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BZU TEXTILE ENGINEERS
BZU TEXTILE ENGINEERS
D raw ing
Pure ly from comm erc ia l po in t o f v iew it is
o f ve ry little sign ific an ce and it u su a lly
con tr ibu tes le ss th an 5% to p rodu c tion co sts o f
th e ya rn . H ow eve r its in flu ence on q ua lity ,
e sp ec ia lly evenness , is a ll th e g rea te r fo r th is .
F u rthe r if th e d raw fram e is no t p rop e rly
ad jus ted , the re w ill a lso b e e ffec ts o n ya rn
s treng th and e lo nga tio n .
BZU TEXTILE ENGINEERS
There are 2 main reasons for the considerable
influence of the drawframe on evenness.
1-Within the sequence of m/c in cotton spinning mill,
the drawframe is the definitive compensation point for
elimination errors. Inadequacies in the product leaving
the drawframe not only pass into the yarn, they are
actually reinforced by drafting effects following the
draw frame. The yarn is never better than the draw
frame sliver.
BZU TEXTILE ENGINEERS
2-A defect arising at the draw frame can
exert an effect of significant proportions
on the overall process. High performance
draw frame currently produce over 200
KG of sliver per hour at each delivery.
Very large quantities of poor quality
sliver will be produced in the time that
elapses before discovery of the defect.
BZU TEXTILE ENGINEERS
At drawing stage, material passes not only one m/c
but usually 2, arranged 1 after the other & combined
to form a group. Processing in 2 passages is
necessary completely to fulfill the requirements. The
2nd passage is often superfluous after combing m/c
because then it does not normally generate any
improvement in quality.
In old machinery 3 drawings were used, breaker,
intermediate & finisher. But now in latest m/c only 2
drawings, breaker & finisher are used & in D-35 only
one drawing is used.
Explanation:
BZU TEXTILE ENGINEERS
Tasks of the draw frame:
• drafting
• equalizing
• parallelizing
• blending
• dust removal
BZU TEXTILE ENGINEERS
Drafting:
The reduction of weight / yard of sliver
and increase in length is called drafting.
Or Attenuation of sliver without breaking
is called draft.
Break draft:
Draft b/w the 2nd and 3rd rollers is called
break draft.
Main draft:
Draft b/w the 2nd and front rollers is called
main draft.
BZU TEXTILE ENGINEERS
Total draft:
Total draft = break draft * main draft
BZU TEXTILE ENGINEERS
Types of draft:
1. actual draft:
It is the ratio b/w material feed and
material delivered.
Length/count delivered
Actual draft =
Length/count fed
Or
Weight fed / yard
Resultant Draft =
Weight delivered / yard
BZU TEXTILE ENGINEERS
1. Mechanical draft:
It is the ratio b/w the surface
speed of delivery roller and surface speed of feed
roller.
Surface speed of delivery roller
Mechanical draft = Surface speed of feed roller
BZU TEXTILE ENGINEERS
Drawing rolls:
Mainly a set of 3/3, 3/4, 4/3, 5/4 drafting
rollers is used in drafting action. And the top and
bottom rollers of each set are made of different
materials.
� Bottom roller is made of steel.
Top roller is also made of steel but covered with
leather for better grip of fiber strand.
BZU TEXTILE ENGINEERS
Draft gear:
Draft constant
Draft gear =
Draft
Draft constant is calculated by putting the value of
changeable gear equal to 1, in draft equation.
BZU TEXTILE ENGINEERS
E q u a l iz in g :
� O n e o f t h e m a in ta s k s o f d r a w f r a m e i s im p r o v in g
e v e n n e s s o v e r s h o r t , m e d iu m a n d e s p e c ia l l y , lo n g
te rm s .
� C a rd s l iv e r f e d h a s h ig h d e g r e e o f u n e v e n n e s s , a n d
th e s l i v e r f r o m c o m b e r c o n ta in s in f a m o u s p ie c in g s ;
th e s e m u s t b e o b s c u r e d .
� I t i s m i s ta k e to a s s u m e th a t s l iv e r e v e n n e s s ,
e s p e c ia l l y o v e r s h o r t l e n g th s , c a n b e s i g n i f ic a n t l y
im p r o v e d b y u s e o f s e v e r a l p a s s a g e s .
