1. Mixing department
Report Submitted to:
Mr. Hamid Iftikhar (Manager)
Mr. Kamran (Production engineer)
Report submitted by:
Hassan Bilal (MTO)
Factory code: 01848
2. Faculty:
Supervisor (Mehdi shah sahib)
Foreman = 7
Workers: 140 to 150
Materials used:
Rubbers:
1) Natural rubber( obtained from hevea tree)
RSS ribbed smoke sheet ( RSS 4 is used )
SIR ( standard Indonesian rubber)
1260 kg palate with 36 bags. 35 khg/ bag
SMR( standard Malaysian rubber)
1260 kg palate with 36 bags. 35 khg/ bag
2) Synthetic rubber
Butyl rubber ( import from russia)
30 kg each bale.
SBR 1502 (light yellow) styrene-butadiene rubber
(Mostly used in bead wire compound)
SBR 1712 (oil extended rubber)
(Import from Korea Used in tred and ply compound)
3. PBR (orange yellow rubber) poly-butadiene rubber
(made in iran)
EPDM ( eyhylene propylene diene monomer)
Compounds in which load (strength) is requirement SBR is used
and if load and speed both is required PBR is used.
3) Reclaim rubber ( vulcanized rubber) :
Butyl reclaim ( import from india)
Natural reclaim
(50 kg each bag)
Natural and butyl rubber cannot be mixed so their setup is
separate. Bale cutters and mixers are also separate.
To increase the heat resistance of natural rubber it is blend
with SBR
Strength of 1502 is greater than 1712
Butyl rubbers are used to make tubes.
Butyl colours are used to stick on compounds
Hexane is used to separate rubber which stick to each other
4. Fillers ( mechanical holding strength increases):
Reinforcing fillers:
1) Carbon black
N-220
N-330
N-339
N550
N-660
Particle size of N330 < N660
55 bags in each palate each of 25 kg.
Non- reinforcing fillers: (cost reducing)
1) CaCO3
2) China clay
3) Crumb( recycled rubber from tyre scrap)
Activators:
1) ZnO
2) Stearic acid
Plasticizers (increase fluidity):
1) Aromatic oil (thick oil green in colour, highly viscous)
2) Paraffin oil (white oil)
3) Napthenic oil (colourless)
Retarders (anti scorching):
1) PVI/CTP ( pre vulcanization inhibitor)
6. Products formed:
TB400 for butyl tubes
B100 for bead (natural rubber)
T100 for MC tyre tread
T600 for tractor front tread
T610 for tractor rear tread
T614 for light truck tread
F100 for MC tyre ply
F110 for rickshaw ply
F614 for LT ply
F1260 for tractor ply
T110 for rickshaw tread
I900 for inner liner
C614 cushion product for rickshaw, tractor
C900 cement solution
AB900 air bag
RP900 rim putty
I900 inner liner
7. Types of compound:
1) Green compound
(Tests are done by plastimeter , viscometer, rheometer)
2) Cure compound
Weighing mechanism:
Weighing scales are used to weight every material that is used.
After weighing put in plastic bags.
Carbon portion is separate. Carbon is also weighed on lever
scales.
Identification criteria of chemicals:
The chemicals are weighed on the weighing scale and then are
put in plastic bags. Then each chemical is given its product
name like F100, TB 400.
After this naming the mixer number is written below in which
this chemical is to be used like mixer 1 or mixer 3 etc.
8. Processes:
1) Master to final
2) Direct final
1) Master to final :
Master:
Temp range: 140 t0 150 degree centigrade
Speed: 40 rpm
Final:
Temp range: 100 t0 110degree centigrade
Speed: 22 rpm
Master to final is a long process. It is used for making tread.
After master final is made after 12 to 24 hours. Their timing
in mixers is master (5min) and final (3min)
Master + Final = 8 min
Master to final process is done only in mixer 4 due to
temperature issues.
Final product not stored for long due to sulfur reaction.sulfur
blooming can occur.
Master can be stored.
2) Direct final :
In this process direct final compound is made in a
continuous process (done on mixer 1 and 3).
9. Banbury mixers:
Banbury was named after Fernley H. Banbury.
Banbury Mixer 1:
Model: F270
Speed: 49 rpm constant
Product: only butyl tubes are made on it
Type of process:
Only direct final process is done
Temperature dependent process
Operation is manual
Type of rooters:
Tangential rooters are present
Gap between rooters is known as nip.
Capacity:
Its capacity is 240 liters converted to Kg by specific gravity
formula.
Batch weight = capacity of mixer x fill factor x specific gravity
Filler factor:
Defined by manufacturer is 0.75
Time:
Rubber (3min) +carbon, oil, chemical (4min) = 7 min total
10. Ingredients:
Butyl slab (each 30 kg)
Carbon
Reclaim butyl
TB400 chemical
White oil
Total batch weight = 240 to 245 Kg.
