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7/25/2019 IJFTR 25(4) 309-311
1/3
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
2/3
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
3/3
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.
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