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CHAPTER 1

1. INTRODUCTION OF THE COMPANY

1.1. INTRODUCTION

Loadstar had been established in1984 as a BOI Company with collaboration of Jinasena group of

companies and Solideal loadstar in Belgium. Recently in at end of the year 2010, it was combined with the world

best track producer Camoplast. Actually now Loadstar (pvt) Ltd is changed as camoplastsolideal. But still people

knew this company as Loadstar (pvt) Ltd.So, earlier the brand name was solideal but now it changed as

camoplastsolideal Loadstar (pvt) Ltd. It was the largest member of Jinasena group of industries which had extended

its activities in many industries. Electrical, mechanical and material are the major engineering disciplines involved

with this group of companies. Loadstar (pvt) ltdis one of the leading tyre and track manufacturers in the world. It is

said to be the second largest tyre manufacturer in the world and world’s largest solid tyre manufacture. And also it

buys 70% of the natural rubber produced in Sri Lanka. So, Loadstar (pvt) ltd is a main contributor in country’s

economy. Loadstar is fully customer focused factory. They always try to full fill their customer needs and wants. So

they are providing not only the tyres and tracks but also other tyres and tracks base semi product.Loadstar (pvt)

ltdconsist of several factories to cover those areas in tyre industry. All those factories are involved almost all

activities that are related to tyre manufacturing process.

Loadstar is trying to build a lean organization. So, they have make plans to eliminate the wastage in the

factories. So they introduced loadstar production system (L.P.S.) concept which very same for lean manufacturing

system. As they feel that Quality without Innovation is meaningless, they have taken the Japanese concept of

continuous improvement (KAIZEN) and blended it with innovation to come up with something which quite accurately

describes their belief and attitude. Loadstar has a big name in the world market. Normally, Loadstar sells its

products to the European and American market. Therefore the marketing procedure is taken care by the Solideal

loadstar in Belgium. At the moment Loadstar (Pvt) Ltd is the main solid tire producer for the world market. They

supply more than 25% of the world solid tire requirements. They export their product to American, European, Asian

countries and Australia. Main buyer is USA. They consume 45% of the loadstar production. Loadstar (Pvt) Ltd

supplies more than 5% of world pneumatic tire requirements. The work force of Loadstar (Pvt) Ltd is nearly five

thousand workers, with 400 staff members. The total production capacity of all factories is about, 210 tons per day.

The main raw material of the factories is rubber. Loadstar is not a typical company they like a family. So they has

set up its vision and mission not only by considering commercial goals but also has paid attention to welfare of the

workers and social and cultural values. Now loadstar works with the camoplast company. So they also has a

mission and values according to their goals. So now these two companies were made their mission and values

under camoplastsolideal company name.

LOADSTAR

VISION - To be the premier manufacturer of mobility systems for the productive world by harnessing and

nurturingpeoples’ abilities.

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MISSION -We will manufacture quality and cost effective tyres, tracks and wheels, efficiently for our

worldwide customers through empowered and self-driven teams, working together to improve our

people, company, society and environment.

VALUES

Empowerment -Every day we ask ourselves: "Is there a better way?"

Integrity -"We do what is best for CamoplastSolideal and our customers."

Commitment -"We do what we say with excellence."

Teamwork -"As a team, we win when everyone is fully engaged."

Loadstar is not an isolated factory. It consists of 11 factories along with an administration Centre and a

training Centre.

JIP,Ekala

Kotugodatyre division

Air tyre division

Solid tyre division

Central mixing plant

Casting factory, Kotugoda

R & D Department

OREX

Kyotho

North pole

Sinco

Ekalatyre division

Midigamatyre division

Kuruwitatyre division

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1.2. ORGANIZATIONAL STRUCTURE

Organizational structure is so made that the information, commands and decisions travel from top to bottom

rapidly which is a huge advantage in running such a large organization. On the other hand management has rapid

access to information from the flow that will make the decision making fast.

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1.3. JINASENA INDUSTRIAL PARK (JIP)

There was a best opportunity to work in JIP, This is a main maintenance section of all loadstar factory. I’m

working as a trainee in Jinasena Industrial Park at all the main divisions during six month.

SECTIONS OF THE JINASEANA INDUSTRIAL PARK.

