Manual of

Yarn Manufacture Laboratory - I

(TXP 221)

Department of Textile Technology

Indian Institute of Technology Delhi
2018
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 Table of Content

Experiment Page
Title of Experiment
No. No.
1 Study of drives and functions of blowroom machines 5-13
2 Determination of fiber openness in bale, lap, and sliver 14-16
3 Determination of cleaning efficiency of blowroom and 17-19
carding machines
4 Determination of draft and production of carding 20-25
machine
5 Study of machine setting in carding and drawframe 26-28
machines
6 Production of card sliver of given linear density 29-30
7 Study of fibre transfer coefficient in carding machine 31-32
8 Study of fibre neps in carded web 33-34
9 Determination of fiber orientation in card and 35-39
drawframe slivers
10 Determination of draft in drawframe machine 40-43
11 Production of drawframe sliver of given linear density 44-45
12 Study of generation of drafting wave in drawframe 46-47
13 Study of effect of draft and doubling on mass 48-49
irregularity of drawframe sliver
References 50

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 EXPERIMENT 1
STUDY OF DRIVES AND FUNCTIONS OF BLOWROOM MACHINES
The principal functions of blowroom are opening and cleaning of the fiber material.
Typically, a modern blowroom line consists of a mixing bale opener, mono cylinder
cleaner, flexi cleaner, and aerofeed system to card. A brief description of these
machines is given below.
1.1 MIXING BALE OPENER
1.1.1 Overview
The schematic diagram of a mixing bale opener is shown in Figure 1.1. The fibers taken
from bales are fed to this machine and the fibers get mixed, opened, and cleaned by
this machine.
1…feed apron
2…photocell to (1)
3…mixing chamber
4…photocell to (3)
5…inside feed apron
6…upright lattice
7…dust extraction
8…upward waste
conveyor
9…cleaning roll
10…stripper roll
11…upward material
delivery
Figure 1.1 Schematic diagram of mixing bale opener [1] 12…take-off roll
13…filling trunk
14…photocell to (13)
15…feed roll pair
16…opening roll
17…grid knife

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The gearing diagram of this machine along with some important data of this machine is
shown in Figure 1.2

Figure 1.2 Gearing diagram and machine data of mixing bale opener [1]

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1.1.2 Observations
Identify each element in the machine as mentioned in Figure 1.1
1.1.3 Calculations
Calculate the surface speed of the various machine elements like stripper roller,
cleaning roller, take-off roller, feed roller and opening roller with the help of gearing
diagram (Figure 1.2).

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Report the rotational speed and the surface speed of the various elements in Table 1.1
Table 1.1 Results of calculation of speed of various elements of mixing bale opener
Machine element Rotational speed (rpm) Surface speed (m/min)
Stripper roller
Cleaning roller
Take-off roller
Feed roller
Opening roller

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1.2 MONO CYLINDER CLEANER
1.2.1 Overview
The schematic diagram of mono cylinder cleaner is shown in Figure 1.3. It processes
the fiber material while it is in free flight and opens and cleans the material by the striker
elements that are widely spaced on the opening roller.

Figure 1.3 Schematic diagram of monocylinder cleaner [2]

1.2.2 Observations
Identify the various elements of monocylinder cleaner.
Understand the material flow and critical functions of various elements.
1.2.3 Calculations
Count the number of strikers on the opening roller.

Calculate the rotational speed (rpm) of the opening roller.

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1.3 FLEXI CLEANER
1.3.1 Overview
The schematic diagram of flexi cleaner is shown in Figure 1.4. It processes the fiber
material when it is clamped by the feed rollers and opens and cleans the material by the
striker elements that are narrowly spaced on the opening roller.

1…feed head with fan

2…material supply
3…exhaust air chamber
4…material delivery
5…laminae chute
6…plain drum
7…dust cage
8…feed roller
9…opening roll
10…suction duct
11…waste chamber
12…drive motor
13…knife grid
14…waste removal pipe

Figure 1.4 Schematic diagram of flexi cleaner [3]

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 Figure 1.5 Gearing diagram of flexi cleaner [3]
1.3.2 Observations
Identify the various elements of flexi cleaner.
Understand the material flow and critical functions of various elements.
1.3.3 Calculations
Count the number of strikers on a saw tooth disc and the total number of disc on the
opening roller.

