1. THE GENERAL TYRE AND RUBBER
COMPANY OF PAKISTAN LIMITED
INTERNSHIP REPORT
BY
REHAN AAMIR BHATTI
HASSAN KHALID
&
WASSEM ABBAS
STUDENTS OF PLASTICS TECHNOLOGY
CENTRE 4TH (FINAL) YEAR
B.E POLYMERS ENGINEERING
Submission of report to Mr.MOIZ SARWAR
(Head of Compounding Department) on 14
April 2014
2.
3. Acknowledgement
ALHAMDULILLAH forfour weeks we undergo our
internship that begins on 19th of March 2014 till 15th
of April 2014, we successfully completed our
Internship. We would like to extend our admiration to
our internship advisor Mr. Khalid Khan for their
advices and generously guiding us through while we
were training in General tyre as an Internee. All the
staff working at General Tyre, We appreciate their
kindness and sharing knowledge when we were
training here.
During these 4 weeks we were learnt many new things
which are very precious for us to learn and carry out
with affection when we start working as professionals
in the future. We also realized that learning
theoretical is never the same when it comes to
practical work. There is a lot more to experience than
learning from the book. We also realized the
importance of team work while working with a well
established organization. We also learnt that time is
an important factor for the development of an
organization. As we know that the world of
professionals is a completely different phase
compared to the time when we are studying, therefore
by going on an industrial training program we hope
and pray that we will be well prepared and have self-
belief to serve the industry.
4. The General Tyre and Rubber Company of Pakistan
Limited (Gentipak) is Pakistan‘s premier industry. It was
established in 1963 by General Tire USA and has been in
productionsince 1964.
Gentipak has a TechnicalServices Agreement (TSA)
with CONTINENTAL AG (Germany’s largest tyre
manufacturer) which enables it to produce tyres of
“GENERAL” brand and provides the latest technology for
productionof tyres based on Continental’s,R&D.
Gentipak is a publiclimited listed company with majority
shares held by Bibojee Services Ltd., Pak Kuwait Investment
Company (Pvt) Ltd. and National Investment Trust.
The Plant and the Offices are locatedin suburb of Karachi.
Initialproductioncapacity was only 120,000 tyres per annum
but is now around 2,000,000 tyres per
5. annum. Our plant is constantly upgraded and is equipped
with the most modern technology in tyre manufacturing.
Vision:
To be the leader in tyretechnology by building the Company’s image through
quality improvement, competitive prices, customers’ satisfaction and meeting
social obligations.
The awareness of the “GENERAL” brand name is very high.
Recently, Gentipakhas also launcheda new line of passenger
car tyres of latest Europeandesigns under the brand name
“EURO”. All the radial tyres are tubeless and steel belted and
have a full cap ply for safety and durability.
Gentipak produces radialtyres for passenger cars and light
trucks in rim sizes ranging from 12” to 16”. It also produces
bias(cross ply) tyres for light trucks, trucks/buses and farm
(agricultural) tractors.
Gentipak is the major supplier of tyres to the local
automotiveand tractor assembly plants. It has contracts to
supply 15” radialpassenger car tyres to Toyota and Honda
approved after stringent testing by their principalcompanies
in Japan.Beside above, Gentipak is also supplying tyres to
Pak Suzuki Motor Company, Hino Pak, Ghandhara
Industries, Ghandhara Nissan, Al-Ghazi Tractors, Millat
Tractors and others.
6. Gentipak is also exporting tyres to few neighbouring and
Middle East countries. It is currently exploring other markets
as well for export.
Gentipak employsdirectly and indirectly approx. 1800
persons all over the country. It has offices in three other
cities of Pakistan besides havingits Head Offices in Karachi. It
is selling its products in the replacement (after) market
through a network of more than 100 dealers and has a
backup in the shape of sales and technicalforce covering the
entire territory.
All tyres produced by Gentipak are marketed after stringent
testing and quality assurance and backed up by a
comprehensive after sales warranty.
7. MANAGEMENT
Lt. Gen (Retd) Ali Kuli Khan Khattak
Chairman
Mohammad Shahid Hussain
Nasser Kamal Asif Jameel Ashraf Teli Hussain Kuli Khan
Executive Director
Marketing & Sales
Executive Director
Corporate Affairs / HR
Chief Financial
Officer
Chief Operating
Officer
(Plant & Projects)
Sarfraz A. Zahid Muhammad Amin Khan Jeelani Baig
Brig (Retd) Najam uz
Zafar
Group Resident
General Manager -
Islamabad
General Manager - O.E &
Government Sales / CS
Sr. General
Manager Works
Sr. General Manager
Corporate Services
Raashid I. Malik Zubair A. Mufti Mussarat Ahmed
Muhammad Arshad
Ansari
General Manager Sales General Manager Finance
Head of Internal
Audit
Div. Manager
Industrial Engineering
Tariq Soulat
Div. Manager
Administration
8. Raw Materials:
Rubber Industry
Textile Industry
Chemical Industry
Steel Industry
Rubber Industry:
Natural Rubber:
Latex is obtained from tree called “Hevea Brasiliensis”. Cuts are made in the
tree’s core (cambium) where the rubber is stored; Slanted cuts from left to
right side of 10 to 20 degrees are made.
Natural Rubber is obtained from latex by co-egulating with different Chemicals
e.g. Oxalic, Citric or Formic acid.
In latex the quantity of rubber is 35% and the rest is serum.
Synthetic Rubber:
Elements or Compounds of various synthetic materials, similar to natural
rubber, made by polymerizing Unsaturated Hydrocarbons, such as Isoprene
and Butadiene.
General Tyres are using NR, SBR (O.E),(W.O.E),PBR, IBR, BBR.
Textile Industry:
In GTR Nylon and Polyester fabric are imported from approved sources of
Continental AG (Germany).
Chemical Industry:
The chemicals used in General Tyres according to specific requirements are:
Peptizing Agents, Plasticizers, Carbon Black(filler), Bonding Agents, Organic &
In-Organic Activators, Extenders, White Fillers, Vulcanizing Agents(Sulphur),
Accelerators, Retarders, Mould Release Agents(Silicon).
