Inplant Traing

7/27/2019 Inplant Traing

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Ceat Ltd, Halol, Vadodara Dept. Of PS&RT, CUSAT

IN-PLANT TRAINING REPORT

Done At

CEAT TYRE LIMITED

Halol, Vadodara, Gujarat

Submitted in partial fulfilment of the requirements for the award of thedegree of

Bacelor o! Tecnolo"#

In

Polymer Science & Engineering

B#

Mu$e% $u&arRe"'No()*+**

De.t' o! Pol#&er /c0ence and Ru11er Tecnolo"#

2C3/AT, Coc0-++, 4erala5

APRIL 2013

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ACKNOWLEDGEMENTS

I thank to GOD almighty for giving me courage and pleasure to pursue my task

successfully throughout my project work.

I feel privileged to my In-plant training and Project work in Indias leading tyre

manufacturing industry CEAT LTD,!alol "adodara #ujarat.

I wish to e$tend my special thanks Mr T!m Th!ma" %E$ecutive director & Mr G

#$$i%ri"h$a$%"P !ead-design and compounding '&( andMr &a'!( G)!rg) %"P

!ead product management '&( for giving me such great opportunity.

I e$press my gratitude toDr S*$il KN K*tty !)( Dr KE G)!rg) %Professor Dr

Ra$i &!")+h%Professor Dr Th!ma" K*ria$%Professor (ept. of Polymer Science &

'u**er +echnology ,S+ /ochi for arranging my training and project work at ,eat ltd.

+he person most thanked is MR S*ith Nair #0 & head of compounding '&( ,eat

1td. !alol #ujarat. !is invalua*le and professional guidance personal attention e$pertise

and encouragement throughout the course of this work have ena*led me to complete the

same successfully.

I gratefully acknowledge Mr Lalit Pa$-)y%"P production ,eat 1td. for his e$pertise

proper guidance encouragement during the work.

I wish to e$tend my sincere thanks to Mr G)rg!ry A$t!$y %#0 & plant head Mr

A"h.ath %*mar %0anger tech. and Mr/)llra for their support and encouragement

during my project work.

I acknowledge at this moment the appreciations recognitions favors advices and

encouragement from all amily m)m()r" of ,eat 1td. !alol "adodara has given to me.

I once again sincerely thanks all those who have helped me directly and indirectly during

my project. I take this opportunity to thank all a'*lty m)m()r" "ta" ! !*r

-)+artm)$t a$- my -)ar 'la""mat)"for supporting me throughout my college life.

I heartily acknowledge my +ar)$t" a$- amily m)m()r" for their love appreciations

recognitions and encouragement.

M#KES K#MAR

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CONTENTS

1 INTROD#CTION44444444444444

44 3 5 6

2 STOCK

PREPERATION4444444444444 7

5 78

3 T9RE

:#ILDING4444444444444444

7; 5 83

6 T9RE

C#RING44444444444444444

86 5 8 5 ;2

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8 TESTING ON RADIAL

T9RES444444444 ;3 5 ;>

INTROD#CTION+yre is composed of fi*er reinforced ru**er matri$ nd the main

functions of a tyre is to cushion the ride and provide some means of direction

to the vehicle. 2ut *oth the concepts are opposing. 3hen the cords are at an

angle parallel to the circumferential direction of the tread tyre will give good

directional sta*ility and steering response. 2ut riding will *e harsher. 3hen

the cords are at right angel to the tread circumference the ride will *e softest

and the lateral sta*ility will *e poor. +he *ias tyre was constructed in terms ofa compromise in cord angle to get intermediate performance properties.

2ut the idea *ehind radial ply tyre was to eliminate this compromise in

cord angle and to divide the carcass into two parts. )ne to provide the

desired ride 4uality i.e. radially running plies cords and the other to provide

directional 4ualities.

radial tyre consists of a radial carcass and a sta*ili5ing *elt

underneath the tread. 'adial carcass consists of reinforcement layer of

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fa*ric cords running from one *ead to another at 677to the tread ,entre

line and is designed to hold the air pressure. +he sta*ili5ing *elt consist of

reinforcement layer of high modulus fa*ric cords or steel running

circumferentially around the carcass at an angle of 89-::7

to the tread,entre line *eneath the tread and designed to transmit driving *reaking

and cornering tor4ue. +he function of tread and the sidewall are separated

to a great e$tent such that major shortcomings of *ias construction are

eliminated. +his construction re4uires greater num*er of components than

*ias tyre and very precise placement of component is also necessary.

flow diagram is drawn in ne$t page illustrating steps involved in

manufacturing of passenger car radial %P,' tyre.

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.

6

ead !e"#"$%

"'"$% area

Pl a$d elt Cale$dar"$

Rad"al pl( )*t

+'tr*!"o$

Copo*$d

elt )*tt"$%

Tread- S"de

all

ead

/ree$ t(re 0*"ld"$%

C*r"$%

Tr""$%

Pl(

elt

$$er l"$er

"$al "$!pe)t"o$

U$"for"t( te!t

are o*!"$%

Ra ater"al!


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2 STOCK PREPERATION?

C!m+!*$-i$g Mi@i$g?

1ike *ias compounding radial tyre compounding is normally done in

three stages- master *atches repass and final. In ,E+ tyres ltd. !alol radial

compounding is done in two separate *an*uries provided with modern

accessorise. )ne is for final compound and other for master *atch.

2oth *an*uries consists of two hori5ontal rotors with four wings. +hey

are rotated at a synchronous speed which produce a very high shear rate

during mi$ing. ;or the master *atch mi$ing 2an*ury instead of dump mill and

cracker mills a twin-screw e$truder and a two-roll calendar are used for sheet

out. +his will produce proper *lending with very high uniformity among the

compounds. +hey are provided with a +.,. at cham*er sides rotors and

drop door to maintain highest level of shear during the mi$ing process. +he

final *atch producing 2an*ury is e4uipped with a +.,. on the ram in addition

to the a*ove-mentioned places for *etter temperature control. 'am of *oth

*an*uries is operated *y hydraulic mechanism for o*taining higher pressure

with *etter uniformity.

;or a synchronous rotor the large wing has a heli$ angle of :


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RAW MATERIALS?

+he *road classification of raw materials used for manufacturing tyres

is@

0aterials used for various ru**er compounds

2 0aterials used for tyre reinforcements

, u$iliary materials

A Mat)rial" *")- !r tyr) '!m+!*$-"

+he essential ingredients used in a ru**er compound *y its function is

as given *elow

'aw ru**er

ctivators

'einforcing agents

Process oils

ntidegradants

"ulcani5ing agents

ccelerators

Process aids

Special additives

'u**er as such is a soft semisolid material which does not have anyproperty re4uired for a tyre compound vi5. elasticity strength hardness tear

end fle$ resistance 'aw ru**er when heated with vulcani5ing agents

*ecomes elastic stronger and harder and this process is called vulcani5ation.

!owever the ru**er is to *e heated for :=hrs for achieving full vulcani5ation.

+o increa>e the speed of vulcani5ation accelerators are used. +hus with

vulcani5ing agents and accelerators the vulcanising time is reduced to >7

minutes at practical vulcani5ing temperature. ctivators are used to improve


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the efficiency of accelerators and it improves the strength and elasticity of the

vulcani5ates.

vulcani5ate thus made of raw ru**er vulcani5ing agents

accelerators and activators are still soft. ;or improving the strength hardness

tear wear and fle$ properties suita*le for a tyre compound reinforcing agents

are added. +he major reinforcing agents are car*on *lacks and silica.

Incorporation of fillers is difficult and to facilitate easy incorporation process

oils are added. 0ost of the ru**ers are suscepti*le to degradation when

su*jected to heat fle$ and weather and to take care of this antidegradants are

added.

Process aids are added to the compound to improve processa*ility at

e$truder calendar or to improve surface tack.

)ften low cost fillers are added to reduce cost *ut this method is used

only for some particular compound application. Sometimes special additives

like corrosion inhi*itors *onding agents hardening agents are added for

specific vulcani5ate properties.

RAW RUBBERS:

Nat*ral R*(()r

Aatural ru**er occupies the top position as the general-purpose ru**er.

It gives good strength tear wear and fle$ resistance good crack growth

resistance good processa*ility and tack low heat *uild up and good a*rasion

resistance. It is slightly inferior in crack initiation skid resistance and traction.

It finds application in carcass compounds tread compound for heavy-duty

truck tyres. 'SS-= and ISA'-:7 are the major used grades.

,repe grades are used in non-critical applications.

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R)'laim R*(()r

'eclaim ru**ers are de-vulcanised ru**er manufactured from waste

ru**er products. +his is however a low cost ru**er and has good

processa*ility. !owever due to inferior dynamic properties it finds applications

like (" tyres and flaps

Styr)$)5(*ta-i)$) R*(()r S:R

+his is the first synthetic ru**er developed. It offers good strength and

tear good crack initiation resistance good a*rasion resistance good

processa*ility. It also offers very good skid resistance and traction. 2ut it has

inferior crack propagation and higher heat *uild up and poor tack.

S2' is mainly used in passenger tyres *ecause of its high skid

resistance and traction. It is used generally in *lends with P2( for *etter fle$

resistance and traction. S2' is also recommended for high hardness *ead

compound.

P!ly(*ta-i)$) R*(()r

It offers the *est a*rasion resistance and fle$ resistance. It has low heat

*uild up good heat resistance and good weather resistance. It is inferior in

processa*ility skid resistance traction lug chip resistance and surface tack. It

finds application in sidewall compound and light duty truck treads in *lends

with natural ru**er. It is also used for passenger treads in *lends with S2' for

*etter wear and fla$ resistance

:*tyl R*(()r

+he outstanding air impermea*le together with high heat resistance

makes *utyl the *est ru**er for inner tu*es. Its halogenated varieties are used

in tu*e less tyre interlinear. It also finds application in curing *ladders *ecause

of its high heat resistance EP(0 'u**er.