Operation:
Put all the rubber on conveyor and feed it.
Ram down and start the timer (180 s)
Ram up and feed oil
Door close and ram down.
Ram up at 260 s
Ram down 300 s
Ring bell at 320 s
Ram up at approx. 340 s to control temp and also open the
door
Ring bell at 400 s
Open drop door at 420s
When red light is on close drop door.
The mixture is dropped through hopper to reduce its speed.
Then the mixture is rolled over dump mill dimension 24x84
(accelerators are added )
After that rolled on stock blender mill (sulfur is added/temp
is at 90 degree centigrade)
Then rolled on above roller
11. Powder and water dryer
Then collected in folds 400 to 450 kg on pallet.
After cooling temp is 35 degree centigrade.
Batch off unit has the capacity of 4 to 5 batches storage.
K-type Thermometers are used to check temperature
Banbury Mixer 3:
Model: 11-A
Capacity: 185 kg
Speed: 19 rpm
Time: 9 to 10 min
Temp: 140 to 145 degree centigrade
Ingredients:
(Friction compounds are made)
F100:
SBR 1712
Reclaim natural
SIR
Oil(thick + white)
Carbon N660
Chemical
12. Buttons:
Red green close drop door, red green (opposite) open close door
Black rotating switch timer reset.
Green button conveyer, side red door open, side red ram up,
upper + buttons door close and ramp down
Wait 5 min after each dump.
Process:
Close drop door and wait 5 min.
Feed rubber and ram down
Wait 180s( 3 min)
Ram up and feed oil and chemical
Ram down and door close
Up down ram 2 times (320 to 340s up ,340 to 440
down,440 to 540 up)
Bell at 520s
Dump at 540s
1 min door opening closing time
On rollers down 15 min are required for mixing that’s
why after every dump we have to weight 5 min.
Dump mill is 22x 60 and the blending mill is 24 x 84.
Same rolling and cooling is done at end. Batch off
unit has the capacity of storing 2 batches.
13. Banbury mixer 4:
Model: XM270
Product: Used to form tread of all kind.
Temperature:
Temperature dependent procedure is followed
Master: 145 degree centigrade with rpm 35
Final: 105 degree centigrade with rpm 21
Inter meshing rooters are in mixer 4(temp is increased due
to greater friction but time is reduced)
Procedure:
The mixer is fully automatic but can be operated manually
Master to final procedure is followed in this mixer.
Time:
Master (5min) + final (3 min) = total 8 min
rpm:
Master (min 36, max 40)
Final (min 20, max 25)
Capacity:
220 Kg.
14. Components:
Main motor:
The banbury is provided with a main motor. Its speed and
temperature is controlled by sensors. The gears are used
afterwards. The motor is D.C operated by a D.C drive.
TCU:
Temperature control unit is present for temperature control of
the mixer. Three motors are present for drop door, rotors,
body for temperature controlling.
Oil cabinet:
Oil cabinet is present for oil providing. Oil can also be heated
in it by convection.
Silos:
4 silos are present on the top floor for feeding carbon to the
banbury. Each capacity is 1.5 ton.
Oil tanks:
Thick oil tank and white oil tank are present on top floor for
feeding oil. Each can have 1000 liters of oil.
Weighing station:
The carbon from the silos is added to the weighing station for
proper weighing.
15. Standby station:
Below the weighing station there is a standby station in which
carbon is added after weighing.
Opening for extra carbon:
Below the standby station there is an opening for the
collection of extra carbon. Butterfly valve is present for the
control of flow of carbon in the mixer or at the collector
backside.
Vibrator:
A vibrator is present to make the carbon flow which settle in
the mixer.
Lubricating oil tank:
A lubricating oil tank is present with the control room for the
lubrication of various parts of the mixer.
Dust collector:
Dust collector unit is present on the sides of the silos it is used
to collect the carbon and this carbon can be used again
afterwards.
Drop door:
Drop door is operated by a lock the complete mechanism is
operated on hydraulics. The pressure require to open it is 80
bar.
16. Weighing of products:
Weighing is done on the weighing conveyer. A procedure of
screen changing is present. When the thing being weighed is
up to the required quantity the screen changes and then the
next thing is weighed. Screen is not changed until the required
weight of the product is not present on the conveyer.
Feeding conveyer:
A feeding conveyer is present after the weighing conveyer for
feeding the weighed product into the mixer.
Control room:
In the control room the operation can be done automatically
or can be done manually. Buttons are present for manual
control of each part. All the parts have separate option for
manual or automatic control. A computer s present with the
computer software to give commands to the mixer. It contains
all the recipes of every compound. The temp, rpm, capacity,
amount etc. etc. all are given as input by it. Number of badges
are also given as an input.
