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S.NO CONTENTS Page

#1 Introduction 12 Tire 23 Manufacturing process 34 Production planning and control 95 Industrial engineering

department11

6 Product industrialization department

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7 Mixing 178 Dual extruder 189 Triplex extruder 1910 4 roll calendar 2011 3 roll calendar 2212 Bead and band building 2313 Tire building 2514 Radial tire building 2715 Bias tire building 3016 Mechanical maintenance 3117 Curing 3318 Final finish 3519 Finish good ware house 3620 Product evaluation 3721 Sales 3922 Conclusion 39

1. INTRODUCTION:We the students of NED university of engineering and technology

(Industrial and manufacturing department) visited General Tire and Rubber company for internship program from date 2-dec-2009 to 31-dec-2009.

In the company we had visited many sections and areas according to the schedule provided by IE department. The following pages consists our report about the company.

INTERNEES: RASHID MUNIR RAO ABDUL SABOOR TALHA AHMED

1. ABOUT GTR:The General Tire 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 production since 1964.

Gentipak has a Technical Services Agreement (TSA) with CONTINENTAL AG (Germany’s largest tire manufacturer) which enable it to produce tires of “GENERAL” brand and also receive the latest technology for production of tires based on Continental’s, R&D.

The Plant and the Offices are located in suburb of Karachi. Initial production capacity was only 120,000 tires per annum but is now around 2,000,000 tires per annum. It has been constantly upgraded and boasts the latest equipment in tire manufacturing.

COMPANY PRODUCTS: Passenger car tires Light truck tires Truck / Bus tires Tractor tires Tubes

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2. TIRE:WHAT IS TIRE?

Tire is a Dressing of wheel. As far as manufacturing is considered it is the assembly of different components, build up on drum. Later is cured in a press under heat and pressure.

2.1. COMPONENTS USED IN TIRE ASSEMBLY:

Tread

Side wall

Belts

Body ply

Inner liner

Beads

Inner liner: Extruded rubber sheet with low air permeability.(alternate for the tube)

Body ply: Calendared sheet of rubber and reinforcement (fabric).

Tread: Thick extruded profile that comes into contact with the road.

Side wall: Non reinforced extruded component with antioxidants.

Beads: Bands of high tensile strength steel, encased with rubber.

Belt: Calendared sheet of rubber and closely spaced steel cords.

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Cushion gum: Thin sheet of rubber. Applied on the inside of the tread.

3. MANUFACTURING OF TIRE:

Five steps involved in the manufacturing of a tire.

Compounding and Mixing Component preparation Building Curing Final finish

3.1. Materials used:

Rubber (Natural and synthetic)38%

Fillers (Carbon black, silica, carbon chalk)30%

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Reinforcing materials (steel, rayon, nylon)16%

Plasticizers (oils and resins)10%

Chemicals for vulcanization (sulphur, zinc oxide, various chemicals)

4%

Chemicals as antioxidants to counter ozone effects and material fatigue

1%

Miscellaneous 1%

3.2. Compounding and Mixing:

Operation of bringing together all ingredients required for mixing a batch of rubber component. Then applying mechanical work to the ingredients in order to blend them into a homogeneous substance.

Internal mixer is used consisting of two counter rotating rotors. Heat is generated, cooled by water so that vulcanization should not begin.

In the first step the compounds are brought together and mixed in the internal mixer. Each mix is then milled with additional heating to soften the batch and mix the chemicals forming the master compound. In a third step, the master batch goes through a mixer again, where additional chemicals

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are added to form what is known as the final mix. During all three steps of mixing, heat and friction are applied to the batch to soften the rubber and evenly distribute the chemicals. The chemical composition of each batch depends on the tire part—certain rubber formulations are used for the body, other formulas for the beads, and others for the tread.

