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Ind

ia

n Journ al of Fibre Textile Research

Yo \ 25. December 2000. pp. 309-3 11

Short ommunications

Optimization of draw frame setting based on

cotton single fibre length data

a

Ari

nd

am Basu

h

&

N Ramakr ishnan

Th

e South

In

dia Textile Research Association.

Coimbatore 64 1014. Ind ia

Received 3 1 Jallllary 2 : revi

se

received

3

Ap r

l

2 :

acce

ple

17 April 2

A new method , hased on single libre length data, ha s been

proposed to opti mi ze the rolle r se ttings in draw frame. Yarns

pro

du

ced using the se ttings based on the new method have lower

Classimat

fa

ults as compared to th ose produced using the

conven lional

se

ttings. The observed phenomenon

is

explained

in

terms of libre arrangement

in

sliver.

Keywords:

AF

IS. Digital librograph, Fibre length, Floating libre,

Hvl Shon libre content

For the conversion of co tton fibres into yarn, th e

fibre st rand is drawn or drafted in more than one

places, s

uch

as draw frame, flyer frame and ring

frame to reduce th

e thickness of strand. When the

fibres are drafted by two pairs of rollers , two

imp ortant but contradictory points are to be ke

pt in

mind. During drafting, the fibres should be pulled in

such a manner th at

th

e long fibres do not break, i.e.

it

has to be wide enough to preve

nt

one fibre being

caught by tw o pairs of rollers at a time. On the other

han J , the se ttings should be close

to

reduce too much

free movement of floating fibres . In practice, a

compromise is made to get the optimum result

s.

Presently, the di stance between two drafting ro llers is

fixed on the basis of 2.5 span length The

irregularity introduced by drafting depend s on

th

e

process condition

s,

including roller settings The

measurement of span lengt h by di g

it

al fibrograph and

high

vo

lume ins truiTicn t (HVI) is biased towa

rd

s

longer fibres , as very short fibres are not cons

id

ered

in

length measurement. The

id

eal fibre

Ien

o

th

to

measureme

nt wo

uld be to measure th e individual

length of a large number of fibres and then to carry

' Part of this paper has been presented at the

41

st Joint

Technological Conference of

AT IR

A, BTRA. SITRA and

NITR A. Mumbai. India, February 2000

whom

all the

correspondence should be addressed.

Phone : 574367-9:

Fax

:

0091

-0422-57 1896; Emai\:sitra

@vs

n\.com

out statist

ical

analysis . It is not poss ibl e for cotton

fibres

as

the process is more laborious and time

consuming due to th e high variation

in

fibre length.

Under the normal

wo

rking conditions, raw material

contributes about 50 ,draw frame sli

ve

r 30 and

roving process th e remaining 20 of the roving

irregularity . The count CV shows an in crease with

the

in

crease

in

draw frame s li ve r irregu larity.

particularly

in

th

e finer count range. The advent of

advanced fibre information system (AFIS) has mad e it

possible to measure the length of a large number of

fibres

in

a short period. The application

of

AFIS

leng

th

data was suggested by Yankey In this paper.

an

attempt ha s been made to find out the application

of

si

ngle fibre leng

th

data

in

determining the optimu m

di stance be

tw

een

th

e pairs of drafting ro

ll

ers on draw

frame.

Carded sl vers were collected from various mi

li

s

for carry

in

g out

th

e experimental work. The fibres of

different lengths ran g

in

g from 25mm to 38mm (2.5

span length) were cons idered for

th

e st ud y. The length

parameters of the sli ve rs based on 2.5 AFIS length.

5 AFJS length a

nd

2

.5

span length for vari

ou

s

counts are shown

in

Tab le 1.

Draw frame slivers were produced at three

different se ttings (Table 2), m

ai nt

aining a ll other

parameters

of

draw frame at th e sa me level. These

slivers were processed through flyer frame and ring

frame. For

all

the three sett

in

gs,

th

e flyer frame and

ring frame parameters were kept constant. The above

sliver samples were processed on fly frame and ring

frame to produce yarns ranging between 24s and 92s.

The yarn samples were tested for classimat faults.

The draw frame sliver irregul arity is very mu ch

dependent on the roller settings. It has marked

influence

on

th e medium-te

rm

variati

on in

yarn which

can affect th e fabric appearance

in

the form of

streak iness. The va rianc e-leng

th

curve is a measu(e of

mass-va riation of the sliver at different cut lengt hs.

The mass

va

riation at 1m and 10m cut lengths

is

found to have great influence on yarn irregularity

in

medium-term and long-te

rm va ri

ations. The variance

length curves of s live rs produced at th ree different

settings are shown

in Fig l It

is obser

ve

d from the

figure that the mass variation at 1m a

nd

10m cut

leng

th

s is lower by abo

ut

0.9 a

nd

l.2

CV

for

7/25/2019 IJFTR 25(4) 309-311

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310

Mill

No.

2

3

4

5

6

7

Count

24s K

30s K

32s K

40 s K

60s K

80s C

92s C

2.5%

length

mm

32.6

39. 1

37.6

43 .7

40.1

47 .6

48.2

INDIAN

J.

FIBRE

TEXT.

RES., DECEMBER 2

000

Table

I-Fibre length parameters of

car

d s

li

vers

AF IS

5% Mean SFC 2.5%

length length

(W)

SL

mm mm

%

mm

30.2

22.2

7.4 25.2

35. 8 25.8 7.6 29. 1

34 . 1

23.6 12. 3 29 .0

38 .7 27.5 4 .6 33.5

36.8

26

.2 8.9 33. 1

43 . 1 30.0 4.8 37 .8

43.5

30.5 3.8

37.6

HVI

50%

SL

mm

10 .7

11.9

13.7

14 .5

15.6

16 .4

16.7

K- Carded, C - Combcd, SFC (W) - Shon Fibre Content (Weight)

SL - Span Leng th ; and UR - Uniformity Ratio

- -

30

. . .