Calculate the surface speed of opening roller, blind roller, dust cage roller, 80-mm
cylinder roller and 60-mm cylinder roller.

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Report the rotational speed and the surface speed of the various elements of flexi
cleaner in Table 1.2.
Table 1.2 Results of calculation of speed of various elements of flexi cleaner
Machine element Rotational speed (rpm) Surface speed (m/min)
Opening roller
Blind roller
dust cage roller
80-mm cylinder roller
60-mm cylinder roller

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1.4 AERO-FEED SYSTEM
1.4.1 Overview
The fiber material is fed from the flexi cleaner to the carding machine by aero feed
system. The schematic diagram of aerofeed system is shown in Figure 1.6.

1…separating head
2…exhaust air housing
3…feed chute
4…perforated clamp
5…air camping space
6…feed rolls
7…guide plate
8…opening roll
10…baffle plate
11…light barrier
12…filling trunk
12…take-off roll
13…feed roll on card
14…feed roll drive
15…opening roll drive

Figure 1.6 Schematic diagram of aero feed system [4]

1.4.2 Observations
Identify various elements of aerofeed system.
Understand the material flow and critical functions of various elements.
1.4.3 Remarks, if any

Teacher’s Signature & Date

13
 EXPERIMENT 2
DETERMINATION OF FIBER OPENNESS IN BALE, LAP, AND SLIVER
2.1 Overview
The cotton fibres are procured in the form of bales. Each bale consists of a very large
number of tightly packed tufts of fibres. The fibre tufts are processed through a series of
opening machines where the larger tufts are broken into smaller tufts and the fibres lose
their tightness of packing, thereby reducing tuft density or increasing its specific volume.
The reduction in tuft density or the increase in its specific volume is known as a
measure of fibre openness.
2.2 Procedure
Fiber openness is generally
d
determined by a simple method,
which is known as beaker test
method. This uses a beaker of say Beaker
3
1000 cm volume, a perforated
plexiglass disc having cross-
sectional area same to that of the
beaker, and a measurement scale. Disc

This method is described with a view

to Figure 2.1 as follows. h
(a) Collect 100 gm of tufts from a Tuft

bale.
(b) Fill the beaker as uniformly as
possible. Tuft should be seen Figure 2.1 Schematic diagram of apparatus
against light so as to make sure
that two tufts are neither sandwiched nor buried into each other.
(c) Place the plexiglass disc on the tuft and allow it to settle down for 30 sec.
(d) Note down the height ( h ) of the compressed tuft and inside diameter ( d ) of the
beaker.
π 2
(e) Calculate the volume ( V ) of the tuft from the following expression: V = d h.
4

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(f) Take out the tuft from the beaker and weigh ( M ) it using an electronic weighing
balance.
(g) Calculate apparent specific volume ( υ ) of the tuft from the following expression:
υ =V M .
(h) Calculate fiber openness of tuft by using the following expression: ζ = υρ , where ρ

is the density of fiber. [ ρcotton = 1.52 g/cm3 ].

(i) Repeat the test for five times.

(j) Repeat step (a) to step (i) for lap and sliver.
2.3 Measurements and calculations
Write down your measurements and calculations made on the cotton bale in Table 2.1.
Table 2.1 Data for bale of cotton fibers
Test No. h[cm] d[cm] V⎡cm3 ⎤ M [g ] ζ ⎡cm3 g ⎤ υ[−]
⎣ ⎦ ⎣ ⎦

1
2
3
4
5
Average fiber openness in bale =
Standard deviation of fiber openness in bale =
Coefficient of variation of fiber openness in bale =
Write down your measurements and calculations made on the cotton lap in Table 2.2.
Table 2.2 Data for lap of cotton fibers
Test No. h[cm] d[cm] V⎡cm3 ⎤ M [g ] ζ ⎡cm3 g ⎤ υ[−]
⎣ ⎦ ⎣ ⎦

1
2
3
4
5
Average fiber openness in lap =

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Standard deviation of fiber openness in lap =
Coefficient of variation of fiber openness in lap =
Write down your measurements and calculations made on the cotton carded sliver in
Table 2.3.
Table 2.3 Data for carded sliver of cotton fibers
Test No. h[cm] d[cm] V⎡cm3 ⎤ M [g ] ζ ⎡cm3 g ⎤ υ[−]
⎣ ⎦ ⎣ ⎦

1
2
3
4
5
Average fiber openness in carded sliver =
Standard deviation of fiber openness in carded sliver =
Coefficient of variation of fiber openness in carded sliver =
Complete Table 2.4.
Table 2.4 Openness of cotton bale, lap, and carded sliver
Material Mean fiber Standard deviation of Coefficient of variation
openness (-) fiber openness (-) of fiber openness (%)
Cotton bale
Cotton lap
Cotton carded sliver
Compare the fiber openness data in bale, lap, and carded sliver and state the reason for
the data.