3.3. Component preparation:Component preparation involves

Extrusion Calendaring Bead building

3.3.1. Extrusion:

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Extrusion applies heat and pressure to the compound. In the extruder, the batch is further mixed and heated and is then forced out through a die—a shaped orifice—to form a layer of rubber. This is then cut into lengths automatically by a cutter run by PLC. The cut lengths are loaded into large, flat metal cases called books. Two components are extruded

Tread Side wall

3.3.2. Calendaring:

Calendar is a set of large diameter rolls that squeeze rubber compound into a thin sheet. Fabric calendar produce an upper and lower rubber sheet with a layer of fabric in between. Calendar used to produce.

Body plies Belts

3.3.3. Bead building:

Bands of high tensile strength steel encased with rubber cut in circumferential manner on a machine. It provides mechanical strength to fit tire into the rim. For the beads of a tire, wire bundles are formed on a wire

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wrapping machine. The bundles are then formed into rings, and the rings are covered with rubber.

3.4. Tire Assembly:

It involves assembling all the components onto a tire building drum. Tire building machines can be fully automatic or manual. Final product of tire building machine is green tire (uncured state).

3.5. Curing:

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Green tire obtained from tire building machines is then cured in a press. The tire is applied heat and pressure by means of a bladder which is filled with steam or hot water. Vulcanization takes place and all the components are bonded with each other. The imprints on the mold in which the tire is pressed are obtained on the tire.

3.6. Final finish:

After the tire has been cured, there are several additional operations such as trimming and bulge testing etc. Tire uniformity measurement is a test where the tire is automatically mounted on wheel halves, inflated, run against a simulated road surface, and measured for force variation. Tire balance measurement is a test where the tire is automatically placed on wheel halves, rotated at a high speed and measured for imbalance.

Large commercial truck/bus tires, as well as some passenger and light truck tires, are inspected by X-ray machines that can penetrate the rubber to analyze the steel cord structure.

In the final step, tires are inspected by human eyes for numerous visual defects such as incomplete mold fill, exposed cords, blisters, blemishes, and others.

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4. PRODUCTION PLANNING AND CONTROL DEPARTMENT:4.1. Working:

The working of production planning and control starts with the sales forecast by the sales department. In which the demand of tires has been elaborated. The PPC department keeping in view of that forecast and the production capability of the floor plans the production, which is further transformed into daily schedules to be sent to different sections and areas of the company.

Functions:

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4.2. Demand Planning:

Taking in account the forecast of marketing department, production time, capacity and labour is estimated for the production. Demand can be from

OEM (original equipment manufacturer) Replacement

4.3. Schedule:

Pre formulated timings of every machine operation, labour, setup time and department to department transportation time, a schedule is made in backward integration manner (reverse procedure of production).

For a particular department it is partitioned and forwarded to that department. Any reasons for late arrival of components alternatives are planned.

4.4. Material and labour reporting:

This involves data linking between different departments of production and PPC department. Material and labour is reported every day. Time utilized for the production is also reported.

4.5. Material requirement:10

PRODUCTION PLANNING AND CONTROL DEPARTMENT

DEMAND PLANNING SCHEDULE

MATERIAL AND LABOUR REPORTING

MATERIAL REQUIREMEN

T

CAPACITY AND REQUIREMENT

PLANNING

PROCESS PRIORITY

Material is ordered according to the demand or the forecast from the marketing department three or four months before the production. This is helped out by the quarterly forecasts. Depends upon the type and quantity of tire allowance is provided.

4.6. Capacity and requirement planning:Negotiations are made between the capacity of the plant and

requirement of dealer. Inventory is not raised in warehouse .out sourcing if required is also managed.

4.7. Process priority:Raw material shortage or machine downtime causes low productivity

then according to the priority process are made.

Priority refers to the demand and the relation with the customer and the profit of the process.

5. INDUSTRIAL ENGINEERING DEPARTMENT:INDUSTRIAL ENGINEERING department concerns with

Design Improvement of system of man, machine, material and

money. Installation

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5.1. Functions:

5.2. Work study: Work measurement Methods study

5.2.1. Work measurement:

Production planning and control department’s reports are based on the time study provided by the IE department.

