cylinders requiring

continuous lengths up to 300 feet. The setting of the wire is such that there is hardly

a line where 2 filletss abutt each other. The “setting” or “set” of card clothing is the

pattern in which the crowns are pressed into the foundation. Crowns are arranged

across the width of the foundation, 4 per inch is called “12 crown” clothing.

Two type of setting commonly used today are:

a) Twill set used for sheets and flats:- Twill pattern is made by setting each row of

crowns slightly to the left of the preceding so that the crowns of the 17th row are

directly under the crowns of the 1st row. This set is sometimes called “ 6 twill”

because it repeats on 6 lines.

b) Rib set used for fillet:- In this clothing it perform a series of broad lines, running

the length of the foundation. Each broad line is the result of arranging is the

result of arranging 3 lines of crown to make a very steep diagonal line. The

distance which successive lines are set to the left is short enough so, the crown of

the 2 ribs does not overlap. There is a narrow open space separating the “ribs”.

A “Nogg” is one repeat of the lengthwise pattern used into the foundation.

It is unit of measure tells the closeness of points


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Nogg for sets are:

Twill set Rib set

6 lines of crown 3 lines of crown

5 to 13 noggs per inch 10 to 27 noggs per inch

Count : 10 times noggs per inch Count: 5 times noggs per inch

Another measure for closeness of setting of points is “no of points per square

foot”.

Types of grinding:

1. Top Grinding: It consists of grinding away the top of the wire to make the top end of

every wire flat and in the same plane as all the others. This gives what is called a

chisel point.

2. Side Grinding: It consists of grinding away a little from the side of each point,

making it somewhat narrower at the point.

3. Plow Grinding: It consists of grinding with the disks b/w the points. These disks

project into the wire nearly to the knee. They grind away the sides of each point and

so leave more space for the cotton. There is much variation in how the points are

ground. After plow grinding, it is customary to top grind.

In ordering card clothing some items are standardized. These items are:

1. Fillet or Flat( Rib or Twill set)

2. Counts (Noggs per inch)

3. Wire Gauge.

4. Grinding (Top and Plow Grind)

Metallic Card Clothing:

It is similar to very fine licker-in wire. This wire consists of a beveled, steel band with

teeth punched in the thin side and a thick rib on the other side, The rib is left soft so it may

conform to the curvature of the cylinder but the points of the teeth are hardened to prevent wear.

The metallic wire used for cotton carding are: Height of wire: 3/16” and Height of rib: 1/16”.

The tooth wire is wrapped as one continuous spiral over the entire width of the cylinder

or doffer, with each wrap touching the preceding one. The starting and finishing ends are

soldered to the flanges at several places around the circumference. If the wire is broken, or if

portions needs to be replaced, it is possible to solder the 2 ends together to make the continuous

length. Common card averages to last anywhere from 12 to 35 years.

Theory of Carding Actions:

All the actions accomplished by the use of card clothing may be considered as brushing

actions. Each surface covered with card clothing is really an immense brush in which all the wire

is inclined in a given direction. Each of the actions in card requires 2 surfaces, working together.


19

The direction of motion of these surfaces, the inclination of the wires and the relative speeds

control the effect on the cotton being processed.

“Carding action” is that used to continue the opening of the cotton, i.e, separating one

fibre from other. This action is obtained by having one surface of card clothing inverted above

the other, so that the points of the wire are but a few thousandths of an inch apart and inclined in

opposite directions called “Point against Point”. Normally the lower surface travel at a high rate

of speed in the direction toward which wire is inclined. The upper surface may be stationary.

However, it usually travels at a very slow speed in the same direction at the lower surface. The

speed of the Upper surface may be increased until it approaches that of the lower surface but less

work is done as the speed increases.

The lower carding is supplied with cotton which brings to the upper surface. As the

points of the lower wires carry the small tufts of cotton by the points of the upper wires, the latter

catch into the tufts and hold some of the fibers. As a result, the tufts of cotton are pulled apart

until practically every fiber is separated from others. This is the most complete opening action

which there is in the cotton manufacturer.

Fig 7. Carding Action Fig 8. Stripping Action.

“Striping Action” is that used in removing cotton from the surface of card clothing. It is

commonly done with a 2nd surface of card clothing close to the 1st with the inclination of the wire

in the same direction as that on the 1st surface known as “Point against Back”. Normally, one

surface travels at a slower speed and the cotton is removed from it by the other surface which

travels at a higher speed. If the speed of the lower surface ( fig 8) increases until it exceeds that

of the upper surface, conditions will reversed and the lower surface will remove the cotton from

the upper surface.

Stripping is also done by means of a “ comb”, made of a long, thin steel blade with fine

teeth along 1 edge. The comb vibrates very rapidly in an arc quite close to the slowly moving

surface. The teeth of the comb move against the back of the wire of the clothing and so a “Point

against Back” action is obtained.

Card Construction:

Fig 10 shows a cross section through a card emphasizing the working parts. Taken in

conjunction with fig 9, this should give a fairly complete idea of the main card parts and their

relative positions. In fig 9 and 10, the lap from the picker is fed at the left and the silver is

delivered at the right.

The “size” of cotton cards is generally given in 2 ways:

1) Width of the working surfaces of the card.


20

2) Diameter of the unclothed doffer.

While early cards were as narrow as 24 inches, modern cards are either 40 or 45 inches wide,

with a larger portion of cards in the 40 inch wide.

The early, narrow cards had doffers as small as 15 inches in diameter. Doffer diameters have

progressed through 18, 21 and 24 inch sizes until most cards have 26 or 27b inch diameters

doffers today.

The “ front” of the cotton card is the delivery or coller end, where the silver is deliverd.

The “ hand” of a cotton card is determined by the side on which the driving pulley is

located when viewing the machine from the driving pulley is on the right side of the card, it is a

right hand machine.