2.4 Remarks, if any

Teacher’s Signature & Date

16
 EXPERIMENT 3
DETERMINATION OF CLEANING EFFICIENCY OF BLOWROOM AND CARDING
MACHINES
3.1 Overview
The cotton fibres are procured in the form of bales. Each bale consists of a very large
number of fibres along with various kinds of trash such as leaf, seed coat, soil and dust
particles, etc. The trash content should reduce as the fibers are processes through a
series of opening and
Table 3.1 Classification of cleaning efficiency of blowroom
cleaning machines.
Cleaning efficiency (%) Interpretation
The cleaning efficiency
>40 Very good
of a machine is
calculated in terms of 30-40 Good

percentage of the 20-30 Average

quantity of trash 10-20 Bad

removed by the <10 Very bad

machine to the quantity

Table 3.2 Classification of cleaning efficiency of card
of trash present in the
Cleaning efficiency (%) Interpretation
material fed to the
>90 Very good
machine. According to
80-90 Good
Zellweger Uster, the
70-80 Average
cleaning efficiency of
60-70 Bad
blowroom and carding
<60 Very bad
machines can be
classified as shown in
Table 3.1 and Table 3.2.
3.2 Procedure
The cleaning efficiency of blowroom and carding machines is determined by using
Shirley trash analyzer. The procedure for determination of cleaning efficiency is
described below.
(a) Take a sample of raw cotton of 50g from a bale and open it gently by hand.

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(b) Clean out delivery box and trash tray of Shirley trash analyzer. Run the machine
for 2 min to 3 min, keeping feed roller inoperative.
(c) Spread the sample evenly on the feed table. After having opened the valve to its
fullest extent, engage the clutch in order to run the sample through the machine.
When the specimen has completely passed through the machine, disengage the
clutch and close the valve momentarily to allow the lint to be collected in the
delivery box.
(d) Take out collected lint and pass through the machine second time.
(e) Remove the lint from delivery box, collect separately and weigh it (W1).
(f) Now, selectively remove lint from the trash tray and run it through the analyzer.
The lint extracted from the trash should be collected from the delivery box and
pass it again through the machine without disturbing the trash tray. Collect the
lint from the delivery box and weigh it (W2).
(g) Remove trash from tray and weigh it (W3).
(h) Do the following calculations:
Total quantity of lint = W1 + W2
Cage loss = 50 – (W1 + W2) – W3
Trash % = (W3 ÷ 50) × 100
(i) Repeat step (a) to step (h) for blowroom lap
(j) Calculate cleaning efficiency of blowroom from the following expression:
Trash in bale ( % ) - Trash in lap ( % )
Cleaning efficieny of blowroom ( % ) = ×100
Trash in bale ( % )

(k) Repeat Step (a) to Step (h) for carded sliver

(l) Calculate cleaning efficiency of card from the following expression:
Trash in lap ( % ) - Trash in sliver ( % )
Cleaning efficieny of card ( % ) = ×100
Trash in lap ( % )

(m) Calculate cleaning efficiency of combined blowroom and card from the following
expression
Trash in bale ( % ) - Trash in sliver ( % )
Cleaning efficieny up to card (% ) = ×100
Trash in bale ( % )

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3.3 Measurement and calculations
Carry out the experiment and complete Table 3.3 and Table 3.4.
Table 3.3 Trash content in cotton bale, blowroom lap, and carded sliver
Material W1 (g) W2 (g) W3 (g) Total Cage loss Trash
Lint (g) (g) content (%)
Bale
Lap
Sliver

Table 3.4 Cleaning efficiency of blowroom, carding, and combined

Machine Cleaning efficiency (%)
Blowroom
Card
Combined blowroom and card

Interpret the cleaning efficiency of the blowroom and carding machines you used with
reference to Table 3.1 and Table 3.2.