Work measurement includes

Time study P. M. T. S. Synthesis Aid to control Activity sampling Comparative and analytical

5.2.2. Method study: Method study includes higher productivity

Problem solving Imported systems Plant layout Aid to improve Material handling productivity Value analysis

5.3. Job Analysis:Systematic process of collecting information about jobs. Including

purpose of each job, duties, place, organizational hierarchy, and its working condition and employee requirement.

Components of job analysis.

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IE DEPTT.

FEASIBILTY STUDY

WORK STUDY

JOB ANALYSIS

INCENTIVE SCHEME

MATERIAL HANDLING

PLANT LAYOUT

SYSTEM ENGINNERING

MANPOWER PLANNING

Positional description Job standards Job description

5.4. Job Evaluation:Job evaluation includes wage, authority, responsibility and promotion.

This must be in parity with other companies.

Components of job evaluation.

Job ranking Job grading Factor comparison Point system

5.5. Material Handling:This includes the following factors regarding material.

Movement Time Quality Safety

Good material handling outputs.

Increased productivity Increased production capacity Reduced fatigue and easy work Clean shop-floor, enabling smooth and efficient functions of the

factory Less wastage, spoilage and damages

5.6. System engineering:Process of developing large scale complex man machine systems

within cost, performance and time. Man power required on a machine is estimated according to the running of the machine and then it is provided to the department.

5.7. Plant layout:

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Arrangement and location of different departments and machineries.

Good plant layout effects

Reduced effort of labour Reduced number of handling Provides better working condition Minimizes accidents Reduces number of workers Minimizes lost motion between operators Minimizes maintenance and tool replacement costs Effective cost control Eases the burden of supervision

5.8. Manpower planning:Right quantity of right men at right time on the right job.

This includes

Making correct estimate of man power requirements Managing the manpower Guide in recruitment and selection Maintain correct production level Reduce manpower cost

5.9. Incentive scheme:System which motivates the worker to increase the production. This

includes monthly bonus or good work reward.

The incentive scheme currently running in GTR must be reviewed and must be provided to all the workers on the same criteria so that every body will be motivated for work.

6. PRODUCT INDUSTRIALIZATION DEPARTMENT:

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6.1. Design and development:This includes two main things in GTR.

Die shop Repair shop

6.2. Product engineering:This includes construction check of two types

Radial Bias

6.3. Action plan:Action plan includes several steps

1. Design input: study existing ,PR check, study competitor2. Design output: drawing development, modification, finalization3. Design review: review final drawing, prepare development

sheets4. Mold manufacturing: raise PR to procurement, vendor forwarded

tread pattern5. Mold inspection: mold inspection to be carried out at vendor’s

premises6. Product development: building specs, cured tire analysis7. Validation and verification: indoor testing, outdoor testing8. Control of design development changes: changes needed are

made9. Release new product: new product is marketed

6.4. Molds:15

PI

DESIGN AND DEVELOPMENT PRODUCT ENGINEERING

The mold in the curing press is the cavity in which tire is cooked and is given the final shape. The mold has the embossed imprints of the tread pattern and the codes printed on the sidewall of the tire. The two basic types of mold used are

Segmented molds Two parts mold

6.4.1. SEGMENTED MOLD:

These molds are divided into segments in the circumferential projection of the tire. The number of segments can be 6 or more depending on the size of the tire. The engravements of sidewall are on a separate part.

6.4.2. TWO PARTS MOLD:

These molds are divided into two parts along the centre line of tread. The engravements are on both the parts of the mold.

6.4.3. MARKINGS ON THE SIDEWALL:16

7. MIXING:7.1. Purpose:

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To bring together all the ingredients required to mix a batch of rubber component and then applying mechanical work in order to blend them into a homogeneous substance in the form of sheets.

