SLIVER LAP
TECHNICAL DATA :
Make : Lakshmi Rieter
Model : E
2/4a
Ends up : Normally 24 ends up possible
Count of sliver fed : Ne 0.12
to 0.18
Can dimensions : 16" to 24" (400 to 600 mm) upto
50" (1250
mm) height
Weight fed : 75 to 120 gms/mtr
Draft : 1.5 to 2.0
Lap width : 250 mm in case of Ribbon Lap
feeding lap
Lap weight : up to 130 kg
Working speed : up to 65 mtr/min
Drafting system :
4 over 6 pneumatic (DK2 model)
WEIGHT OF THE MACHINE :
Auto lap : 1440 kg
Drafting system : 490
kg
Table : 240
kg
Total weight : 2170 kg
COMPRESSED AIR :
Pressure : 6 ata
Quantity : 1 Nm3/Hr
POWER :
Motor : 4 HP
Speed : 1440 rpm
Frequency : 50 Hz
Supply Current : 440 v
Control circuit : 220 v
Stop motions : 6 volts
PRODUCTION CALCULATION FORMULA FOR SLIVER LAP
:
Delivery wt * Delivery speed * 60 min
Prdn/Hr:----------------------------------------
1000
Del wt : Grams/mtr
Del Speed : Meter/minute
1000 : Grams to kilo grams conversion
DRAFTING ARRANGEMENT : The sliver lap E 2/4a is provided with
DK2 drafting system. This comprises two double nip assemblies of
2 bottom rollers each topped by rubber
rollers, remain 2 bottom
rollers each topped by steel straight fluted
rollers.
(In 4/6 drafting system)
The fluted roller pair have the advantage
that they hold securely
even the large fibre mass. However the delivery rate of the
roller pair is as much as 20% higher than
that calculated on the
roller diameter and this factor must be taken
into consideration
in draft calculation.
TOP ROLLER WEIGHTING: The drafting arrangement is
pneumatically weighed. A tube running under the drafting
arrangement on each side contains flexible
hose, which has an
internal over pressure and forces a row of
pressure shoes down
within the range of weighing hook. This takes pressure from the
shoes and transmits it over a draw bolt to
the top rollers.
The compressed air to the drafting system is
obtained from the
compressor pipe line through a pressure
regulator. The three way
valve helps to cut-off the pressure in
drafting system. It
permits weighting and relieve immediately wihout affecting the
pressure setting.
WEIGHT ADJUSTMENT : Adjust the nuts on the draw hooks to the
distance of 8 mm as shown in figure with out
any stock in
drafting arrangement, but with normal
pressure in the hose.
The level adjustment need be carried out only
for erection and
after each grinding of top rollers, but not
roller setting in the
drafting arrangement.
DRAFTS :
LAP WEIGHT :
In
put sliver weight | noof slivers *
sliver weight
In put in gms/mtr
Total draft : --------------------------
Out put in gms/mtr
TOTAL DRAFT AND BREAK DRAFT : When the total draft is greater
than `1.5', the break draft should be kept as
1.3. In this case
45 T gear is to be fixed on the roller `4'
and 46 T gear on the
roller `6'.
In special cases if a lesser break draft is
required it is
possible to obtain. For example a break draft of 1.22 can be
obtained by fixing 48 T wheel on the roller 4
and 1.15 by fixing
51 T wheel on the roller 4.
When the total draft is less than 1.5 a break
draft of 1.05 is
recommended.
In this case 50 T gear is fixed on the roller 4 and
37 T gear on the roller 6.
ROLLER SETTING : The setting of drafting arrangement with
respect to roller distance and pressure can
be determined from
the following table. The value `a' is equal to the 5% staple,
obtained from staple diagram.
| | | |
LAP WEIGHT |ROLLER SETTING |ROLLER SETTING |
PRESSURE |TOP ROLLER
(gm/mtr)
|MAIN ZONE (mm) |PRE DRAFT ZONE | OF LAP | PRESSURE
| | (mm)
| (ata) | (kg/cm3)
| | | |
55 | a +5
| a +8 |
1.6 | 2.5
60 | a +6
| a +11 |
2.0 | 3.1
65 | a +6
| a +12 |
2.2 | 3.4
70 | a +7
| a +14 |
2.4 | 3.7
| | | |
NOTE :
Prior to roller setting, relieve
the drafting
arrangement.