Jin

asen

a In

du

stri

al P

ark

(JIP

) Welding and

Fabrication Shop

Machine Shop & Heavy Machinery Unit

Hydraulic & Pneumatic Shop

Mould and Engraving Shop

Electrical and Electronic Unit

Strategic Engineering Unit

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CHAPTER 2

2. TRAINING EXPERIENCE

2.1. MANUAL METAL ARC WELDING

Welding Technique Successful MMA welding depends on the following factors:

1. Selection of the correct electrode 2. Selection of the correct size of the electrode for the job 3. Correct welding current 4. Correct arc length 5. Correct angle of electrode to work 6. Correct travel speed 7. Correct preparation of work to be welded.

2.1.1. Electrode Selection When we select an electrode the only consideration of selecting an electrode of similar composition to the parent metal. However, for some metals there is a choice of several electrodes. Often, one electrode will be more suitable for general applications due to its all round qualities.For example, the normalwelder will carry out most fabricationusing mild steel and for this material has a choice of variousstandard electrodes, each of which will have qualitiessuited to particular tasks.

2.1.2. Electrode Sizes The size of the electrode generally depends on the thickness of the section being welded, and the thicker the section the larger the electrode required. This means that, if 2.0 mm sheet is being welded, 2.5 mm diameter electrode is the recommended size. The following table gives the maximum size of electrodes that may be used for various thicknesses of section. Recommended Electrode Sizes,

Plate thickness Electrode size

1.5–2.0 mm 2.5 mm

2.0–5.0 mm 3.2 mm

5.0–8.0 mm 4.0 mm

≥8.0 mm 5.0 mm

2.1.3. Welding Current Correct current selection for a particular job is an important factor in arc welding. With the current set too low, difficulty is experienced in striking and maintaining a stable arc. The electrode tends to stick to the work, penetration is poor and beads with a distinct rounded profile will be deposited. Excessive current is caused by overheating of the electrode. It will cause undercut and burning through of the material. Normal current for a particular job may be considered as the maximum, which can be used without burning through the work, over-heating the electrode.

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2.1.4. Welding Defects and Problems Manual metal arc welding, like other welding processes, has welding procedure problems that may develop and which can cause defects in the weld. Some defects are caused by problems with the materials. A poor welding technique and improper choice of welding parameters can cause weld defects.

Defects Caused by Welding Technique

1. Slag Inclusions

Slag inclusions occur when slag particles are gone inside the weld metal, which produces a weaker weld. These can be caused by:

erratic travel speed

too wide a weaving motion

slag left on the previous weld pass

too large an electrode being used

2. Porosity

Porosity is gas pockets in the weld metal that may be scattered in small clusters or along the entire length of the weld. Porosity weakens the weld in approximately the same way that slag inclusions do. Porosity may be caused by:

excessive welding current

rust, grease, oil or dirt on the surface of the base metal

excessive moisture in the electrode coatings

impurities in the base metal

too short an arc length

travel speed too high

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3. Lack of Fusion

Lack of fusion is when the weld metal is not fused to the base metal.This can occur between the weld metal and the base metal or between passes in a multiple pass weld. Causes of this defect can be:

excessive travel speed

electrode size too large

welding current too low

poor joint preparation

letting the weld metal get ahead of the arc.

4. Undercutting

Undercutting is a groove melted in the base metal next to the toe or root of a weld that is not filled by the weld metal. Undercutting causes a weaker joint and it can cause cracking. This defect is caused by:

excessive welding current

too long an arc length

excessive weaving speed

excessive travel speed.

2.1.5. The Tests that are used to find Welding Defects and Other Cracks..

Dye Penetration Test (DP Test)

Dye Penetration inspection is used to locate surface breaking defects in all non-porous materials. Dye Penetration

testing kit contains with three parts. The aerosol cans as Cleaner, Penetrant and Developer. This inspection should

be done on a smooth clean surface.

First remove any loos materials by using wire brush. Then applied the cleaner to remove oil and dust particles. Once

cleaned, applied the penetrant which has the colour “red”. Sprayed the penetrant on the crack surface and leaved the

dye to penetrate normally at about 20-30 minutes. After that, remove the excess dye from the area by applying the

cleaner. Finally, sprayed the Developer, a “white” substance and let it to dry in few minutes. After few minutes, it was

able to see red marks along the crack in front of brilliant white Developer back ground.

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Ultrasonic Test

Ultrasonic test is widely used in Loadstar Mould and Engraving shop to find cracks and holes inside the mould

casings.Ultra sound technology uses high frequency sound to carry out examinations and make measurements. In

this, the sound energy is introduced and propagates through the materials as a wave form. When there is

discontinuity in the wave path, the path of the wave will be reflected back from the flow location. Then the reflected

wave signal is converted in to an electrical signal by a transducer and displayed on a screen.