+his is new generation synthetic ru**er which offers e$cellent heat and

weather resistance and good fle$ resistance. It finds application in tu*es

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where it reduces the softening of *utyl tu*e in service. It is also used for radial

tyre sidewallB especially in white sidewall a *lend of A' with halo *utyl is used

for weather resistance and colourfastness.

: /#LCANISING AGENTS

SULPHUR

The cross linking of rubber is generally achieved by addition ofsulphur or sulphur donors.

+here are two types of sulphur

Solu*le sulphur

Insolu*le sulphur

+he commonly used sulphur donors are

+0+( %+etra methyl thiuram disulfide

(0(S %(imorphoilinyl disulfide

+he sulphur donor system gives *etter heat resistance than sulphursystem *ut inferior fle$ resistance.

ACCELERATORS

ccelerators are classified *ased on the speed of vulcani5ation.It is also classified as primary accelerator and secondaryC accelerator.

Secondary accelerator is the one which is used as *ooster to a

primaryaccelerator +he commonly used accelerator in tyre industry is as

follow@

T9PE CEMICAL NAME #SE IN T9RE

Slow (iphenyl guanidine Secondary accelerator in

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ccelerator S2' compounds

0ediumfast

accelerator

,yclohe$yl*en5othia5ylSulphenamide%

,2S

+ertiary *utyl*en5othia5ylSulphenamide %+22S

0orpholinothio*en5othia5ylSulphenami

de

%02S

(icyclohe$yl*en5othia5ylSulphenamide%(

,2S

sed in *ead compounds

Primary accelerator in

S2' compound

3idely used in tyre

industry

sed mainly in retread

materials

;ast

accelerator

0ercapto*en5othia5ole%022+

0ercapto*en5thia5ole disulfide%02+S

2utyl tu*e

;lap compounds

ltra fast

accelerator+etramethylthiuram disulfide%+0+(

+etramethylthiurammonosulfide%+0+0

0ainly for *utyl and

secondary accelerator for

S2' compounds

Secondary accelerator in

tread *ase compounds

Super ultra

fast

accelerator

Dinc diethyl dithiocar*amate%D(,'epair compounds

ACTI/ATORS

+he general activators are 5inc o$ide and stearic acid. Instead 5inc

stearate can *e used *ut a higher dosage is re4uired.

C REIN=ORCING AGENTS?

+he commonly used reinforcing agents are car*on *lack and

precipitated silica.

+here are three types of *lackC *ased on the manufacturing techni4ue

they are

,hannel *lack

+hermal *lack

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;urnace *lack

In furnace *lack there are different grades characteri5ed *y the particle

diameter and structure. s the particle diameter decreases the reinforcement

increases. !igher the reinforcement higher the strength the modulus tear

fle$ a*rasion resistance and higher the heat *uild up. s the structure

increases modulus increases *ut fle$ fatigue resistance decreases. +he heat

*uild up increases slightly.

Precipitated silica offers *etter tear resistance than car*on *lack.

!owever the heat *uild up is higher and silica is not easily dispersi*le in

ru**er.

#rade

Particle

(iameter

%nm

Structure

%(2P Aopplication

S; :: 88: ?7+ruck treads cap sidewall and *ead

insulation.

;E; 8=? 8:7)uter ply cushion 2reaker tread *ase

,ompound S4ueegee

#P; ?7 67 Inner ply inner liner for tu*eless flap

Precipitated

silica>7 A 'adial tyres )+' tyre tread

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D PROCESS OIL

+hese are used to improve car*on *lack incorporation in a ru**er

compound and also to improve compound process a*ility at calendar and

e$trusion. Process oils are classified *ased on the "#,

,lass "#, Staining!eat

resistance

,ompati*le

'u**ersse

romatic 8 es #oodA' S2' P2

'eclaim

#eneral purpose

process oil

Aapthenic 7.6 0ild 2etter -(o- 3hite sidewall

Paraffinic 7.9 Ao 2est 2utylFEP(0+u*e

2ladder

E ANTIDEGRADANTS

,hemicals name Staining)$ygen

resistance

)5one

resistancese

Styrenated phenol Ao 0ild Ail 3hite sidewall

(ihydrotrimethylGuinoline 0ild #ood Ail,arcass

compound

cetone amine condensate Strong #ood Ail,arcass

compound

(i-aryl p-Phenylenediamine Strong "ery good 0ild+read and

Sidewall

(imethyl*utylparaphenylen

ediamine

"ery

strongE$cellent 0ild

+read and

sidewall

0icrocrystalline wa$ no Ail E$cellent+read and

sidewall

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= PROCESS AIDS

Process aids are those su*stances which are added to ru**er compound for

reducing viscosity of the stock for increasing tack for improving process

safety or for improving the surface finish. +he various types are given *elow@

+ype Aame ;eature se

Pepti5er

Dinc salt of

pentachlorothio

phenol

;aster *reakdown of A'

during master mi$ing

0astication

purposes

+ackifier

Phenol

formaldehyde

+ackifier I resin

;or *etter surface tack

Ply sidewall and

cushion

compounds

'etarder

,yclohe$ylthiopth

alimideImproves scorch

Safety

Practically added

in all compounds

G SPECIAL ADDITI/ES

15

,lass Aame pplication

(ry *onding

2onding agents

'; 'esin !000

Precipitated silica

;or *etter *ond strength In

SteelFglassFaramidskim compound

!ardening

agents

+hermosetting P;

resin

;or hard compounds like *ead

insulation filler etc

,orrosion

inhi*itor

,o*alt comple$es ;or steel cord skim compound for

'educing corrosion


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22 MIBING #NIT

In a ru**er industry mi$ing is the foundation step upon which every

further step is dependent on. 0i$ing is the most critical component of ru**er

processing. +he aim of mi$ing is to produce a product that has the ingredientsdispersed and distri*uted sufficiently thoroughly that will process satisfactory

in the ne$t process cure efficiently and give the re4uired properties for the

end application. 0i$ing re4uires deciding the formulation what e4uipment to

use and the times speeds pressures temperatures. +he aim should *e to

minimi5e the la*our energy and e4uipment cost per unit volume of product.

(ue to the partly elastic nature and very high viscosity of ru**er power

intensive sturdy machinery like mi$ing mills and internal mi$ers arenecessary.

In ,E+ +yres !alol there are two 2an*ury continuously in operation

to get compounded ru**er for further processing. mong two 2an*ury one is

for master mi$ing and another one for final mi$ing.

:AN:#R9?

+he 2an*ury mi$er is a tangential type internal mi$ing machine in

which two slightly spiralled rotors revolve side *y side toward each other

within a cham*er shaped like two short cylinders lying together with adjacent

sides open. +he cham*er has a top opening called hopper which can *e

closed *y a pneumatic means for inserting the material and a *ottom gate

which can *e hydraulically opened to drop out the contents after mi$ing.

+he 2an*ury is charged *y raising the ram completely out of hopper

and dropping in *ales of ru**er weighed up properly to fill the cham*er. +he

ram is then lowered under pressure and the ru**er forced and held in the

cham*er while it is kneaded and *lended *y the rotors. 2reakdown of ru**er

is accomplished *y the shearing action *etween rotor *lade tips and rotor

walls and *etween rotor-rotor with one rotor running slightly faster than the

other to prevent sticking to the *lades.

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:AN:#R9 CONSTR#CTION

+he physical demands upon 2an*ury mi$er are enormous. 'u**er is

e$tremely tough compounds are a*rasive pressures and temperatures

developed are high. ;or the purpose of description the machine parts can *e

divided into following categories.

A OPPER ASSEM:L9

RAM?

'am consists of a rod and floating weight. +he ram utili5es not only its

own weight *ut also an additional e$ternal force to e$ert a certain pressure on

the mi$. +raditionally the ram is operated pneumatically. n air-operated

piston in a cylinder holds it. In the raised position the ram *ottom is a*ove to

the hopper door allowing the introduction of material into the mi$ing cham*er.

+he ram is raised *y compressed lu*ricated air. It is lowered *y floating %no

air or *y regulated air pressure. Aormal pressure used is =.< -H.H /gFcm :.

Sealing of the pneumatic piston rod is a very sensitive design element.

nother pro*lem with the pneumatic ram is the variation of ram pressure ram

pressure decreases when ram goes down. "ariations in ram pressure have a

*ig effect in mi$ing 4uality.

+he tell-tail rod of ram indicates the position of floating weight. (uring

normal mi$ing the material inside the cham*er moves the ram up and down.

+he total up and down motion of the ram is directly indicated *y the tell-tail rod

to the operator who can there *y assess the status of the mi$ing process.+he floating weight may have several configurations

a Single slope " *ottom.

* Single slope ;lat *ottom.

c (ou*le ga*le " *ottom.

d (ou*le ga*le ;lat *ottom.

OPPER?

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+he hopper of the mi$er is simply a *o$ through which ingredients are

fed and through which the ram weight travels. +he front of the *o$ is a hopper

door through which material is fed through a conveyer. +he hopper door is air

operated and hinged at the *ottom. chute is provided near the hopperassem*ly to provide the weighed car*on from the day *ins *y means of

automatic car*on discharge system. ll hoppers are e4uipped with a method

for venting gases and powders which accumulate in the hopper area *y

means of air suction. +his makes the area near *y the mi$er clean and tidy.

TE PNE#MATIC S9STEM?