9. Steel Industry:
Steel cords (Brass coated) are used In General Tyre for the formation of Bead
& Steel Belts.
Components Of A Tyre:
Radial Tyre Bias Tyre
• Tread – it is thick layer (approx. 18-20 mm) of rubber which comes into
contact with road.
• Rib – it is designed for noise suppression.
• Grooves – to traction in all weather, directional control, cool running
and all rolling resistance.
• Sips– serves as the support for the wheel moving on the road.
• Shoulder – upper portion of the side wall just below the tread edge
that affects tyre heat behavior and cornering characteristics.
• Cap Plies – main load baring components layers of fabric cord
extending from bead to bead to reinforce the tyre and maintain the
shape.
10. • Steel Belt –located below cap plies to increase tensile strength of
tyre. steel belt or layer provides well balanced combination of rubber &
fabric. Thickness is 0.2 to 0.38 mm. this are the steel cord plated with
copper or zinc.
• Radial Plies – thin layer of rubber inside the tyre containing
compressed air tube.
• Sidewall –portion between tread to bead. it is rubber sheet 1.5 to 3.5
mm thick protecting tube from any kind of mechanical or physical
damage and moisture penetration.
• Bead Chafer – narrow strip of flex material around the outside of
the bead that protects tyre against wear & tear and prevent dirt and
moisture from getting into the tyre.
• Bead – structure composed of high tensile strength steel wire which
holds the tyre assembly onto the rim of the wheel for handling
performance.
• Inner Liner – The Inner liner is the air retaining member and is usually
calendared as a two layer laminate having stepped edges. Usually
thickness=2.5mm
• Breakers- . These are fabric plies placed directly on the upper-most
ply beneath the tread rubber. They disperse stress throughout the tyre.
Rubber Compounding:
The objectives of rubber compounding may be essentially defined as
providing optimised performance and process ability, generally at
minimum cost, by the incorporation of non-rubber ingredients.
Optimised performance in this context refers not only to mechanical
properties but also, for example, resistance to bacteria or particular
chemicals. In some applications a rubber may also need to be
11. coloured, or bonded to another material, and further ingredients
may be required. For many years, rubber compounding was largely
empirical and frequently described as a black art. Today it is
practised predominantly on the basis of scientific principles
Elucidated over years of study and is still the subject of intensive
research.
Properties Of Different Rubbers:
Properties NR SBR Poly
butadiene
Butyl Neoprene Nitrite Silicone
Tensile
Strength
E P P F G P P
Tear Strength G P –
F
E G G G F
Abrasion
Resistance
E G –
E
E F – G E E F
Heat
Resistance
G G G G – E G G E
Impermeability F G P – F E G G F
Flame
Resistance
P P P P E E F
Aging
Resistance
P P P – F G – E E E E
Acid
Resistance
G F –
G
G E E G G
Solvent
Resistance
P P P P G G G
Animal +
Vegetable oil
Resistance
P –
G
G P – G E G G G
E = Excellent, G = Good, F = Fair, P = Poor
The various ingredients may be classified according to their specific function
in the following groups [2]:
fillers (carbon blacks and non-black fillers);
plasticized and softeners (extenders, processing aids, special
plasticizers);
12. age resistors or antidegradants (antioxidants, antiozonants, specialage
resistors, protectivewaxes);
vulcanizing and curing ingredients (vulcanizing agents, accelerators,
activators);
Special-purposeingredients (colouring pigments, blowing agents, flame
retardants, odorants, antistatic agents, retarders).
However, many ingredients are capable of functioning in more than one
manner.
Creating A New Compound:
When creating a new compound there are three main criteria compounders use
to guide them. Listed in order of importance they are as follows:
1. Customer requirements
2. "Process ability"
3. Cost
Nearly all new compounds are modifications of some existing formulations.
Nowadays,development of a completely new compound is seldom attempted.
Moreover, such an attempt is usually unnecessary. In order to be efficient and
effective in rubber compounding, chemist should take full advantage of technical
information readily available inside as well as outside of his organization. He must
be analytical, resourceful, and innovative.
The FollowingIs A Useful Procedure To Guide Compound
Development:
1. Set specific objectives (properties, price, etc.)
2. Select base elastomer(s).
3. Study test data of existing compounds.
4. Survey compound formulations and properties data presented by material
suppliers in their literature.
5. Choose a starting formulation
6. Develop compounds in laboratory to meet objectives.
7. Estimate cost of compound selected forfurther evaluation.
8. Evaluate process ability of compound in the factory.
13. 9. Use compound to make a product sample.
10. Test product sample against performance specification.
Five Main Systems:
Compounding can be broken into fivemain systems as follows:
1. Elastomer System:
One or more elastomers for characteristics
Elastomers for improved processing
2. Filler System:
Reinforcing filler
Semi and non-reinforcing fillers
Plasticizers
3. Protectants
Antioxidents
Antiozonants
Inhibitors/Promoters
4. Processing Aids
Mixing Aids
Modling Aids
5. CureSystem
Vulcanizing Agents
Activators
Accelerators
Scorch retarders
One important detail to note is that nearly all compounders usethe unit of
measureof "parts per hundred"(PHR) for their formula. This is a unit of
weight for the relationship between the elastomer systemand the other
systems. If wealways utilize 100 parts of elastomer for all formulas then it is
much simpler to changethe other systems to create changes and different
formulas.
14. Manufacturing Of Tyre
Tyre manufacturing is a complex process which involves various steps which
are as follows:
Mixing
Calendaring
Side wall and Tread Construction(Extrusion)
Bead construction
Green tyre making
Tyre curing
15. Flash trimming
Final inspection and testing
Mixing:
Just like selection of rubbers & additive, mixing is necessary to achieve desired
properties and performance of a rubber product. It is also important to know
how these different ingredients should mix i.e. procedure of mixing, time
duration, temperature, energy consumption, batch weight etc.
In General Tyre we visited Mixing department under the supervision of Mr.
Abdul Bari who guided us about the mixing operation for different
components.
