Process Study of Tyre Industry

CONTENTS 1.

INTRODUCTION

01

2.

PROCESS STUDY OF THE ORGANISATION

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a. Mixing

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b. Calendaring c. Extrusion d. Bead Preparation e. Tyre Building Process f. Curing (Vulcanization) g. Post Cure Inflation h. Trimming i. Final Inspection

3.

AIM AND SCOPE OF PRESENT WORK

36

4.

METHODOLOGY

37

5.

CONCLUSION

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6. REFERENCE

40

Industrial training at JK Tyres CHAPTER-1 JK TYRE INDUSTRY COMPANY PROFILE JK Tyre and Industries is a mega corporate entity that is emblematic of excellence, diversification and pioneering new technologies. A part of JK Organization which ranks among the top private groups private groups in India, JK Tyre and Industries is committed to self reliance and follows an ethic that views customer satisfaction as an index of achievement. Over the years, the company has expanded and diversified its business portfolio. It has developed into a multi product, multi-location corporate entity comprising of following business divisions. Ever since its inception it has been JK Tyre's belief in the value of technological superiority that has made it grow by leaps and bounds. This division produces and sells tyres and tubes under the brand name "JK Tyre" for Truck, Buses, Passenger Cars, Jeeps, Light Commercial Vehicles, Multi Utility Vehicles and Tractors. The company pioneered Steel Radial Technology in India in 1977 and continues to be the industry leader in the Radial segment in India. JK Tyre is the only Tyre Manufacturer in the country to produce high performance 'T' & 'H' -rated steel radial tyres. JK Tyre has consciously followed a policy of continuously modernizing and expanding its tyre manufacturing facilities to retain its edge in the market place. Our customer base covers virtually the entire Original Equipment Manufacturers (OEMs) in India together with Replacement Market for four wheeler vehicles, Defence and State Transport Units. Besides India, we have a worldwide 1

Industrial training at JK Tyres customer base in over 45 countries across all 6 continents. To keep pace with the market demand as well as technological leadership in Indian market, J.K. Industries acquired Vikrant Tyres Limited, Mysore in 1997. J.K. Industries and Vikrant Tyres Limited are the only tyre companies in India to have received all three ISO 9001, QS 9000 and ISO 14001 certificates. This indeed is a true reflection of our commitment to system oriented approach. The company has a technical collaboration with M/s Continental AG, Germany, which is among the top five tyre manufacturers in the world to keep pace with latest technological developments. To stay at the forefront of technological advancements a state of art Research & Development Centre, HASETRI, was set up, which remains the nerve centre for providing cutting edge technology. In a short span of time it has emerged as the 17th largest tyre manufacturer in the world an achievement in itself. With three plants located in Rajasthan, Madhya Pradesh and Karnataka, JK Tyre is the largest manufacturer of truck and bus tyres in India. The truck and bus tyres produced account for nearly 74% of the total tyre business in India, thus giving JK Tyre an undisputed position. Additionally, JK Tyre is the only manufacturer of truck/ bus steel radial tyres, and the second largest manufacturer of 4-wheeler tyres in the country. Also, JK Tyre is the largest exported tyre brand from India. It was awarded the CAPEXIL's Highest Export Award for 1997-97 by FIEO. It enjoys preferred premium brand status in Truck Bias market in USA and across many markets in Africa, Middle East and South East Asia.

2 Industrial training at JK Tyres QUALITY POLICY OF JK TYRE INDUSTRY We the people of JK Tyre will have an organization committed to quality in everything we do. We will continuously anticipate and understand our customer's requirements, convert these into performance standards for our products and services and meet these standards every time. Full customer satisfaction - both internal and external is our motto. Quality Management ISO 9001 JK Tyre world's first tyre company to receive 'ISO 9001' certification for its entire operations in 1995 in one go. Our Quality Management System is completely integrated into all aspects of our operations. QS 9000 JK Tyre the world's first tyre company to receive Quality Management System certification QS 9000', in 1998 for multi location operations. We are using 'QS 9000' system as a tool for continuous incremental improvement. Environment Management System (ISO 14001) JK Tyre recognizes the impact that our business has on the environment and take our responsibilities for maintaining harmony with nature. We are the first tyre company in India to receive 'ISO 14001' certification for multi location operations in 1999. 3