� A s e c o n d p a s s a g e b r in g s h a r d ly a n y im p ro v e m e n t
a n d a th i r d c a n a c tu a l l y l e a d to d e te r io r a t io n .
E q u a l iz in g i s a lw a y s p e r fo rm e d b y a f i r s t p r o c e s s ,
n a m e ly d o u b l i n g , a n d c a n o p t io n a l l y a l s o b e
p e r fo rm e d b y a s e c o n d p r o c e s s , n a m e ly a u to le v e l i n g .
BZU TEXTILE ENGINEERS
P a r a l le l iz in g :
� T o o b ta in a n o p t im a l v a lu e fo r s tr e n g th in th e y a rn
c h a ra c te r is t ic s , th e f ib e r s m u s t b e a r r a n g e d p a ra l le l
in th e f ib e r s t r a n d .
� I t fu l f i l s th is ta s k b y w a y o f th e d r a f t , s in c e e v e r y
d ra f t in g s te p le a d s to s t r a ig h te n in g o f f ib e r s .
� T h e v a lu e o f d r a f t m u s t b e a d a p te d to th e m a te r ia l ,
i .e . to s e v e r a l f ib e r s p a r am e te r s ( h e r e , m a in ly th e
s ta p le le n g th ) a n d a ls o to :
� T h e m a s s o f f ib e r s :
� T h e v o lu m e o f th e s tr a n d :
� T h e d e g re e o f o rd e r (p a r a l le l
d is p o s i t io n ) .
I t w il l b e c le a r th a t th e d r a f t c a n n o t b e h ig h
im m e d ia te ly fo l lo w in g th e c a rd ( i f p o s s ib le n o t a b o v e
8 ) , b u t th e r e a f te r c a n in c r e a s e f ro m m /c to m /c .
BZU TEXTILE ENGINEERS
B le n d in g :
� In a d d it io n to th e e q u a l iz in g e f f e c t , d o u b l in g a ls o
p ro v id e s a d e g re e o f c o m p e n s a tio n o f r a w m a te r ia l
v a r ia t io n , b y b le n d in g .
� T h is r e s u l t i s e x p lo ite d in p a r t ic u la r in th e
p ro d u c tio n o f b le n d e d y a r n s c o m p r is in g
c o t to n /s y n th e tic o r s y n th e t ic / s y n th e t ic b le n d s .
� A t th e d r a w f r am e th e m e te r in g o f in d iv id u a l
c o m p o n e n ts c a n b e c a r r ie d o u t v e r y s im p ly b y
s e le c t io n o f th e n um b e r o f s l iv e r s e n te r in g th e
m a c h in e .
� F o r e x am p le , to o b ta in a 6 7 :3 3 b le n d , fo u r s l iv e r s
o f o n e c o m p o n e n t a n d tw o o f o th e r a r e fe d to th e
d ra w f r am e . O f c o u r s e , th e s e s l iv e r s m u s t h a v e th e
s a m e h a n k .
BZU TEXTILE ENGINEERS
Dust removal:
� Dust is becoming a great problem both in
processing and for the personnel involved.
� It is therefore important to remove dust to the
greatest practical extent at very possible point
within the overall process.
� Unfortunately, dust removal can only be carried
out to a significant degree when there are high
levels of fiber/fiber or fiber/metal friction, since a
large fraction the smallest particles (dust) adhere
relatively strongly to the fibers.
� Such friction arises especially at the card and the
draw frame: in the latter case, mainly owing to the
drafting operation.
BZU TEXTILE ENGINEERS
Production:
Production of drawing frame depends
upon following factors:
1. speed of some parts
2. size of sliver delivered
3. hours per day
4. Stops.
BZU TEXTILE ENGINEERS
Stop motions:
A stop motion is a device arranged to stop
the machine when certain undesired conditions exit.
Stop motions are applied at several places on
drawing machine. Although stopping the machine
causes a reduction in production, this disadvantage is
overbalanced by the improved quality of the product.
The three common drawing frame stop
motions are:
1. The spoon or back stop motion
2. The trumpet or calendar roll stop motion
The full can stop motion.