16. There are three basic techniques of mixing a rubber compound.
Conventional method.
Late oil addition method.
Upside down mixing method.
Conventional Method:
In this method, rubber is first grinded and dry ingredients are added and then
oil is added after ingredients are well dispersed. This method achieves a
homogenous dispersion of all ingredients, including filler of very small particle
size. However mixing time required is long. In a conventional mix low polymer
content is difficult to mass at the start of the cycle simply because so little is
present.
Late Oil AdditionMethod:
In this case also rubber is grinded first and oil is added after addition of dry
ingredients. This method is used when highly viscous oils are used.
Upside-Down Mixing Method:
This is the fastest and simplest way of mixing. It is specially efficient and
effective for those compounds containing a large volume of plasticizers and
large particle size fillers.
In this method all dry ingredients are added first, then all liquids and finally all
rubber on top. This method is not suitable where small particle size fillers are
used, or high loading of oil is used & rubber of high Mooney viscosity is used.
Conventional and late oil addition cycles are most often used with polymers
having good self adhesion.
Two Stage Mixing:
Premature vulcanization of a rubber compound, scorch, can occur if the
reaction temperature of curatives is reached before time.
17. Breakdown of rubbers and incorporation of different ingredients require high
temperatures and long duration. That is why a master batch is mixed first, is
cooled and allowed proper aging before curatives are added in the 2nd
stage
which is done at lower temperatures and for shorter duration.Proper Aging (2
to 4 hrs) of all master & finished batches is necessary so that all reactions that
take place during mixing are completed & stabilized.
Mixing Equipment:
1.Mixing Mills:
These are open two-rollmills of various sizes ranging from 13"to 84", for batch
capacities.
18. Front & back rolls have either same friction ratios or are different depending
upon usage. The gap/nip between the two rolls is adjustable. The back roll
usually runs faster.
The surface of these rolls is made of specially treated steel for corrosion &
scratch resistance. The rolls are hollow from inside for cold/hot water/steam
circulation through pipes or directly from one end to other.
The rolls are heated for easy breakdown of compound & cooled to avoid
scorching. The temperature of the rolls and gauges and other specification is
given by compounding department of general tyre.
2- Internal Mixers:
The basic concept of mixing is the same in an internal mixer as is with the open
rolls i.e. the rubber is broken down in between two rolls running in opposite
direction at different speeds. In this case there are two spiral-shaped rotors
enclosed in a chamber where mixing takes place with water cooling
arrangement for rotors, casing, drop door and ram.
A hopper is at the top to receive compounding ingredients for mixing, an air
operated ram is there to exert pressure on the batch and to prevent it riding up
the hopper. A door is at the bottom for discharging the mixed batch. A
thermocouple is attached either at the rotor end frame of the chamber or at
the drop door to indicate the temperature at which the mixing is carried out at
different stages.
19. Probableflow lines
and filling
configuration of an
internal mixer
Principal components of an Internal
Rubber Mixer
Banbury 2-wing
Banbury 4-wing
Shaw intermix 3-wing
Werner & P.Fleiderer4-
wing
Mixing Process:
Itis the firststep in developing productfor tyre. Rubber sheets are made by
mixing of rubber and different ingredients. In General Tyre making is carried
out by by Banburry (InternalMixer) HF-270. Thespecs of mixing is different for
each component e.g. temperature, pressure, time duration, energy.
20. There are different ingredients used in making of rubber compound for tyre.
Most probably weuse rubber and other is filler. Many types of filler are
present but in tyre manufacturing differentgrades of carbon black are used for
making different compound for differentobjectives and carbon filler provide
higher strength and used due to black colour of tyrestandard.
Standards Of Rubber:
There are major standards of rubber in the world.
ISNR(Indian Standard Natural Rubber)
SIR(Standard Indonesian Rubber)
SLR(Standard Lankan Rubber)
SMR(Standard Malaysian Rubber)
And all these standards sub divided in two standards depends on quality
i.e. grade 10 and grade20.
(Grade 10 is more efficient than grade 20 in finishing and
smoothness whereas grade 20 is not much more efficient in all
these properties).
In GTR, four major rubbers areused for different application such as Natural
rubber, Styrene Butadienerubber (Oil Extended, Without Oil Extended), Poly
21. Butadiene rubber (PBR) andButyl rubber (HalogenatedButyl rubber), first
three used for tread and sidewall. Butyl rubber is used for inner liner in radial
tyre and for tube purposebecause it has a property of air retention.
There are two steps for mixing operation firstwe make “Master” and then
“Finish”.
Preparation Of Master:
In preparation of master batch there is no addition of cure package. In master
batch making, rubber, filler and some processing aids areused in Banbury
mixer (HF-270) at(170-180 °C) and createa master batch of 200 to 240kg of
rubber compound in three minutes. In Banbury operation differentcarbon
grades (FurnaceBlack) silo (carbon bags) are attached to the Banbury mixer
and used according to given specs. The temperature is very high that’s why
cure packageis not added during this process. Then this batch is placed for 2 to
4 hours for Aging.
Preparation Of Finish:
Master batch is used for finish process at a temperature of (110-115°C) the
addition of cure packagesuch as Sulphur, Accelerator and different curing
agents with specific recipes. There are two types of Sulphur used (Oil treated
and Without Oil treated). And oil is used as Plasticizer (547 highly paraffinic
oil). After mixing the compound, passes to the Permolsolution for providing
protective layer and avoid it to stick to each other.
Mixing Steps:
The following steps for mixing are done in a Banbury.
The Feed door is open and feed is entered through conveyers.
Then Feed door is closed and ramp moves downward and exerts
pressureon feed and rotors rotate at a set rpm for mixing action.
Now Ramp moves upward and door opens and carbon feed enters and
then door closed and ramp again moves downward and mixing starts.
Again ramp moves upwards, oilfeed enters (plasticizer) and door is
closed.
Ramp moves downward and mixing continues.
When mixing is done, door opens and mixed compound drops on the
dump mill.