7.2. Equipments:Two banburys. Each with two sheeter mills and a cooling line.

7.3. Banbury:A banbury is an internal mixer consisting of two counter rotating

rotors in a sealed housing.

The construction of banbury includes two motors. One associated with

the rotors and the other controls the hydraulic system for closing and opening of doors.

All the raw materials for a particular tire are weighed and then automatically dropped in the banbury by the conveyor operated by the software. The banbury mixes the compounds and then the batch is dropped over the sheeter mill which transforms it into sheets.

For a particular tire compound batch is mixed two times in different banburies. The final product of mixing is called finish which is tested in a laboratory and if the composition is found ok then this is sent to component building. And if the batch is not according to the specification it is reused in mixing. Hence no scrap from mixing department. A schedule and a specification chart from PPC and compounding department respectively are received by the mixing department according to which the batch is prepared. This batch is now raw material for the component building department.

COMPONENT BUILDING18

8. DUAL EXTRUDER:8.1. Purpose:

To form tread (component of tire which comes in contact with the road surface) and sidewall (bridges between tread and bead) of truck, tractor and passenger Bias tires.

8.2. Construction and working:Two large diameter screws in a sealed housing having individual feed

area. Driven by a single motor. Rpm of screw and line speed adjustable by panel. Die inserting, a cooling line followed by a conveyor and a cutter run by a separate motor and having a separate cooling system

Both the screws push the rubber compound (wing tip and cap area compounds) towards a single die having the cavity of the size of tread or sidewall to be extruded. Cushion gum if required is applied separately after extrusion from the die. The extruded component is then sent to the cooling line and after cooling it is sent towards cutting where according to the size it is cut by automatically running cutter.

Dual extruder is hot feed that’s why two mills are installed separately for making the feed warm and soft.

A specification chart from product industrialization department and a schedule from production planning and control department respectively is received by the operator according to which extrusion of rubber is carried out.

Die is provided by the die shop running under the supervision of product industrialization department.

8.3. Maintenance:Maintenance is done by maintenance department. Predicted,

prevented, and scheduled. Lubrication is manual.

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9. TRIPLEX EXTRUDER:9.1. Purpose:

To form tread (component of tire which comes in contact with the road surface) and sidewall (bridges between tread and bead) of radial tires.

9.2. Construction and working:Three screws of diameters 90mm, 200mm and 150mm in a sealed

housing having individual feed area. Housing is fitted with small pins to blend the rubber properly. Multiple dies can be installed at the same time. Cushion gum if required is applied separately and also an option in the extruder itself. Cooling line is provided so that the rubber shrinks before it is cut into size.

Triplex extruder is cold feed that’s why no separate machinery is required as in dual extruder to warm up the feed. A cutter is provided at the end of the shrinkage conveyor for cutting the tread and the sidewalls into sizes which runs according to the recipe fed in the PLC.

Line speed of the shrinkage conveyor is adjustable and the variation in line speed is automatically induced in the rpm of the screws so as to compensate if material shortage occurs at die.

Triplex extruder is designed on the phenomenon of safety first that’s why multiple safety switches and sensors are installed for this purpose. Three metal sensors are installed at the individual feed insert so that no metal can get inside the housing of the screws and cause wear to them.

A specification chart from product industrialization department and a schedule from the department of production planning and control is received by the operator for the production. Triplex extruder runs only in one shift as it produces the requirement of the other departments in it.

9.3. Maintenance:Triplex extruder is maintenance free.

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10. 4 ROLL CALENDAR:A machine for calendaring the fabric with rubber sheets on both sides.

The machine consists of four large diameter rollers for the operation.

10.1. Produce:4 roll calendar produces calendared sheet of rubber with fabric inside

known as ply. Used both in radial tires and bias tires. Before 4 roll calendar was installed in the company this operation was done on 3 roll calendar which utilized more time because it was done in two stages.