3.4 Remarks, if any

Teacher’s Signature & Date

19
 EXPERIMENT 4
DETERMINATION OF DRAFT AND PRODUCTION OF CARDING MACHINE
4.1 Overview
The gearing diagram of carding machine is shown in Figure 4.1. The draft between any
two rotating rollers is
defined as the ratio of the
surface speed of delivery
(output) roller to the surface
speed of feed (input) roller.
The total draft of the
carding machine is
calculated by the ratio of
the surface speed of coiler
calendar roller to the
surface speed of the lap
roller. When the draft
change wheel is assumed
to have only one tooth, the
total draft calculated
between the coiler calendar
roller and lap roller is
known as ‘draft constant’.
The rate of production of
card is calculated by
multiplying the surface
speed of the coiler calendar
roller to the linear density of
the sliver delivered by the

Figure 4.1 Gearing diagram of carding machine [5] coiler calendar roller. When
the production change

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wheel is assumed to have only one tooth, the rate of production calculated is known as
‘production constant’.
4.2 Observations and calculations
Using the gearing diagram, calculate the rotational speed (rpm) and surface speed
(m/min) of lap roller, feed roller, taker-in, cylinder, doffer, table calendar roller, and coiler
calendar roller. Report your results in Table 4.1.

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 Table 4.1 Speed of various elements of carding machine
Table Coiler
Lap Feed Taker-
Variables Cylinder Doffer calendar calendar
roller roller in
Roller roller
Rotational
speed
(rpm)
Surface
speed
(m/min)
Calculate the draft between various elements, total draft, and draft constant of carding
machine. Report your results in Table 4.2. Identify the draft change gear teeth in the
machine. Find out the relation among total draft, draft constant, and draft change gear
teeth.

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 Table 4.2 Draft between the elements of carding machine
Variables Value
Draft between feed roller and lap roller
Draft between Taker-in and feed roller
Draft between cylinder and taker-in
Draft between doffer and cylinder
Draft between cylinder and table calendar roller
Draft between table calendar roller and coiler calendar roller
Total draft (draft between coiler calendar roller and lap roller)
The value of draft constant in the carding machine is
The relation among total draft, draft constant, and draft change gear teeth is

Calculate production rate and production constant of carding machine. Report your
results in Table 4.3. Identify the production change gear in the machine. Find out the
relation among production rate, production constant, and production change gear teeth.

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 Table 4.3 Production of carding machine
Variable Value
Rate of production (kg/h)
The value of the production constant in the carding machine is
The relation among the rate of production, production constant, and production change
gear teeth is
4.3 Remarks, if any

Teacher’s Signature & Date

25
 EXPERIMENT 5
STUDY OF MACHINE SETTING IN CARDING AND DRAWFRAME MACHINES
5.1 Overview
The relative position and spacing between any two machine elements is known as
setting. The so called “machine-setting” of the carding and drawframe machines is of
great importance. Optimal and gentle treatment to the fibers is only possible if each and
every element of carding or drawframe machines has the correct settings. Too narrow
spacing causes fiber
Leaf gauges of
breakage and too wide different thickness

spacing leads to formation

of neps. Machine setting of
carding machine is
measured by “Leaf Gauge”.
Leaf Gauges are metal
leaves used to measure the
distance between two
elements of carding
machine. Thickness of
Figure 5.1 Schematic diagram of leaf gauge
leaves is different for
measuring different settings. The thickness is specified in the unit Thou (1/1000 inch).
So the card setting is measured by the unit Thou.
5.2 Locations of card
setting
The necessary locations of
machine setting of a
carding machine are
shown in Figure 5.2. G
5.3 Measurements of
card settings
Measure the settings of
different positions of Figure 5.2 Locations of card setting

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carding machine with leaf gauge and report the results in Table 5.1
Table 5.1 Card settings
Measured Setting Value
Serial No. Setting Position
(Thou)
1 A: Feed plate to feed roller
2 B: Feed roller to taker-in
3 C: Feed plate to taker-in
4 D: Mote knives to taker-in
5 E: Back plate to cylinder
6 F: Taker-in to cylinder
7 G: Cylinder to doffer
8 H: Front plate to cylinder
9 I: Doffer to under casing
10 J: Doffer to doffer comb

5.4 Roller setting of

drawframe

The distance between the

nips of the rollers is called
roller setting. Typical roller
settings of drawframe vary
according to fibre types and
roller drafting system.
5.5 Location of roller
settings of drawframe
The necessary locations of
machine setting of a
Figure 5.3 Locations of drawframe roller setting
drawframe machine are
shown in Figure 5.2.
5.6. Measurements of roller setting of drawframe
Measure the roller setting of drawframe and report the results in Table 5.2.