+he floating weight or ram cylinder and the cylinder operating the

hopper door are air actuated. +hese are actuated *y means of sensors fitted

near to the hopper assem*ly. +he flow of air to the weight and hopper

cylinders is controlled *y solenoid-operated valves which are actuated *y

switches on the 2an*ury control panel.

: MIBING CAM:ER

It is the section of the mi$er *elow the hopper assem*ly and a*ove the

*edplate. +he important parts of mi$ing cham*er are

CAM:ER SIDES?

+he portions of the mi$er that enclose the mi$ing cavity are the

cham*er sides. +hese sides consist of heavy shells *ored with laterally drilled

holes for the circulation of steam andFor water. +he internal surface of the

cham*er is treated with satellite for wear resistance.

END =RAME ASSEM:L9@

It supports the cham*er with rotors. Each end frame assem*ly

consists of the frame the rotor *earing seals and the rotor end plates. +hey

are made of heavy iron castings with spherical roller *earings including

thermocouple for *earing temperature measurement. +here are two ends in

the 2an*ury mi$er the water end and the drive end. +he water end is the area

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through which the heating or cooling water is introduced. +he opposite is the

connection point of for the machine drive arrangement. ,ooling water passes

through large drilled passagesB the design used causes tur*ulence of water

and good heat transfer. +he *ores are welded with hard wear resistantmaterial clamp plates and *olts secure the sides to the end frames which

ena*les the fitting on site of new sides without machining or causing serious

distur*ance to end frames.

ROTOR?

+he two rotors perform the mi$ing action *y rotating in opposite

direction and at slightly different speeds. Each rotor have *lade like

projections called wings. +he edge of the rotor wings are called 'otor tip. +he

rotors are set in the mi$ing cham*er so that the long wing of one rotor is

opposite the short of the other. In CEAT Tyr)", al!lB the rotors are = winged

designs. +his helps in the increase of the rotor surface area and *etter shearB

intern helps effective and faster heat transfer.

+he two types of rotor design are

8. +wo wing rotor

:. ;our wing rotor

two-wing rotor has one short wing and one long wing. four-wing

rotor has two of each. +he rotors turn within the cham*er toward each other

and at une4ual speeds. +his is done so that the relative wing-to-wing positions

are constantly changing. 2ecause of the shape of the rotor wings materials

are always sheared against mi$ing cham*er and then toward the other rotor.

+he curvature of the rotor wings causes the materials *eing forced *ack and

forth from one end of the mi$ing cham*er to the other. Since the rotors are

running at une4ual speeds the mi$ is also *eing pushed from side to side in

the cham*er. 'otors have varying speeds of rotation with faster *reakdown

*eing o*tained as speeds go up.

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+he rotors are one piece steel castings accurately shaped on the

mi$ing *lade profiles. +here are no internal joints which could cause leakage.

Steam or water circulating through the centre of each shaft controls the

temperature. 0ost rotors have spray cooling. Spray heads which have smallenough orifices to properly *reak-up the water stream are used.

D#ST STOP?

+here are four dust stops on each 2an*ury one at each point where

rotor shaft passes through the *ody. +heir function is to seal the mi$ing

cham*er around the rotor shafts. 1u*rication is critical for the satisfactory

operation of dust seal. +wo types of dust seals are in use ;! and SS.

In the ;! type dust seal hydraulic cylinders are used to load the

sealing rings against the rotor ends they are so arranged that as the rotors

move a$ially during mi$ing the sealing rings are always in contact with the

rotor ends. +he frictional heat generated *y ;! dust stops is low and heat

sensitive stocks can *e mi$ed at high rotor speeds without cured particles

*eing formed. +he design eliminates all areas where material could *e

trapped and su*se4uently causes contamination.

In the SS type dust seal design the sealing faces are preloaded *y

springs and additional sealing pressure is generated during mi$ing *y a small

process oil feed which loads the *ack face of the floating ring and which

cannot escape *ecause of the compound in the mi$ing cham*er. floating

metal split ring rides in a collar against the *ack of a flange on the rotor end

plate. +hese two surfaces are kept flooded with light ru**er process oil and

as the compound forces its way into this joint this oil traps and holds it. ny

e$cess oil enters the *atch and is harmlessly a*sor*ed.

Earlier rotating 2a**itt or *ron5e sealswere usedB *oth the life and

sealing of these were poor. ,ompounds and ru**ers were forced through the

seals and were lost their way into *ron5e *earings on which rotors turned and

damaged them and journals. ;loating rings of tin nylon and many others weretried *ut jamming of journal rings resulted in failures.

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DISCARGE DOOR?

;''E1 ; :?7 2an*ury is furnished with drop type discharge door.

+he drop door is mounted on a support shaft which pivots parallel to the shaft

rotor. +he offset hinge arrangement allows swinging down and away from the

door opening permitting the finished *atch to discharge. hydraulic rotating

device called ')+, opens and closes the door. hydraulically operating

door latch locks the door in place when the door is closed and creates a tight

seal.

)lder *an*uries are e4uipped with a wedge shaped doors which slide

hori5ontally on a pair of rails into position. +he rails lift the door very slightly as

it reaches the closed position *ut wear on rails is rapid. 1arge pistons move

them and demands close original fitting and proper maintenance to prevent

leakage. Proper maintenance of the piston and rails are difficult and

e$pensive. nd failures which prevent the opening with a *atch inside can *e

disastrous. +heir movements are also slow. +he new drop door type is faster

and thus shortens cycle times. Some pro*lems of metal lining failure and

metal failure in swing arms have noted in them.

+he drop door top has passages with inlet and discharge fittings for the

circulation of cooling water or steam. +he door top is normally cooled to

prevent the sticking of stock at the time of discharge. ,ooling or heating the

door top is also effective in controlling the *atch temperature. +he discharge

door profile has an ape$ to eliminate Cdead spotsC while allowing the re4uired

thermocouple projection. +wo thermocouples are sometimes fitted in the door

one for normal operation and one for a safety override.

MIBING ACTION?

It is a popular misconception that all the mi$ing in a *an*ury takes

place in the gap *etween the rotor tips and the cham*er walls. t the start of

the cycle when the polymer is normally in large pieces and the powders are

still loose the initial *reakdown and mi$ing takes place in the large space*etween the rotors and against the door top. s the material softens flow over

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the rotor tips starts to take place *ut until the viscosity of the mi$ has fallen

sufficiently most of the work is done *etween rotors along the rotor heli$

angles and *etween rotors and discharge door top. +he area just in front of

rotor tip is similar to the nip of a mill and causes internal shear in the material.

+he mi$er should *e cooled to remove heat generated *y the

mechanical energy of mi$ing. !eat transfer and cooling efficiency is

dependent on the temperature differential *etween material *eing mi$ed and

machine components. t the start of the cycle when the feed material is cold

and stiff most work is done *etween the rotors as the mi$ing progresses the

material softens and deforms to make e$tensive and close contact with the

rotor mi$ing cham*ers walls and door top at which point they all are availa*le

to transfer heat from compound to the machine components and so to remove

it *y the cooling water. +he material at the door top is su*jected to high

pressures and a highly tur*ulent action.

C 9DRA#LIC S9STEM

+he discharge door the door latch dust stops and grease pumps are

actuated *y hydraulic oil under pressure. +he hydraulic system consists of two

major assem*lies the pumping assem*ly and the control valve assem*ly.

P*m+i$g A"")m(ly?

,onsist of a motor driven vane type mounted on a reservoir tank. )il is

pumped to the control assem*ly which directs high-pressure oil to various

components of the system.

C!$tr!l al)"?

,ontrol valves are electric solenoid type and are energi5ed from the

2an*ury control panel. +hese valves are providing directional control for the

hydraulic fluid so that the drop door can *e opened or closed and the door

latch engaged or disengaged.

D ACCESSOR9 E#IPMENTS

22


23/82


1 W)ighi$g '!$)y!r" a$- ))-i$g '!$)y!r

Each 2an*ury is e4uipped with electronic weighing conveyor *alance

and feeding conveyor. Electronic weighing conveyor has two load cells with a

capacity of


24/82


day *ins automatically get filled with car*on *lack when the lower limit of the

car*on level is reached.

+he *lack stored in the day *in is collected to a hopper near to 2an*ury

with an automatic weighing system and conveys to 2an*ury through a chute

opening at the sides of the hopper assem*ly.

+he parameters affecting the easy fluidisation and conveying of car*on *lack

areB

0oisture content

Pellet hardness

Pour density

;ineness content

Pellet si5e distri*ution

3 T)m+)rat*r) '!$tr!l *$it

+he introduction of drilled sides improved rotor cooling and *etter water

circulation in the door top coupled with rotor action has dramatically improved

the cooling efficiency of *an*ury mi$er. 3hen the surface temperature of the

metal in contact with ru**er is too low the ru**er slips on the cold surfaces.

;or good dispersion and *etter mi$ing it is necessary to put shear strain

energy into the mi$ this can occur only when the ru**er is gripped *etween

the rotor tip and cham*er wall or *etween rotors. ;or this reason it is not

desira*le to have the mi$ing cham*er too cold as the frictional contact

*etween ru**er and metal is influenced *y temperature.

+, assem*ly consists of a tank divided into three divisions each

receiving cold water and hot water and over flow water which is corrected for

temperature. 3ater from rotor cham*er and drop door is mi$ed with factory

cooling water at >?->97,. +his mechanism

of sensing and actuating the water flow is done *y sets of solenoid valves.

24


25/82


+hese temperature corrected water is then circulated *y means of > pumps

with varying capacity depending upon the amount of water to *e circulated.

0i$ing of the compound should do as per timeFtemp given on the mi$ing

specification card.

6 D*"t '!ll)'t!r"

2an*ury is e4uipped with dust collectorB this is to collect the fly off dusts

of car*on *lack chemicals and vapours. +he car*on dust collector system is

designed to return the car*on *lack into one place from all 2an*ury.