Industrial training at JK Tyres "E-mark" JK Tyre is the only Tyre Company in India having the E-mark certification on their products, a mandatory requirement for exporting tyres to European Markets. "DOT" (Department of Transport) JK Tyre have the DOT certification on its products, a mandatory requirement for exporting tyres to US Market. "INMETRO" (Instituto Nacional De Materiologia - Brazil) We also have the certification from INMETRO a mandatory requirement for exporting tyres to Brazil (South America). This is a product as well as a system certification. Also this is a proof of superior quality of JK Tyre and our ability to meet stringent international standards. DEFINTION OF TYRE: A Tyre is a most essential component of a vehicle. Depending on the various factors several definitions may be attributed for the Tyre. Geometrically --- A Tyre is a Torus. Mechanically --- A Tyre is a flexible membrane pressure composite. Structurally ----- A Tyre is a high performance composite. Chemically------ A Tyre consist of materials composed of long chain macro molecules. A TECHNICAL DEFINTION: A Tyre is a Toroidal- shaped inflatable envelope made of an elastic material, natural or synthetic rubber or a blend reinforced with textile cord ply fabric carcass. Thus Tyre is a strong and elastic shell, which takes over stresses, ensures adherence to road avoids side slip and protects the tube. In other words “It is a thick rubber ring, often filled with air to carry the load, which is fitted around the edge of the wheel of a vehicle, allowing the vehicle to stick to the road surface and

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Industrial training at JK Tyres improving the smoothness of the journey by acting as a shock absorber”. BASIC FUNCTIONS OF PNEAUMATIC TYRE: The Tyre has a major contribution to motor vehicle performance like,

1. Load carrying capacity. 2. Cushioning and enveloping. 3. Transmit driving and braking torque. 4. Provide lateral stability / dimensional stability. 5. Provide cushioning and flotation. 6. Resist to abrasion. 7. Provide steering force / response. 8. Low rolling resistance. 9. Minimum noise and road vibration. 10.Durable and safe. So, a Tyre must provide high adherence, proper ride characteristic, and stiffness, low rolling resistance and noise, high reliability (fatigue and separation) and wear resistance (including bruise, cutting cracking and tearing resistance).

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Industrial training at JK Tyres CLASSIFICATION OF TYRES: The Tyres can be classified accordingly to many criteria. But they are mainly classified base on their construction into three classes as: 1. Standard Diagonal Ply Tyre (Bias Tyre) 2. Belted Bias Tyre 3. Radial Ply Tyre

BIAS TYRES: A bias Tyre has a carcass which is made of fabric cords crossed over each other at an angle of 35 to 40 degree to the center line. The number of such crossed layers is called plies, which functions as the load carrying member, related inflation pressure and can range from two plies for scooter Tyre to as much as 40 plies or more in an earth mover Tyre. The fabric cords generally use are rayon, nylon and polyester. A bias construction is continuous in its carcass structure from bead to bead.

RADIAL TYRES: A radial Tyre consists of a Radial carcass and a stabilizing Belt 6underneath the Tread. Radial carcass consist of reinforcement layers

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Industrial training at JK Tyres of steel cords running from one bead to other at 90 degree to the tread center line and is designed to hold the air pressure. The stabilizing belt consist of reinforcement cords of high modulus steel cords running circumferentially around the carcass at an angle of 1822 degree to the tread center line beneath the tread and is driving/ breaking / cornering torques. It is built such that the major short comings of the bias construction are eliminated. ADVANTAGES OF RADIAL TYRES OVER BIAS TYRES: 1. Increase in mileage. 2. Overall fuel efficiency up to 5% to 7% for car Tyres and 10% to truck Tyres. 3. Excellent Traction and breaking on both dry and wet roads. 4. Safe high speed cornering. 5. Excellent riding comfort especially at high speed. 6. Improved endurance life and Retread ability. 7. Radial Tyres runs quieter. 8. Excellent impact breaks resistance.

TYPICAL TYRE SECTION:

7 Industrial training at JK Tyres COMPONENTS OF A TYRE:

DEFINTION AND FUCTIONS OF THE COMPONENTS OF A TYRE: 1. BEAD: Part of the Tyre which is so shaped, so as to fit the rim and hold the Tyre on to it. It has core made of several of inextensible steel wire, with the ends of plies wrapped the core for anchorage. 2. SIDE WALL: The part of Tyre between bead and tread which flexes in service. 3. SIDE WALL RUBBER: The rubber layer on the side wall of the Tyre and over the carcass, which may include protective rims and fittings lines to assist in centering of Tyre on to rim. This protects Tyre from scuffing and damages.

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Industrial training at JK Tyres 4. TREAD: It is the part of Tyre which comes in contact with road and through which driving, breaking and cornering forces are transmitted. It is made of special rubber compound to give good wearing properties and in conjunction with the tread patterns to transmit these forces. 5. CORD: Textile or Non-textile strands (treads) used in various components of the Tyre like carcass, plies, belts, breakers etc. 6. PLY: A layer of rubber coated fabric cords. 7. CARCASS: The rubber bonded cord structure of a Tyre integral with the bead, which provides the requisite strength to carry load. 8. BREAKER (Diagonal): Immediate rubberized fabric layers / Plies between the carcass and the tread which help in bonding as well as protect the casing from road shock.