“Creeling” consists of laying the picker lap on the lap roll at the back of the card,

unwrapping the outside layer of the lap and guiding it, in smooth condition, under the feed roll.

“Doffing” consists of removing the roving can, full of sliver, from the coiler and placing

an empty roving can in its place.

Path of Cotton through the card:

The cross section through the card has allows on each of the moving parts to indicate the

direction of motion. Following the diagram it will be seen that the fibers pass over the feed plate

and are carried downward to the right by the licker-in. This opens up the lap a great deal because

the surface speed of the licker-in is in the vicinity of 1000 feet per minute, while the feed roll

surface speed is in the vicinity of 1 foot per minute.

The slow motion of the flat is used to carry them forward, so that they may be stripped of

accumulated fiber and dirt and returned to action, clean. The motion is slow enough so it does

not affect the carding action but fast enough to prevent loading the flats with too much fibre.

Beyond the flats, the cylinder carries the cotton downward to where it is transferred to the

doffer. The surface of the doffer moves at a slow speed, averaging around 72 feet per minute,

and in same direction as the cylinder, where they approach each other. The 2 surfaces are

generally set about .007 of an inch apart.

After making half a turn on the doffer, the fibres come up under the doffer comb. This

comb vibrates very rapidly, and , as moves downward, the points move against the back of the

doffer wire, producing a definite stripping action. The point of the comb will be about .010 of an

inch away from the doffer wire.

The web is much too thin to attempt to handle it and so the entire width is carried forward

to a funnel- shaped “trumpet”, where it is drawn through a small hole by a pair of cylinder rolls

and “condensed” to a sliver. The fibers retain this rope-like form due to the pressure resulting

from passing through a trumpet. It is then led upward and into the coiler.


21

The coiler is a cast-iron stand attached to the front of the card. It has a foot projecting

from one side of the bottom to hold the roving can and a top projecting over the foot with a

device for coiling the sliver in a regular arrangement in the can. There is a small trumpet in the

top of the coiler, a pair of small calendar rolls to draw the sliver through it and a revolving plate

gear carrying an inclined tube, through which the sliver passes. The “Tube gear” turns, arranging

the sliver in a coil a little to one side of the preceding coil. The result is a series of coils in a

spiral, making a regular, compact arrangement in the can from which the sliver may be

withdrawn without tangling

Under the Licker-in are mote knives and screen. Joined to the Licker-in screen is a large

screen under the cylinder. Above the licker-in is a metal cover and, adjoining it, the “back plate”

covers the cylinder from the licker-in to the flats. At the front, there is the “percentage plate”,

which covers the cylinder from the flats down to the doffer. Over the doffer is a sheet metal

cover, leaving only open space enough for stripping and grinding. Taken with the card framing

and flats, these parts make a very complete enclosure for the rapidly moving parts of the card.

Feed works:

All modern cards are equipped with a special feed plate, feed roll and licker-in, designed

to feed the cotton in the most advantageous form.

The Lap roll, usually about 6 inches in diameter, may be of wood or sheet metal. It often

has a series of wide, shallow flutes to reduce any tendency of the lap to slip.

The Feed plate is smoothly polished, cast iron plate extending from the lap roll to the

licker-in. The front end of the plate is curved upward slightly to fit around the feed roll,and then

bevealed of sharply towards the licker-in.

The feed roll is fluted steel roll, of 2 ¼ inches outside diameter. The roll rests in the

curved formed by the upturned nose at the front of the feed plate.

Licker-In:

It consists of a hollow cylinder, 9 inches in diameter, covered with” licker-in wire” set

quite close to the cylinder of .007” and the feed plate is set quite close to it of .010” to .018”.

Standard licker-in wire averages about .055 of an inch thick at the rib and tapers to about .010 of

an inch at the tips of the points. Points are spaced about 3 ½ to 4 ½ per inch, depending upon the

style.

This construction build a cylinder with 30,000 to 40.000 very sharp points much like a

series of closely spaced circular saws(4000to 5000 points per square foot) . Common Licker-in

speeds vary from 300 to 450 r.p.m. In general, lower speeds are used for long staple cottons and

higher speed for short staple cottons.

Mote Knives:

In order to retain a cotton in the licker-in and yet permit dirt to be separated from it, the

under side of the licker-in is enclosed by two ” mote knives” and “licker-in screens”.


22

The purposes of the mote knives are:

1) To leave spaces where dirt may drop through or be knocked through, as at the picker

grid bars.

2) To catch or scrape off bits of dirt carried with the cotton.(Dirt in this place refer to any

material foreign to cotton).

The usual arrangement of mote knives consists of 2 steel bars with quite sharp edges,

held quite close to the surface of the licker-in just below the feed plate. The bars are

sometimes of a triangular cross section.

The waste removed at these knives is known as “motes”. A mote is a particle of seed,

leaf, boll, shale, or stem. Along with the motes, there is always some fibre waste should be

short and of no value for spinning. Good cotton is found under the mote knives, various

settings should be examined.

Licker-in Screen:

The Licker-in screen is intended to:

1) Hold the cotton on the licker-in.

2) Permit dirt to be thrown off.

The usual licker-in screen consists of several triangular bars followed by a sheet of metal

curved to fit close to the licker-in. These bars are generally about 5/16 of an inch wide

and ½ inch high, with space about ¼ of an inch wide between them.

The back end of the licker-in screen should be from 1/8 to 3/16 of an inch from

the points of the licker-in wire and the front part should be about .030 of an inch from

them.

The waste removed at the licker-in screen is called “fly” and is mostly short

fibers, some motes and some dirt. In some cards, a sheet metal wall separates the space

under the licker-in and waste mix to some extent. Some mills leave separation of these

wastes to the judgment of the operative cleaning the machine, while other mills make no

effort to separate them.