7 Oil "t!rag) ta$%"

+here is a centrali5ed tank for oil storage. +his is connected to the

2an*ury through pipelines. +his oil is collected in small tanks kept near*y

2an*ury. +here are : tanks one for process oil and the other for hydraulic oil.

8 Oil +i+)li$)

)il pipelines are used for delivering different oils. (ifferent oils

collected are process oil for mi$ing & for dust seals and hydraulic oil for

pressure application mechanism. )il is o*tained *y operating solenoid valve

which in turn operates the diaphragm valve of pipelines. )il is measured in

litters in the cali*rated measuring tank. )il pipelines are connected to the

measuring tank with diaphragm valve for control. +he oil pipelines are

e4uipped with electric heat tracing to maintain the oil temperature at around

H7 degree

; Oil 'harg)r

2ottom of the oil tank is connected *y a pipeline with motor driven

pump which injects oil into the 2an*ury through a pipeline. )il is charged to

the 2an*ury from *oth front and *ackside at side-*ottom level through oil

injecting valves. +hese are non-return valves. +he measured volume of oil is

taken into the oil charger from the measuring tank *y operating diaphragm

valve of the tank and is held till the specified temperature %H7 7, in the mi$ing

cycle is reached. fter each addition oil for the ne$t mi$ is collected andweighed properly and kept ready.

25


26/82


:at'h ! mill

n 9=-inch mill has *een provided in each 2an*ury. +he *atches

dumped on mill from the 2an*ury is further mi$ed and passed directly on to

the *atch off unit. +he num*er of cuts given is two for master and one for final

*atches. In the mill the compounded is *lended well and sheeted to the

re4uired width and thickness to effectively cool the compound. 2lender *ars

are provided to facilitate the cross mi$ing action there*y attaining more

uniformly mi$ed compound.

10 :at'h ! *$it

,omponents of the *atch off unit

1 Ta%) a.ay '!$)y)r5+i!t)- ty+)? 5

+his is e4uipped with varia*le speed drives to control the speed of

*atch off.

2 Im+r)""i!$ +ri$t)r *$it? 5

+his is to print the compound code *y impression method. +his

identification further helps to sent sample to the 'heo la* without any

am*iguity in the material code.

3 Sh))t !*t mill? 5

+his is in si5e similar to that of dumping mill. +his is e4uipped with knife

arrangement and correct nip gap setting to get re4uired gauge and width to

the sheet. +he compound from this mill is conveyed to the dipping tank.

26


27/82


6 Di+ ta$% -!*(l) '!m+artm)$t .ith "tirr)r", 'ir'*lati$g +*m+" a$-

'!!li$g? 5

(ip tank contains diluted soap solution to avoid sticking of ru**er

compound at the lay down unit. Soap solution that overflows or moves

outside the tank is collected in an underground tank. +his collected soap

solution is filtered and pumped to the dipping tank to avoid the material loss.

+o maintain proper concentration of soap solution and to ensure the mi$ing of

pumped soap solution stirrers are also provided.

7 P*ll !*t m)"h ()lt .ith h*gg)r '!$)y)r"? 5

+he compound after dipping is pulled *y two-mesh *elt moving together

*y enclosing the compound. +his mesh provides dripping of e$cess soap

solution though the holes.

8 =)"t!!$ '!!li$g ra'% .ith a$"? 5

+his is the longest portion of the lay down unit. +his contains moving

chain *elt with *oth sides connected with *ars. 'u**er sheets from the

hunger conveyer are fed to the moving *ars of the cooling rank. +hese *arsact as hangers for the ru**er sheet and maintain specific loop length. +his

length is maintained to ensure proper drying of the sheet. +he entire length of

the cooling rack is fitted with =-< sets of cooling fan units on *oth sides. Each

fan unit contains =-9 individual fans. Sides are covered *y metallic covers to

ensure the retention of the cooling air.

; P)$-*l*m '!$)y)r


28/82


facilitated packer stacker system at few *an*uries. +his is a wigwag lay down

system which automatically lays down the compound without any manual

operation with proper laying of sheets with e$cellent consolidation.

8: 3eighing ta*le@ -

sually a skid consists of = *atches from *an*ury. +o check this

parameter each skid is taken to the weighing ta*le for weightment.

PROCESS?

+ake off section is situated in front of dip unit with two adjusta*le knives

having a cutting width of H77-677 mm. It includes a hinged take off conveyerwhich receives the ru**er sla* from the mill and conveys it to dip tank. +he

take off conveyer is provided with an impresser type printer to imprint figures

into ru**er sla*.

t the *eginning of the *atch off unit compound sheet is dipped into the

anti tack solution. +he dip unit is a sheet steel reservoir mounted in a

structural steel frame. fter passage through take off the ru**er sla* is

received *y a *elt this *elt conveys the strip through dip solution and

thereafter to the cooling festoon rack. +he ru**er is retained on *elt and

guided upwards *y hugger *elts. 2atch is carried in continuous sheet form

over the chain *ars running in cooling conveyor. t the cooling conveyor

cooling fans are mounted one side of the conveyor which e$pedites cooling

compound sheets on to the am*ient temperature.

Stock code is em*ossed and written with crayon throughout in all

*atches and compound code is tied to the last sheet of the each *atch at the

point of lay down in order to distinguish *etween different *atches. 2an*ury is

e4uipped with fi$ed *ar chain cooling conveyor system and the other end has

*een mounted with wigwag system. +he compound sheets are passed

through the wigwag and laid on the skid in continuous sheets.

C!m+!*$-i$g "tag)"?

2


29/82


(epending upon composition and processing re4uirements

compound mi$ing is done in following stages.

Ma"t)r (at'h mi@i$g?

t master *atch mi$ing stage ru**er is intimately mi$ed with fillers

processing aids activators antio$idants wa$es etc. 0aster *atch mi$ing is

usually done at temperatures around 8>7-8H7 Jc. 0aster *atching improves

the physical properties of those compounds where a high degree of car*on

*lack dispersion would *e achieved. +he master *atches can *e varied

depending on the compound i.e. the master *atch recipe may *e the same

as the compound recipe *ut without curatives or it contains only ru**er filler

sand some softeners.

Since high speed and high- pressure internal mi$ers are used for

master *atching it is not advisa*le to incorporate accelerators in the master

*atch as the temperature of the ru**er is likely to e$ceed. +he master

*atches have poor *lack dispersion so a milling operation is essential to

achieve ade4uate dispersion of the car*on *lack.

R)5+a"" "tag) mi@i$g?

In re-pass stage master *atch is further re-mi$ed to improve

dispersion ofthe compound. +his is also done at a temperature range of 8:7-

8H7J,. (uring re-pass stage the compound viscosity is reduced according to

the re4uirement of su*se4uent operations. +his is usually done for very hard

compounds like high car*on loading and the car*on *lack is incorporated intwo stages for getting *etter dispersion.

=i$al '!m+!*$- mi@i$g? In this stage master *atches are converted into

final compounds. +his is usually mi$ed around 677, to 877J,. In final stage

mi$ing curatives like sulphur accelerator retarder etc. are added to the

master *atch.

27


30/82


D#MPING CRITERIA

+here are num*er of varia*les such as temperature power energy

mi$ing time etc. which influence the mi$ 4uality. In a company where large

production of ru**er compounds is made some optimisation has to *e set in

the mi$ing parameters to get ru**er compound with ade4uate properties.

+ime temperature and energy are the main dumping criteria. In 8stand :nd

2an*ury = set points are fed in the software of the 2an*ury on those set

values of energy mi$ing se4uence and dumping time are carried out during

the mi$ing. ;or other *an*uries set values of temperature and energy are fed

in the software. If temperature is e$ceeded from a set value dumping takes

place irrespective of the set energy values.

:ASIC OPERATING C9CLE?

8 Start operation -(ischarge door closedi. 'am up

ii. !opper door open

: 0i$ing started -'u**er K chemical powders

> ,lose hopper door

= ,harge car*on *lack is fed


31/82


CONTROLLA:LE =ACTORS

8. 2atch si5e:. Se4uence of addition

>. 'am cylinder pressure

=. 'otor speed


32/82


' /=ell

/e$erall(, !ell "! de)rea!ed 0(

a. ?oer ;"!)o!"t(

0. H"%er eat of !to)= or e9*"pe$t). ore or= perfored o$ !to)= : H"%er ar *p

d. Add"t"o$ of reor=

e. U$der:"'ed !to)=

f. ?o ead pre!!*re

Sell "! "$)rea!ed 0(> :

a. H"% ;"!)o!"t(

0. ?o teperat*re! of !to)= or e9*"pe$t

). H"% ead pre!!*re

d. A$( !)or) "$ !to)=

Ade9*ate )o$trol! of all te!e ;ar"a0le! are 0*"lt "$to )opo*$d"$% for*lat"o$!,

pro)e!!"$% !pe)"f")at"o$! a$d e9*"pe$t de!"%$. Caref*l o0!er;a$)e of all te!e are

fea!"0le a$d "ll re!*lt "$ 0ot 9*al"t( a$d 9*a$t"t( of prod*)t"o$.