29

5

'1

1 1 .

..

.

9

B

6

5

Q

;>

U

3

V

V

Z

I. 5

.... ........ ........

::

:

..........................

.

.

......

....

..

....

...

....

:

.

..

.

..

..

.

.........

..

.......

. .

...

..

...

.......

.

...

.

::::::::::

:

:

:::::::::::::::;

::::

.

::::

::::::::::: i:

::::::

:::::

::::::::::

:::::i:

::

::::::::::

:::::

::

j ..

.. . :

.......

.

..............

j ._

..

.

.

..........1............

.....

.......

..L

.....

......

.....

.

.

: .

u .. . . ............_.L

l f " Spnn

l+gth

2.5

: : : Af lS 5.0% : :

I

0.8

e.6

9.5

o.

e.3

............................. ........

..

.

.......

.......

...

,

.

.

.. ....

.................... .................

..

......... , ..............

.. ...

,.

::::::::

::::::::::::::::::::1::::::

:::::

:::::::::

:

:

::::1:::::::::::::::::::::::::::::::: ::::::::::::::: : i:: :

...................

...

.

...... ......

......

...

... ..

_

r

.

.

.l ....

...

r

50

5e

lee

Z0e 5ee

cm

Cut length

Fi

g. I- Varian

celength

curves

of

s

li

ve rs at

diff

ere nt ro

ll

er se ttings

UR

%

47.4

45 .6

47.4

46 .0

47.2

45 .8

46 .0

se ttin gs a nd C res pe

ctively when

compared to the

conventional settings.

The

CV % for lon

ger

cut lengt h

is minimum when setti ng B is used on the draw

frame. This reduction

in

mass variation is mainly

caused by the better contro l

of

fibres in the drafting

zone and

effective hook

removal tendency.

Table 2- Deta

il

s o f roller

se

ttings

in

draw frame

Raw material faults,

drafting

faults , long thick

faults and long thin faults

(g

iven by C l

ass

imat) of

yarn sa mpl

es produced

from

three different

settings

are shown

in

Table

3.

It

is

observed

that

Classimat

faults

show impr

ovement: drafting faults by about

30

in

carded counts

and 47

% in

combed

counts

(Fig .2) and long thick faults/long thin faults by about

50

%

in

both carded

and combed counts. This

is

mainly ach ieved by the decrease in floating fibres in

the draft

in

g zon e at AFIS 5% length setting

and

straig htenin g

of

fibres .

Single fibre length data can be used more

ef

fIcien

tl

y for rolle r se tting

in

draw frames; AFIS 5%

length fo r front zo ne setting has been found to be the

optimu

m. In the

case

of

finisher

draw

fra me,

another

Setting

A

B

C

Front zone

2.5% AFIS length

5% AFIS length

2.5 % Span length

Back zone

2.5 % AFIS length

+

4mm

5% AFIS length

+

4mm

2.5 % Span length

+

10mm

Table 3 0 ass imat faults of yarns produced from three

diffc rent se ttings (uncleared yarns)

Count Setting

Raw Drafting

lAlng lAlng

mate ial

faults

th ick thin

f a ' . : l t ~

(C&D) faults

fa

ults

(A& B)

(E,F&G)

(H&I)

20s K A

2730 62

I I

13 13

B 2 167

26 0

253

C

3065

50

12

492

60s K

A

19

880

154

40 462

B

18778

102 36

588

C

15697

112 65

1196

80s K A

23914

170 75

1971

B

18942 110

49

11 89

C

19627 207

101 2232

A to I refcr to the C lassimat

fa

ults with varying length and

size

7/25/2019 IJFTR 25(4) 309-311

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SHORT COMMUNICATION

3

11

220 r----------------

I

Carded

170

.'

..

.. l

3 5 Carded

70

45 Carded

_ _

_ _

J

A

B

Setlings

c

Fig. 2 Effect of roller se ttings on drafting

fa

ult s

2mm

allowance may be given for both front zone and

back zone settings.

The variance length curve of

draw

frame s li ver

produced from AFIS length settings shows less mass

variation at 1 m and 10m

cut

lengths

The yarn quality improves when setting B (i.e.

based on 5 AFIS length) is used in draw frame .

cknowledgement

The authors are thankful to the Mini stry

of

Textiles, Government of India , for spon soring thi s

project.

They

are also thankful to Ms

lndr

a

Doraiswamy, Director, SITRA , for her continLloLls

encouragement

and to Mr.T V Ratnam, Advisor.

SITRA, for his valuable sugges tions. The member

mills are acknowledged for the ir he lp during the

study.

References

I Ratnam T Y, Chellamani P Karthikcyan S.

Ill diall

J

ib re

T

ex

I Res

14 (

19

89)

14

7.

2 Cavaney B Foster

GAR, J TexI IIISI 46

(

19

55) T 529.

3 Cavaney B Foster GAR, J TexI III

SI

46 (

19

55) T 55 1.

4 Control of short-term irregularity of draw frame s

li

vcr,

SI

TRA

FOCIIS

No.2

T

he South India Textile Research Associa

ti

on .

Coimbatore), Jul y

19

86.

5 Yankey M J , USler SO/lIlioIlS No .06 (Ze

ll

weger Uster Inc

USA), Jul y 1997.