BZU TEXTILE ENGINEERS
C om b in g
C o m b i n g i s a n i n t e r m i t t e n t
o p e r a t i o n i n w h i c h t h e s h o r t
f i b e r s , n e p s & d i r t a r e r e m o v e d
f r o m s l i v e r l a p b y f o l l o w i n g s t e p s .
1 . A n a r r o w l a p o f f i b e r i s
f i r m l y g r i p p e d a c r o s s i t s w i d t h
b y a p a i r o f s p e c i a l l y d e s i g n e d
j a w s .
2 . A s e r i e s o f f i n e c l o s e l y
s p a c e d n e e d l e s i s p a s s e d
t h r o u g h t h e f i b e r s p r o j e c t i n g
f r o m j a w s .
T h e t r e a t e d f i b e r s p r o j e c t i n g
f a r t h e s t f r o m t h e j a w s a r e d r a w n
a w a y t h r o u g h a n o t h e r s e r i e s o f f i n e
n e e d l e s .
BZU TEXTILE ENGINEERS
Tasks of combing:
• To remove short fibers.
• To remove any neps & dirt
remaining with the
cotton.
To straighten the fibers and make
them parallel to each other.
BZU TEXTILE ENGINEERS
V a l u e o f c o m b i n g :
T h e r e a r e s e v e r a l w a y s
i n w h i c h c o m b i n g m a y b e o f v a l u e
i n t h e m a n u f a c t u r e o f c o t t o n y a r n .
T h e v a r i o u s y a r n c h a r a c t e r i s t i c s
w h i c h m a y b e i m p r o v e d b y c o m b i n g
a r e l i s t e d a s f o l l o w s .
D u e t o m o r e u n i f o r m s t a p l e :
� C o m b i n g m a k e s p o s s i b l e s p i n n i n g a
m o r e u n i f o r m y a r n .
� C o m b i n g m a k e s p o s s i b l e s p i n n i n g a
s t r o n g e r y a r n .
� C o m b i n g m a k e s p o s s i b l e s p i n n i n g a
f i n e r y a r n .
BZU TEXTILE ENGINEERS
D u e t o s t r a i g h t e n e d c o n d i t i o n s o f
f i b e r s :
� C o m b i n g m a k e s p o s s i b l e s p i n n i n g
s m o o t h e r a n d m o r e l u s t r o u s y a r n .
D u e t o r e m o v a l o f n e p s a n d d i r t :
� C o m b i n g m a k e s p o s s i b l e s p i n n i n g a
c l e a n e r a n d f i n e r y a r n .
� I n a d d i t i o n y a r n m a d e o f c o m b e d
c o t t o n n e e d l e s s t w i s t t h a n c a r d e d
y a r n .
H o w e v e r t h e s e q u a l i t y i m p r o v e m e n t s
a r e o b t a i n e d a t t h e c o s t o f
a d d i t i o n a l e x p e n d i t u r e , o n m a c h i n e ,
f l o o r s p a c e & p e r s o n n e l t o g e t h e r
w i t h l o s s o f r a w m a t e r i a l .
BZU TEXTILE ENGINEERS
Note:
1 . E l i m i n a t i o n o f s h o r t
f i b e r s p r o d u c e s a n
i m p r o v e m e n t i n s t a p l e l e n g t h
b u t i t a l s o e f f e c t t h e
f i n e n e s s o f r a w m a t e r i a l .
2 . I t a l s o i n c r e a s e s
p a r a l l e l i z a t i o n o f f i b e r s b u t
t h e h i g h d e g r e e o f
p a r a l l e l i z a t i o n m i g h t r e d u c e
i n t e r f i b e r a d h e s i o n i n t h e
s l i v e r t o s u c h a n e x t e n t t h a t
f i b e r s l i d e s a p a r t w h i l e
b e i n g p u l l e d o u t o f c a n .
D u e t o t h i s h i g h d e g r e e o f
p a r a l l e l i z a t i o n f i b e r s b r e a k o r
f a l s e d r a f t m a y p r o d u c e .
BZU TEXTILE ENGINEERS
Degree of combing:
In some cases, combing is
classified by the amount of noil
removed.
� Where the percentage of noil is
not over 10%, it is often spoken
as semi combing.
� Where the noil percentage is b/w
10% to 20%, it is called as
regular combing.
Where the noil percentage is b/w
20% to 30%, it is called double
combing.