Para&eter% o! E:trudate

a' THERMAL /HRIN4AGE

Te $o$:@eto$"a$ $at*re of r*00er pol(er! a$d e;er )a$%"$% for*lat"o$! *!ed "$ te

t(re "$d*!tr( a=e te e!ta0l"!e$t of !r"$=a%e e9*at"o$! ;er( d"ff")*lt. T"! ea$! tat

ea) )opo*$d 0ea;e! d"ffere$tl( "t re!pe)t to !r"$=a%e. @at*ral r*00er )opo*$d!

te$d to a;e "%er !r"$=a%e. Var"at"o$! "$ "'"$% a$d ar *p prod*)e *) %reater

;ar"at"o$! "$ $at*ral r*00er e'tr*!"o$! ta$ "$ te !($tet") r*00er e'tr*!"o$!. Te

;ar"a0"l"t( "$ d"e$!"o$! "ll 0e te "$"* e$ te e'tr*date a! te "$"*

e$trapped !tre!!. Te!e !tre!!e! are )a*!ed 0( te 0a!") pol(er reolo%")al rea!o$!, or 0(

teperat*re. /";"$% a loop of oderate !"#e "ed"atel( after te d"e fa)"l"tate! rel"e;"$%

te!e !tre!!e!. A lar%e loop "ll "$trod*)e !tre!!. Al!o, a for)ed !r"$=a%e "ll fa)"l"tate

rel"e;"$% of !tre!!e!.

32


33/82


1' /HAPE /TABILITY

+;e$ to*% lo ;"!)o!"t( "$)rea!e! prod*)t";"t( a$d 9*al"t( of te e'tr*date, te( !a%,

)ollap!e, a$d al!o "ll %et 0adl( defored "$ !*0!e9*e$t !ta%e! of operat"o$ !*) a!!t"t)"$%.

+.%.> Tread !t"t)"$% "$ T(re 0*"ld"$%

c' TAC4

/e$erall( "%er e'tr*!"o$ teperat*re fa)"l"tate! "%er ta)=. Hoe;er after a tre!old

teperat*re, re;er!al of "$!ol*0le "$to !ol*0le S*lp*r ta=e! pla)e, a$d a( affe)t

ta)="$e!!. All !to)=! te$d to 0e !t")="er "f r*$ at "%er teperat*re! $at*ral r*00er !to)=!

;ar( ore ta$ !($tet"). Soot !*rfa)e! are !t")="er ta$ ro*% !*rfa)e!. Soft !to)=! areal!o ta)="er. S*rfa)e ta)= a( 0e affe)ted 0( )ool"$% ;er( rap"d )ool"$% !peed! *p 0loo

a$d loer! ta)=. A"r )ool"$% a$d !lo ater:)ool"$% a"$ta"$! ta)="$e!!. Sto)=! rapped

ot "$to l"$er! a( lo!e ta)= 0e)a*!e of te rap"d "%rat"o$ of te pro)e!!"$% o"l a$d re!"$!

to te !*rfa)e.

>' E6TR3DED COMPONENT/

Te a


34/82


Depe$d"$% *po$ te teperat*re of feed, e'tr*der! )a$ 0e )la!!"f"ed a!

1. Hot feed e'tr*der!

2. Cold feed e'tr*der!

Copar"!o$! of ;ar"o*! a!pe)t! of ot a$d )old feed e'tr*der! are %";e$ 0elo.

S. @o. HOT ++D +BTRUD+R CO?D ++D +BTRUD+R

A D+S/@ PARA+T+RS

1 Sort 0arrel ?o$% 0arrel

2 ?oer ?-D rat"o 4>1 to 5>1 H"%er ?-D rat"o 18>1 to 15>1

3 Copre!!"o$ rat"o appro'.1 Copre!!"o$ rat"o 1

4 Dept of te fl"%t "! 1-6tof D"a. Dept of fl"%t "! 1-t to 1-18tof D"a.

5 Co$!ta$t or ;ar"a0le p"t) Var"a0le p"t)

6 Co$!ta$t fl"%t dept Var"a0le fl"%t dept

PROC+S@/ ACTORS

1 Copo*$d pre ared Cold )opo*$d

2 Te$de$)( to !)or) ?e!! !)or)"$%

3 eed ;ar"e! "$ teperat*re &

;"!)o!"t(Co$!ta$t teperat*re & ;"!)o!"t(

4 D"ff")*lt to a"$ta"$ )o$!"!te$)(

of e'tr*dateetter d"e$!"o$al )o$trol

5Prod*)t"o$ e9*"l"0r"* atta"$ed

"t"$ a !ort t"eTa=e! lo$%er t"e for e'tr*!"o$ to !ta0"l"#e

C +CO@OC ACTORS1 H"%er "$;e!te$t ?oer "$;e!te$t

2 H"%er la0o*r )o!t ?oer la0o*r )o!t

3 Re9*"re! lar%e floor area ?e!! !pa)e re9*"red

4 ?oer fre9*e$)( of repla)ee$t

of !)re a$d l"$er re9*e$t repla)ee$t of !)re a$d l"$er

5 H"%er o*tp*t ?oer o*tp*t

34


35/82


+ PART/ O7 AN E6TR3DER

Te e'tr*der )a$ 0e d";"ded "$to !"' 0a!") part! for ea!e of de!)r"pt"o$.

a. Te arrel

0. S)re

). eed opper

d. Head

e. D"e.

f. Dr";e a$d

%. Teperat*re )o$trol

"%> D"a%ra of e'tr*der

a' BARREL

Te 0arrel e$)lo!e! te !)re a$d "! ade of arde$ed !teel. Te "$$er l"$"$% of 0arrel "!

ade "t a ;er( ard allo(. all! *!t 0e ea;( to re!"!t te rad"al pre!!*re! de;eloped

"$!"de. +;e$ %reater are te lo$%"t*d"$al pre!!*re! a! te !)re %e$erate! e$oro*!

!eparat"$% for)e! "$ p*!"$% te !to)= tro*% te re!tr")ted d"e. Te!e for)e! are ta=e$ *p

"$ te rear 0( tr*!t 0ear"$%! a$d te a!!";e$e!! of te!e 0ear"$%! re;eal te a%$"t*de of

te pre!!*re! de;eloped.

Te )a!t o*ter 0arrel a! a t"0le or 0*!"$% "$!ert "t r"0! r*$$"$% d"a%o$all( aro*$d "t

"$ te pre!!*re area. e$ te t"0le "! "$!erted "$ te 0arrel, te !pa)e! 0etee$ te r"0!

35
http://www.google.co.in/url?sa=i&rct=j&q=extruder+diagram&source=images&cd=&cad=rja&docid=XWGqRqzVIR577M&tbnid=kamAaaIac2_BtM:&ved=0CAUQjRw&url=http%3A%2F%2Fwww.ineer.org%2FEvents%2FICEE1997%2FProceedings%2Fpaper233.htm&ei=MbVeUeDRFsTJrAfruIHoDQ&bvm=bv.44770516,d.bmk&psig=AFQjCNGsb7m_xphJQPq9c8OSSBawF6Sl6w&ust=1365247606703618


36/82


for te )a$$el! tro*% ") te )ool"$% ater )"r)*late!. Te t"0le "$ t*r$ )o$ta"$!

a$ e'treel( ard etal reo;a0le l"$er, ") pro;"de! a ear re!"!ta$t !*rfa)e

!*rro*$d"$% te !)re. T"! )a$ 0e repla)ed rap"dl( a$d e)o$o")all( e$ or$.

Te r*00er )opo*$d "! !eared 0etee$ te all! of te 0arrel a$d fl"%t! of te !)re 0(

te fr")t"o$ 0etee$ r*00er a$d 0arrel. or t"! rea!o$, te 0arrel !o*ld $ot 0e )ooled too

lo, a! )o$de$!at"o$ of ater o$ te all "ll red*)e te fr")t"o$ a$d )a*!e "$eff")"e$t

e'tr*!"o$. Al!o te 0arrel *!t $ot 0e ar too "%, a! t"! "%t )a*!e !)or)"$%.

Te o*tp*t of a$ e'tr*der "! depe$de$t o$ te relat";e %r"p 0etee$ te !)re a$d 0arrel,

te "%er te %r"p of 0arrel, "%er te o*tp*t.

1' THE /CRE?

Te rotat"$% !p"ral !)re "! te eart of te e'tr*der. t "! a treaded !aft, ") l"e! )o:

a'"all( a$d or"#o$tall( "$!"de te 0arrel. t "! )o$$e)ted "t a otor a$d rotate! a$t":

)lo)=:"!e. Te "porta$t paraeter tat deter"$e! te eff")"e$)( of te !)re "! "t! ?-D

rat"o. t "! %";e$ 0(,

Te le$%t:to:d"aeter ?-DE rat"o> : Te rat"o prod*)ed 0( d";"d"$% te effe)t";e le$%t of

te !)re 0( "t! d"aeter.

+a) !)re a! %ot a def"$"te ?-D rat"o. Te ?-D rat"o "! a a1 to 12>1 for )old feed e'tr*der!.

o!t r*00er !)re! are prod*)ed fro "% ol(0de$* !teel, t*r$ed a$d %ro*$d to

!ape, flae arde$ed, a$d te$ )roe plated. T"! "pro;e! te l"fe 0( red*)"$% te

ear rate a%a"$!t te l"$er.

Te pr"ar( p*rpo!e of te !)re "! to )o$;e( ater"al alo$% te 0arrel. Te r*00er

)opo*$d "! )o$;e(ed fro te feed e$d to te d"e e$d 0( te re)"pro)at"$% o;ee$t of

te !)re a$d 0*"ld! *p !*ff")"e$t pre!!*re !o a! to for)e te r*00er tro*% te d"e.

36


37/82


A! te r*00er %et! or=ed "$!"de te e'tr*der, a lot of eat "! %e$erated. A part of t"! eat

"! ta=e$ o*t 0( )ool"$% te !)re 0( )"r)*lat"$% ater "$!"de te !)re. Te !)re "! dr"lled

"$ter$all( to per"t ater to 0e )"r)*lated o$ "t! "$!"de.