CLASSIFICATION OF TREAD PATTERNS TREAD PATTERNS: Different Tyres have different tread patterns. Tread may define the field of application of Tyre. A Tyre tread has pattern to take water from the ground engaging tread surface on a wet road so its tread can engage the road surface and to provide edges to give grip on road conditions such as mud, ice and snow. Road surfaces vary greatly and there are many differing vehicle Tyres and conditions of use different patterns are used. The tread pattern generates noise as its edges contact the road. The tread pattern also affects other properties of Tyres, its reaction to breaking and cornering forces. As a results there are many different patterns, The basic types of highway truck Tyre designs are:

1. RIB TYPE TREADS: Tyre with Rib Tyre tread are “all position” Tyres. They can be used on all wheel positions at legal highway speeds.

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Industrial training at JK Tyres These tyres are always recommended for steering wheel use on long haul, high speeds service. The circumferential groove design provides maximum steering capability and good skid resistance.

2.

LUG TYRE TREADS: Lug type Tyres are designed for drive wheel service. The provides greater traction in high torque application.

3. SEMI LUG TREADS: Semi lug tread types are designed for drive wheel service and are suitable for many “Off The Road” operations. These tread design provide maximum resistance to wear and greater traction in high torque service. These designs are also suitable for steering wheel applications.

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Industrial training at JK Tyres TYRES MANUFACTURED IN VIKRANT TYRE PLANT: In the Vikrant Tyre Plant, Unit-1, Nylon Tyres are manufactures for various automobiles such as passenger cars, agricultural application vehicles, animal driven vehicles, trucks and other Off-TheRoad vehicles.

TYRE MANUFACTURING PROCESS: Tyre manufacturing is a consolidated process of many steps, which themselves are on their own, are complex processes. The different stages of the Tyre manufacturing process are enclosed. The steps involved are further dealt in brief separately in the following paragraphs.

1. Mixing 2. Calendaring 3. Extrusion 4. Bead Preparation 5. Tyre Building Process 6. Curing (Vulcanization) 7. Post Cure Inflation 8. Trimming 9. Final Inspection

11 Industrial training at JK Tyres Mixing: Banbury unit

The description of the features of Banbury is explained below. i. Body: Chamber sides are made out of heavy cast iron fabrication end frames are the main supports that carry the chamber sides and in which rotors bearings are based. Both the rotors are drilled at the center for water cooling system and coated with hard chromium plating to resist the wear. ii. Doors: The doors comprises of an air cylinder carried on side rails of the bottom part of the body of the mixer. The doors apex is mounted on top of the cylinder and slides pneumatically to open and close the bottom of the chamber. iii. Dust rings or Dust seals: Helps preventing of materials leakage from the chamber due to the high internals pressure exerted while mixing. iv. Feed hopper: This is the entrance, through which all the ingredients are fed into the mixer. v. Ram: Is also called as float. This works pneumatically moves up and downs through a vertical cylinder above the feed hopper. As

12 the ram pressure increases the time of the mixing decreases. vi. Drive system: The internal mixers are powered by a heavy duty motors and reduction gear units.

COMPOUNDING: Is a process of mixing all the necessary ingredients with elastomer, when compounding the ingredients are added step by step. General compounding consists of following ingredients. 1. Base Polymer: The basic components of all rubber compounds may be in the form of rubber alone or blends. The elastomer is selected according to the physical properties. Normally Natural rubber, Synthetic rubber (SBR, IIR, Reclaim rubber, Neoprene etc...) 2. Reclaim rubber: For the purpose of cost reduction the reclaim rubber is also used. 3. Reinforcing agent: Carbon black is the most widely used. It increases the tensile strength, hardness and modulus of elasticity. It has resistance to abrasion. 4. Processing oils: They are the dark green colored viscous liquids, which are used as processing aids; commonly used oils are pine tar, cast or oil, Napthanic oil, Paraffin oils, Aromatic oils. 5. Activators: ZnO and Stearic Acid are used as activators. They mainly help in the curing. ZnO gives high tensile strength and Stearic acid increases the vulcanizing rate. 6. Anti-degredants: These ingredients oppose the degradation by ozone and atmospheric oxygen during service condition. 7. Cross-linking Agent: Sulphur is mainly used as the cross linking agent to carry out the vulcanizing process. 8. Accelerators: Accelerators are used to accelerate the curing agents, thus increasing the curing rate and decreasing the curing time, The compounding process mainly consists of the following three processes: 1.