BZU TEXTILE ENGINEERS
Comb waste:
The waste from comb is noil.
It consists of short fibers, neps &
dirt. The noil percentage is
calculated as:
Weight of noil
Noil percentage =
Weight of lap feed
BZU TEXTILE ENGINEERS
Subdivision of combing:
For the purpose of detailed
study, combing may be considered a
series of independent operations,
each of which may be studied as an
isolated mechanical action, where
all are so timed and located that
the cotton passes through one after
the other process.
BZU TEXTILE ENGINEERS
S t e p s o f c o m b i n g a c t i o n s :
C o m b i n g a c t i o n c a n b e e x p l a i n e d a s :
F e e d i n g :
T h i s i n t r o d u c e s t h e r i b b o n l a p s i n
a s e r i e s o f s h o r t l e n g t h s .
N i p p i n g :
T h i s g r i p s t h e f i b e r s b / w t w o j a w s
a s f o r h o l d i n g t h e f i b e r s w h i l e t h e
s h o r t f i b e r s , n e p s & d i r t a r e b e i n g
r e m o v e d .
C o m b i n g :
T h i s p a s s e s m a n y r o w s o f c l o s e l y
s p a c e d n e e d l e s t h r o u g h t h e f i b e r s
f o r p a r a l l e l i z a t i o n .
BZU TEXTILE ENGINEERS
D e t a c h i n g :
T h i s c o n s i s t s o f :
M o v i n g t h e p r e v i o u s l y c o m b e d c o t t o n
b a c k w a r d s o t h e n e w l y c o m b e d f i b e r s
m a y o v e r l a p t h e o t h e r s .
D r a w i n g t h o s e f i b e r s w h i c h p r o j e c t
t h e f a r t h e s t f r o m t h e l a p i n t h e
n i p p e r s .
T o p c o m b i n g :
T h i s d r a w s t h e b a c k e n d o f t h e
d e t a c h e d f i b e r s t h r o u g h a r o w o f
c l o s e l y s p a c e d n e e d l e s , t h u s
s t r a i g h t e n i n g a n d c l e a n i n g t h e m a n d
p r e v e n t i n g s h o r t f i b e r s f r o m b e i n g
c a r r i e d a l o n g b y c o n t a c t w i t h t h e
l o n g f i b e r s .
BZU TEXTILE ENGINEERS
Condensing:
This passes the web from the
detaching rolls through a trumpet
forming it in to a sliver.
Drawing:
This passes the slivers from all
the heads, as a narrow sheet,
through a series of drawing rolls
produce them to a normal weight.
Coiling:
This puts the sliver into a roving
can with a uniform arrangement.
BZU TEXTILE ENGINEERS
Figure:
BZU TEXTILE ENGINEERS
1. lap roller
2. lap roll
3. lap lattice
4. feed roller
5. bottom nipper
6. top nipper
7. comber
8. cylinder
9. brush
10. aspirator
11. detaching roller
12. short fibers(noil)
Major Parts Of Combing M/C.
BZU TEXTILE ENGINEERS
R o v in g
R o v in g a s n e c e s sa ry e v il:
T h e d raw fram e p ro d u c e s a s liv e r th a t a lre a d y e x h ib it
a ll th e c h a ra c te r i s tic s re q u ire d fo r th e c re a tio n o f a
y a rn , n am e ly a n o rd e re d , c le a n s tra n d o f f ib e r ly in g
p a ra lle l to o n e a n o th e r .
I t is a fa ir q u e s tio n th a t to a sk w h y th is s l iv e r is n o t
u se a s fe e d m a te r ia ls fo r th e r in g s sp in n in g m a c h in e ,
in s te a d o f b e in g p ro c e sse d in a n e x p e n s iv e m a n n e r to
c re a te a ro v in g a s fe e d fo r sp in n in g .
The roving m/c itself is complicated, liable to faults,
causes defects, adds to production costs and deliver a
product that is sensitive in both winding and
unwinding.
BZU TEXTILE ENGINEERS
Use of the machine is forced upon the spinner as a
necessary evil for two principal reasons.