EQUIPMENTS USED IN GENERAL TYRE FOR MIXING PURPOSE:
22. F-270 BANBURY MIXER (4 wing rotor)
HF-270 BANBURY MIXER (2 wing rotor)
KNEADER-1 (KN-1) (2 wing rotor)
KNEADER-2 (KN-2) ( 2 wing rotor)
HF 270 and f 270 is used formaking master batch because master need very high
temperature where as finished is made on F-270, one major drawback in HF-270
is that we cannot change its parameter with respect to our specificationand
requirement, but in f 270 we have no drawback because its parameter changes
with respect to our requirement so that’s why we make master as well as finished
in F-270.
Kneader:
The kneading reactor is a horizontal mixing machine with two Sigma, or Z-type
blades. These blades are driven by separategears at different speeds, one
running 1.5 times faster than the other. The reactor has one powerfulmotor
and a speed reducer to drive the two blades. The kneader reactor usually has a
W-typebarrel with a hydraulic tilt that turns it, and a heating jacketoutside. In
General Tyre Kneader is used for making Finish batches.
23.
24. Components Manufacturing:
Extrusion:
Rubber extruded products will differ from
moulded rubber productsbased on the process where
extruded parts are forced through a die of the required cross
section under pressure of an extruder, this process is called
extrusion.
There are two types of extruders used in GTR.
Dual Extruder
TriplexExtruder
25. Dual Extruder:
A machine in which two hoppers are connected to producetwo components
of a product. Itis a hot feed extruder.
Mr. Osama and Mr. Akhter guided us a lot about the operation of Dual
extruder.
The operation consists of following steps:
Breakdown mill
Holding mill
Feeding mill
Hoppers
Two screws of differentsizes
Die
Process:
Finish sheets of rubber from mixing depart are subjected to Breakdown
mill, holding mill then feeding mill. In feeding the gauges are set(according
to required specification). The three roll mill setup is ideal for hot feed
extrusion. Sheets fromfeeding mill go into hoppers through conveyers. Two
different sizes of screws are used for extrusion (i.e. 8 ½” & 10”). “Y-head”
die is used. The screws move with different rpm according to required
specification. Compound is extruded from the die. After extrusion through
the die cushion compound is applied if required from separate cold feed
extruder. The extruded part then passes through the cooling line by
conveyer belt. After cooling the automatic running cutter cuts the part
26. according to the given sizes. After cutting the part is booked in a shafered
truck.
Triplex Extruder:
Triplex is a machine which can extrude three components of a productat a
single time. Itcan also work as dual extruder for inner liner, side wall extrusion.
Itis a cold feed extruder.
Process:
Feed is conveyed by conveyer belt to three hoppers. Thesehoppers are
attached to their respective barrels and the extrudates which are extruded
through die. Self skiving is done. Then the extrudate part passes through
dancing rollers which maintains the tension in it. Then to the weighing
27. conveyer for weighting and also this function is done by camera sensing
weight. Then the partis set for chilling and chilled in a zig zag manner. After
cooling, the automatic running cutter cuts the part according to specification.
Then part is booked in shafered truck.
Triplex is used for the extrusion of sidewall and tread of passenger car and light
truck tyres in GTR.
Extrusion Temperatures:
The temperature of the extruded treads shall be measured with a Pyrometer at
the centre line of the tread and sidewall.
Booking Temperatures:
A needle Pyrometer shall be used to determine the temperature of cooled
treads and sidewalls at the thickest temperature.
Treads and sidewalls shall be air blown so as to be completely free formwater
before booking.
Calendaring:
Calendaring is a very important process in tyre building because the plies used
in a tyre gives strength to tyres are made by calendaring.
We visited calendaring department under the supervision of Mr. Nusratullah
who guided us aboutthe technology and the procedureof calendaring.
28. Four Roll Or Z Calendaring:
In this process, tyrecord fabric coated with rubber on both sides passes
through four rollers known as “Four roll calendaring” or “Z calendaring”.
Major Raw Materials:
Rubber:
Natural
Synthetic
Fabric:
Nylon(for bias tyres)
Polyester(for radialtyres)
Procedure:
Let off unit
Splicing unit
Tensiometer unit
Pre curetension unit
Banana rolls
Trimming unit
Rubber is feeded to four roll calendar through following process.
Calendaring Mills:
Breakdown mill
Warmup mill
Feeding mill
Holding and Blending mill
After coating with rubber on both sides of fabric.
Perforater
Postcalendar
EPI(ends per inch)
Cooling down
Accumulator unit
29. Windup
Storage
Every fabric procedureis done by specification given by compounding
department.
Three Roll Calendaring:
Two mills are used in this process one is for blending (XM-12) and
second is for feeding (XM-11).
Then passes through conveyer belt to 3-rolls which as direction 1st
and
3rd
moves in clockwisedirection and 2nd
roll moves in anti clockwise
direction.
Four gauge knives are used for cutting.
These three rolls are heated by a steam and the temperature of these
rolls is above 100 degree Celsius.
Here after cutting there are four rolls for accumulation and for cooling.
In this process tensionativerolls are used to producetension.
A wind up table is used for winding.
There are four rolls at a time two rolls are in working and these two are
completely fills next two rolls ready for winding.
These rolls are subjected to temperature of 45-50 degreeCelsius.
These winded rolls again let off for the pasting of squeegee layer.
Squeegee layer is used because it has high air permeability.
On three roll calendaring process GTR produce inner liner for the radial
tyres.
30. Steelastic Area:
Steelastic area produces steel belts which are used in Radial tyres.
Hightensilebrasscoatedsteelcordsareusedintheconstructionoftyrebelts.
Thebrasscoatingisdonetomakerubberadheretothesteel.
The storage of these brass coated steel cords is in a temperature and
humiditycontrolledenvironmentwhichiscalled “Creelroom”.
Thetemperatureiskeptaround27degreesCelsiusandhumidityaround30%.
Duetomoisturecorrosioncanoccurwhichmaycausethesteelcordtoloseadhesion
withrubber.
The steel wire passes fromthe creel room through rollers.
Thenthesewiresarecoatedthroughcrossheadextrusionwithrubber.
Ensureproperpenetrationofrubberbetweenthecordsanddesiredadhesion
betweenrubberandsteel.