To fully appreciate the work of the licker-in, it is necessary to consider the

condition of the cotton being fed. This varies with drafts and lap weights. If a 13 oz. lap

Is considered a fairly normal weight to feed and a draft of 100 is taken as average, a

normal speed for the feed roll is about 1 foot per minute and a normal speed of licker-in

Is about 1100 feet per minute. This gives a reduction or draft of 1100. The 13 oz lap

weighs 5687.5 grains per yard which becomes about 5.2 grains per yard on the licker-in.

This means there is thin film of fibers on the surface of licker-in. Under these

circumstances, it should be clear that the cotton is very much opened at this point, which

makes an excellent opportunity for the cleaning desired.

The surface speed of licker-in is much lower than any of the beaters used in

opening. The rate of feeding is much slower for opening and picking, which results in a

much higher “blows per inch”.


23

On the average, there are about 45,000 licker-in points per yard, which means that

5.2 grains of cotton fibre are distributed over 45,000 points. On the basis that there are

about 120,000,000 cotton fibres per pound.

It is important to stress the point; this is a gradual action, even if carried out at a

very high speed. The lap is fed very slowly. Only the upper surface of the lap comes

within reach of the licker-in wire.

Back Plate:

It is sheet metal cover, following the curvature of the cylinder, which encloses the

space between the licker-in and the flats. Its function is, mainly one of covering the surface

to prevent the throwing of cotton. The Plate is set from .022 to .034 of an inch from cylinder

wire.

Cylinder and Flats:

The card cylinder is the heart of the card. All other parts are built around it.

Cylinder does the work of carding. Cylinder is the active unit and usually gets the greater

part of the credit, the flats are of great importance. It is a large cast iron cylinder, 50 inches

outside diameter. The purpose of cylinder and flats are:

1) To open the cotton completely, even to the separation of one fibre to all the others.

2) To collect short fibres and dirt and separate them from the longer fibres, the flats being

expected to hold the dirt and short fibres.

Cylinder Clothing:

Clothing for cylinders is standard rib set, 2 inch fillet, which means that there are

8 rows of wires.

Flats and Bend:

Flat is a long cast iron bar of “ T” shaped cross section. The top of the cross

section is the working surface and the 2 end of the cross bars are carefully milled. There are

110 flats on a card. About 45 of these are face down , over the cylinder, moving forward in

a working position. In the working position, the ends of each flat rest and slide on the

“flexible bends”.

The cylinder is 50 inches in diameter and the clothing is 3/ 8 of the inch additional.

Grinding away 1/8 of an inch would be accessive. The maximum change of diameter the

bend is likely to be no more than ¼ of an inch in 50 inches or about ½ of 1%..

Flat Clothing:

When the flats are ground, the surface is concentric with that of the cylinder but

each is ground so that the back edge (That which the cotton reaches 1st)is further from the

cylinder than the front edge. This has been called the “toe” and “heel” of the flats.


24

If flat are set about .010 of an inch from the cylinder at the heel, the toe opening

will be in the variety of .030 of an inch.

Flat Drive:

The speed at which cards driven is about 3 inches per minute it was slow enough

to prevent the flats overloading and causing poor carding.

Calculating the basis of the figures gives the following surface speed of the flats.

𝟏𝟔𝟓𝐗𝟓 ½ 𝛑𝐗 𝟏𝐗𝟏 𝐗𝟖𝛑

𝟏𝟎 𝛑 𝐗 𝟏𝟔 𝐗 𝟒𝟐 = 3.39 inches per minute.

To get some idea of what happens b/w the cylinder and the flats, the real carding area of this

machine, an enlarged diagram of the parts., accurate scale is quite important.

First of all, the cylinder is a circle, while the flats are ground, which would seem

to be quite a discrepancy as working surfaces. The circle cylinder is 25 3/8 radius, giving

circumference of at least 160 inches, Surface of the flat is 7/8 of an inch.

For 110’s wire, the diameter is .014 of an inch, setting are from .010 of an inch

up, while the fibre handled averages .0006 to .0007 of an inch in diameter. The fiber is very

much finer than the wire and many fibers could be arranged one on top of another in the

space between the cylinder and flat wire.

This brings us the bulk of material being handled b/w flats and cylinder. The

assumptions, that were used for licker-in, where there were 5.2 grains per yard, a normal

draft of 2 at the cylinder would reduce to 2.60 grains per yard on the cylinder is sprtead over

40 inches by 36inches. If the cylinder will covered with 110’s clothing 792,000 points to

carry these 2.6 grains of fiber. Again , using 120,000,000 would work out to be about

44,300 fibres per yard are being handled by 792,000 wires. It means that each averages to

carry .055 fibers, there are about 18 card wires for each cotton fiber.

Little attention paid to the effect of high speed which the fibers are being carried

along at 200 feet per minute.


25

Fig 24 page no.36

Fig no 23 page no. 36.

The fibers are very fine compared with any of the device carrying or working them.

Infinitesimally thin film enormous brushes with 1 1/3 million points, which means that there is

very limited opportunity thoroughly opened. Centrifugal force causes these fibers to be drawn

through 1 set of wire.

Front plate or percentage plate:

Functions of the front plate are:

1) To cover the cylinder and prevent fibers from flying away.

2) To keep all other material from the cylinder.

3) To provide the opening for stripping and grinding the cylinder.

The percentage plate regulates the percent of flat strip to some extent. It is built in 3 pieces

top, bottom and center (middle or door). The top plate helps to regulate the strips. It is arranged

from .024 to .034 of an inch from the cylinder wire. The closer the plate set in the cylinder the

more it holds the fibers down against the cylinder and so fewer fibers get away.

The closer setting of the top front plate produce less flat strips.


26

Fig no. 25 page no. 38.