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 Table 5.2 Result of roller setting of drawframe
Serial No. Setting Position Measured Setting Value (mm)
1 A. 2nd roller to 1st roller
2 B. 3rd roller to 2nd roller
3 C: 4th roller to 3rd roller

5.7 Remarks, if any

Teacher’s Signature & Date

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 EXPERIMENT 6
PRODUCTION OF CARD SLIVER OF GIVEN LINEAR DENSITY
6.1 Overview
If the linear density of a lap is known, to get a sliver of desired linear density, the total
draft required can be calculated from the following relation.
Linear density of lap (tex)
Total draft =
Linear density of sliver(tex)
When the total draft required and the draft constant are known, the required teeth on the
draft change gear required can be calculated from the following relation.
Draft constant (-)
No. of teeth of draft change gear =
Total draft (-)
Similarly, for a given linear density of carded sliver to obtain a desired production the
required teeth on the production change gear can be calculated from the following
relation.
Desired production (kg/h)
No. of teeth of production change gear =
Production constant (kg/h)

6.2 Calculations for production of slivers with different linear density

Draft constant:
Production constant:
Table 6.1: Calculations for number of teeth of draft change pinion
Sl. Lap Sliver Required Required number Required Required no. of
No. count count total draft of teeth of draft Production teeth in
(Ktex) (Ktex) change pinion (Kg/hr) production
change gear
1 590.5 5.9050
2 590.5 4.9208
3 590.5 4.2179
4 590.5 3.6906
5 590.5 3.2806

6.3 Production of a sliver

Lap count (Measured):

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Sliver count (Given):

Sliver count (Produced):

Error in sliver count (%):

State the reason of error.

6.4 Remarks

Teacher’s Signature & Date

30
 EXPERIMENT 7
STUDY OF FIBRE TRANSFER COEFFICIENT IN CARDING MACHINE
7.1 Overview
The fiber transfer coefficient of carding machine is defined as the percentage of fiber in
weight transferred from the operational layer of cylinder to doffer due to one revolution
of cylinder. Suppose, P denotes the production of the card expressed in gram per
revolution of cylinder and L denotes the load on cylinder load expressed in gram. Then,
the amount of material offered to doffer is P + L gram and the amount of material
transferred to doffer is P gram, under the assumption that there is no waste of material
taking place. Then, the fiber transfer coefficient γ can be expressed as follows:
P
λ=
P+L
The value of P can be calculated from the production value of the card. To find out the
value for L, the following procedure needs to be followed.
7.2 Procedure
(a) Clean the machine thoroughly in order to keep flats, cylinder and doffer surface
free from fibers.
(b) Take a lap, place it on lap roller and then engage the lap end with feed roller.
(c) Start the machine. Once the machine attains steady state (normally it takes 3-4
min.), stop only doffer, which usually results in stopping the feed also.
(d) Cut off drive to feed roller and flats.
(e) Restart the doffer again. At first the fibers already lying on the doffer surface in
the region between doffer comb and the junction between cylinder and doffer will
come out, followed by fibers left on the operational layer of cylinder. One can
notice a clear dividing line between the two.
(f) Weigh the fibers from the dividing line to the cessation of fiber delivery which is
an approximate estimation of L.
(g) Calculate the value of transfer coefficient using the formula as stated above.

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7.3 Observations and calculations
Report your observations in Table 7.1.
Table 7.1 Observation for calculation of transfer coefficient of card
Test No. P[g ] L[g ] P[g ] + L[g ] γ [ -]

1
2
3
4
5

Calculate the mean fiber transfer coefficient.

Calculate the standard deviation of fiber transfer coefficient.

Calculate the coefficient of variation of fiber transfer coefficient.

Complete Table 7.2.