These results displays in the form of signal with an amplitude represents. The intensity of reflection wave while the

other axis represents, either distance or arrival time of reflection.

Meanwhile you are executing the scanning process, it should be noted that the medium between the probe and the

material which is about to be inspected should be homogeneous and even throughout the material surface. For that

the operators of the machine applied grease throughout the material surface.

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2.2. GAS CUTTING

2.2.1. Process of Gas cutting

Cutting Torch Nozzle

The equipment and accessories for oxy-gas cutting are the same as for oxy-gas welding except that you use a

cutting torch or a cutting attachment instead of a welding torch. The main difference between the cutting torch and

the welding torch is that the cutting torch has an additional tube for high-pressure oxygen, along with a cutting tip or

nozzle. The tip is provided with a center hole through which a jet of pure oxygen passes. Mixed oxygen and

acetylene pass through holes surrounding the center holes for the preheating flames. The number of orifices for

oxyacetylene flames ranges from 2 to 6, depending on the purpose for which the tip is used. The cutting torch is

controlled by a trigger or lever operated valve. The cutting torch is furnished with interchangeable tips for cutting steel

from less than ¼” to more than 12.0” in thickness.

In Loadstar (Pvt) Ltd. There were the following gas cutting machines mostly in the workshop. Which are called

portable gas cutting machine to cut in the linear path ( Plug cutter ) and profiling gas cutting machine to cut the

complex shapes more accurately ( Gig cutter ).

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2.2.2. Practical issues in Gas cutting

In the training location when cutting a few metal plates ,

First marked the sizes of the plates which needed, and placed the nozzle to the straight line which drawn. Then the

acetylene gas valve was opened and light the flame and then adjusted the oxygen valve to the oxidizing flame and

started the cutting process.

When the cutting process was continued , the metal pieces tends to bend as follows. To prevent that error the small

metal pieces were tagged using arc welding tags.

But it was observed that when the second work piece was cut , it tends to bend earlier than first one. In that case had

to make more tags as soon as possible to prevent that bend and it was very difficult to tag metal plates. It was

happened because of the weight of the plates were higher than before.

To prevent that difficulties simply can be take away the work piece which was cut first and then start the next cut.

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2.3. HYDRAULIC SYSTEMS

2.3.1. INTRODUCTION

Hydraulic is used for the generation, control, and transmission of power by the use of pressurized liquids.A Hydraulic

circuit is a group of components (such as pumps, actuators, and control valves) arranged that they will perform a

useful task. In Loadstar (Pvt) Ltd hydraulic systems are used in most of machineries.

In a basic hydraulic system mainly there are following components,

Hydraulic pump Control valves Actuators Reservoir Accumulators Hydraulic fluid Filters Tubes, pipes and hoses Seals, fittings and connections

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2.3.2. HYDRAULIC PUMPS

Hydraulic pumps are used to convert Mechanical power supplied from external source to fluid power.The pump draws in the hydraulic fluid and drives it out into a system of lines. The resistance encountered by the flowing hydraulic fluid cause a pressure to build up in the hydraulic system. The level of the pressure corresponds to the total resistance which results from the internal and external resistance and the flow rate.

External resistance,

Come about as a result of maximum loads and mechanical friction and static load and acceleration forces.

Internal resistance,

Come about as a result of the total friction in the lines and components, the viscous friction and the flow losses (Throttle points).

Thus, the fluid pressure in hydraulic system is not pre-determined by the pump. It builds up in accordance with the resistance in extreme cases until a component is damaged. In practice, however, this is prevented by installing a pressure relief valve directly after the pump or in the pump housing at which the maximum operating pressure recommended for the pump is set.

PUMP CLASSIFICATION.

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HYDRAULIC PUMP CHARACTERISTICS

• Flow Rating

• Pressure Rating

• Volumetric Efficiency

• Noise Level

• Contamination Level

In Loadstar mainly used Single stage vane pumps and Double stage vane pumps because relatively low cost and

easy to repair and maintain.

Single Stage Vane Pumps

Double Stage Vane Pumps

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2.3.3. HYDRAULIC VALVES

Valves are devices for controlling the energy flow. They can control and regulate the flow direction of the hydraulic

fluid, the pressure, the flow rate and, consequently the flow velocity.

MOUNTING SYSTEM OF HYDRAULIC VALVES

• Threaded mounting

• Gasket mounting

• Sandwich mounting (Modular valve)

• Slip in type mounting (Cartridge valve)

• Flange mounting

Sandwich valves have the following features,

• Installation space can be considerable reduced.