Cylinder Screen:

The cylinder screen is an enclosing case for the under side of the cylinder. Its functions

are:

1) To keep the cotton on the cylinder.

2) To let dirt, dust and short fibers fall out.

Bars:

Material used Shape Width Altitude

Metal sheet isosceles triangular

with vertex

downward

3/8 of an inch wide 7/16 to 13/16 of an

inch

The front end of the screen is about 3/16 of an inch. The center point is .058 of an inch and

directly below cylinder shaft The back end where it joins the licker-in is .029 of an inch from

cylinder

The waste found under the screen should be mostly short fiber. The color should be grey to

brown depending upon quality of stock handled. If the waste is white, it indicates long fibers are

present. Setting the screen closer will eliminate the long fibers from the waste.

Doffer:

It is a large cast iron cylinder, 26 or 17 inches in diameter covered with 1 ½ inches fillet.

Ordinarily the doffer is 10 counts finer than the cylinder clothing, which is usually with its

surface .007 of an inch from the cylinder surface. This is one of the most important card setting.

Functions of the doffer are:

1) To collect cotton from the cylinder in a uniform sheet

2) To carry this as a continuous sheet which may be removed to make a continuous card

sliver.

The clothing of the doffer is arranged so that it will work point against point with that of the

cylinder. At their nearest position, the cylinder wire points downward and the doffer wire points

upward. The surfaces are moving in the same direction, the cylinder at about 2000 feet per

minute and doffer at about 72 feet per minute. The action taking place is point against point with

the cylinder moving rapidly by the doffer and is “carding action”.

Much of the cotton is taken from the cylinder by the doffer and the 1st thought is very apt to

be that this must be a “stripping action”. The speed of the cylinder tend to throw fibers off. The

speed of doffer is too low to develop any appreciable tendency in this way. Consequently, there


27

is the theory that fibers, swinging out from the cylinder, come in contact with the doffer wire,

catch in it and are removed from the cylinder. Each inch of the doffer collects fibers from 20 to

30 inches on the cylinder.

Following the calculations used the licker-in and cylinder and assuming about 60 grains of

sliver per yard at the doffer, with 120 count clothing, it will be found that there are about

1,029,000 fibers to be carried by 864,000 points or an average of about 1.2 fibers per point.

Another, help some in transferring the cotton fibers. Doffer has a finer count of clothing.

Summarizing these points, gives:-

The normal tendency of any carding action to deposit some fibers on both of the working

surfaces, plus the centrifugal tendency to throw fibers off the cylinder, helped by the greater no.

of points at a closer setting on the doffer as forces causing fibers to be deposited on the surface

of the doffer.

Doffer Comb:

It consists of a thin steel blade about 7/8 of an inch wide, with fine teeth, about 16 per

inch, cut in the lower edge. Blade is supported by 4 small fingers projected in horizontal

direction from the doffer comb shaft.

The comb shaft is reciprocated in its bearings so that the fingers move the comb blade up

and down from 1 to 1 ¼ inches, on a radius of about 4 inches. An angle of motion between 10

and 20 degrees. At the closest position, the comb blade should be from .010 to .022 of an inch

from the doffer wire. Speed of comb should be 1200 and 1500 vibrations per minute.

The action of the comb is strictly stripping, the points of the comb coming down against

the back of the doffer wire. The upward motion is all lost. Some of the downward motion is lost

also, depending up on the speed of the doffer and the comb.

Calender Rolls:

The function of these rolls are:

1) To draw the web away from the doffer at a uniform rate as fast as it is stripped.

2) To draw it through a trumpet to convert the web to a silver.

3 to 4 inches in diameter, located at the center of the card frame a little lower than

the doffer comb. The top calender roll is similar to the bottom roll, usually 4 inches in

diameter. The doffer web is so thin and delicate effort is made to handle the cotton in

that form. The web is converted to a sliver by drawing it through a trumpet with a hole

about ¼ inch in diameter.

The sliver, from the calender rolls, is drawn upward to the coiler as shown in fig.

10, which, asa explained earlier, is a device for coiling the sliver in a roving can. The

advantage of making these condensed slivers was that more cotton could be packed in a

roving can this increased the time to fill can. A more highly condensed sliver offers more

resistance to drafting at the drawing frame.


28

Coiler:

By means of gear drive turn able causes a can to go from 1 to 5 r.p.m. The coiler plate is

about 2 ½ inches above the top of the can, leaving plenty of clearance for doffing. It is a gear

about 12 inches in diameter . The upper side of the tube gear has a projecting hollow tube

inclined from the outer edge upward over the center of the gear.

For drawing the sliver to the coiler is the pair of calender roll, 2” in diameter, located just

above the tube gear. The surface speed of the coiler calender rolls is just a little greater than that

of the doffer calender rolls. With a hole in the center to permit passage of the sliver, fits over top

of the both calender rolls. The under side is covered with clearer cloth to collect any lint or dirt

which collects on the surface of coiler rolls.

A small trumpet is fitted into the top of the bonnet directly over the center of the tube

gear. The lower end of the trumpet is usually smaller than that of the doffer trumpet plate.

Diameter of hole= Multiplier x √𝐺𝑟𝑎𝑖𝑛𝑠 𝑝𝑒𝑟 𝑦𝑎𝑟𝑑.

The multiplier for card sliver is 0.022

Example: The proper size for a 50 grain sliver would be,

D=0.022 x √50

D= 0.0156”

Card trumpet hole diameters

Sliver 40 45 50 55 60 65 70

Manufacturer .140 .150 .160 .167 .175 .175 .190

Rule .139 .148 .156 .163 .171 .177 .184

Flat Stripping:

As the flats are moving forward with the points inclined toward the back, they are in the proper

position for stripping. The action necessary is very much like that at the doffer. With the flat

comb the entire upward swing is lost. Stripping occurs only at the downward motion.