Table 7.2 Statistical characteristics of fiber transfer coefficient
Characteristic Value Unit
Mean fiber transfer coefficient
Standard deviation of fiber transfer coefficient
Coefficient of variation of fiber transfer coefficient

7.4 Remarks

Teacher’s Signature & Date

32
 EXPERIMENT 8
STUDY OF FIBRE NEPS IN CARDED WEB
8.1 Overview
Nep is known to be a small and entangled knot of fibers that is often caused while
processing of fibers. The presence of neps in carded webs deteriorates the quality of
the slivers produced, which, in turn, deteriorate the quality of the ultimate yarns and
fabrics. Neps in carded webs can be counted manually. For this, a carded web is
required to be kept carefully onto a black colored board and the neps need to be
identified and counted with the help of a magnifying glass. The weight of the web is
required to be measured. Then the nep count, defined by the number of neps per unit
weight of the web, can be calculated.
8.2 Observations & calculations
Count the neps with the help of a magnifying glass and report the results in Table 8.1.
Table 8.1 Results of nep count
Serial No. Number of neps (-) Weight of web (g) Nep count (g-1)
1
2
3
4
5
6
7
8
9
10

Calculate the mean nep count.

33
Calculate the standard deviation of nep count.

Calculation the coefficient of variation of nep count.

Complete Table 8.2.

Table 8.2 Statistical characteristics of nep count in carded web
Characteristics Value Unit
Average nep count
Standard deviation of nep count
Coefficient of variation of nep count

8.3. Remarks, if any

Teacher’s Signature & Date

34
 EXPERIMENT 9
DETERMINATION OF FIBER ORIENTATION IN CARD AND DRAWFRAME SLIVERS
9.1 Overview
The arrangement of fibers in a sliver is often idealized by the fibers lying parallel to the
axis of the sliver. The parallelism of fibers to the axis of slivers is termed as fiber
orientation in slivers. In practice, we observe many fibers are lying parallel to the axis of
a sliver, but, at the same time, many of them exhibit departure from parallelism. The
extent of fiber parallelism in a sliver is a measure of extent of fiber orientation in the
sliver. A method for estimating the extent of fiber orientation in a sliver was developed
by C. H. Lindsley and this method is known as Lindsley’s method [6]. This method has
been found very useful in evaluating the effectiveness of carding and drawing
operations as these operations are designed partly to increase the parallelism of fibers
along the axis of the slivers.
9.2 Procedure (Lindsley’s method)
The apparatus by which we can measure fiber orientation in a sliver following Lindsley’s
method is shown in Figure 9.1. The procedure for estimation of fiber orientation in a
sliver is stated below.
0.5”
(a) Take a sufficiently long sliver. Cut
1.0”
P
the card sliver into many pieces
0.5”
each of length approximately of 8”. R

Twist one end of each piece slightly Q D

so as to mark the direction by which
it was delivered by the carding
Sliver
machine card i.e. forward or
backward.
Figure 9.1 Lindsley apparatus [6]
(b) Take out three plates P (1/2”), Q
(1/2”), R (1”) and place three or four pieces of slivers side by side onto the
bottom plate D, keeping all the marked ends on the same side.
(c) Clamp the pieces of slivers by replacing the plates P, Q and R.
(d) Comb gently the clamped pieces of slivers in the forward direction in order to
remove all the loose fibers in front of the clamp (P). Discard the combed out

35
 fibers. Now cut the fibers using a sharp razor blade at the right edge of the
corresponding plate (P). Label the portion as Wf .

(e) Remove plate (P) and then comb the fibers held below it. Retain the comb out
portion and label it as Cf .

(f) Replace the plate (P) and now cut all the fibers ends extending beyond the edge
of plate (P). Collect it and label it as Ef .

(g) Remove this plate again and now cut the fibers at right edge of plate R. Label
these fibers as N f

(h) Repeat the procedure (4 to 7) for the backward direction and label the
corresponding fibers portions as Wb , Cb , Eb , and N b .