Coolingdrumscooldownthecoatedstrips.
Cuttercutsthebeltsatrequiredangleandlengthaccordingtospecification.
Winderassemblywindsthebeltswhichthengointostoragearea.
31. Bead And Band Manufacturing:
Bead Manufacturing:
Tyre bead wire used for the reinforcement of virtuallyall
types of pneumatictyres such as trucks, buses, passenger
cars, jeeps, OTR equipment,farm equipment, motor cycles,
scooters and cycle tyres. The main function of the tyre bead
wire is to act as reinforcement and it helpsto get a proper
grip of the tyre on the rim. The type of tyre and structure of
bead rings used, determine the size of bead wire.
We visited this depart under the supervision of Mr. Imtiaz
who guided us about different procedures.
33. These machines consistof two rollers which press multiple plies togetherwith
helpofpneumaticpressure.
There are three types of bands made:
1.Firstband-4plies,breakeranddrumsqueegeeassembly.
2.Secondband-Onlyplies
3.Thirdband–2pliesand2breakers
34. Tyre Building:
In this department the components are assembled to form“Green Tyre”.
We visited this department under the supervision of Mr. Akhter. Thestaff
working in this departare very friendly and co-operative.
35. In this department following green tyres are built:
Passenger Car (Bias and Radial both)
Light truck
Truck, Bus tyres
FarmTyres
Rickshaw Tyres
Radial Tyre Building:
The Radial tyres built in General Tyre are
Euro Star
36. Euro Komfort
Euro Glide
Euro Tycoon
Euro Kompact
ST. Radial
XP 2000 II
Radial tyres are built in two stages
1st
Stage Assembly “Carcass”:
The tyre carcass is built on an assembly drum. Components can be added for
example in the following order:
Inner liner
Body ply
Beads
Sidewall
In General Tyrethe assembly drumused in 1-stageassembly consists of a
shaping bladder and rotating drum.
Beads are fitted onto the drumusing specific bead applicators.
By inflating the shaping bladder, the stretching of the tyrecarcass
begins. Whilst this is being done, the distance between the beads
shortens.
In the stage sidewalls and bead area components are stitched.
After the shaping bladder has been deflated, the tyre carcass can be
taken off the drum.
2nd
Stage Assembly “Green RadialTyre”:
The components fitted in this assembly stage:
Belt Package
Cap Ply
Tread
The Carcass is placed on a regular assembly drum.
The tread and belt package is stitched carefully onto the tyre carcass.
37. The stretching pressureis released fromthe tyre carcass, and the green
tyre is taken off the drumand moved to intermediate storage.
Bias Tyre Building:
In theconstructionofbiastyreplycordsextendingfrombeadtobeadareatangleof
30to40degrees.
Inbiastyrebuildingthereisonlysinglestage.
Pliesareatopposingangleslaidovereachothertoformacrisscrosspatternonwhich
thetreadisapplied.
TherearecurrentlysixtyrebuildingmachinesforBiasconstructioninGTR.These
machinesareoldandsomearetotallymanual.
The main components of bias tyre building machine are:
Drum
Beadapplicator
Backtoolassembly
The following components are assembled:
Drumsqueegee
Bands
Beads
Sidewall
Chafer
Breakers(Breakerareusedinbiastyretogivemorestrength)
38. Breakerstobeusedaredependentonthetypeoftyremanufacturedi.e.truck/bus,
tractor.
Tyre Curing:
Curing means treated by a chemical or physicalprocess to improveproperties
(hardness and strength and elasticity)
‘CURING’ is the process wherethe shape of the tyre is set under extreme
pressureand considerableheat using either mechanical or hydraulic press
mould. Smooth functioning of the press mould parts is critical to the final
shapeof the tyreas the process lasts form11.5 minutes to few hours
depending on the size of the tyre.
In General Tyre all curing machines are pneumatic.
In this department we learnt a lot from Mr. Aziz Ur Rehman, Mr. Asad and
Mr. Subhan.
39. Curing Department:
Rubber producthas to be cureeither through moulding or by other means,
either at roomtemperature or at elevated temperature.
Moulding is an act of shaping the green (uncured) rubber into a cured product
of required geometry by using a mould.
Green tyre is lubricated internally and externally. This lubricant helps in mould
releasing.
Bladder Curing:
Although used for many severaldifferent products butmost widely used in
tyre manufacturing.
Basically bladder curing is a special caseof compression moulding.
A bladder inside an uncured (green) tyre pushes it against a hold mould
surface.
In general tyre weusually used bladder curing.
There are two types of curing
All Steamcuring
Steamand Hot water curing
The difference between all steam and hot water is justthat all steam need
very less time for final curing than hot water but the drawback in all steam
40. is that it require very finished green tyre becausea slightly unfinished green
tyre if cured by all steam, the steam cannot recover the unfinished, but in
Hot water this thing cannothappen it will take a long time but can recover
all the losses in green tyre.
Also there is a test name T20 that indicate that how much time required
for curing of any sizeor compound for tyre.
The Steps For All Steam Curing Are:
High pressuresteamenters at 240 psiand at temperature 206 C, and
then drain out.
Low pressuresteamenters at 140 psi and at temperature 186 C and
then drain out, here we suddenly uselow pressurebecause
temperature comes down gradually so that to avoid degradation and
maintain stability.
Then introduce vacuumof 5 inches of mercury and generally mercury
we used because mercury is the high density and viscosity element.
The Steps For Steam + Hot Water:
This is also same as all steam but the differenceis,
Firstly we introduce steamat a pressureof 200 psi/inch and at
temperature 198 C, and then drain out.
Then hot water introduce at a pressureof 250 psi/inch and at
temperature of 166 C and then drain.
Then cold water introduce at a pressureof 250 psi/inch and at
temperature 32 C, justbecause to maintain stability and avoid by
degradation becausecold water brings temperature gradually.
There are two types of machines by which we cures,
1. Dome type (batch).
2. Platten type (continuous).
The major difference is that in dome type, steam flows at specific time so
that afterwards temperaturebecomes low whereas in platten type steam
41. flows continuously buthere wehave no option for setting time but in dome
type we have.