10.2. Working:Four mills of large diameter prepare rubber feed for the calendar.

Break down mill Warm up mill Feeding mill Holding mill

The feed of fabric is given directly to the rollers of the 4 roll calendar. The banana roll calendars the sheet which is then sent to the cooling drum. And then wind up unit in which rolls are prepared of the calendared sheet for easy utilization and storage.

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For radial tire ply another operation is induced in this machine in which ply cords are pressed in the sheet. A separate calendar is installed for this purpose.

A specification chart from the product industrialization department and a schedule from the PPC. Department is received by the operator according to which production is carried out.

10.3. Maintenance:The maintenance of 4 roll calendar is carried out during production as

manual lubrication reducing metal to metal contact. Small troubleshooting is carried out by the mechanic during the working.

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11. 3 ROLL CALENDAR:A machine for calendaring in which 3 rolls of large diameters are used

fro the operation.

11.1. Produce:

3 roll calendar produces

Inner liner for radial tire Squeegee

11.2. Working:

Finish compound is fed to the separately installed mill CM-1 which warms up the compound, this warmed compound is then fed to CM-2 which further mills the compound and from the same mill it is cut into short width sheet and fed to upper two rollers of the three roll calendar. Which forms sheet of larger width whose thickness and width is reduced by the lower two cutters and rollers respectively according to the requirement. The clearance between the rollers is adjustable.

The final sheet from the three roll calendar is passed through two mills sustaining tension in the sheet and is further put upon the conveyor on which manually it is transformed in the forms of rolls packed with cloth.

A specification chart from product industrialization department and a schedule from the PPC. department is received by the operator according to which production is carried out.

Due to manual stock preparation manpower utilization is more.

11.3. Maintenance:As 3 roll calendar is as old that’s why it requires more maintenance

than the 4 roll calendar. Manual lubrication is done daily.

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12. BEAD and BAND BUILDING12.1. Bead:

Part of tire which comes in contact with the rim.

Bands of high tensile strength steel Encased with rubber Coated with special alloys bronze or brass to prevent corrosion Copper in the alloy improves bonding of bead to rubber

It provides mechanical strength to fit tire in the wheel.

12.2. Equipments:Two machines for bead preparation.

12.3. Building:Spools of steel wires are placed over pulleys which can rotate on the

application of tensile force on the wires. A machine pulls at the same time all the wires from the coils and an extruder coats rubber on the wires then automatically it is cut into a circular band of required size by a machine. Further more if required filler is attached too.

The production of bead building in GTR does not fulfill its requirement from other departments. Many of the tires building machines were found down due to the shortage of beads.

12.4. Band:Band is a set of plies utilized in tire building. Plies are cut according to

the circumferential size of tire and at an angle then are build up on the

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machine so that the time for bias tire building is lessened. The plies are build at opposite angles forming criss cross pattern.

12.5. Building It is built according to the ply rating of the tire. Distinguished in two

types of building.

Tractor Truck

12.5.1. TRACTOR:

In tractor band building usually drum squeegee is used. That’s why a different type of machine is used.

12.5.2. TRUCK:

In truck band building no drum squeegee is used. And the plies are built according to the ply rating of the tire.

The bands are then sent to the bias tire building department. Where they are utilized in the tire building.

Band building in the company does not fulfill the requirement from the other departments. More machines are required to be installed.

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13. TIRE BUILDING Since the recent development in the tire industry a new type of tire has come into notice known as RADIAL tire and the former came to be known as BIAS tire. Due to the difference in the construction of both types the tire building is split into two departments one for RADIAL and other for BIAS.

13.1. RADIAL TIRE:It is a type of construction of tire in which ply cords extending from

beads are at right angle to the centre line of tread and parallel to each other.

13.1.1. ADVANTAGES:

Longer life Better steering control Lower rolling resistance Better grip at higher speeds

13.1.2. DISADVANTAGES:

Harder ride At low speed on rough road Decreased self cleaning Lower grip at low speeds

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13.2. BIAS TIRE:

A type of construction of tire in which ply cords extending from bead to bead are at an angle lying between 30 to 40 degrees. Successive plies at opposing angles are laid over each other to form a crisscross pattern to which the tread is applied.