• They can be assembled easily, together with ease and quickness in addition and modification of the circuit.

• Since no piping is required between the valves, oil leak, vibration, and noise problems are minimized.

• Since the valves are arranged close together, maintenance and inspection can be done efficiently.

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DIRECTIONAL CONTROL VALVES

• Solenoid valves

• Solenoid pilot directional control valves

• Pilot controlled directional control valves.

• Manual directional control valves.

• Check valves.

• Pilot controlled check valves.

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These valves control the direction of flow of the hydraulic fluid and, the direction of motion and the positioning of the

working components. Directional control valves may be actuated manually, mechanically, electrically, pneumatically

or hydraulically.

PRESSURE CONTROL VALVES

BALANCED PISTON TYPE RELIEF VALVE

These have the job of influencing the pressure in a complete hydraulic system or in a part of the system. The method

of operation of these valves is based on the fact that the effective pressure from the system acts on a surface in the

valve. The resultant force is balanced out by a counter acting spring.

UNLOADING RELIEF VALVE

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These valves are used to operate the pumps with minimum load in accumulator circuits or in high-low pump circuits. In accumulator circuits, when the system pressure reaches to a cut out pressure (adjusted maximum), the valve acts to divert the pump delivery to the reservoir at low pressure, thus the pump is unloaded automatically. In high-low pump circuits, the valve acts to unload the large volume pump with the same manner during load operation of the small volume pump.

FLOW CONTROL VALVES

• Throttling valves

• Flow control valves

• Flow control valves with shut-off valve

• Pilot controlled flow control valves

• Deceleration valves

• Flow control valves with relief valve

• Flow dividing valves

THROTTLING VALVE

These interact with pressure valves to affect the flow rate. They make it possible to control or regulate the speed of

motion of the power components. Where the flow rate is constant, division of flow must take place.This is generally

affected through the interaction of the flow control valve with a pressure valve.

2.3.4. HYDRAULIC ACTUATORS

Actuators are used to convert energy of pressurized fluid in to mechanical energy (movement) to move the load

(work).

Type of Actuators:

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• Linear - Hydraulic cylinders

• Rotary - Hydraulic motors (continuous)

• Limited angle - Oscillating motor

Hydraulic cylinders,

• Ram type cylinder

• Telescoping cylinder

• Standard Single acting cylinder

• Standard double acting cylinder (Single rod and double rod)

SINGLE ACTING CYLINDER

The fluid pressure can only be applied to one side of the piston with the result that the drive movement is only

produce in one direction. The return stroke of the piston is affected by an external force or by a return spring.

DOUBLE ACTING CYLINDER

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The fluid pressure can be applied in both side of the piston and can be controlled both the extending stroke and the

retraction stroke.

2.3.5. ACCUMULATORS

There are different types of accumulators,

With weight

With spring

With gas – Separating part between gas and fluid (hydra pneumatic)

Piston

Bladder

Membrane

Bladder type accumulators are widely used in Loadstar (pvt) ltd, because that are easy to maintenance, easy to

installation, can be placed horizontal, vertical or in any angular position with the situation used.The hydra pneumatic

accumulators perform different tasks in the hydraulic systems.

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2.4. ELECTRICAL MOTORS & CONTROLLING CIRCUITS.

2.4.1. INDUCTION MOTOR.

An induction motor is an asynchronous AC motor where power is transferred to the rotor by electromagnetic induction. Induction motors may be further divided into squirrel-cage motors and wound-rotor motors. Squirrel-cage motors have a heavy winding made up of solid bars, usually aluminum or copper, joined by rings at the ends of the rotor. Currents induced into this winding provide the rotor magnetic field. The shape of the rotor bars determines the speed-torque characteristics. At low speeds, the current induced in the squirrel cage is nearly at line frequency and tends to be in the outer parts of the rotor cage. As the motor accelerates, the slip frequency becomes lower, and more current is in the interior of the winding. In a wound-rotor motor, the rotor winding is made of many turns of insulated wire and is connected to slip rings on the motor shaft. An external resistor or other control devices can be connected in the rotor circuit. Resistors allow control of the motor speed, although significant power is dissipated in the external resistance. The wound-rotor induction motor is used primarily to start a high inertia load or a load that requires a very high starting torque across the full speed range. By correctly selecting the resistors used in the secondary resistance or slip ring starter, the motor is able to produce maximum torque at a relatively low supply current from zero speed to full speed. This type of motor also offers controllable speed.