Platten curing time is faster than dome time.
Moulds For Machines:
There are two types of mould which are used in GTR,
Segmented mould (latest)
Two piece mould (older)
We can make more than one part on segmented mould but in two pieces we
cannot. Segmented mould is more beneficial than two piece mould becauseat
the time of curing we haveto keep tyredynamics, uniformity and disturbing
values in our mind, In segmented type mould itself moves towards green tyre
so our values cannot changed and maintain as they was, but in two piece type
our green tyre moves towards mould and there is a big chance of changing a
uniformity, dynamicity of a tyre and our tyre also be off cure.
Motorcycle Tyre Department:
Motor cycle department is the latest department in General Tyre. It was
started in 2012 because General Tyres is considering the production of
motorcycle tyres as it looks to expanding its production line.
This depart is equipped with all the latest machinery setup and we visited
this department under the supervision of Mr. Kaleem.
42. Motor Cycle Plant:
General tyre is making different sizes of tyres of motorcycles which are,
Design Hyper Sonic
Available sizes 2.25 - 17F
Load Range C
Description Front tyre for excellent grip.
Design Hyper Sonic
Available sizes 2.50 - 17R
Load Index C
Description For better and comfortable ride
43. .
Design Duro Grip
Available sizes 2.25 - 17F
Load Index C
Description
Rib type pattern provides excellent
road grip.
.
Design Duro Grip
Available sizes 2.50 - 17R
Load Index C
Description
Better fuel economy & cool
running tyre.
Design Mustang
Available sizes 2.50 - 17R
Load Index C
Description
Directional pattern tyre for
excellent traction
.
44. Design Tuff Rider
Available sizes 2.25 - 17F
Load Index C
Description
New generation tread design for
better performance.
.
Construction of a motor bike tyre is very simple as compareto any other rear
tyre or in simple words than a car or a truck tyre.
Bike Front Tyre Construction:
1st
ply at an angle of 32 degree
Then 2nd
ply shorter than 1st
ply in sizealso at an angle of 32 degree.
Then beat applied.(3 turn , 3 wire)
At last tread is applied and then green tyreis sent for curing.
Design Black Cobra
Available sizes 2.50 - 17R
Load Index C
Description
Provides excellent floatation,
powerful control.
45. Bike Rear Tyre Construction:
1st
ply at an angle of 32 degree
Then 2nd
ply shorter than 1st
ply in sizealso at an angle of 32 degree.
Then breaker is applied just oppositeto last ply.
Then beat applied.(3 turn ,3 wire)
At last tread is applied and then green tyreis sent for curing.
Curing Of Motorcycle Tyre:
Platen curing is used for motor cycle tyre .The process is same as for car or a
truck tyre but some specifications are changed i.e.
Temperature of a platen is 175 degree Celsius
Mould temperature is 65-69 degreeCelsius
Internalsteam pressure200 psi.
46. Tube Department:
This is one of the oldest departments in GTR. Some parts which are now made
on the latest machines i.e. The Extruders, Curing machines on which flaps and
bladders are cured.
We visited this department under the supervision of Mr. Kaleem who guided
us about the formation of tube through a number of processes.
47. Tube Department For Bias Tyres
In GTR different sizes of tube are made e.g. 12-4 , 450-12 etc. And bladder, flap
of tyres are also made.
Formation Of Tube:
Basically a tube is torus-shaped balloon made froman impermeable material,
such as soft, elastic synthetic rubber, to preventair leakage. The tubes are
inserted into the tyre and inflated to retain air pressure.
48. In General tyre Butyl rubber is used for tube making and is extruded in a simple
extruder; firstthe compound is blended on a mill and then passes to feeding
mill so that there is no need of proper mixing in extruder then through
conveyer belt it is feed into the hopper of extruder. The temperature of screw
is specified and fixed with respectto given specs. Then the extrudate exits
froma cone shaped die. The die is designed in such a manner that there is a
nozzleinside the die whosepurposeis to spray a powder named “Soft Stone”
inside and outside the tube so that tube material should not stick with each
other. Now the extrudate i.e. the tube is passing through conveyer belt by
different process such that after powdering, westick a Rapcon whosepurpose
is ro remove powder froma part wherewe have to applicate wall, beforethis
Rapcon tube pass through chilling process so as to maintains its temperature
i.e. 56-60 degreeCelsius. The tube is cut to desired size. Then tube is taken to
splicing unit and spliced by heating, by name we came to know splicing
purposeis to joint two ends of a tube. Then the spliced partis taken to chilling
unit and cooled at a temperature of - 9 degree Celsius. After chilling, air is filled
in tube to check the splicing joint. Then tube is taken to the ring unit. This is
done justto give a desired shaped for the mould of a curing machine.
Then after all this processes finally green tube is taken for curing and cured at
a temperature of 100 degree Celsius. The curing of tube is doing by steam
process.
Formation of Bladder:
Generally we say that bladder is a flexible membrane that forms the inside
surfaceof a tyreduring the tyre curing/vulcanizing process.
49. Bladder is cured at a temperature of 200 degree Celsius
Formation of Flap:
Tyre flaps are used for two reasons.
The first being any spooked wheel, to keep the spokenut fromrubbing
against the tube.
The other, being a solid wheel, the flap, or liner is used as a precaution if
there is any scratch or imperfection in the rim, to keep the tube from
rubbing or moving against it.
Flap cures at a temperature of 140 degree Celsius and time taken is 6 min but
the mould of a flap is in 3 parts.
Motorcycle Tube Manufacturing:
The tube is made by Butyl rubber, and it is first blended properly
in some steps that are,
First the Butyl rubber is blended in Dump mill.
Then through conveyer, it is transferred to Feeding mill.
Then it passes through Strainer (extruder type) that decreases its
viscosity.
Then again through conveyer, it is transferred to Breakdown mill.
After Breakdown it is transferred to Feeding mill.
50. And then it passes through extruder where gauges are set
according to specs for final output, and also output is powdered
with Soft Stone Powder inside and outside so that layers should
not stick, that is die has a nozzle inside it that provides powder for
a tube.