Mastication: Mastication process is used for the natural rubber because it has high viscosity. So mastication is done to decreases the viscosity by using peptizer along with heat and pressure to breakdown the molecules. The decrease in the viscosity makes the compounding process easier.

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Industrial training at JK Tyres Pentachlorothiophenol is commonly used as peptizer. 2. Master Batch: Master is the processes of mixing elastomers with specified ingredients expect curing agents and accelerators. A major element in the master batch is the carbon black and other ingredients are also added in stage wise oils are added many times as the processing aids. The following ingredients are used in the master batch are; (i).Masticated rubber or synthetic rubber (ii). Activator, (iii). Fillers, (iv). Processing aids, (v). Antioxidants and antiozonents. Master batch is prepared in the Ban bury with the temperature of 140 +/- 10 C, about 4 to 6 minutes. 3. Final batch: Is the process where the vulcanizing agents such as Sulfur are added to the compound and is mixed.

FABRIC DIPPING Fabric processing takes place in the Zell plant, during which the processing adhesive is applied on the fabric and the woven fabric is treated under electrically controlled conditions of time, temperature and tension. Each fiber and fabric is contracted for different ends uses.

Dip Solution Preparation: The solution is made in two stages under controlled temperature conditions, 1. Master Batch: Contains the Resorcinol and Formaldehyde in water with caustic soda as catalyst for the reaction. The Ph is maintained by the caustic soda. The reaction is allowed between 3 to 6hr at 20-25C. This reaction is exothermic reaction. Resorcinol Formaldehyde is the product of this reaction. 2. Final Batch: Contains the master in the rubber latex and water for better adhesion. Vinyl Pyridine latex gives better adhesion properties. The process contains of the fabrics getting dipped in a containing the dipping solution. After the dipping the excess dipped solution is removed that uniform coating of the solution is obtained.

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Industrial training at JK Tyres Record the observations and identity the fabric after the dipping process. Adjust the width control devices justifiable. During the process if any abnormal visual defects like water patches, oil/greases contamination is observed, then identity neatly on the platform.

FABRIC CALENDERING: Calendar is a machine, which consists of 3 or more rollers held in a frame work. We can obtain rubber sheets of required width and strength. It is used for fractioning and skim coating of the fabrics. Calendar rolls have extra hardness and are made up of chilled cast iron. In a calendaring machine the following things are important:  Continuous lubrication system to roll bearings.  Drilled rolls to maintain temperature.  Precession gears to ensure smoothness of operation. The parameter's that have to be taken care in the calendaring process are;  The roller speed.  The roller temperature.  The friction ratio.  The accuracy in the roller setting. The following are the processing machinery used in the 4 Roll Calendar for the coating of textile fabric. 1. Let off roll: The aged fabric rolls from the Zell plant are loaded to the let off stand. 2. Splicer: Splicer is used to splice the leading end of the first of the fabric and the second roll of the fabric. Splicer having a hot plate which is electrically heated and which used to join the 2 ends of the fabric. 3. Tension variable roll I: This rolls pulls the fabric from the let off rolls in tension. 4. Let off Accumulator: The main purpose of the accumulator is when the let off and tension roll I stopped or the supply of fabric stops in the let off unit. The accumulator stores about 80 mts of fabric. The upper part is fixed and the lower part moves down to

15 store the fabric in this unit the fabric is supplied from the let off rolls, thus enabling a continuous supply of fabric for the processing. 5. Tension variable roll II: It pulls the fabric the accumulator, so that fabric remains under tension and fabric is passed on the next unit. 6. Hot can: The hot cans are used to remove the moisture content from the fabric. It consists of 21 rollers arranged in a zigzag manner of temperature around 110 C. 7. Dancing roll I: It is used to maintain the uniform tension in the fabric. It consists of 3 rollers, in which 2 are kept below the fabric and one is above the fabric and driven by the chain gear system. 8. Photo sensitive centering device I: The centering device centers the fabric while in operation. 9. 4 Calendar: The Z-configuration 4-roll calender is used for coating of the textile fabric. The main advantage of the 4-roll calender is double side coating simultaneously. The upper surfaces of the rolls are ground and high glass polished. The temperature is maintained constants by using steam. 10.Cold cans: It has 6 rolls in zigzag manner. Cold water circulation is provided for the cooling of rollers. The function is to cool the fabric, and no external force is provided. 11.Tension variable roll III: It pulls the fabric from the cold can rolls, so that fabric remains under tension and fabric is passes on the next unit. 12.Tension variable roll IV: It pulls from the wind up accumulator, adjusts the tension and passes the fabric to the center device. 13.Wind up rolls: The set up has two winds up strands where the coated fabric is winded in a liner to avoid sticking of the fabric to one other.