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2.4.2. SYNCHRONOUSMOTOR

A synchronous electric motor is an AC motor distinguished by a rotor spinning with coils passing magnets at the same rate as the alternating current and resulting magnetic field which drives it. Another way of saying this is that it has zero slip under usual operating conditions. Contrast this with an induction motor, which must slip to produce torque. One type of synchronous motor is like an induction motor except the rotor is excited by a DC field. Slip rings and brushes are used to conduct current to the rotor.The rotor poles connect to each other and move at the same speed hence the name synchronous motor.

2.4.3. RELAYS

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A relay is an electro-magnetically operated switch. It consists of an operating coil woundaround an electromagnet pole piece, a moving armature and one or more sets of contacts. Whena voltage of the correct value is applied across the coil terminals, the resulting current flowthrough the coil produces a magnetic field similar to a bar magnet. The armature is attracted bythe magnetic field and so moves a small distance. This movement operates the contact(s). The pole piece is magnetically soft. When current flowthrough the coil ceases, the pole piece loses its magnetism and the armature returns to its de-energizedposition. This allows the contact(s) return to the de-energized or normal state. A relay is a device in which a low value of current and / or voltage operates an electromagneticcoil. This coil in turn operates a contact or contacts, which control or switch a high or relativelyhigh value of current and / or voltage.

2.4.4. CONTACTORS

Contactors are very similar to relays. They are specifically designed for switching loadcurrents. They are used to supply electric motors, heaters, lamps etc. Contactors are designedfor high switching frequency, long life and short switching times. The making / breakingcapacity of the main contacts is matched to the possible motor starting current. High valueoverload currents or short circuit currents can damage the main contacts, therefore protectionmust be provided by fuses or MCB’s.

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Generally contactors have three main contacts plus one auxiliary contact. The current rating ofthe main contacts will depend on the load to be switched and may be as low as 10 Amps or ashigh as 2000 Amps. The current rating of the auxiliary contact(s) is generally around 10 Amps.

2.4.5. OVERLOAD PROTECTION

High temperatures have an adverse effect on insulating materials. It is essential therefore, thatelectric motors should be provided with protection against overheating. Excess current taken bya motor causes overheating. The protective devices most commonly used, detect this excesscurrent. However excess currents do exist during starting, but as these are not for long periodsof time they do not cause overheating. Fuses or MCB’s, cannot be used since the startingcurrent of the motor would cause them to blow / trip. It is therefore desirable for over-currentprotective devices to have a built in “time lag” to facilitate such starting currents. The overcurrentprotective device referred to above is called an overload relay. Fuses or MCB’s areused in conjunction with overload relays to provide protection against short circuits, earth faultsor faults in the main wiring. There are two types of overload device in use;

The thermal overload relay

The magnetic overload relay

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Overload unit auxiliary contacts

Thermal overload Relay element

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2.4.6. DIRECT ON LINE STARTER CIRCUIT

A DOL starter connects the three main lines ( L1, L2 and L3 ) directly to the motor terminals when the start button is pressed. The drawing of a DOL starter is generally done in two separate stages. These are called the Power Circuit and the Control Circuit.

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CHAPTER 3

3. PROJECT WORKS

3.1. PROJECT ON RAMUNITOF270l BANBURY MIXER.

There were several errors of the Ram unit of the 270L Banbury mixer. We proposed some solutions to correct those

errors by making some visits to the Kotugoda Central Mixing Plant. We got a lot of information from machine

operators and factory maintenance team. As we analyzethose information some solutions came out. There are only

some points have been extracted from those solutions.

Mountings of the Hydraulic Jack

In the current Banbary mixer it is used to mount the hydraulic jack to the mixer only by bottom mounting. But when

mounting the hydraulic jack only in bottom, it is not enough to create a proper mount. In that case when working the

Banbary mixer the hydraulic jack tends to vibrate and it causes to damage the oil seals, piston rod end of hydraulic

jack and more damages by misaligning the parts.

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Because of that to avoid that unnecessary vibration of the jack it can be included a upper mounting and to the jack

with an inside rubber bush to absorb the vibration. In the above design it can be minimize the errors due to vibration

of the hydraulic jack.