After the extrudate exits, it passes through Hot blowing (cooling)
and cut off to desired size.
Rapcon paper is also pasted where the air valve is fitted (Hole
punch and Valve punch).
Splicing is done.
After splicing cooling is done.
After cooling air is filled in tube for checking splicing joints and is
placed on a round cylinder to maintain shape.
Finally the Green tube is sent for curing.
After Curing final inspection is done and tube is sent to packaging
department.
Raw Material Ware House (R.M.W.H):
51. R.M.W.H receives, holdsandreleases material foroperations andproduction.
The mainresponsibility oftheR.M.W.H istokeepcontrol of inventory sothat
there isnomaterialshortage. As rubber ismainrawmaterial required tomake
atyreandiscurrently imported,R.M.W.H purchases material from the
approved sources by Continental Tyres Germany andlocallyaswell.Thisis
department isindirect linkwiththeProduction department.
Wevisited thisdepartment underthe supervision of Mr. Abdul BariandMr.
Ubaid Haqqi whoguidedustheworkingprocess ofR.M.W.H.
Itisdivided intothree sections:
HardwareSection
RawMaterialSection
ScrapSalesManagementSection
HardwareSection:
53. ScrapSection:
The purposeof scrap section is to ensurethe sale/disposalof factoryprocess
scrapmaterial,obsoletesparepartsandfixedassets.
Finish Good Ware House(F.G.W.H)
In this department, the finished goods, All the manufactured items stored and
are then supplied to the OEM’s and to the market dealers and retailers of
General Tyre and Rubber Company Pakistan.
We visited this department under the supervision of Mr. Zafar Lodhi who
guided about the sales of goods fromGTR.
54. The products that fulfill all the quality parameters are sent to F.G.W.H
for shipmenttothedealersandOEMs.
Tirepackagingisalsodonehere.
Theyalsocollecttheclaimedtires.
Awarehousesheetisgeneratedintheholdingareawhenthetiresarebeenhanded
over to F.G.W.H.
The sheet is verified and signed by warehousesupervisorbeforethetiresare
letinthewarehouse.
Alockingkeysystemisusedwhichmeanswhentiresareintheholdingarea,the
warehousegateislockedandsimilarlywhentiresareintheF.G.W.H,thegateto
holdingareaislocked.
ASalesInvoiceisgeneratedinthesalesdepartmentwhentiresaretobedispatched
fromF.G.W.H.
Incaseoftransferoftirestobranchoffices,aTransfer Invoiceis generated.
F.G.W.H verifies the invoices and plans the logistics.
Utility House:
This depart provides all those parameters which are used in the manufacturing
of tyres for example Hot water, Cold water, Steam, electricity etc.
We visited this department under the supervision of Mr. Siddique Sheikh who
guided us about the operations of this depart.
55. Boilers:
This department fulfils all the requirements needed for tyre curing
purposes. Itprovides Steamand Hot water at specific temperature
pressure.
In GTR there are two boilers.
1. Train Boiler:
18-tons capacity
260 psiwoking pressure
40000 lb/hr flowrate
2. Deskon Boiler:
22-tons capacity
260-psi
49000 lb/hr
Other Suppliesfrom Utility House:
Steam supply
Hot water supply
56. Cold water supply
Standby generator
Air supply
There are two compressor of 150psi and 100psi.
Two pumps for hot waterand cold water feed.
Two generators of 735KW.
57. Quality Control And Quality Assurance
Department:
Quality Control:
Quality is the main aspect. General Tyre and Rubber Company Pakistan are
very conscious and strict in maintaining the quality standards of their product
for Customer Satisfaction.
We visited this department under the supervision of Mr. AbidRaza who
guided us the various tests performed for maintaining quality standards.
Quality Control includes indoor Product Inspection, whereevery productis
examined visually, and often using a StereoMicroscope for finedetail before
the productis sold to external market. Inspectors are provided with lists and
descriptions of unacceptable Product Defects.
58. Quality control emphasizes on testing of products to uncover defects and
reports to management.
Qualitycontroldepartmentplaysaveryimportantrole.Thisdepartmentisbasicallya
supporterofcustomerbutinrealitgivesvaluableadvantagestothecompany.This
departmenthastochecktheproduct. Withoutchecking,theproductisnotforsalebecause
ifanydefectedproductissoldinmarketitisgreatrisktocompanyandalsoverydangerous
forthelifeofcustomer.Thisdepartment’sresponsibilityistomaintainthequalityofthe
productbyperfecttesting.
QualityControlDepartmenthasfollowingresponsibilitiesandsections.
X-Ray testing
MaterialTestingLab
ReliabilityTest
EnduranceTesting
High SpeedTesting
Plungertest
TireUniformitymachine–usedtocheckifforcesarebalanced.
StatisticalProcessControl.
InProcessInspection
FinalInspection
Qualitycontrolbeginswiththedeliveryofrawmaterials.Companychemistsdorandom
testingoftherawmaterialsintheMaterialTestingLab.Throughoutthebatchmixing
operation,samplesoftherubberaredrawnandtestedtoconfirmiftherubberfulfilsthe
requirement.Avarietyofnon-destructiveevaluationtechniquesarealsousedsuchasX-
rayvideography,reliabilitytesting,andplungertestingforcuredtires.
61. By name it is clear that planning control means “When, Where, Time and
Quality”. The work of this department is to deliver order on time, qaulity and
on when and where basis. This department has three basic functions:
1. Planning.
2. Scheduling.
3. Controlling.
Planning:
Market demand(Saleforecast)
1st
check Technical specification and machine capacity.
Then check our workers efficiency either they are eligible or enough for
the production order.
Scheduling:
Create production forecast.
62. Then create a production forecast: (1st
order divided in three months
then in 15 days and then create schedule on daily basis). This benefit is
to deliver order on time.
Controlling:
Check daily shiftproduction.
And also check all specification is followed or not.
Then check time schedule either it is followed or not.
By checking all these above points we assurethat we deliver our order
on given time.