Before reweighing make sure that draw hooks hang
vertical.
|
60 |
|
50 |
|
40 |
|
30 |
|
20 |
|
10 |
----|-----------------------------------------------------
| 10 20
30 40 50
60 70 80
90 100
100%
At the 5% level drawn a vertical line and its
intersection point
with the curve drawn horizontal line which
cut the Y axis. The
point gives values of which are given in above
table.
EXAMPLE :
Fibre length
: 45 mm
5%
staple : 34 mm
Lap weight
: 60 gm/mtr
setting between the rollers
: Main zone
5%
staple + 6 mm : 34 + 6 = 40 mm
Setting between the rollers
: Break draft zone
5%
staple + 11 mm : 34 + 11 = 45 mm
After referring the staple diagram, the above
distance are set
with little correction.
NOTE :
The best method is to reduce the draft until a slight
pile-up of the fibres occur. Based on this measure, increase the
draft by one tooth of change gear.
THEORY ABOUT SLIVER LAP (E 2/4a) :
In sliver lap machine the motor drives the
main shaft via a `V'
belt and other chain drives. The front bottom calender driven by
a short chain and long chain drives lap
rollers.
Always chain drives work a minimum of
backlash. If the chain is
too loose cuts will occur in the web, when
each time the machine
stopped.
LAP SPOOLS :
The lap spool must conform to our drawing,
especially the length and bore tolerance
should be strictly.
CALENDER ROLLER ARRANGEMENT : The two top calender rollers
arranged one behind the other, are spring
loaded. To give a
measure for the weighting, the bolt of spring
is provided three
notches.
Total load weight
on both sides
Notch 1 : 12 kg 24 kg
Notch 2 : 16 kg 32 kg
Notch 3 : 20 kg 40 kg
SETTING OF TOP DISCS :
Spool out dia :
145 mm
Spool length : 250 mm
Front lap roller : 250 mm length
Back lap roller :
248 mm length
SETTING THE BREAK : As soon as the preselected length (1 mtr)
less than the delivery length is obtained the
break. This
operated S8 for which air supplied by means
of special regulator
with mono meter (after necessary reduction in
pressure)
TABLE GUIDES : The guides knobs are adjusted in way to
approach
the slivers to their neighbours tightly without
running over each
other or pressing the slivers in the center
upwards.
CONTACT TOP ROLLERS : The rust proof contact top rollers will
become coated with thin layer of cotton
wax. This has to be set
removed with the solvent, otherwise the layer
will be so thick as
to delay the action of electric stop motion.
FUNCTION :
When the lap heads drop, the air supply line (6) is
blocked by piston (5) and the lap heads are
retarded by cushion.
LAP LOADING :
The two tables below show the air pressure to be
used.
On no account more than 5 kg/cm2 is to be adjusted.
LAP WIDTH 250 mm :
PRESSURE ADJUSTED |
LAP LOADING | LATERAL GRIPPING FORCE
kg/cm2 | kg/cm2
| OF LAP DISC ON SPOOL kg
| |
3.0 | 16.5
| 150
3.5 | 19.3
| 176
4.0 | 22.0
| 201
4.5 | 24.8
| 226
5.0 | 27.6
| 251
LAP WIDTH 300 mm :
PRESSURE ADJUSTED | LAP LOADING
| LATERAL GRIPPING FORCE
kg/cm2 | kg/cm2
| OF LAP DISC ON SPOOL kg
| |
3.0 | 13.8
| 150
3.5 | 16.0
| 176
4.0 | 18.4
| 201
4.5 | 20.7
| 226
5.0 | 23.0
| 251
SOME SETTINGS AND ITS EFFECTS :
Magazine settings:
1.
Clearance at rear from spool centering wall is 1 mm. This
setting controls the spools come freely from spool magazine
to
lap disc.
2.
Clearance at delivery side from spool to centering wall 5 mm
This setting control the spool damage, and also good winding
on
the spool.
Lap discs :
1.
Insert rings or bearing cover clearance should maintain
0.5
mm (setting inside lap disc piston)
2.
Setting between lap disc to lap roller with spool position
1
mm should be maintained. This control
lap edge position.
This setting is to adjusted by means of ;distance rings
provided inner side of lap disc chamber.