Feeding Door

Feeding door is also an important point of the mixer as observed. The current feeding door system of the mixer has

more errors. It is a sliding type door and it cannot stop the carbon dust and other chemical dust leaking to the

environment. As shown in below figure2.1 it can be seen that the RAM has gone down but the some compound has

not been delivered to the mixing chamber. So in the case again the RAM should get upper position and pull the

compound which undelivered and compress by the RAM. It is also a time wasting thing and affect to the production.In

the HF mixture it is provide a better seal and the error due to undelivered compound is not happened in that mixer

door. Because the RAM goes down after shut the door and there is no more space between the door and the RAM

moving path. But in the HF mixture it has a mechanism to make a seal for the feeding door shaft.It can be improved

the door to make a proper seal and to avoid error due to undelivered compound as shown in the figure 2.2.

In here, there is no need to provide a complex system to the feeding door shaft because the door shaft has been

shifted a bit away from the opening. But it can be make a perfect seal as shown in figure 2.2.

Figure 2.1 Figure 2.2

Lubrication System

The RAM unit makes movements always and when moving parts up and down it occurs more losses due to the

friction and generates lots of heat. To avoid those errors it should be provided a more reliable lubrication system to

the RAM unit. In the current RAM unit the lubrication system is not reliable.

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As

in the above figure it has been provided some main points which must be added lubricant to make an oil film between

parts. Oil seals must be added which are withstands to the heat if not the oil will leak out from the system and it can

be a reason to wear parts and generates heat.

RAM Cleaning Process

The current RAM weight cleaning process is done by the four air jets. But the all four air jets are in the one side of the

RAM weight and therefore RAM weight does not be cleaned properly.

The four air jets placed in the same side. It can be improved the RAM weight cleaning process by placing air jets

around the RAM weight as for proper cleaning it must be provide an automatic cleaning after few batches or it must

be provide information to operator to clean the RAM weight after every four or three batch mixing as observed.

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Hose Couplings

It can be observed that the hose coupling of the hydraulic jack of the mixture is not reliable. In current situation it can

be observe the oil pipes are not flexible and due to that reason if any vibration occurs in the hydraulic jack it is

affected to the damage the coupling point of hydraulic jack and the pipe. It can be seen that in the above figure 9.1

clearly.

Because of that it had it had to replace coupling recently and it affected to the production also. But in the HF mixture

it can be clearly identified that there has been included flexible pipes and proper couplings. As shown in the figure 9.2

it can be identified flexible pipes are more suitable to provide hydraulic fluid to the cylinders and it can be minimized

maintenance and increase the reliability.

3.1.1. BASIC ENGINEERING DESIGN PROCESS.

Engineering design is an orderly process of collecting, recording, and analyzing all the facts and data needed to arrive at a satisfactory solution to a problem.

When preparing an engineering design, The following basic steps should be followed for allengineering designs (regardless of complexity):

Identification of the problem and its scope.

Site Investigation.

Collection of basic design data.

Assembly and analysis of data.

Design.

Preparation of plans and specifications.

Review and approval of plan.

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3.1.2. Ram unit modification and Designing all parts in Solid Works.

As the first step the Ram box was measured and drawn in the Solid Works. We drew the all Ram unit as the Ram

box we measured. The old 270 L mixer Ram unit had a problem with the bottom hydraulic jack mounting part. It was

a small fixing part as shown in below.

It was fixed with only six bolts to the Ram box and when load is applied on that, the bolts tend to loosen. That was a

main failure of the old Ram unit. Other problem was the thread failure of link between hydraulic jack and the moving

part of the Ram. It has been proposed to replace the old hydraulic jack (80mm internal diameter) with 140 mm

internal diameter hydraulic jack.

Then new jack fixing part was designed as shown in below figure. When we designed it we had to consider some

points to make it perfectly.

Not to disturb existing parts of Ram box.

As an example feeding door shaft and other things.

Lower the damages to the Ram box.

We used existing bolts to fix as far as we can to avoid weaken the Ram box.

Considered about easy of disassemble the part.

As an example we made holes to remove the pin. If that holes were not exists it will very difficult to remove

the pin.

Simulate the newly designed part by applying the load.

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We used Solid Works simulation to check whether the part can be withstood to the loads applied.

New designed part The part in the Assembly

Main Assembly of Ram Unit

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3.2. TYRE HANDLING UNIT FOR PRESS LINE

3.2.1. Factory visit and Production Configuration

The Midigama air tyre division has been requested a tyre handling system for a press line of Module 07. Then we

had to go on a factory visit to Midigama air tyre division to observe about the press line.

The Details of Press Line and tyres of Mod-07 for the handling system.