OtherOperationsofthisdepartmentare:
ComponentsManufacturingSchedule
InventoryManagement
ProductionControl
Material Testing Department:
General tyre has the state of the art material testing department equipped
with all the latest and updated testing equipments, all the compound firsttest
in the material testing lab and are then forwarded to other departs for further
processing.
We visited this department under the supervision of Mr. Shahid and Mr. Amir
who guided us aboutvarious testing equipments used and the tests performed
on daily basis.
Material Testing Lab:
63. All compounds after mixing 1st
come to test in material testing lab before
further processing. Itis the responsibility of lab to check all the mixed
compounds fulfil the requirements according to specifications or not. If not
then lab has authority to hold or reject the compound batch.
The material testing lab is divided into two sections:
Rheology Testing Section.
General Testing Section.
Rheology Testing Section:
MDR is used in this section (Moving Die Rheometer)
Alpha technology Rheometer:
FastRheometer
Upper temperature is 372 *F
Lower temperature is 372 *F
Time 2 min 30 sec.
Torque sensor (MH indicates hardness of compound)
Define all Curing Properties
RegularRheometer:
Itis slow rheometer.
Time and temperature is constant.
Temperature is 320 degree Celsius.
Itshows the actual picture of curing behaviour.
Mooney Rheometer:
This reheometer is also known as mooney viscometer and
mooney means viscosity.
Temperature is 100 degree celcius.
Time taken 4 min.
64. Components of Rheometer:
Heater
Rotors
CARBON BLACK ADSORPTION TEST:
DPB solution is used.
Adsorption rate of Carbon Black is checked after specific internal
of time.
Petroleum Distillation:
This test is done for Neptha.
Process is similar as Fractionl distillation (obtaining of materials at
their boiling points).
Condensation of Product is done to obtain Neptha in liquid form.
Density Test (Specific Gravity Test):
Density is compared to water.
Distilled water is used
Other tests performed in General Tyre are:
Extraction Test
Automatic Hardness Test
Abrasion Test
65. General Testing Section:
Equipments used in control lab section are used to test the raw material. Test
performed are Mechanical, Chemical and Physical properties of the raw
material beforeuse.
Instruments Used For Testing:
Instron (used to test the strength of material for example nylon)
Adsorption (used to test the carbon’s iodine number and pore density)
Twist counter (used to test at paricular distance how many twist are
there)
Monosorb (used to test chemical surfacearea)
Wallace Rapid Pastimeter (used to test the plasticity of the natural
rubber)
Absometer (used to test Carbon grade)
PRI (Plasticity retention index)
Product Industrialization Department:
This department has its own value because the machine repairing ,operating ,
mould designing and then tyre designs, sizes areall under their considerations.
We visited this department under the supervision of Mr. Shaheer, Mr. Ayub,
Mr. Umair.
66. Functions of PID:
Mould and Equipment design.
Productdesigning & development.
Departments:
Repairshop:
All the machine parts are repaired.
Die Shop:
General tyre is making their own dies.
Drawing:
This depart draws themechanism of a tyreaccording to its Drive, Flexibility
and one very important factor which is its Comfort.
Specification:
This department gives specification about the mechanismor procedure
which should be applied to get desired result.
Tyre Nomenclature:
67. Compounding Department:
Compounding department has a widerole in GTR starting fromprocurement
to curing department and all the departments that are in contact with the
product.
In Compounding department Mr. Khalid Khan, Mr. Aziz Ur Rehman and Mr.
Moiz Sarwar benefited us with their knowledgeand experience and guided us
about various functions of this department.
Operations Of Compounding:
Compounding department covers a large area which starstfromprocurement
to ware house, then to mixing & then it further goes to material testing lab,
then to 4/3 roll calendaring, then to Dual/ Triplex Extruders and then to curing
department. Because the products that are made from the recipes given by
them arecirculated in all these departments and how to process, temperature
and then they apply check and balance on them. Compounding department
makes recipes for the tyres and then forwards itto a specified department.
There are two types of recipes:
68. Theoretical Recipe (PHR).
Plant Recipe (Kgs).
Ingredients PHR Plant Recipe (kg)
Natural Rubber 80.0 57.31
BR 20.0 14.33
Plasticizer 12.0 8.59
Antioxidant 1.5 1.07
Antiozonant 1.5 1.07
Carbon Black 60.0 42.98
Stearic Acid 2.0 1.43
Zinc Oxide 3.0 2.15
Sulfonamide 1.2 0.86
Sulphur 1.8 1.29
TOTAL 183.0 131.1
Things We Appreciate Of General Tyre
& Rubber Company:
Healthy environment inside company
premises. Workers avoid any kind of drug
usage/Smoking.
Staffs are very co-operative.
Employees are highly talented and
professional regarding to their work.
Security measures are taken efficiently and
Cameras are installed in company premises.
Daily meetings are conducted to discuss any
problems regarding product or machinery.
69. Medical and Transport facilities provided to
staff.
General Tyre doesn’t approve any sort of
defected product in the market no matter
how much loss they have to bare.
General Tyre really appreciates their
customer and tries to fulfil their
requirements efficiently.
Suggestions:
Automatic machines should be used instead of Manual machines to
reduce errors and defects.
Safety measures should be taken in mixing department due to spreading
of Toxic gases and Carbon black e.g. Masks, Gloves and workers should
wear full sleeves clothes to avoid contact. Strictness should be implied
for it.
More Ventilation systems should beinstalled in Curing Department to
control the excessive heat.
Lectures should be conducted for workers to create awareness about
their work so that they can work moreeffectively.
R & D department should be developed so General Tyre can produce
their own standards or specifications.
Latest designing softwareshould beprovided to PID so the work can be
done more efficiently and saveprecious time.
70. Safety vehicles should be on standby in the premises of General Tyre to
counter any kind of harmful situation immediately.
Sometimes it is observed in Curing department that machine is free due
to unavailability of Green tyres. Steps should be taken for this so that
time should not be wasted and required production target can be
achieved.
Too much scrap is generated; it should be re-
71.
72. used by company itself through De Vulcanisation process.