Flat comb common speed is 70 to 100 reciprocations per minute. The length of stroke

varies from 1 to 1 ½ inches. It means the flat comb moves about 100 inches per minute in either

direction. Only a very small motion of comb is used in stripping.

The flat stripping comb removes the strips from the flats and allows them to drop to the doffer

bonnet.

Card drive:


29

Cards are most commonly driven with belting, in groups. While some installations made

with individual motors, they have to specially connect to permit reversing the direction of

cylinder for grinding. So the individual drive is not of great value.

Fig. 34 page no. 51

Fig 33 Page no 51

Card Draft:

Draft is a measure of the degree to which a sheet or strand of fibres is reduced in passing

through a machine and may be expressed by a comparison of the material as fed and delivered,

or by a comparison of the rates of delivering and feeding.

Draft may be defined as “The process of uniformly attenuating a strand of fibrous

material without breaking its continuity”. (Attenuate= to make thin or slender). Draft range is

from 80 to 120 in some cases it is up to 150. Average draft is about 100.


30

The feed roll licker-in working point, the draft will be about 1000. This draft is, partially

offset by the accumulating action at the doffer. Draft can be considered under 2 headings:

1. Actual Draft.

2. Mechanical Draft.

Actual Draft:

It is a measure of how much lap is reduced. Actual draft is determined by dividing per

yard of the lap fed by the grains per yard of the sliver delivered.

𝑾𝒆𝒊𝒈𝒉𝒕 𝒑𝒆𝒓 𝒚𝒂𝒓𝒅 𝑭𝒆𝒅

𝑾𝒆𝒊𝒈𝒉𝒕 𝒑𝒆𝒓 𝒀𝒂𝒓𝒅 𝑫𝒆𝒍𝒊𝒗𝒆𝒓𝒆𝒅= actual draft

Example: If a card is fed a 14 oz. lap and makes a 55 grain sliver, what is the actual draft?

437.5 grains per ounce,

14 oz. lap weighs 14x 437.5=6125 grains per yard.

Then, 6125 𝑔𝑟𝑎𝑖𝑛𝑠 (𝑓𝑒𝑑)

55 𝑔𝑟𝑎𝑖𝑛𝑠 (𝑑𝑒𝑙𝑖𝑣𝑒𝑟𝑒𝑑) = 111.4 actual draft

Example: If the actual draft of a card is 100 and a 13 oz. is fed, what is the grain sliver

delivered?

13 x 437.5 (fed

𝑔𝑟𝑎𝑖𝑛𝑠 𝑑𝑒𝑙𝑖𝑣𝑒𝑟𝑒𝑑 = 100

13𝑥437.5

100 = 56.88 grain sliver

Example: If a 50 grain sliver is desired and the actual draft for the card is 120, what lap

should be fed?

𝑜𝑧.𝑙𝑎𝑝 𝑥 437.5

50 = 120

Oz. lap = 120𝑥50

437.5 = 13.71 oz. lap

Mechanical draft:

As an appreciable part of the reduction in weight in carding is due to the removal of

waste, it is important to make allowance for this loss in calculating for proper mechanical draft.


31

1. Mechanical draft which much result from the speed of the delivery rolls and feed rolls after

allowance made for the reduction due to waste removal.

2. There is a point of view what gears are necessary to produce the required speeds to give the

proper reduction.

Waste in carding varies from 4 to 8 percent, the common is to multiply the weight per yard fed

by the appropriate figure usually between .92 and .96.

Example: If a card is fed a 14 oz. lap and makes a 55 grain sliver makes 6% waste, what

must be the mechanical draft?

The weight per yard fed must be reduced by 6% to represent what cotton is delivered.

That is, 6125x 0.94

Then, this weight (clean cotton fed) divided by 55, tells the increase in speed necessary

between the delivery rolls and the feed rolls.

14𝑥437.5𝑥0.94

55 = 104.7 mechanical draft

Example: If the actual draft of a card is 100 and a 13 oz. is fed, it took out waste 5%, what

is the mechanical draft?

13 x 437.5 (fed

𝑔𝑟𝑎𝑖𝑛𝑠 𝑑𝑒𝑙𝑖𝑣𝑒𝑟𝑒𝑑 = 100

13𝑥437.5

100 = 56.88 grain sliver

Then,

13𝑥437.5𝑥0.95

56.88 =

5403.125

56.88 = 94.99 mechanical draft

Example: If a 50 grain sliver is desired and the actual draft for the card is 120, what would

be the mechanical draft when the waste is 7%?

𝑜𝑧.𝑙𝑎𝑝 𝑥 437.5

50 = 120

Oz. lap = 120𝑥50

437.5 = 13.71 oz. lap

13.71𝑥437.5𝑥0.93

50 =

5578.26

50 = 111.56 mechanical draft

General equation,

𝐿𝑒𝑛𝑔𝑡ℎ 𝑑𝑒𝑙𝑖𝑣𝑒𝑟𝑒𝑑

𝐿𝑒𝑛𝑔𝑡ℎ 𝑓𝑒𝑑 = mechanical

If the weight per yard is reduced, a given quantity of cotton must take more yards and so

the ratio of weights is the inverse of ratio of lengths.


32

In studying draft, the best procedure is to trace through the gearing from the lap roll to the coiler

calendar rolls, making certain just what gears are involved. Then, go over this train of gears a

second time and determine which are idlers, so they may be eliminated from considerations. ( In

this connection, it is important to remember that it is possible for a gear to be An idler for one

calculation while it is not for some other calculation.)

Having determined just what gears connect the two rolls;

1. Assume that the lap roll makes one turn,

2. Find the turns of the coiler rolls.

3. Find the length delivered,

4. Divide the length delivered by the length fed, the lap roll circumference.

Fig 35 Page no. 58

Example: Using above figure, with a 15 draft gear, what is the mechanical draft?