EXTRUSION OF TREAD: Extrusion is carried out through the extruder machine, which forces the rubber through a nozzle or a die to give a profile strip of the material. Screw extruder is used in the plant here. In the screw extruder, a helical screw turning in a cylinder forces the compound through the die. It is operated by the electric motor through the reduction gear. The extruder consists of feed hopper through which the rubber compound is fed into the extruder.

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Industrial training at JK Tyres The following are the machineries used in the extruder section are; Cracker mill, Homogenizing mill, Feeding mill, Single screw extruder, 3-roll-calender, cooling conveyor and Cutting circular blade. Steps in the Extrusion process;

(I). Compounding Milling: •

Open water circulation to the mill during the milling operation and close the water when not in use.

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Take respective compound for milling as per requirement.

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Load the compound required to the cracker mill/ warm up mill and mix well to get smooth surfaces by giving cut and rolls.

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Pass the compound to the feed mill.

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Set the feed strip dimension according to specifications.

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Pass the compound strips to the extruder hopper or over head conveyor.

(II). Extrusion: •

Pick up the required die the pre-former from the hot chamber, which is required for the extrusion as per shift schedule.

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Change the die and the pre-former. Apply the soap solution.

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Slide the die and the pre-former in the slot and clamp it.

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Start extruder and guide the compound strip to the extruder hopper.

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Set the RPM and ensure feed of the compound as specified.

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Apply under tread cushion centrally as per specifications.

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Apply under tread polythene to truck and OTR treads.

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Allow tread to continue on inclined and cooling conveyor.

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Set the specified length and weight as per specification.

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Pass the extruded treads from the cooling to booking conveyor through dancer rollers.

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Put auto switch in auto position and start cutting.

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Ensure the length and weight of treads extruded in each size randomly while booking.

Book accepted treads in clean and neat leaf trucks and store the treads in such a way that polythene/ under tread surface is facing

upward.

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Industrial training at JK Tyres BIAS CUTTING: Bias cutter is a machine, which is used to cut the rubber-coated fabric at the required width and angle, so as to suit it for the production of various types of Tyres. Bias angle is the angle of cords in Tyre w.r.t center line. The width is adjustable from (135-1300mm). The cutting angle changes from 32-90 degree. The cut fabrics are spliced in a roll of either 80 or 60 degree cuts. The fabric is shifted on a driving roll. As the conveyor pulls the fabric, the coated fabric comes out from the let off roll. The fabric moves with the help of the photo-cell, which instructs the motor to run by means of limit switches. The width is adjusted before putting it into operation. The motor placed on the carriage drives the cutting disc tools, which cuts the fabric. The cutter runs on the cutting rail, which is diagonally adjustable to the longitudinal axis of the conveyor.

BEAD PREPARATION: One of the major components in the Tyre is the bead. The bead, which anchor's the Tyre safety to the rim and it, functions as the supporting components to carry the load. The bead is the combination of multi treads copper coated high tensile steel wires. They have the function of providing rigidity to the Tyre and to retain the inflated Tyre on the rim under all condition of loading. The bead consists of number of strands of copper coated steel wires embedded in a semi-hard rubber compound secured in the turned up loops. All carcass plies are symmetrically wound around the bead wires. The purpose of using copper coated steel wires is to help in the better adhesion between steel and compound and also protect the wire from corrosion during the service of the Tyre. The diameter of the steel wire is of 0.0905 +/-0.075 the Tyre. The bead wire are made up of high carbon steel which has in extensibility as on of the main property. 18

Industrial training at JK Tyres For the construction of the bead following stages are carried out. 1. Bead building unit. 2. Fillering machine. 3. Flipping machine. 4. Wrapping.

TYRE BUILDING UNIT: (Eg.) Truck\RT-Building (Pocket Type). 1. Apply drum cement and collapse. 2. Insert the inner bead; center the beads on rings, (With hold too loose/too tight beads). 3. Insert the pocket and centralize by finger feeling. 4. Expand the drum and confirm centralization. 5. Turn down the ply ends and apply naphtha. 6. Apply both the beads after applying naphtha’s. 7. Turn up plies without wrinkles and air trap. 8. Stitch the turn up with hand stitcher. 9. Apply naphtha and fix the chafer as specified. 10. Stitch with turn up stitcher by hand. 11. Apply naphtha and fix the tread centrally by hand uniform pulling. (without short/long treads). 12. Apply naphtha on tread ends and stitch by hand stitcher. 13. Remove air trap and wrinkles on tread. 14. Stitch by hand stitcher. 15. Apply bottom spinner. 16. Collapse the drum and remove the Tyre.