Meters:
Meters are present on the panels for:
Rotor speed
Motor power
Motor current
Rubber temp
Ram pressure( 6 bar)
17. C.B weight
Oil tank 1 temp
Oil tank 2 temp
Temp of the mixer
Sensors
Display unit:
A display unit is present which is operated with touch
screen all the measures are shown own it.
Procedure:
Master batch:
Rubber + chemical feed
Close feed door
RAM down(20 s)
Ram up
Feed Carbon black(N330)
Ram down(30 s)
Ram up
Feed oil
Ram down(20 s)
Ram up and then ram down
Check temp till 145 degree centigrade
Ram up and drop door open
Ram down and then door close
18. Final batch:
Rubber +chemical feed
Close feed door
Ram down( 30 s)
Ram up
Ram down
Check for time and temperature to reach required
limit( 30 s / 105 degree centigrade)
Ram up and open discharge door
Ram down and close discharge door
On the lower floor the roller mills are present for
rolling
After that cooling and powdering is done.
Batch weight:
Batch weight = chamber volume x specific gravity x fill factor
Mastication process:
Mastication process is done for the natural rubber to decrease its
viscosity so that it can be mixed with synthetic rubber. It is done
on mills by rolling it again and again for 30 to35 minutes.105 kg
(35 kg x 3 slabs are added)
Peptizol-7 is also used to decrease viscosity.
19. Compound identification:
The compound formed is identified by different methods:
Every palate has a name written on it by the laborer,
compound type, shift name is also mentioned. A stamp is
also made on it.
Master is given yellow or red colour but no card is attached
to it
Final is painted no colour.
Mixing give cards to be placed on compound. Yellow is for
natural rubber compound. Pink T610, purple T100, Red
TB400, every card has its name printed.
Lab card are also given after tests. Blue card is for butyl,
bluish green for friction ply, yellow for tred and other
compounds.
After cards are placed on the palate. The lifter loads them
and take them to the weight machine. After weighing take
it to the store.
If a sample batch is made no cards are placed on them but a
large paper is attached to it for its identification.
20. Laboratory:
Rheometer:
Two rheometers are present to check the properties of
compounds in mixing and afterwards.
Different parameters are checked on them:
ML (minimum length/min torque)
MH (maximum height/max torque)
TS1 (1st
scorching temp)
TS2 (2nd
scorching temp)
TC10 (10 percent cure temp)
TC50 (50 percent cure temp)
TC 90 (90 percent cure temp)
Tyre is checked at 160 degree centigrade.
T610 checked at 155 degree centigrade
Tube is checked at 180 degrees centigrade.
Every test is temp dependent.
Viscometer:
Viscometer is used to check the viscosity of compound.
Readings are plotted as graph between mooney and time.
Rooter rotation: 2 rpm
Pressure: 4 bar
Pre heat time: 1 min.
Test types: ML 1+4 for natural at 100 degree centigrade.
ML 1+8 for butyl at 125 degree centigrade.
21. Mooney required range:
Friction: 38 to 52.
Tyre: 55 to 60.
Tube: 60 to 65
Mixing grader:
It is out of order these days.
Dispersion of carbon black is checked on it. A magnified image
of carbon can be see with the help of lens present in apparatus.
Plastimeter:
It is used to check softness and hardness and the flow of
compound.
Physical testing of finished product:
Ageing oven:
It is used to check the results and properties after ageing the
temp maintained is 120 degrees.
The component under testing is placed inside it at extreme
conditions to check its results at them. Time is 72 hours to 90
hours depending upon the requirement.
Abrasion tester:
Abrasion test is done on it to check the properties of compound
after constant contact with the roller.
2.5 N force is applied and before abrasion and after abrasion
weight is measured. The difference is divided by specific gravity
of substance to get abrasion.
22. Specific gravity meter:
Specific gravity of only solid compounds is measured on it.cut
specimen and weight in air. Then weight in water. Calculate its
specific gravity using calculate button.
Tensile machine:
Tensile machine is used to check the tensile strength. The
specimen is cut with the specimen cutter and placed in the clips.
The specimen dimensions are entered in the software.
Joint test:
Joint test of the tube is made to check the force which break it.
Body test:
The body test of the tube is made by checking the force which
can break it.
Adhesion test:
Adhesion test of tyre is also done and the maximum force is
calculated.
Max force x max width in cm= adhesion
For cars and rikshaw standard adhesion is between 24 and 25.
For Mc tyre the standard adhesion is 20.
Hardness tester:
Hardness of the material is checked by durometer. The thickness
of the material must not be less than 6mm and the angle must be
90 degrees.
Production:
The average production is 70 to 80 ton in 20 hours.
The record production of 113 ton is recorded.