48𝑥120𝑥22𝑥180𝑥24𝑥20𝑥20𝑥2𝜋

17𝑥15𝑥22𝑥19𝑥16𝑥20𝑥20𝑥6𝜋 = 107 mechanical draft

To determine a draft constant this simplifies the determination of draft gears to use under

different conditions. The constant is found substituting “one” in place in the usual draft equation.

Example: What is the draft constant for figure 35?

48𝑥120𝑥22𝑥180𝑥24𝑥20𝑥20𝑥2𝜋

17𝑥1𝑥22𝑥19𝑥16𝑥20𝑥20𝑥6𝜋 = 1605 draft constant

The constant delivered by mechanical draft desired will give the necessary gear.

𝐷𝑟𝑎𝑓𝑡 𝐶𝑜𝑛𝑠𝑡𝑎𝑛𝑡

𝐷𝑟𝑎𝑓𝑡 𝐺𝑒𝑎𝑟 = mechanical draft,

Or,


𝑀𝑒𝑐ℎ𝑎𝑛𝑖𝑐𝑎𝑙 𝐷𝑟𝑎𝑓𝑡 = draft gear


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Example: Feeding a 13.71 oz. lap and producing a 50 grain sliver when removing 7%

waste, what gear is needed for fig 35? The necessary mechanical draft was found to be

111.6.


𝑀𝑒𝑐ℎ𝑎𝑛𝑖𝑐𝑎𝑙 𝐷𝑟𝑎𝑓𝑡 =

1605

111.6= 14.4 gear

In this case, where the solution gives a gear about halfway between 14 and 15, the gear

selected would depend up on whether the carder would rather have his draft higher or lower than

that wanted. This, in turn, would depend upon whether he would prefer his sliver to be lighter or

heavier than 50 grains.

Draft Constant= Draft gear x Mechanical draft

By increasing the size of the draft there is an inverse ratio between draft gears and drafts.

Old Gear

New Gear=

New Draft

Old Draft

Solving this proportion, the first step would be:

Old Gear

Old Draft=

New Gear

New Draft

Larger draft gear will give a heavier sliver, which means that there is a direct proportion between

these two.

Old Gear

New Gear=

Old Weight

New Weight

Intermediate Drafts:

A study of the intermediate drafts of a card brings out some interesting features regarding

what happens in the card and helps to clarify some of the reasons why a card can do what it does.

Example: What are the intermediate drafts for fig 35 when using a 15 draft gear and a 24

doffer gear?

Lap Roll to Feed Roll,

48𝑥2

1

4𝜋

17𝑥6𝜋 = 1.059 – draft

Feed Roll to Licker-in,

120𝑥22𝑥180𝑥104𝑥9𝜋𝑥9

3

4𝜋

15𝑥22𝑥24𝑥26𝑥6𝜋𝑥21

4𝜋

= 1560 draft

Licker-In to Cylinder,


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7 𝜋𝑥50

3

4𝜋

19𝜋𝑥93

4𝜋

= 1.917 draft

Cylinder to Doffer,

19𝜋𝑥6𝜋𝑥26𝑥24𝑥 263

4𝜋

7𝜋𝑥9𝜋𝑥104𝑥180𝑥503

4𝜋 = 0.318 draft

Doffer to Calender,

180𝑥 27/8𝜋

19𝑥263

4𝜋

= 1.018 draft

Calender to Coiler,

24𝑥20𝑥20𝑥2𝜋

16𝑥20𝑥20𝑥278

4𝜋 = 1.043 draft

Card Production:

Production is measured in pounds per hour, day or week. The most common pounds per

day. The same principle outlined Picking, it can be said that production depends upon 4 items:

1. The rate of delivery of material

2. The size of the product

3. The length of time used as a standard

4. The percent of stops for the operation

Doffer Speeds:

The cylinder speed for any given installations is rarely changed. This speed is not an

indicator of the card production. There is a change gear in the drive from the doffer by means of

which different delivery speeds are obtained.

The speed of a card is generally speed of the doffer which depends upon size of doffer

change gear used.

Example: Using fig 35 and a cylinder speed of 165 r.p.m , what is the doffer speed when a

24 doffer gear is used?

165𝑥19𝜋𝑥6𝜋𝑥26𝑥24

7𝜋𝑥9𝜋𝑥104𝑥180 = 9.95 r.p.m doffer

A constant may be determined for this expression using”1” in place of the doffer gear.

Example: What is the doffer constant for fig 35?

165𝑥19𝜋𝑥6𝜋𝑥26𝑥1

7𝜋𝑥9𝜋𝑥104𝑥180= 0.414 doffer constant


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Example: What speed will a 20 doffer gear give for fig 35?

0.414x20=8.28 r.p.m

Since the constant multiplied by the gear gives the r.p.m of the doffer, the r.p.m of the

doffer divided by the constant will give the gear necessary for speed.

Example: What gear is needed to give 12 r.p.m for fig 35?

0.414x G=12 r.p.m

G= 12

0.414 = 29 doffer gear

The size of card sliver, being given requires only to be divided by 7000 to convert it to pounds.

Common sizes range between 50 and 60 grains with some sliver running as low as 35 grains and

some up to 70 grains.

Example: What is the production of 50 grain sliver per 8 hours with 5% stops? Use fig 35,

a cylinder speed of 165 rpm and a 24 doffer gear.

165 𝑥 19𝜋 𝑥 6𝜋 𝑥 26𝑥 24 𝑥 24 𝑥 20𝑥 20𝑥 2𝜋 𝑥 50 𝑥 60 𝑥 8 𝑥 85

7𝜋 𝑥 9𝜋 𝑥 104 𝑥 19 𝑥 16 𝑥 20 𝑥 20 𝑥 36 𝑥 7000 = 100.45 lbs production

Example: What is the production constant for fig 35 per 8 hours with 15 % stops?