C' HOPPER

$ all e'tr*der!, te !)re "! pro;"ded "t a feed opper, ") a( 0e of re)ta$%*lar or

)"r)*lar ope$"$%, ") re)e";e! )opo*$d "$ a !tr"p for )o$t"$*o*!l( a$d %*"de! "t

do$ "$to te Ffeed fl"%t!G of te !)re. Te !ape a$d lo)at"o$ of opper !e)t"o$ are

"porta$t fa)tor! "$ te )o$trol a$d o*tp*t of te e'tr*der. Te!e *!t 0e !*) tat te

feed !tr"p "ll 0e pre!e$ted to te !)re 0"te "t te lea!t "$terfere$)e a$d "$ a )o$!"!te$t

a$d eff")"e$t po!"t"o$. Te opper "! te lar%e!t )opat"0le "t te !"#e, "! off!et toard

te 0"te !"de of te !)re a! "t re;ol;e!, a$d a! %e$tl( tapered !oot !"deall! to pre;e$t

te feed !tr"p fro 0r"d%"$% a! "t fall!. Te 0arrel "! *$der)*t o$ te floor of te opper

0e$eat te !)re tat "!, "t "! )*t aa( !o tat a )leara$)e of a alf:"$) or ore 0etee$

te t"p of te !)re a$d te floor 0efore "t "! p"$)ed off.

d' HEAD

Te ead of a$ e'tr*der "! te ea$! of )o$!ol"dat"$% te roll"$% )ol*$ of r*00er

eer%"$% fro te 0arrel a$d !)re "$to a oo%e$eo*! a!! of d"!tr"0*t"$% t"! a!! to

te d"e a! e;e$l( a! po!!"0le a$d of o*$t"$% te d"e a$d a))e!!or"e!. t old! te

)opo*$d a! a re!er;o"r, ") e$!*re! e;e$ pre!!*re at te eer%"$% e$d of te e'tr*der

"$ !p"te of ;ar"at"o$ "$ feed rate.

Heat tra$!fer fro te ead "! ;er( "porta$t. *) of te %e$erated eat a! 0ee$

de;eloped e$ te !to)= lea;e! te !)re, !o teperat*re )o$trol!, ") pro;"de a$d

a"$ta"$ )o$!"!te$t )o$d"t"o$! "le te !to)= "! "$ te ead, are $e)e!!ar(. T"! ea$!

tat te ead "! eated pr"or to te r*$ !o tat te !to)= at te !tart of te r*$ doe! $ot lo!e

"t! eat "$ ar"$% te ead. After !tart *p, a teperat*re )o$troller "ll a"$ta"$

opt"* e'tr*!"o$ )o$d"t"o$!. +a) ead "! )ored or )a0ered for !tea a$d ater

)"r)*lat"o$. U!*all( 0ot pro;"!"o$! are %";e$ to eat te ead "$"t"all( a$d te$ to )ool.

Alter$at";el(, teperat*re )o$trol *$"t! are *!ed.

3


38/82


!' DIE

D"e de!"%$! a$d a$*fa)t*re "! a a


39/82


"' DRIVE

+'tr*der dr";e! *!t pro;"de ade9*ate tor9*e to t*r$ te !)re o;er "de ra$%e 8 to 288

rp "t pre)"!e !peed )o$trol. Te rotat"o$al !peed at te e'tr*der e$d "! $orall(

a)"e;ed 0( )o*pl"$% te e'tr*der !aft tro*% a %ear tra"$ "t te otor. Te %ear

red*)t"o$ !(!te "! *!ed to red*)e !peed a$d *lt"pl( tor9*e.

' TEMPERAT3RE CONTROL/

Teperat*re "! to 0e )o$trolled "$ te ead, 0arrel, !)re a$d d"e of te e'tr*der to

prod*)e %ood 9*al"t( )ro!! !e)t"o$! a$d to a"$ta"$ )o$!"!te$)(. A teperat*re )a$%e of

18IC "$ te !to)= "ll )a$%e te !ear rate 0( appro'"atel( 1.3J. T"! "ll affe)t te

rate of flo tro*% te d"e a! ell a! te d"e !ell )ara)ter"!t")!. Te )o$!"!te$)( of

teperat*re "! ore "porta$t ta$ te a)t*al teperat*re, ") a( 0e !et depe$d"$% o$

te pro)e!! a$d )opo*$d )ara)ter"!t")!.

or pre)"!e )o$trol of e'tr*!"o$, *lt" #o$e 0arrel, ead, !)re a$d D"e- D"e )lap 0lo)=

teperat*re! are !eparatel( !et a$d )o$trolled. To etod! of teperat*re )o$trol are "$

*!e>

1. D"re)t ere te )ool"$% ed"*, !a( ater "! d"re)tl( ad"tted "$to te e'tr*der #o$e!

a! re9*"red $orall( for "% )ro!! !e)t"o$ e'tr*!"o$! 158 !9.

2. $d"re)t !(!te, ere a )"r)*lat"$% fl*"d "! pa!!ed tro*% a eat e')a$%er, ")

reo;e! te eat fro te )"r)*lat"$% ed"*

CALENDERING O= =A:RIC?

PRINCIPLE O= CALENDERING

+he majority of the calendars installed in general ru**er good

companies are three roll units where as four roll calendars are normally used

*y tyre manufacturers. +he advantage of >-roll calendar is its versatility and it

can produce a sheet of ru**er and a friction or a skim coat on one side of a

fa*ric. +he main advantage of =-roll calendar is its a*ility to top the dou*le

side of a fa*ric is single operation. ,ommonly used four roll calendars are@

37


40/82


8 Th) i$)rt)- L5'!$ig*rati!$

+his was the first major change in the *asic vertical calendar design. It

has all the versatility of the *asic three-roll calendar *ecause of the *ottom

and off set rolls is keyed to provide *oth even and odd sheet.

: 5r!ll '!$ig*rati!$

+his calendar is generally used in the tyre industry as the heart of high

production cord coating line speciali5ed in e4uipment capa*le of continuous

high 4uality output. +he main advantages of D-roll calendars are it eliminates

the nip force interaction and roll float. +he nip force act in a plane at 677 to

each other and roll float are minimal *ecause the direction of resultant of nip

force *eing relatively insensitive to change in these force. +he main

disadvantage is that it lacks some fle$i*ility for automatic gauge control.

,alendaring process can *e descri*ed *y means of com*ined drag flow

and pressure flow. +he clearance *etween the rollers and viscoelastic

*ehavior of the ru**er will determine the thickness of the sheet. +he counter-

rotating roll will drag the material in the converging region of the calendar nip

through the clearance. (ue to this highly converging flow a high pressure is

*uild up in the nip region. +his is also a function of compound viscosity

clearance line speed and rolling *ank height. part of dragged material is

pushed *ack *y the pressure flow. +his will results in rolling *ank in the

calendar nip. +his nip pressure causes a nip force and therefore a roll

deflection.

+he roll separating force is a calendar is given *y

;L:"'h %8Fh-8F!

3here

Lviscosity of the *ank

"Lspeed of the roll

!Lthe nip *etween the rolls

'L radius of the calendar rolls.

48


41/82


;or good 4uality product following precautions should *e taken@

,onstant and steady nip feeding

,onstant stock temperature

,ord tension should *e as low as possi*le *ut sufficient to keep cord

distri*ution

,alendar to *e e4uipped with crowned rolls e$ternal roll *ending and

adjusta*le cross a$is setting

+hickness control e4uipment

Peak in tension to *e damped

2atch to *atch variation should *e avoided

0ajor changes in the line speed should *e avoided

41


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42


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C!$tr!l ! ga*g)

8 Cr!.$i$g

+he calendars are huge and designed to resist great separating force

*etween their rolls. +hese forces *end the rolls and stretch side frames somuch. +he rolls must *e ground to accommodate and counteract this *ending

or deflection. So the rolls are grind with varying diameter from the middle to

the end of the roll and it is known as crown. 3arm up of the stock on mill

change in the roll temperature thickness of the skim si5e of the calendar

*ank and speed of the calendar effect the separating force and thus the *end

of the roll. +he deflection can *e calculated from the formula of deflection of a

*eam supported at *oth ends and loaded uniformly over its length. +hisproduces a regular curve which is an arc of a circle. "ariation in estimates of

total separating force resulted in total calculated deflection of 7.77: to 7.77


44/82


> R!ll 'r!""i$g

'oll crossing is accomplished *y tilting the plane a$is of one of the two

adjacent rolls in relation to the common plane a$is of the two. +he journal

*o$es of the crowning roll slide not only towards and away from their mateson the adjoining rolls *ut can *e moved at 677 from these latter. +his is

achieved *y mechanical screw similar to roll skew downs hydraulic system

and sliding wedges. 0echanism of roll crossing is complicated.

T)m+)rat*r) '!$tr!l

,alendar reac4uires a uniform and well-controlled temperature profile

across the surface of the roll. +he temperature control system for calendar

due to the short residence time cannot compensate effectively for transient

change in feed material. So the main consideration is for maintaining

temperature sta*ility in calendared rolls. ;or this the *asic function of a

calendar temperature control system is to hold inlet temperature of the roll

constant and take away the heat developed *y normal calendaring. +he

different types of roll cooling systems used in calendars are

a C!r)- r!ll

,ored rolls are mold casted with internal cores and are machined on

the outer surface only. +hey have variation in wall thickness due to casting

irregularities. +he walls tend to *e heavy so that heat transmission for cooling

is slow and uneven. +hey can *e used at lower speeds with good accuracy.

* Drill)- r!ll"

+hese rolls have a *ored center-hole a*out 9M in diameter and a

concentric rings of 8F=M holes drilled from end to end a*out 8-8F:M *elow the

circumference and water is circulated through this. It will improve the rate of

heat transfer from roll surface and to remedy the temperature fall off at the roll

edges.