13.2.1. ADVANTAGES:

Flexibility in the tire Smooth ride on rough surface

13.2.2. DISADVANTAGES:

Increased rolling resistance Less control Less traction on high speed

13.3. Green tire testing:If any defect is found in the green tire then the material can be

reused hence no scrap. But If the tire is cured then any defect comes out, the material gets scrap. There are much many defects that are because of improper building. Some of them can be pointed out by visual inspection but there are many which cannot be pointed out for example the uniformity of tire.

If the green tire is tested for any defect in it then the scrap of company can be reduced. There is a system which can monitor the green tire developed by BYTEWISE. Known as green tire monitoring system.

www.bytewise.com

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14. RADIAL TIRE BUILDING DEPARTMENT14.1. PRODUCE:

Green tires of radial construction in which all the components from component building department are assembled together.

14.2. Radial tire building:Green tire of radial construction is build up in two stages. In first stage

a carcass is built in which

Inner liner Ply-1 Bead Chafer (if required) Side wall

Are assembled on the tire building drum.

In second stage

Belt -1 Belt-2 Cap ply Tread

Are assembled over the carcass formed in first stage .the final product after second stage is green tire and it is ready for curing.

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14.3. Tire building machines:

Tire building machines (TBMs) are machines over which tire components are assembled over a drum to produce green tire.

Radial Tire building department utilizes two different types of TBM machines. One for the first stage building and other for second stage building.

This is because a radial tire has steel belts which require actual shape of tire to get assembled. The steel belts in radial tire consist of thin closely spaced steel cords calendared with rubber. And then cut in angle to increase the individual length of each cord. Finally two belts are applied at different angles to form criss cross pattern.

The main components of first stage machine are

Drum Bead applier Turn up assembly

And the main components of second stage machines are

Belt and tread drum Transfer ring Expander

The TBM machines in GTR, Radial tire building department are automatic. Controlled by PLC (program logistic control). Recipes are already fed in the

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machines by product industrialization department. An operator and a helper over a single machine are required for production. Around two and a half minutes required for a single tire to be built in both stages. This gives the production of above 200 green tires depending upon the size of tire.

Due to the different downtimes for example no material, machine fault the production schedule badly suffers. And if no down time is there on the machine then schedule is achieved and a possibility for over scheduled production due to the incentive scheme proposed by the industrial engineering department.

14.4. Downtimes:

On the day of orientation to the department three machines were found down due to the shortage of material. Machine PB-16, PB-17 and PB-15 were running short of the sidewalls of the tire they were building. Triplex extruder responsible for the production of these sidewalls had produced the sidewalls of that particular tire according to the schedule by the PPC department one day back.

Another case of shortage of tread was noticed on the machine PR-2 .production was badly suffered because of the shortage. Triplex extruder was again referred for the production check of last day and it was found that the production was achieved according to the schedule by the PPC department.

A specification chart from product industrialization department and a schedule from the department of production planning and control are received by the operator for the production of tires.

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15. BIAS TIRE BUILDING

15.1. PRODUCE:

Green tires of bias construction ready to be cured.

15.2. BIAS TIRE BUILDING:

Green tire of bias construction is assembled over a tire building drum in a single stage. That’s why only one machine is required for the assembly. The following components are assembled.

Inner liner Band Beads Chaffer Tread

15.3. Tire building machines:

Tire building machines for bias tires are different from that of radial tire building, as all the components are installed in a single stage and upon a single machine. The main components of bias tire building machine are.

Drum Bead applicator Back tool assembly

6 six tire building machines for truck tire building. The machine fault frequency is increased and no material condition in the department is also much more.