165 𝑥 19 𝜋 𝑥 6𝜋 𝑥 26 𝑥 1 𝑥 24 𝑥 20 𝑥 20 𝑋 2𝜋 𝑋 1 𝑋 60 𝑋 8 𝑋 0.85

7𝜋 𝑋 9𝜋 𝑋 104 𝑋 19 𝑋 16 𝑋 20 𝑋 20 𝑋 36 𝑋 7000 = 0.837 production constant cylinder

Since, both the doffer gear and the grain sliver appear in the numerator of this expression,

the constant must be multiplied by the doffer gear and the grain sliver to determine production,

giving the general expression:

Production constant X Doffer Gear X Grain Sliver = Production

Example: What would be the production of 50 grain sliver with a 24 doffer gear for fig 35?

0.837 X 24 x 50 = 100.44 lbs production

Example: What doffer gear should be used for fig 35 to produce 110 lbs of 60 grain sliver

per 10 hours with 5% stops?

0.837 X G X 60 = 110

G = 110

0.837 𝑋 60 = 21.9 or 22 doffer gear


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If it is desired to consider changing both the grain sliver and doffer gear, a proportion can be

written including both of these where they are both directly in proportion to the production.

𝑂𝑙𝑑 𝐺𝑒𝑎𝑟 𝑋 𝑂𝑙𝑑 𝑆𝑙𝑖𝑣𝑒𝑟

𝑁𝑒𝑤 𝐺𝑒𝑎𝑟 𝑋 𝑁𝑒𝑤 𝑆𝑙𝑖𝑣𝑒𝑟=

𝑂𝑙𝑑 𝑃𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛

𝑁𝑒𝑤 𝑃𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛

Stripping:

It is the process of removing fibers from the various surfaces leaving them clear and

ready for another production. As explained in previous section, Flats are stripped automatically

and continually. Either the card tender on the stripper goes along the can, gathers up the flat

strips and takes them to a rack or to a suction conveyor system which draws them away to the

waste house. If the rack is used, it is taken to the waste house later.

The frequency of stripping varies from twice a shift to may be 4 times a shift. One

interesting feature is card producing 120 lbs to 150 lbs per day be stripped while cards producing

75 lbs per day probably be stripped 3 times daily.

Plain Stripping Roll:

The simplest device used in stripping cotton card cylinders and doffers is the plain

stripping brush or roll. This device consists of a 11

8 inch shaft about 60- inches long, carrying a

wooden roll about 6 inches in diameter and 42 inches long. The wooden roll is covered with

stripper clothing, in fillet form.

The particular point is that the surface speed of the stripping brush must exceed that of

the cylinder which it is stripping. On this account, it is necessary to stop the card cylinder before

starting to strip. Then, the cylinder is driven very slowly while being stripped. The doffer may

run at normal speed and direction of stripping.

The following table gives the steps as commonly taken in stripping a card with the plain

stripping roll.

Stripping a Card:

1. Stop the card

2. Remove the roll of flat strips.

3. Disengage the doffer gear.

4. Put the stripping roll on the stripping strands of the cylinder so it runs with the points

down where it comes in contact with the cylinder.

5. Put on the shorter stripping roll band from the loose pulley to the stripping roll, crossed.

6. Slip the main belt halfway on to the tight pulley to turn the cylinder slowly. Keep the

loose pulley up to speed all the time.


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7. After one complete turn of the cylinder, remove the stripping roll band, and lift the

stripping roll out of the stands, AT ONCE.

8. Move the main belt to the tight pulley.

9. Strip the stripping roll by turning it backward in the stands of the stripping box.

10. Put the stripping roll on the doffer stands, as on the cylinder.

11. Put on the longer stripping roll band, crossed.

Fig 36 Page 61

12. Move the belt part way back on the loose pulley to drive the stripping roll. The rest of the

card will run by momentum previously obtained.

13. Start the doffer in the usual way.

14. Disengage the doffer calendar and coiler gearing when the end of the web leaves the

doffer.

15. After one complete revolution of the doffer, remove the stripping roll band, and lift the

stripping roll out of the strands, AT ONCE.

16. Strip the stripping roll as before.

17. When the web is up to weight, break off clear across, hold the end in doffer calendar roll

and re-engage the calendar roll drive.

18. Let the sliver run on to floor for 2 or 3 minutes before starting it into the can. (As the

cylinder and doffer collect fibers very rapidly, directly after stripping, the first few yards

of sliver will be abnormally light. Discarding the production of the first 2 or 3 minutes

eliminates the lightest of this yardage).

Dustless Stripper:

An effort to improve stripping, Parks Portable Dustless Card Stripper was developed.

This stripper consists of stripping roll, partially enclosed in a hood from which a large flexible

tube leads to special stripping truck. The fan exhausts into a fabric bag much like those used in

domestic vacuum cleaners.

The Dustless Stripper is used exactly like the plain stripper, except that the fan is kept

running during the stripping of the cylinder doffer. As a result, the dust which would normally be

thrown into the air is drawn away by the suction and collects in the dust bag.


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Air Stripper:

The Saco-Lowell air stripper entirely eliminates the stripping truck. Each card has, built

into it, one small stripping brush, covered with special stripper clothing placed just above the

junction of the doffer and cylinder. The roll is enclosed within a special, hollow doffer cover,

which is the end of a suction line. All the stripper needs is a short belt to drive the stripping roll.

The stripper roll about 3 inches in diameter and covered with special stripper wire.

Vacuum Striper:

The vacuum card striper, as made by the Abington Textile Machine Works, is one which

uses no stripping brush. The removal of strips is done entirely by suction. This system requires

special air pumps to maintain a high vacuum and large waste receiving drums where the wastes

are collected.