Lap spool (Tolerance) : The diameter of the lap spool must not
differ by more than 1.0 mm. The cloth should
over lap 10 to 20
mm.
Both spool and cloth should coated with high
grade neoprene
adhesive such as Balco me.
AUTO LAP WORKING IN SLIVER LAP & RIBBON
LAP :
AIR PASSAGE :
The pressing cylinder (10) and guide head (9) are
connected pneumatically by tubes (8) &
(11).
The upper chamber (4) of the pressing
cylinder (10) communicates
with the outer chamber (2) of the guide head
(9) via the tube
(11).
The lower chamber (3) of the pressing cylinder (10)
communicates with inner chamber (1) of the
guide head (9) via the
tube(8).
WINDING ON (Lap loading or running time)
Figure.5 :
Chamber (4) and (2) obtained compressed air via valve S3
RELIEVING THE LAP : To serve the lap valve S3
closes and the air
escapes from chamber (4) and (2). Chamber (3) and (1) receive
compressed air via valve S2. The pressing pistons (5) stroke-up
and lap discs open.
NON RETURN VALVE (Figure.6) : A non return valve (7) is fitten
in the air line S2 before the two pressing
cylinders (3), to
ensure that the lap heads drop very slowly in
lower range.
CHANGE PLACES AND ITS EFFECTS
CHANGE PLACE | EFFECTS
|
Motor Pulley | It alters delivery speed and
also
| effects in all speeds
|
Calender roll & Shell |
These wheels alters only shell roller
roll sprocket wheels |
speed
Calender roll wheel | 24 T & 25 T wheels only possible
Back
shell roll wheel | 76 T wheel is only possible
Front
lap roll | 77,78,79 but normally
78 T preferred
|
Number wheel (Wn) | This wheel alters the 4th roll speed
| (Alter it when you
required high break
| draft )(54 to 65 available)
Less no of teeth | Higher break
draft
More no of teeth | Lower break
draft
|
Feed change wheel (We) | It alters the steel
roll and creel rolls
| speed. It effects tension draft also.
Less no of teeth | Higher feed
rate
More
no of teeth | Lower feed rate
|
Driving wheel (Wa) | It alters all drafting rollers speed,
| except calender roller
speed.
Less no of teeth | Lower draft
between cal to front roll
More no of teeth | Higher draft
between cal to front roll
|
Mating gear (Z) | It alters back roller speed in
drafting
| system except front
roll.
Less no of teeth | Higher main
draft
More no of teeth | Lower main
draft
|
Driving wheels for | It alters delivery rate. Alters only
front roll (17,18,19) | draft between front roll to cal roll.
|
Break draft change | It alters the 6th roll speed (45 to 48)
gear | Another wheel at end of
the 6th roll
| alters the break
draft.
|
GEARING CALCULATIONS :
Motor speed : 1420 rpm
Motor pulley : 190 mm
M/c pulley : 450 MM
1420 * 190 * 17 * 24
1. Shell roll speed : ------------------------ = 54.6 rpm
450 * 59 * 76
54.6 * 410 *
3.142
2. Delivery rate : ------------------------ = 70.34 mtr/min
1000
1420 * 190 * 17
3. Calender roll speed :
---------------------- = 172.75 rpm
450 * 59
1420 * 190 * 17 * 55
4. Front roll speed :
--------------------------- = 527.85 rpm
450 * 59 *
18
527.85 * 50 * 30
* 24
5. 2nd & 3rd roll speed :
-------------------------- = 779
rpm
53 * 23 * 20
527.85 * 50
6. 4th roll speed : ------------------ = 498 rpm
53
527.85 * 50 * 51
7. 5th & 6th rolls speed :
---------------------- = 590.6 rpm
53 * 43
527.85 * 50 *
51
8. Feed & creel roll speed :
------------------------ = 546 rpm
53 * 52
DRAFT CALCULATIONS :
54.6 * 410
1. Calender roll draft : --------------- = 1.01
172.74 * 128
(Shell roll to calender roll draft)
527.85 * 35 * 1.2 (Factor)
2. Main draft
: ------------------------------
= 1.05
779.0 * 27
(Front roll to 2nd roll draft)
172.75 * 128
3. Delivery draft :
---------------------------- = 1.0
527.8 * 35 * 1.2 (Factor)
(Calender roll to front roll draft)
779 * 27
4. Tension draft : ------------------------- = 1.0
498 * 35 * 1.2 (factor)
(3rd roll to 4th roll draft)
498 * 35 * 1.2 (Factor)
5. Break draft :
------------------------- = 1.3
590.6 * 27
(4th roll to 5th roll draft )
590.6 * 27
6. Feed draft
: --------------- = 0.9
546 * 32
(6th roll to feed roller draft )
546 * 32
7. Creel draft : ------------ = 1.0
546 * 32
(Feed roll to calender roll draft)
NOTE :
In all above calculations 1.2 has taken as constant
1.2 means 20% excess dia will be taken
that particular
roller in that calculation.