44


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> =))- '!$tr!l

+he supply of a material of uniform flow properties to calendar nip at

constant rate is a prere4uisite for dimensional accuracy and good surface

appearance for calendared sheets. uniform roll separation fore is important

and the temperature *and in which successful calendaring can take place

may *e 4uite narrow. +he rolling *ank si5e influences *oth temperature and

roll separating force. s calendar speed is increased the control of flow

properties and feed rate necessary for successful manufacture *ecame more

critical. ;or uniform feed rate and even feed across the width of calendar nip

a conveyor feed from the pre-plastici5ation machine terminating in a

pendulum head which can oscillate *ack and forth across the width is used.

Cal)$-)r -)"'ri+ti!$

45


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'oll si5e ?: N :9M inclined D calendar

'oll design (rilled'oll crowing 7.89 mm on I & I" throll

,ross a$is Ao2ending es'oll speed :H.9 rpm'oll temperature 677,'eed temperature 997,

+he roll ends are fitted with rotary joints for connection to the water

system. .

S+))- rati!

+he speed of >rdroll is specified as the speed of calendar. ll other

motors in line are synchroni5ed with motor running in > rdroll. +he speed ratio

are given *y

8F: 8@8. [email protected]

>F= 8.


47/82


they cannot *e open unless the seat in loading position and the cam will close

the chuck when it is rotated.

2 S+li'i$g +r)""

hydraulically operated splice press is used to join the successive rollends to form a continuous we* of fa*ric supply to the calendar unit. +he

press has two electrically heated platen of si5e :77 N 8H?H7 O:7 ;

and a pressure >7 seconds. pper plate is insulated from the press head and mounted on astationary position on a *olster plate. +he lower platen is connected to a

hydraulic cylinder for closing force. +he hydraulic unit is a separate unit to

which the press is piped and each cylinder is provided with hydraulic

e4uali5ing to assure a uniform pressure throughout the length of plate

3 T)$"i!$ ")tt)r

+his tension setter is used to keep the fa*ric in tension in the line.

Aormally the tension applied in this tension setter is a*out 8777/g.

6 L)t ! a''*m*lat!r ))- r!ll

+his feed roller will draw the fa*ric from the let off at a steady rate and

synchroni5e with the other fa*ric driving mechanism in the system. +he roll

stand has one driving roll one air operated nip roll and three steel idler

passing rolls. (uring the time of edge splicing nip roll will press against the

feed roller and will prevent the loosing of the free ends of the ended fa*ric

rolls. It will also act as a hold *ack when the following accumulator provides

the fa*ric to the system towards the *eginning of a new fa*ric roll. +he

pneumatic load cell which senses the fa*ric tension so that one can control

the let off tension in mounted under the idle roller *earing. +his roll will have a

tension of a*out


48/82


It is a top floating hydraulically operated simultaneously arranged

complete with entering and leaving idle reactor controller unit which provide

the storage of fa*ric at the time of roll change. It can store a*out 8:7m of

fa*ric in 8:7seconds. +he clearance *etween the idle rollers is >9mm.#enerally the floating carriage is in the top position having sufficient storage of

fa*ric and is move down for giving time for joining of two fa*ric ends i.e. when

the accumulator feed roll stops the fa*ric is fed into the system *y lowering of

floating platform. +he traveling platform is carried *y a chain from the four

corners. +he accumulator is provided with two control switches one for

operation at the top with full accumulator and one for operating at a*out

:


49/82


C)$t)r g*i-)

It consists of pair of rollers which can move to keep the fa*ric in thecentre line. +his consists of type frame sensor that keeps the fa*ric

tracking within a preset limit. +he edges of the fa*ric will travel *etween a

sender and a receiver. +his will read the fa*ric location through an electronic

unit and transmit the mechanical action to the roll to keep the fa*ric in center.

10 S+r)a- ma"t)r (a$a$a r!ll

It consists of two *owed rolls and it is hydraulically controlled. +he

edge of the fa*ric is sensed *y a photocell. +hese must *e positioned forvarying fa*ric width. 3hen fa*ric passes over this roll against convert *ow

ness the fa*ric width reduces and when faces the concave *ow ness fa*ric

width increases.

11 E-g) )@+a$-)r

It consists of three finger lime rolls arranged hori5ontally at the fa*ric

edges. 3hile in operation the top roll will move a*ove the fa*ric and two

*ottom rollers *elow the fa*ric. +he *ottom rolls are fi$ed and the top rollers

move in and out in *etween the *ottom rolls. +his help to avoid crowdedness

of the cords at the edges or variation in ends per inch.

12 Cal)$-ar r!ll"

+he four roll calendar has an inclined D type configuration. +he chilled

cast iron rolls are mounted on the roll *earing which are attached to the main

housing of the machine. +he roll si5e of this is ?: N :9Q and a roll speed of

:H.9 rpm. Each roll has individual drives. +he rolls are maintained at a

surface temperature of 997,. +he temperature is given *y hot water at

=/gFcm:pressure circulated through drilled holes. !ydraulic pump is used at a

pressure 8< /gFcm: for roll *ending. In order to provide roll *ending higher

force is to *e transmitted. So main roll *earing is arranged at a greater

distance from the au$iliary *earing. +wo hydraulic cylinders are used which

act on roll journal to provide uniform gauge. +he *ending force can *e preseton hydraulic cylinder on *oth sides. +he common line speed of the calendar

47


50/82


is H7mFmin. +he fa*ric is entered *etween :ndand >rdrollers. +he compounds

are fed *etween I & II and III & I". 2etween the rollers I & II and III & I" a

frictional ratio of 7.H is given. +he roll *ending pressure is applied *etween I

&II is a*out =


51/82


It consists of three rolls to provide a tension of :7-:77/g of the

calendared fa*ric to keep the coated fa*ric in line.

1


52/82


A'')""!ri)"

8 Warm *+ mill"

3arm up mill is a two roll mill 7f si5e :9 N 9=Q. Since the consumption

of ru**er in the calendar is very high it stores the stock from the warm up mill.!old mill is provided with a stock *lender *ar. It is cooled *y passing chilled

water. +he stock in the feed mill is conveyed to the feed mill via conveyor.

: =))- mill

;eed mill supply the compound for the calendar. +he feeding of the

ru**er is through a pendulum conveyer. +he mill is fitted with a knife to cut

the compound to the correct width which is *eing fed to the calendar. +he

mill is cooled *y passing chilled water.

Cal)$-ari$g !+)rati!$

+he dipped fa*ric after a maturation period it is taken into the

calendaring unit through ;I;) system. +he *lack cover is removed and

splicing gum is applied at the leading end of the fa*ric. +his gum has

appro$imate width of H inch and 7.7 ;.

fter a cure time of =7 sec it will automatically open. (uring this time let off

accumulator will provide fa*ric for the calendar unit.

tension stand is provided after the splice press to keep the fa*ric in

line *y the application of tension. fter let of accumulator the fa*ric will pass

through a heating 5one consisting of :7 cylindrical drum of surface

temperature of 677,. +his heating 5one will remove any type of moisture

a*sor*ed in the fa*ric surface. It will create some pro*lem in final tyre during

service. ;ollowing this a dancer roll is there to a*sor* any slack formed in the

fa*ric. In order to keep the fa*ric in centerline with specified EPI fa*ric will

52


53/82


pass through centre guide rollers *anana rollers and trio canter *efore

entering into the calendaring rolls.

+he fa*ric enters into the calendar *etween second and third rollers.

+he compound to *e coated is fed though a pendulum conveyer *etween I &II and III & I" throllers. 2efore enter into to the calendar the compound is

passed through series of mill for proper *lending and *reakdown. +he

compound applied to the calendar will have a temperature of near 977,

otherwise there will *e variation in the property of the fa*ric. +his skim coated

compound is passed through post calendar dancing roll to the cooling drum.

+he cooling drum has a surface temperature of >77, to cool the fa*ric

to room temperature. fter this 5one *leeder yarns are applied to thecalendared fa*ric for proper identification. +his fa*ric then pass through

picker rolls pick *reaker to remove any air in the fa*ric. fter passing through

the wind up accumulator and wind up let off roll the fa*rics are wound on a

wind roller with a liner. In order to keep the fa*ric in centre a centre guide is

attached to the assem*ly. +his wind up rollers with identification tag is stored

in the racks and taken into the *ias cutter in ;I;) manner.

C!mm!$ -))'t" i$ th) 'al)$-ar)- a(ri'?5

,old stock and rough surface

Split fa*ric and crush fa*ric

;oreign matter

1umpy compound in fa*ric

3rinkles and folds

1oose cord and loose coating

)ff *alance coating

#um edge

Improper gauge and width

0issing cords

St))l '!r- 'al)$-ari$g

53


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Steel cord calendar is used for the production of steel *elt i.e. in a steel cord

calendar the two sides of the steel wires are coated with a ru**er compound

*y maintaining a specified ends per inch. +he important components of the

machines are

1 Cr))l r!!m

+he steel wires are coated with *rass material for *etter adhesion and

prevent the corrosion. +o protect this the steel wires are stored and let off

from a room called creel room. +he temperature is maintained at =7 7c with a

relative humidity of >.H /gFcm:should *e maintained in the cord for getting the

re4uired EPI. +he compounds are introduced *etween the first and second

rolls and *etween third and fourth roll. +he compound should *e warmed up to

977c *efore introducing in the calendar. +wo side coated compound is passed

through the cooling drum and wound on the liners in the wind up 5one. +he

speed of the calendar is very small to o*tain good coating on *oth sides.