Production Configurations,

a) Number of Press in Mod-07 Press Line - 28 No’s b) Ave. Number of tyres for press per 24hrs. – 15 No’s (Min. 13 No’s & Max. 16 No’s) c) Ave. Cycle Time – 86min (Min. 80min & Max. 100min) d) Exhaust Time – 6min e) Tyre Handling Time – 4min

Tyre Details

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Site Plan of Module 07 Press Line

Then we studied the actual situation of the press line and compared with the request they send. There were all

twenty eight press machines which consists of fourteen press machines in one line.

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We studied site plan of the press line and had to consider about the space available there. As the requirements of the

workers of the press line and the feedbacks we got, we have to design a suitable tyre handling system as they

required also.

After observation of the line we decided to change the design we made before the factory visit and make a new

design which is most suitable and easy of handling to the operator.

After an idea came to make a gantry and a handling machine. But when considering the space available and the

weight of the tyre it was harder to apply that situation.

We got a lot of details from the factory visit and we had to think on a different way to make a batter tyre handling

system.

3.2.2. Designing Process of Tyre Handling Unit

A tyre handling system for Midigama air tyre division was designed by using Solidworks software. They required to

load the green tyre to press machine and unload the tyre after cured.

It was very difficult to load the green tyre to the press machine to the workers because the weight of the tyre is more

than 90kg.

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To clamp the tyre we used two jaws as above figure, by using two hydraulic cylinders to the opposite directions. The

moving distances and the curved shape of the jaws was decided by considering the outer diameters of the largest

cured tyre. To avoid damages to the tyre it was used few rubber plates as shown in above figure.

Another problem was the gap between upper and bottom mold of the press machine was not enough to load the

green tyredirectly , because of the bladder has some height.

Therefore we had to angle the green tyre and load it in to the press machine. For that we used a rotating link with a

hydraulic jack as shown in above figure.

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Two telescopic jacks are used to make horizontal and vertical movements. An electric motor is used to make a

circular movement at the bottom.

It is proposed two tyre handling units for one press line. Then , only four units require to all twenty eight press

machines.

The final assembly of the tyre handling unit can be seen in below figure and it is proposed a hydraulic unit and a

electrical panel board to fix to the tyre handling unit.

Final Assembly of Tyre Handling Unit

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3.3. ANALIZING THE FAILURE OF DROP DOOR SPLINE SHAFT

3.3.1. Study of Spline shaft failure of the drop door

The drop door of 270L Bambury mixer was failed by the spline shaft of the coupling. To analyze that issue first all

parts were modeled and assembled them in Solid Works. The spline shaft fails as shown in below figure when the

torque was applied on it.

By using hydraulic oil pressure of the hydraulic jack and the diameter of the piston, the torque applied on the spline

was calculated.

Then by the use of Simulation express option the torque which calculated before was applied on the spline shaft and

observed that how it behaves.

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When we analyzing by applying forces on teeth of the spline shaft as above figure, it was observed that the maximum

Von mises stress generated in the spline shaft is closer to the yield strength of the material.

The maximum von mises stress generated was 2.37 x 108 N/m2 and the yield strength of cast alloy steel was 2.41

x108 N/m2 . Then we can assume that material after yielding point it will not get its original position again.

The displacement of the splines were as shown in the following figure and the maximum displacement of the splines

were 8.5 x 10-2 mm.

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3.3.2. Spline shaft Modification

As a solution for the failure of spline shaft we introduced a new design by reducing number of teeth and the depth of

a teeth of spline as shown in below figure.

As a result of the modification the maximum von mises stress built in the spline shaft was reduces to the 1.61 x 108

N/m2 from 2.37 x 108 N/m2 . Then it will not be failed due to plastic deformation.

3.4. MOTION STUDY

In the EkalaTyre Division 02 we did a motion study to identify the time wasting points in the solid tyre production line

which is called T10 press line. Motion study is a study which is used to analyze all the motions of a big process and

to get a decision about that process. In here our main object was to identify the most time consuming and wasting

part and give a solution for that case of part.

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First, a big process of solid tyre production were divided in to small sub processes. Then the time taken to each sub

processes were recorded while considering tyre sizes and press machine number used. Then it is easy to analyze

data and give more suitable solution cause then we know the distances to each press machines and tyre sizes are

important because it is taken different times to heel rolling, soft rolling and thread rolling processes according to the

tyre.

Then all the data were tabulated in a excel sheet and got average values for each and every sub processes. Then

the graphs were derived from the data as show below.

When observing the graph it can be simply identified that the time taken to travel to target destination is considerable

after weighing process. Is unable to reduce the time taken to move to the heel rolling, soft rolling and thread rolling

processes. So we don’t consider about that times, but to reduce the time taken to travel to the target destination, it

can be proposed an automated system and then it can be increased the production.