� The first reason is related to the require draft sliver
is thick, untwisted strand that tends to drafting
arrangement of ring spinning machine in their
current forms , are not capable of
processing this strand in a single drafting operation
to create a yarn of short staple fibre that metals all
the demands. The fine, twisted roving is
significantly better suited to this purpose.
� The second reason is that drawframe cans represent
the worst conceivable mode of transport and
presentation of fed material to the ring spinning
machine.
BZU TEXTILE ENGINEERS
In spite of this, considerable effort has been
extended over decades to eliminate the roving
frame. The effort is justified, but unfortunately
in relation to ring spinning it remains without
success. On the other hand, in all new spinning
process in the short staple spinning mill, the
roving frame has been made superfluous.
BZU TEXTILE ENGINEERS
T a sk s o f r o v in g fram e:
1 . T he ch ie f ta sk o f ro v in g fram e is a tte nu a tio n o f
th e s liv e r .
2 . A s th e re su ltin g fin e s tra nd h a s sc a rce ly a n y
co he ren ce , p ro te c tiv e tw is t m u s t b e in se r te d in
o rd e r to h o ld it to g e th e r .
3 . T he th ird ta sk is n o t d ire c tly re la ted to
sp in n in g , b u t it is fo rm a tio n o f la rg e p ack age
th a t c an b e tra n sp o rted , s to red and d o nned o n
th e r in g sp inn in g m ac h in e .
I t is w ind in g o p e ra tio n ab o ve a ll th a t m ake s ro v ing
fram e a com p le x and tro ub le p lag ued m ach in e . T h is
w ind in g o p e ra tio n req u ire s , in a d d itio n to th e sp ind le
and fly e r , a c o n e d r iv e tran sm is s io n (o r v a r iab le
g ea r) , a d iffe ren tia l g ea r a nd a b u ild e r m o tio n .
BZU TEXTILE ENGINEERS
Hank:
One hank equals 840 yards. And hanks per pound are
determined as follows:
7000 grains (1 pound)
Hanks per pound =
840 yards
1000 grains 8.33 grains
= =
120 yards 1 yard
================
Now 8.33 is a constant for calculating draft by
dividing 8.33 by weight of sliver.
BZU TEXTILE ENGINEERS
Imparting tw ist:
T he flyer inserts the tw ist. Each flyer
ro tation creates one turn in the roving. In the final
analysis therefore, since the flyer ro tation rate is held
constant, tw ist per unit length of roving depends upon
the delivery rate and can be influenced accordingly,
since tw ist is given by:
F lyer ro tation rate (rpm)
T urns per meter =
Delivery speed (m /m in)
H igh levels o f roving tw ist therefore always
represent p roduction losses and possib ly d raft
p roblems in the ring sp inning machine. O n the o ther
hand low tw ist can cause false d rafts o r even roving
breaks during bobbin winding.
BZU TEXTILE ENGINEERS
Twist per inch:
The number of times the strand has
been twisted in one inch length. This is often
called as turns per inch and abbreviated as T.P.I.
BZU TEXTILE ENGINEERS
The builder motion:
� This device has to perform 3 important tasks
during a winding operation:
1. Shift the cone belt corresponding to increase
in the bobbin diameter.
2. Reverse the direction of movement of bobbin
rail at the upper and lower ends of the lift
stroke.
Shorten the lift after each layer to form tapered
ends on the bobbins.
BZU TEXTILE ENGINEERS
BZU TEXTILE ENGINEERS
Roving frames F 15 / F 35:
BZU TEXTILE ENGINEERS
Benefits of F 15 / F 35:
- Redesigned and more open machine concept for
better accessibility and therefore improved handling
- Up to 160 spindle positions with low space
requirement due to 110 mm gauge
- 6” and 7” bobbins possible
- Touch screen with 10” display
- Setting of all working parameters directly on the
panel
- ROJ - Electronic control of roving tension
- Roving ends down control with one photocell or
optionally with ROJ - optical sensors on each spindle
- Separate servo drives for flyers and spindles
BZU TEXTILE ENGINEERS
Quality Data(For back process)
0.780.720.550.661.60CVm (3m)
1.300.910.600.891.95CVm (1m)
4.483.182.422.943.24CVm
3.562.541.912.342.58U%
RovingCombingFinisher
Drawing
Breaker
Drawing
CardParameters
BZU TEXTILE ENGINEERS