TYRE CURING: The Tyre curing is a process of cross-linking of the rubber compound through the heat and pressure. In the curing process the

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Industrial training at JK Tyres Tyre is cross-linked in a series of chemical reaction. The press contains the mold that determines tread design and final Tyre dimensions. Before the curing process, some of the preliminary process must be carried out. They are;

1. Splice Jamming and Painting. All green Tyres are to be splice jammed. The splice jamming is done only to the tread joining area. After splice jamming operation Tyres are taken for the Tyre painting area.

2. Green Tyre Awling. Awling is done to the green Tyre to reduce the Tyre defects by providing escape for the air trapped in between bladder and Tyre while shaping and the air that is trapped stitching operation while building.

CURING CYCLE: There are different methods of curing used depends upon the type of the Tyre. They are;

1. Dome Steam, Bladder Steam: Usually used in production of small Tyres like passenger car Tyre, bicycle Tyres, and agricultural Tyres.

2. Dome Steam, Hot Water in Bladder: This is the most common method in production of big Tyres. Often circulation of cooling water is used at the end of curing phase to cool the Tyres before release.

3. Nitrogen Curing: Steam or hot water in the bladder is replaced by nitrogen. With nitrogen curing, the curing time can be shortened and problems caused by water or steam can be eliminated. This method decreases energy consumption in curing compared to hot water or steam curing. 20

Industrial training at JK Tyres Green Tyre Curing Process: A curing cycle starts just after the mold closing and last up to. Apply naphtha mold opening. In between these there are many steps, each having their own functions. These steps and its duration change depending upon the type of Tyre. The major steps involved are the following; 1. Dome heating: Circulating steam does dome heating. This is to heat the mold thus helps to flow the compound. For truck Tyres steam is applied at 146 C. 2. High pressure steam (HPS): High pressure steam as applied to heat the bladder since the bladder compound (butyl rubber) is a poor conductor of heat. For truck Tyres HPS has a temperature of 194 C and 13.4kgsn pressure. 3. Circulating hot water (CHW): Circulating hot water with high pressure and temperature is applied to enhance the cross linking process. It has a temperature of 168C and a pressure of 26kgs. The high pressure (double pressure than HPS) will consolidate the rubber compound into mold cavity. 4. Circulating cold water (CCW): This is applied to cool the bladder and Tyre. 5. Vacuum: Vacuum is applied to release the bladder from Tyre.

Types of Moulds used: 1. Two piece mould:  Mold has two equal parts, open from middle.  Mold is heated between heat platens.  Sidewalls are attached to the actual mold

2. Segment mould:  In this type of mold the tread pattern is divided into 8 segment pieces. Sidewall plates are separate from the actual tread part. Segment pieces are installed into container that is mounted into press.  Segment mold is also heated between platens, but in addition to 2-pieces mold also the container part is heated. 21

Industrial training at JK Tyres Curing Presses: There are different types of curing, but the most popular is bladder curing. The presses used are known as Bag-o-Matic press. There are different types of presses mainly; 1. Hydraulic Curing press. 2. Mechanical Curing press.

Post Cure Inflation (PCI): The PCI stage involves mounting the green Tyre on the flanges, inflating it and cooling it according to a predetermined and preselected procedure. The Nylon Tyres, which has thermal shrinkage property, or post – inflated under stretched conditions, soon after the Tyres come out of the mold after curing, by inflating with compressed air to avoid deformation of Tyres and hence to stabilize their shape. This should be done within three to five Min's of Tyres ejection from the mold and PCI should be treated till the Tyre cools to 60 – 70 C.

PCI Process: 1. Refer the specification series displayed in the individual curing processes. 2. Verify and ensure that the PCI air pressure and time are set as per specified in the pressure gauze and timer provided. 3. PC Inflate all Nylon cure Tyres using PCI units as per specifications. 4. Release the Tyre from the PCI unit after specified duration of PCI treatment. 5. PCI treated Tyres/defective Tyres are to be sent to trimming and inspection area. 6. For “Off The Road” OTR Tyres, soon after the Tyre is unloaded from the press, insert no. of wooden peg sets for OTR Tyres at the bead region at equal distances.

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Industrial training at JK Tyres FINAL FINISHING: The final finishing consists of the following stages;

 trimming: It’s the process of removing the excess material that includes vents. The cured Tyre is kept on the trimming machine and rotated by motor, while the trimming device is held to the Tyre, thus removing the excess material that makes the Tyre look good.