(i) Remove the remaining fibers from the under plate R and label it as M .
(j) Weight all labeled portions using an electronic weighing balance.
(k) Repeat 1 to 9 five times to get five sets of readings.
(l) Calculate cutting ratio, combing ratio and projected mean fiber length using the
following formulas.
Ef
Cutting ratio (forward): γ f =
Nf
Eb
Cutting ratio (backward): γ b =
Nb
Cf
Combing ratio (forward): λ f =
E f +N f
Cb
Combing ratio (backward): λ b =
E b +N b
Ef
Orientation index (forward): ηf = 1 −
Nf
Eb
Orientation index (backward): ηb = 1 −
Nb
Wf + Wb
Projected mean fiber length: ξ = ×t
( Cf + Ef + N f ) + ( Cb + Eb + N b ) + M

36
where, t denotes the combined width of three plates and f and b indicate the forward
direction and reverse direction, respectively.
9.3 Measurements and Calculations
Measure and calculate cutting ratio, combing ratio, orientation index, and projected
mean fiber length both in forward and backward directions of cotton carded sliver and
cotton drawn sliver.

37
Report your results obtained on the carded sliver in Table 9.1.
Table 9.1 Results on fiber orientation in cotton carded sliver
Test No. γ f [ −] λ f [ −] ηb[−] γ f [ −] λ f [ −] ηb[−] ξ[mm]

1
2
3
4
5
Mean value
Standard
deviation
Coefficient
of variation

38
Report your results obtained on the drawn sliver in Table 9.2.
Table9.2 Results on fiber orientation in cotton drawn sliver
Test No. γ f [ −] λ f [ −] ηb[−] γ f [ −] λ f [ −] ηb[−] ξ[mm]

1
2
3
4
5
Mean value
Standard
deviation
Coefficient
of variation

Compare fiber orientation in carded and drawn sliver and state the reason for the data.

9.4 Remarks, if any

Teacher’s Signature & Date

39
 EXPERIMENT 10
DETERMINATION OF DRAFT IN DRAWFRAME MACHINE
10.1 Overview
This practical uses DO/2S twin-delivery drawframe machine. Its gearing diagram is
shown in Figure 10.1.
As shown, this machine
has 3-over-5-roller
drafting arrangement,
that is, it has three top
rollers and five bottom
rollers. In this machine,
the top rollers loaded by
Draft
Change
pneumatic weighing
Wheel
system. In the back
region, one top roller is
placed over one bottom
roller. In the middle
region, one top roller is
situated over two
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bottom rollers. Also in
the front region, one top
roller is positioned over
two bottom rollers. It
thus has two drafting
zones: back zone and
front zone. The ratio of
the surface speed of
fourth bottom roller to
the surface speed of
Figure 10.1 Gearing diagram of DO/2S drawframe
back bottom roller is
called as back zone draft. Similarly, the ratio of the surface speed of second bottom

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roller to the surface speed of the third bottom roller is called as front zone draft. If we
multiply these two individual drafts then we obtain total draft of this machine. The same
value can also be obtained by dividing the surface speed of the second bottom roller to
the surface speed of the back bottom roller. When the draft change wheel is assumed to
have only one tooth, the total draft calculated between the front bottom roller and the
back bottom roller is known as draft constant.
10.2 Observations and calculations
Calculate rotational speed (rpm) and surface speed (m/min) of back roller, fourth roller,
third roller, second roller, and front roller. Then calculate drafts of various drafting
zones. Identify draft change wheel in the machine and calculate draft constant.

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Report the results obtained on the rotational speed and the surface speed of different
drafting rollers in Table 10.1.

Table 10.1 Results of roller Speed

Variable Value
Back roller Fourth roller Third roller Second roller Front roller
Rotational
Speed (rpm)
Surface
speed
(m/min)

Calculate the draft between the rollers and report the results in Table 10.2.
Table 10.2 Draft between the rollers in drawframe
Variable Value
Draft between back roller and fourth roller
Draft between third roller and second roller
Total draft between back roller and second roller
Draft constant

10.3 Remarks, if any

Teacher’s Signature & Date

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 EXPERIMENT 11
PRODUCTION OF DRAWFRAME SLIVER OF GIVEN LINEAR DENSITY
11.1 Overview
If the linear density of all input slivers is known, to get an output sliver of desired linear
density total draft required can be calculated as follows.
Total linear density (tex) of all input slivers
Total draft required=
Linear density (tex) of output sliver
Now, when the total draft and draft constant are known, the teeth of draft change wheel
required for producing the desired sliver can be calculated from the following
expression.
No. of teeth of draft change wheel =Draft constant × Total draft
11.2 Procedure
(a) Take six card slivers and measure their linear densities.
(b) Note down the linear density of the sliver to be produced.
(c) Find out the total draft required for production of this sliver.
(d) Note down the draft constant of the machine from your previous experiment.
(e) Calculate the number of teeth of draft change wheel.
(f) Set the machine accordingly and produce the sliver.
(g) Measure the linear density of the sliver produced.
11.3 Measurements and calculations
Linear density of input slivers =