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3.5. SAFETY CABLE FIXING PART DESIGN FOR GANTRY

The casting plant of Loadstar has a 10Ton gantry and it’s working height is more than 20feets. If some error occurs

the technicians have to climb on the gantry and repair the hoist and for cleaning purposes they have to climb on the

gantry. But it has a safety hazard the climbing on the gantry. Because of that it has been proposed to fix a safety

cable to avoid that safety issue.

So, I have to design two supports for both end of the gantry and had to think about how to fix them to the gantry. As a

result of a factory visits and the information I got from the factory. I designed the following assembly as a solution for

both issues.

After that I had to do a Simulationfor the designed part to check whether it can be withstand to the required loads and

stresses. By using SolidWorks simulation express option I did the simulation and generated the following report

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Model Information

Model name: moving part

Current Configuration: Default

Solid Bodies

Document Name and Reference Treated As Volumetric Properties Document Path/Date

Modified

Fillet1

Solid Body

Mass:136.624 kg Volume:0.0177433 m^3

Density:7700 kg/m^3 Weight:1338.91 N

Jun 05 16:02:32 2014

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Material Properties

Model Reference Properties Components

Name: Alloy Steel Model type: Linear Elastic Isotropic

Default failure criterion: Max von Mises Stress Yield strength: 6.20422e+008 N/m^2

Tensile strength: 7.23826e+008 N/m^2

SolidBody 1(Fillet1)(moving part)

Loads and Fixtures

Fixture name Fixture Image Fixture Details

Fixed-1

Entities: 1 face(s) Type: Fixed Geometry

Load name Load Image Load Details

Force-1

Entities: 1 face(s), 1 plane(s) Reference: Front Plane

Type: Apply force Values: ---, ---, 5000 N

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Mesh Information Mesh type Solid Mesh

Mesher Used: Standard mesh

Automatic Transition: Off

Include Mesh Auto Loops: Off

Jacobian points 4 Points

Element Size 28.7131 mm

Tolerance 1.43566 mm

Mesh Quality High

Mesh Information - Details

Total Nodes 16508

Total Elements 8453

Maximum Aspect Ratio 8.8295

% of elements with Aspect Ratio < 3 96.1

% of elements with Aspect Ratio > 10 0

% of distorted elements(Jacobian) 0

Time to complete mesh(hh;mm;ss): 00:00:05

Computer name: SAMZERO-PC

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Study Results

Name Type Min Max

Stress VON: von Mises Stress 1834.79 N/m^2 Node: 630

8.77602e+006 N/m^2 Node: 16496

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moving part-SimulationXpress Study-Stress-Stress

Name Type Min Max

Displacement URES: Resultant Displacement 0 mm Node: 169

0.0594986 mm Node: 14837

moving part-SimulationXpress Study-Displacement-Displacement

Name Type Min Max

Factor of Safety Max von Mises Stress 70.6952 Node: 16496

338143 Node: 630

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moving part-SimulationXpress Study-Factor of Safety-Factor of Safety

Name Type

Deformation Deformed Shape

moving part-SimulationXpress Study-Displacement-Deformation

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CHAPTER 4

4. CONCLUTION Loadstar Jinasena Industrial Park is a very important place to train for especially for any Mechanical engineering student, who wish to obtain a good training with a overall knowledge. I think I was fortunate to have this chance as a Mechanical engineering student. This was my first industrial experience that I ever got. I was really able to get a good knowledge about how the industry behave and how we have to behave in an industry. Loadstar has good vision and good plan about the trainees. All the training works are manage from the training center and in JIP there is a training division with an experienced engineers too. All the technicians and workers give their helping hands to the training student well. According to their gaudiness trainees will be able to get a good training within their training period in loadstar premises. The treatments at Loadstar to the trainees are excellent. So, I believe that this is one of best companies in Sri Lanka to be trained as an engineering student. They conduct a well-organized schedule for the trainees with giving more valuable projects to them. I am also fortunate to involve directly to their projects. The guidance is carried out by a supervisor for each trainee when doing the project and training activity is very important. I am glad to say that Loadstar have very proactive staff, while they are doing their works with well manner they pay their attention to the trainees also. They consider trainees are also their responsibility. I like to make a chance to give my gratitude to this wonderful place, and that wonderful people, who give their maximum support to me in my training period. Finally I think I spent really valuable time period in my life time. I could able to gather most of things to my personal life and my professional life.