On the day of visit to the department production log book and the schedule from production planning and control department was checked out and there was a lot of difference in the number of tires to be produced and the number of tires produced without any downtime. The reason which was given was that the time study by IE department is of the rating 120 and the

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worker operates at the rating of around 90. Another reason which was given was that different allowances like prayer and bathing are not given in the time study but are necessary for the worker to perform are not provided in the time study.

16. MECHANICAL MAINTENANCE

16.1. Purpose:

To prevent hazards, to maintain production and troubleshoot the machines.

16.2. Working:

On floor maintenance Maintenance planning

Every time a machine is being maintained as lubrication is provided to reduce metal to metal contact between the moving parts.

16.2.1. PREVENTED MAINTENACE:

Maintenance carried out before any hazard or maintenance to prevent hazard is called prevented maintenance. For prevented maintenance history of a machine is prepared according to which a yearly plan for maintenance is prepared acting upon which maintenance is carried out.

16.2.2. PREDICTED MAINTENANCE:

Maintenance which is carried out on prediction of technician is called predicted maintenance. A technician is assigned to the machine whose work is to troubleshoot any smaller problems and if he finds any sign for a big problem he calls for maintenance in which the particular area which was found to be causing problem is maintained, in another case the operator raises the work order for any problem he finds out in the machine, which is received by the maintenance planning department. Then if PPC

department allows, downtime for maintenance is given to that machine.

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Any spare part work is done in the workshop in GTR. And if not possible then outsourcing is done according to the case. Some times foreign countries are also referred.

16.3. Work shop:

In GTR a work shop is managed in which small and easily manufacturable parts are fabricated. The main equipments are lathe machines, milling machines and drilling machines etc. Easily repairable parts are repaired in the workshop and reused.

16.4. Tool shop:

In GTR a tool shop is managed which provides almost all the tools required for maintaining any machine in GTR. Tools are provided to any mechanic from GTR on loan basis. Mechanic after use returns it back to the tool shop.

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Investigation Plan Action

17. CURING:

17.1. Produce:

The curing is where tires get their final shape and tread pattern. Hot molds like giant waffle irons shape and vulcanize the tire. The molds are engraved with the tread pattern, the sidewall markings of the manufacturer and those required by law.

17.2. Equipments:

Curing machines commonly known as Press. These machines are installed with the particular size of mold in which tire is cooked by means of heat and pressure which is in the form steam or hot water depending on the type of machine being used.

17.3. Curing machine:

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A green tire is placed inside a large mold for the curing process. A tire mold is shaped like a monstrous metal clam which opens to reveal a large, flexible balloon called a bladder. The green tire is placed over the bladder and, as the clamshell mold closes, the bladder fills with steam and expands to shape the tire and force the blank tread rubber against the raised interior of the mold.

During this curing process, the steam heats the green tire up to 280 degrees. Time in the mold depends on the characteristics desired in the tire.

17.4. Bladder:

The bladder is the flexible rubber that is filled with steam or hot water when tire is being cured. The bladder is attached to the inside of the mold.

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The failure of bladder can cause the tire to become scrap. The common failure of bladder is the leakage. A single bladder lasts for 200 curing.

In GTR there are 139 cavities capable of producing 6000 tires a day. But the production a day is around 5300 tires.

17.5. Maintenance:

The maintenance of curing machines is assigned to the instrumentation department inside area 3. The downtime frequency due to machine fault is more which can be reduced by prevented maintenance during the downtime for no material condition.

The cured tires are then sent or received by the final finish department.

18. FINAL FINISH:

Each tire is thoroughly inspected for flaws such as bubbles or voids in the rubber of the tread, sidewall, and interior of the tire. Then the trimming of the vent rubber is done then again the inspection is carried out in which more closely a tire is inspected. Bulge test is also done. If anything is wrong with the tire – if anything even seems to be wrong with the tire, even the slightest blemish – it is rejected. Some flaws are caught by an inspector's trained eyes and hands; others are found by specialized machines.