 Buffing: There are two types of buffing a). Rag Buffing and b).Emery Buffing

 Inspection: All cured Tyres are inspected for visual defects. The defective Tyres are held up separately for the modification work. The production and the technical staff inspect the held up Tyres and classify the Tyres according to the quality.

TYRES MANUFACTURED IN RADIALTYRE PLANT:

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Industrial training at JK Tyres ADVANTAGES OF RADIAL TYRES OVER BIAS TYRES: 1. Increases in mileage 2. Overall fuel efficiency up to 5% to 7% for car Tyres and 10% to truck Tyres 3. Excellent Traction and breaking on both dry and wet roads 4. Safe high speed cornering 5. Excellent riding comfort especially at high speed 6. Improved endurance life and Retread ability 7. Radial Tyres runs quieter 8. Excellent impact breaks resistance RAW MATERIALS 1. NATURAL RUBBER 2. SYNTHETIC RUBBER 3. CARBON BLACK a. N 339 b. N220 c. N320 d. N326 4. INSOLUBLE SULPHUR 5. PARAFFIN WAX 6. SILICA 7. 6 PPD (Antiozonant) 25

Industrial training at JK Tyres 8. PEPTIZER 9. PROCESSING OIL 10.

BEAD WRAP

11.

BEAD WIRE

12.

STEEL WIRES FOR BODY PLY

SPECIALITIES OF TRP MIXER •

The only mixer available in India for silica mixing

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Mixing based on heat history

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Variable rotor speed (6-60rpm)

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Hydraulic ram (variable ram pressure during mixing)

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Tip hardened rotors for silica mixing

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Equipped with fume extraction system to eliminate silica – silane reaction by product

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High energy input into the compound leading to shorter mixing time

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Fully automated feeding and mixing sequence

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Equipped with twin screw sheeter

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Industrial training at JK Tyres SILICA MIXING TECHNOLOGY Silica is used because •

Low rolling resistance ,better efficiency

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Better wet grip

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Lower heat generation

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Better cut /chip resistance

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Improved dynamic properties

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Higher tear strength

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Improved adhesion to fabric and steel

BANBURY DETAILS Intensive mixer Mixer manufacturer: Krupp Mixer make: GK 270 Mixer volume: 246ltr Mixer motor type/KN: AC motor (variable)-1500 Ram dia: 22” Radial Compounds Compound Name

Description

B 99

Body ply coating

B 176

Breaker skim compound

B 333

Nylon chafer compound

B 715

Tread under cushion

R 158

Flange cushion

B 610

Shoulder pad

PS 47

Sidewall compound

PT 208

Tread

T 6629

Tread

T 6730

LCV tread compound

22 G

Tubeless inner liner

H 272

Tubeless inner liner compound

A 1032

Soft apex

A 1031

Hard apex

T 4063

Tread base

S 54

Bead wire coating

S 105

LCV Apex

T 542

Tread

JT 434

Sidewall LCV

K1

Inner liner LCV

STEEL WIRE CALENDERING

PROCESS

Steel Tyre cord Body ply and Belts required for building All steel Truck Radial Tyres are calendar at Hot Calender line. Creel room is maintained as per the specified Humidity and Temperature. Steel Tyre cords after conditioning in the creel room are mounted on the creel stand let off and drawn out. Four roll Calender has “S” form axis of the rolls Nos. 1 and 4 is placed 45° over the vertical axis. Rolls are made from chilled alloyed cast iron and are peripherally drilled. Individual wires are spread in to the Comb roll through the Reed and fed in to the Calender gap between roll nos. 2 and 3. 28 Industrial training at JK Tyres By feeding rubber compound from feeding mills through swinging conveyors in to the gap between Roll No1 and 2 and between roll no 3 and 4 rubber films of the required thickness are drawn on the roll no 2 and 3. The thickness of the rubber films are controlled through the scanning heads of the thickness measurement device (Beta gauge control)

Rubberized steel cord is passed through the cooling cans and accumulator and wound in to the liners at wind up unit. The Calender roll temperatures are monitored with the help of TCU. STEEL BELT CUTTING PROCESS

Equipment: Fischer Belt Cutting Machine Belts/Steel Chipper required for Building All steel Truck Radial Tyres are cut and prepared at Belt cutter The Calendared Rolls are mounted on the let off stand of the Belt cutter and passed on the let off conveyor to the Cutting Blade nip The let off is mounted on a carriage, which can be set to the required angle between 15° to 75°. The machine settings are done with the help of PLC.The cutting Blades are operated hydraulically. The material to be cut is fed to the Blade nip with the help of advancer consisting of electromagnet battery and cut to the specified width and angle. Cut material is transferred to the Splicing head through the conveyor and the belts are spliced at the splicer head using zipper tool. Gum Strips are applied at both the edges of cut belt and turned down using turning down tool. 29