TROUBLE SHOOTING :
1.
FAULT : Outer layers are wound soft (loose)
CAUSE : Lap rollers are running too slowly
REMEDY : Use smaller front lap roller sprocket or
large
calender roll change gear,
2.
FAULT : Lap sheds hairs
CAUSE : Air condition (RH%)
REMEDY : Keep temperature at 23 - 25 C (RH% 50 - 60 %)
3.
FAULT : Lap shows `cuts'
CAUSE :
Not enough loading on drafting arrangement.
REMEDY : Check the load of drafting arrangement
4.
FAULT : Ribbon is drawn down between lap roller and
lap discs
CAUSE : Ribbon guide set too wide
REMEDY :
Set the ribbon guides closer.
6.
FAULT : Ribbon has excessively thick edges
CAUSE : Unsatisfactory sliver guide on the table
REMEDY : Set guide pins properly on the table
7.
FAULT : Ribbon emerges wavy from drafting arrangement
CAUSE : a. Incorrect draft
b. Drafting arrangement set
too close
REMEDY : a. Correct draft with delivery change gear,
check load of drafting
arrangement.
b. Set wider
8.
FAULT : Ribbon is cloudy & wavy length wise
strips
CAUSE : a. Pressure on drafting arrangement too low
b. Drafting arrangement set
too wider
c. Sliver running each other
on the table
REMEDY : a.
Raise the pressure
b. Set closer
c. Move eccentric guide pins
on the table or
reduce no of slivers.
MECHANICAL & PNEUMATIC TROUBLES:
1.
FAULT : Guide head works sluggishly
CAUSE : a. Fine filter clogged
b. Rubber seal is dry
REMEDY : a. Clean the fine filter
b. Increase the micro fog
lubrication rate.
Raise and lower lap discs
about 20 times,
then reset lubrication
back to normal
2.
FAULT : Lap spool not seized properly by lap discs
CAUSE : Spool magazine has been moved
REMEDY : Adjust spool magazine setting according to
manual
3.
FAULT : Pressure hook drawn in to drafting
arrangement
CAUSE : Electrical stopmotion not working on account
of
lap up
REMEDY : Re-adjust contact pins and plates in cover of
drafting arrangement.
4.
FAULT : Bad start when winding time
CAUSE : a. Spool is not properly pressed lap rollers
(Piston restricted by
dirt)
b. No cloth on the spool
REMEDY : a. Clean
b. Stick cloth on
5.
FAULT : Lap disc catching
CAUSE : Too little clearance
REMEDY : Check settings
6.
FAULT : Lap drops out slant wise
CAUSE : Bearings are journals defective, unequal
piston strokes.
REMEDY : Overhaul the cylinder
ELECTRICAL TROUBLE SHOOTINGS :
1.
FAULT : Stopmotion for sliver breakage not quite
reliable.
CAUSE : a. Contact rollers coated with layer of
cotton
b. Contact to contact rollers
hazardous
owing to greasy brush.
FAULT : a. Remove the layer with solvent
(petrol or kerosene)
b. Clean the contact brush
FAULT : Stopmotion for sliver breakage not function
CAUSE : a. Associated lamp is loose or defective
b. Shunt is defect
REMEDY : a. Tighten or replace the lamp
b. Replace the resister
3.
FAULT : Stopmotion for wrapping on delivery or
contact
roller are not functioning
CAUSE : Lamp is loose or defective shunt
REMEDY : Tighten or replace the lamp
Replace the resister
4.
FAULT : M/c suddenly stops
CAUSE : Contact over delay or calender rollers set
too close
REMEDY : Increase the contact distance
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