Total linear density of all input slivers =

Desired linear density of output sliver =

Total draft required for production of the sliver =

Draft constant of drawframe (Experiment 10) =

Required no. of teeth of draft change gear =

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Linear density of the sliver produced (measured) =

Error (%) =

Report your observations and calculations in Table 11.1.

Table11.1 Results of production of drawframe sliver
Variable Value Unit
Total linear density of all input slivers
Desired linear density of output sliver
Required draft
Required no. of teeth of draft change gear
Linear density of sliver produced
Error

11.4 Remarks, if any

Teacher’s Signature & Date

45
 EXPERIMENT 12
STUDY OF GENERATION OF DRAFTING WAVE IN DRAWFRAME
12.1 Overview
The uncontrolled motion of the floating fibers during drafting causes a wave like
irregularity in the thickness of the drawn sliver. This type of irregularity is called drafting
wave. It is known that amplitude of the drafting wave depends on the following factors:
proportion of short fibers, total draft, roller setting, and degree of effectiveness of fiber
control in drafting zone. The wavelength of drafting wave lies in-between 6 cm to 8 cm.
12.2 Procedure
(a) Take a sliver made of dark colored short fibers (preferably, cotton fibers) and
another sliver made of long fibers (preferably, manmade fibers).
(b) Set the nip to nip distance of various drafting rollers a few mm longer than the
length of the longest fiber.
(c) Keep the draft around 6.
(d) Feed 4 slivers of manmade fibers and one colored sliver, the later preferably at
the middle position.
(e) Run the machine for few minutes and then stop.
(f) Observe the disposition of colored fibers in the drafted product.
(g) Note down your observation.
(h) Vary the draft and settings and see the effect.
12.3 Observations
State your observations.

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12.4 Remarks, if any

Teacher’s Signature & Date

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 EXPERIMENT 13
STUDY OF EFFECT OF DRAFT AND DOUBLING ON MASS IRREGULARITY OF
DRAWFRAME SLIVER
13.1 Overview
The purpose of doubling is to reduce the mass irregularity of the output sliver so that the
ultimate yarn that can be made with less irregularity. When n numbers of input slivers
are drafted with a draft n , then output sliver would be of same linear density as that of
the input sliver. If the machine does not introduce irregularity, then the following
relationship can be written
CV of mass irregularity of input sliver (%)
CV of mass irregularity of output sliver (%)=
no. of doubling (n )

13.2 Procedure
(a) Select the number of doubling and draft as 4, 6, and 8.
(b) Run the machine so as to get around 20 m sliver.
(c) Measure average linear density and coefficient of variation of linear density of
both input and output slivers.
(d) Record you result in the table given.
13.3 Measurements and calculations
Average linear density of input sliver =

Coefficient of variation of linear density of input slivers =

Average linear density of output sliver =

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Coefficient of variation of linear density of output slivers =

Complete Table 13.1.

Table 13.1 Effect of draft and doubling in mass irregularity of drawframe sliver
Test No. of Draft Linear density of Coefficient of variation of linear
No. Doubling (-) output sliver density of output sliver
(-) (ktex) (%)
1 4 4
2 6 6
3 8 8

Comment on the results obtained.

13.4 Remark, if any

Teacher’s Signature & Date

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References
[1] Operating Instructions for Mixing Bale Opener Model LB3/2, Lakshmi Machine
Works Ltd., India, 1998.
[2] Operating Instructions for the Mono Cylinder Cleaner Model LB4/2, Lakshmi
Machine Works Ltd., India, 1999.
[3] Operating Instructions for Flexi Clean Model LB5/6, Lakshmi Machine Works Ltd.,
India, 2001.
[4] Operating Manual for the Card Feeding System Finefeed LA7/5, Lakshmi Machine
Works Ltd., India, 1998.
[5] Operating Instructions for MMC Card.
[6] Lindsley, C. H., Measurement of Fiber Orientation, Textile Research Journal 21,
39-46, 1951.

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