Industrial training at JK Tyres Belts are rolled in to Liners at Windup station and stored on Belt storage trolley

BEAD WINDING PROCESS

Hexagonal Beads required for building all steel Truck Radial Tyres are produced on the Bartell Single wire bead winding machine. Bead wire spool is mounted on the let of stand of the winding machine and passed through the wire pre heater to the Extruder. Wire are rubberized with the specified compound at 21/2” extruder and passed through the Festooner to the winder. The wire is wound to the specified construction on the former with the help of pay on wheel and lying unit. The machine settings are done using PLC program. Wound Beads are stored on trolleys with identification. The extruder temperatures are controlled with the help of TCU

BODY PLY CUTTING PROCESS

Equipment: Body Ply Cutting Machine Body ply material required for Building All steel Truck Radial Tyres are cut and prepared at Ply cutter The Calendar Body Ply Rolls are mounted on the let off stand of the Ply cutter and passed on the let off conveyor to the Cutting Blade nip The machine settings are done with the help of PLC.The cutting Blades are operated hydraulically. 30

Industrial training at JK Tyres

The material to be cut is fed to the Blade nip with the help of advancer consisting of electromagnet battery and cut to the specified width at 90° angle. Cut material is transferred to the Splicing table and spliced using zipper tool.

Gum Strips are applied at both the edges of cut Body ply and turned down using turning down tool. Prepared Body ply material is wound in to Liners at Windup station and stored on A frame storage trolley with identification.

II Stage Green Tyre Preparation: Tyres are Painted on the Inner Liner with Water Based Inner Lube and hung on the chuck loaders of the Tyre curing press.

TRUCK RADIAL TYRE CURING PROCESS Equipment: 1. 63 1/2” SKODA BOM PRESS 2. KRUPP HYDRAULIC PRESS Moulds: SEGMENTED TYPE (8 Segments assembled in the container) Advantages: •

Perfectly Centered Moulding of Tyres

•

Stress free moulding of Tyres as the Moulds approach the Green Tyres during Press Closing.

•

Better Uniformity of Tyres

•

Improved Lateral and Radial Run outs of cured tyres 31

Curing Process:

Ensure the Moulds are free from contamination before loading

Place the Green Tyre centrally on the Bladders with the help of chuck loaders

Shape the Green Tyre with the Shaping Steam as per specification

Collapse the Chuck loaders when the Tyre attains specified Shaping

Segments will Open /Tyres are Unloaded from the Press Takeout the Chuck loaders and Close the Press/Timer Starts

Press Opens after the completion of the Cure Cycle

CHW with Specified Pressure enters inside the Bladder

Dome Steam Enters at the Specified Time/ In case of Hydraulic Press Platens are continuously heated in place of Dome Steam

Vacuum starts at the specified time through Ventury effect

Drain Cycle starts at the specified Time

Tyres sent to Trimming followed by Visual and X ray inspection

32

Industrial training at JK Tyres TRUCK RADIAL TYRE INSPECTION PROCESS Cured Tyres after Trimming are inspected before W/H.Tyre inspection consists of Visual and x-ray Inspection

1. Visual Inspection: All the Cured Tyres are checked for any Visual defect as per the standards

and

Okayed.

Rejected

tyres

are

Repaired/Scrapped

depending upon the severity and merit of the defect. 2.X-Ray Inspection All the Cured tyres are checked on x-ray to ensure the structural integrity. Equipment: Tyre x-ray inspection System LumenX Company,USA The Tyre X-Ray inspection system is completely automated for online inspection of Tyres for all the construction parameters like Ply cord spacing, turn ups, Belt step off and splice, and concentricity of Bead Bundles. The X-Ray system The Gemini X-Ray system will provide X-ray energy .X-Rays are emitted from panoramic tube head in a 270 degree vertical arc. The Xrays penetrate the Tyre in different amounts depending on the tyre density and material of construction 33

Industrial training at JK Tyres The Image System: The linear diode array (LDA) image scanner head in C – shape will provide the image on the screen.

Tyre engineering: Components used in Radial tyre building 1. Bead 2. Splice strip 3. Inner liner 4. Nylon chipper (750 -65mm) 5. Steel chipper 6. Body ply 7. Apex 8. Nylon chipper (450-90mm) 9. Flange 10. Sidewall 11Crayon application 12. Carcass 13.Tread pack

35

CHAPTER- 3 AIM AND ACOPE OF PRESENT WORK

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BIBILOGRAPHY JK TYRES INDUSTRIAL MAGAZINE www.jktyres.com www.vtp.com