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18.1. Bulge test:

Every tire is mounted on the rim and is inflated with an air pressure of 40 psi. Then if any penetration of air is found in the tire it is rejected. This can be checked by any bubble appearing in the tire after it is inflated.

Most of the defects in the tires are due to improper building of the tire.

Tires that qualify from all the inspections are sent to product evaluation department.

19. FINISH GOOD WARE HOUSE:The products that are qualified from all the tests are sent to finish

good ware house for the shipment to the dealers or OEMs. The delivery of tires from finish good ware house is done by the invoice which comes from the sales department. The storage and handling tires is done manually or by the cranes which can handle a batch of products.

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The art of handling the goods in the ware house is a great job. Accommodating more and more goods in a proper manner in a small area requires skills of handling. Easy withdrawal of goods at the time of shipment is made possible.

20. PRODUCT EVALUATION DEPARTMENT:

20.1. Purpose:

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To check the performance of the tire and evaluate it according to the specifications provided by the product industrialization department.

20.2. Working:

Quality control begins with the suppliers of the raw materials. Today, a tire manufacturer seeks suppliers who test the raw materials before they are delivered to the tire plant. A manufacturer will often enter into special purchasing agreements with a few suppliers who provide detailed certification of the properties and composition of the raw materials. To insure the certification of suppliers, tire company chemists make random tests of the raw materials as they are delivered.

Throughout the batch mixing process, samples of the rubber are drawn and tested to confirm different properties such as tensile strength and density. Each tire assembler is responsible for the tire components used. Code numbers and a comprehensive computer record-keeping system allow plant managers to trace batches of rubber and specific tire components.

When a new tire design is being manufactured for the first time, hundreds of tires are taken from the end of the assembly line for destructive testing. Some of the tires, for example, are sliced open to check for air pockets between body plies, while others are pressed down on metal studs to determine puncture resistance. Still other tires are spun rapidly and forced down onto metal drums to test mileage and other performance characteristics.

A variety of nondestructive evaluation techniques are also used in tire quality control. X-ray videography provides a quick and revealing view through a tire. In an X-ray tire test, a tire is selected at random and taken to a radiation booth where it is bombarded with X-rays. A test technician views the X-ray image on a video screen, where tire defects are easily spotted. If a defect shows up, manufacturing engineers review the specific steps of tire component assembly to determine how the flaw was formed.

In addition to internal testing, feedback from consumers and tire dealers is also correlated with the manufacturing process to identify process improvements.

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20.2.1. Tire uniformity machines:

A tire when enters or exits the foot print it deforms, rubber is compressed during this cycle due to which some forces are imparted on the vehicle which depends upon the uniformity of tire. The uniformity of tire is characterized by the three forces

Radial force variation Lateral force variation Tangential force variation

These forces are measured by the tire uniformity machine which provides the exact value of the forces which are imparted. The machine has a rim in which the tire is mounted and inflated with the air. Then it is run on the pulley whose circumferential area is as like that of road. The sensors installed in the machine check the performance of the tire and display I ton the computer.

The high point (a point at where the weight of tire is more) is also marked with a colored spot which helps the tire consumers to balance the tire.

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21. SALES:

21.1. Purpose:

To sell the products of industry. And to reveal and forecast the demand of product in the replacement market.

21.2. Working:

The sales department receives the demand from the dealers all over the country. GTR has 120 dealers all over the country divided in 8 zones. Additionally surveys are done. Keeping in view the total number of vehicles running on the roads of Pakistan a replacement factor is calculated according to the formula

Replacement factor= Number of tires in the vehicle

Years of service

By the replacement factor the demand from all over the country is optimized and forwarded to the PRODUCTION PLANNING AND CONTROL department.

22. CONCLUSION:Our visit to the company was very helpful. All the personals we were

referred to were very cooperative. We learned a lot by them and their experience.

Special thanks to the INDUSTRIAL ENGINEERING department and specially Mr. Tahir Hussain who guided us a lot about the company and regarding our field.

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