Attached just above the doffer hood of each card, this system uses a traverse tube,

extending the full width of the card. The underside of the tube has a wide slot. Within the tube is

the traverse screw, a long rod with a thread having ½ inch pitch.

Card Grinding:

The good condition of wire is called “sharp”. Point of wire is like that the fingers will rub

easily against the wire. When the wire is dull, the resistance to fingers against the points is much

less.

Grinding Medium:

1. The medium used in grinding having a granular formation.

2. While emery is arranged on fabric tape and called “emery fillet”.

3. The rolls may be plain or grooved.

Grinding Instruments:

The instruments used in grinding card clothing are:

1. Long roll grinder

2. The traverse grinder.

Long Grinder:

It is often called a dead roll grinder or drum grinder. It is a steel shell about 7

inches in diameter and 42 inches long (47 inches for a 45 inch card)

Traverse Grinder:

It is also called a horsefall grinder. It consists of a narrow roll 3 ½ inches wide

and 7 inches in diameter, mounted on a hollow steel shell 46 inches long( 51 inches for a

45 inch card) .Within the hollow card is the traverse screw, a long central shaft in which

are cut 2 wide threads, 1 right hand and 1 left hand, which join at the two ends.


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Grinding a Card:

Cleaning the card:

Page no 77,79,80

Flat grinding:

To maintain the “heel and toe” conditions of the flats, it is necessary to have a special

grinding device for them. The device usually consists of two parts. These are:

1. Some weighting arrangement which hold the flat pressed against the surface area

while it is being ground.

2. The surface arrange to hold the flat is at proper angle.

Average card Settings:

S. No. Place Setting Order

1 Feed Plate to licker in 10 to 18 7

2 First Mote Knife 17 6

3 Second Mote knife 12 5

4 Licker-In Screen- Back 125 4

5 Licker-In Screen- Front 29 3

6 Licker-In to cylinder 7 2

7 Back Plate to cylinder 22 8

8 Flats to cylinder 9 to 11 10

9 Percentage Plate 24 to 34 9

10 Doffer to Cylinder 7 11

11 Screen to Cylinder-Front 187 1

12 Screen to Cylinder-Center 60 1

13 Screen to Cylinder-Front 29 1

14 Doffer Comb to Doffer 12 12

15 Flat Comb to Flats 12 13

Wastes in carding:

The 2nd object of carding is to clean the cotton further by removing dirt, short fibers and neps.

There are 4 general classes of wastes:

1. Motes

2. Fly

3. Strips or stripping

4. Sweeps.

Cylinder strips has high percentage of long fibers and shows short fibers than the flat strip array.

In making a visual comparison of these arrays, it should be kept in mind that each array

represents about the following %age of the weight of cotton fibers fed:


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1. Sliver- 94%

2. Flat Strips- 3%

3. Cylinder strips-0.5%

4. Fly-0.5%

Motes:

These are particles of seed, leaf, boll shale or stem. In card mote waste include some dirt

and some short fibers, when the parts are properly adjusted, the fiber contents of motes should be

small and the fibers should be short and unsuited to spinning.

1. The closer the feed plate is to the licker-In, the more complete is the opening of the

lap fed. It is possible to more completely clean the cotton which gives more waste.

The first mote knives may be adjusted vertically, horizontally or for angle. The

second mote knives are usually set closer than the first.

2. The closer the knives are set the greater is the greater is the amount of waste

removed. The more nearly the knives are set the greater is the motes and the less loss

of cotton.

3. Higher the Licker-In speed the greater the mote waste. Licker-In speed would give

more “blows per inch”.

Fly:

It is a term applied to short fibers which are thrown off by the cards. This name applied to

those fibers which collect under screens. Considering fly as the material under the screens, it is

mostly short fibers. The closer the screen is set to their cylinders, the less the fly should be

expected. If screens are too far then the long staple cotton will lost. Amount of motes and fly is

from 1% to 3%.

Strips:

These are subdivided into, Flat Strips, Cylinder Strips, and Doffer Strips. Flat Strips

contain little dirt, dust and small vegetable particles. The control of the %age of flat is very

important. It depends on the setting of the front or percentage plate rather than their own settings.

Flats must be set correctly to get good carding. Percentage plate setting is used to control the

percentage of waste. Way to check waste is to weight flat strips from each card.

Sweeps:

Sweeps are the waste swept from the floor, quite a little of which is material blown or

brushed or cleaned off the card frame and covers. Some of the sweeps is fly which has settled in

the alleys. Stripping with a plain stripping brush adds to the fly which goes into sweeps. Some of


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the sweeps may be good cotton dropped from laps or sliver, walked on and considered too dirty

to back into the regular processing. The control of sweeps is through close supervision and good

housekeeping. Avoiding fly from card stripping and keeping good cotton off the floor are main

steps in keeping sweeps at a minimum.

Neps in Carding:

Neps, sometimes called “nips” or “nits” are very small tangled masses of cotton fibers.

They are usually smaller than the head of a common pin (up to as much as 0.070 of an inch in

diameter).

Opening machinery may make neps, especially if the air currents are too low and cotton

does not passes quickly through the various machines. Neps are so small that opening machinery

is not expected to remove them. Even though cards are supposed to remove neps, damaged

licker-ins, incorrect settings, stray air currents, dull wire or lack of stripping may cause the card

to make a greater quantity of neps than it removes.

An unopened mass of the cylinder and flats to work upon. Carding action, between the

cylinder and the flats, it is likely that some fibers are pulled away from the neps but many of the

neps will lodge in that flat wire and become a part of the flat strips.

It is just possible that in opening some of the larger tangled masses of fibers, often called

“naps” a card may pull together loosely tangled fibers and produce neps.

Number of Neps per 100 sq inches of card web

1. 15 and below Low

2. 16 to 30 Average

3. 31 to 45 High

4. 46 and above Very High


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CARDING by Khare

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