54


55/82


St))l .ir) '*tt)r

Steel wire cutter is used for cutting the calendared steel fa*ric into a specified

degree of angle and splices the pieces to form a continuous strip. In ,E+

tyre !alol two steel cutters are employed for cutting the calendared steel

fa*ric.

;irst the fa*ric to *e cut is loaded in the let off stand. +he ply from the let off

stand is passed through a let of festooner which control the tension in the

fa*ric. +his festooner operation is controlled *y limit switches and actuated *y

the length measuring device. fter the festooner the fa*ric enters into a

hori5ontal ta*le conveyor.

+he cutter used for cutting the steel *elt consist of two rotating roller which are

step off to each other. +he shearing action *etween the rotors gives the

cutting. +his cutter assem*ly can *e adjusted for a specified angle.

+his cut ply is transferred to the splicing ta*le *y a magnetic material and

leading end is spliced with the tail end of the wound ends. 2efore winding in

the liners gum strip is applied using gum strip assem*ly

Ca+ +li)" "litt)r?,ap ply slitter used in ,E+ +yres !alol is made *y +ech. edge (elhi. It can

operate with a line speed of >7 rpm. ,ap ply slitter is used for slitting a

calendared cap ply fa*ric into cap ply strip of re4uired smaller width. +he

main parts of this machine are

1 =a(ri' l)t !

+he fa*ric let off is controlled *y unwinding the liner. constant speed is

ensured *y the let off motor drive system. +his let off station is mounted over

a moving *ase and tensioning device operated *y hydraulic centering system.

0ovement of the *ase is activated *y the automatic centering system which

consists of a light source and receiver.

2 Slitti$g %$i)

55


56/82


Slitting knife is pneumatically operated and distance *etween the knives can

*e adjusted depends on the width of the cap ply re4uired. +he silted pieces

are separated *y independently adjusta*le idle rollers which are vertically

mounted.

3 Ta%) a.ay '!$)y)r a$- .i$- *+ "tati!$

+ake away conveyor is driven *y a (,- motor. +here are four stations along

with one set of each stand *y winding up for the continuous winding f slit

rollers. +he winding is done *y engaging the roll with the conveyor. +he liner

tension from the liner let off in wind up can *e adjusted down *y a particle

*reak. ll wind ups are provided *y air motor to ensure a positive and tightwinding.

Ca+ "tri+ '*tt)r?

1 =a(ri' l)t !

;a*ric is let off from the roll *y unwinding the liner. constant speed is

ensured *y the let of dancer system. +his will also achieve centering and

proper tensioning of the ply.

2 K$i) "y"t)m

/nife fitted to a toggle shaft which are guided *y the cord direction. +he

distance *etween the knife can *e independently adjusted depends on the

width of the ply. Silted fa*rics are separated *y independently adjusta*le

vertically mounted idle rollers.

3 Wi$-*+ "tati!$.

ll winders are provided *y a tensioner device to ensure the positive wind up

tension. Some supply stations are there which can move parallel to the

winder in such a way that uniform supply of fa*ric.

A"")m(ly li$)r Li$)r +r)+arati!$?

In order to reduce the tyre *uilding cycle time in passenger car tyresB

chafer is assem*led with the inner liner in assem*ly liner preparation unit.

56


57/82


Peculiarity of this unit is it uses highly sophisticated charge code digital

camera for centering the chafer and inner liner. +he different component s

of this machine is

8 S*))g)) +r)+arati!$ *$it+he s4ueegee preparation unit is com*ination of a cold feed e$truder and a

two-roll calendar. +he head of the cold fed e$truder is connected to a two-roll

calendar So that the s4ueegee with a very fine thickness and 4uality is

o*tained. +he calendar rolls are provided with two knives adjusted a particular

distance same as that of width of the s4ueegee. +his s4ueegee is pulled *y a

take away conveyor. +he speed of the calendar rolls and the line speed of the

conveyor are synchroni5ed. Speed of the conveyor is synchroni5ed. guider roll is provided for proper placing of the s4ueegee on the conveyor.

: Cha)r "*++ly

+he cut chafer can *e placed on a let of station. +here is a let off accumulator

for making the process continuous. +o place the chafer on proper position it

is passed through a moving *ase whose movement can *e actuated *y the

signals from ,,( camera.

O+)rati!$?

+he inner liner compound is introduced in the cold feed e$truder. +he

e$truded inner liner is taken through the nip of the calendar and allowed to

wind on it. +he cutting knifes are adjusted for the specified width and the cut

s4ueegee is introduced in the take off conveyor. +he s4ueegee is then passed

over the guide roller and the space of the guide roller is adjusted for proper

centering. +he moving *ase assem*ly and ,,( camera do the appropriate

centering of the s4ueegee.

(uring this time the chafers are loaded in the chafer let off assem*ly

and introduced on the inner liner through let off accumulators. +he chafers

should *e properly centered using ,,( camera. +his assem*ly is then wound

at the winding station.

5


58/82


:)a- a$- a+)@ (*il-i$g *$it?

In radial high performance tyres smooth *uilding up of stress from the

rim to the carcass is necessary for *etter riding comfort and steering

response. So the dimensional sta*ility of the ape$ed *ead should *e of very

high 4uality. In ,E+ +yres !alol for the preparation of *ead with very good

dimensional sta*ility they are using a *ead ape$ing machine called ;0; -

,onti 2ead ape$ing machine. +he machine is semi-automatic. +wo *eads

can *e ape$es at a time with this machine. +he different components of the

machine are@

1 E@tr*-)r

cold fed e$truder is used for preparing predetermined profile of filer.

+he e$truder used is a ?< mm e$truder. +he e$truder is provided with a

temperature control system and the temperature of the e$truder is normally

set at 677,. ;actory cooling water is used for cooling the drum.

+he drum is rotating at very low rpm. fter cooling the filler is stored in an

accumulator. +here are five series of accumulators arranged parallel to each

other and the accumulator supplies the filler to the ne$t section. +he

controlled *y light sensors.

5


59/82


3 A+)@i$g *$it

pe$ing unit consist of a servicer and a *ead placing *ladder. +his

device provides the two filler in appropriate position on the drum. +his is

achieved through photo sensing device. +o cut the filler at desired length a

hot knife is provided. +he knife is heated at :>7, for smooth cutting. +he

cutting angle is almost =


60/82


drum. +he splicing should *e minimum and spliced portion is consolidated *y

a series of needle like structure automatically.

(uring this time the *ead servicer is ready with the *ead holder

assem*ly. 3ound *ead should *e placed on the *ead hold assem*ly in sucha way that to get a spotting of 8977*etween wound *ead splice overlap and

filler splice overlap. It will move lateral to the drum containing filler and

placed on the appropriate position. (uring the time drum e$pands and hold

the *ead. +he distance *etween the *ead and the lip of the filler should *e >

mm. +he *ead servicer moves to its original position. +hen *oth the rim

come closer to each other and e$pansion of the drum take place at the

position *etween the *eads in such a way that the *ead ape$ should *eplaced over the *ead and *end against the holder assem*ly. fter this the

rim move away and the drum is returned to the original position. +he wound

*eads are taken and placed on the rack.

igh ta(l) (ia" '*tt)r?

!igh ta*le *ias cutter is used for cutting the plies to a re4uired width

and angle from the calendared roll to produce continuous length of the fa*ric.

+he cut plies are spliced manually and wound on liners.

+he main parts of the machines are a let off unit and festooner a ta*le

conveyor cutting knife assem*ly splicing ta*le and a wind up unit.

+he let off station consist of a chuck provided with *reak for

maintaining suita*le tension in the fa*ric. ;rom this the fa*ric is passed

through a festoon drive which is operated *etween two limit switches. +his

festooner is operated *etween limit switches. +his festooner controls the

supply of the fa*ric to the other units. fter that the fa*ric is drawn through a

ta*le conveyor on which the cutting of the plies takes place. +he knife

assem*ly consists of a round knife supported on a high mass to provide

re4uired moment of inertia. +his knife assem*ly can *e set according to the

re4uired angle. Aormally the angle is set in the range of 99 7 to 6:7. +he knife

assem*ly is actuated *y a length measuring device set for specified value.

+he cutting ta*le is placed at a height from the splicing ta*le. +his cut ply fall

68


61/82


down to the splicing ta*le. +his plies are spliced manually and wound in liners.

+he movement of the wind up assem*ly is controlled *y photo sensors.

Cha)r "litt)r,hafer slitter is used for the manufacture of chafer. +his involves the

cutting of calendared fa*ric from the = roll calendar and this is further silted in

ohnston slitter for further use in tyre *uilding and assem*ly liner. +he spitted

calendared fa*ric is placed on the let off roll. +he fa*ric is taken and is lead

through the centering roll to the knife assem*ly unit. +he liner is wound in

another empty sell. +he knives are pneumatically operated and engage the

cuter into the fa*ric. +he knife assem*ly is adjusted in such a way that the

center distance *etween the cutters is as per the chafer width to the slit. +he

station consist of five wind up stand can engage with the conveyer for uniform

winding. ll wind up stations are provided with air motor to ensure the positive

tight winding.

+he cut chafer is first wound on the hollow s4uare *ars and engages it

with the conveyor *y the pneumatic switch. 3hen the *ar is full raise the

stand the put new *ars for filling.

Tyr) (*il-i$g +r!')""?

:*il-i$g ma'hi$)

'adial tyres are *uilt in two stages due to the ine$tensi*le *elt package.

In first stage carcass with the side wall are prepared and the *elt and tread

packages are applied in the second stage. +he important components of the

tyre *uilding machines are given *elow

1 I"t"tag) (*il-i$g ma'hi$)

a :*il-i$g -r*m

2uilding drum is mounted on a shaft which is attached to an ., drive.

+he *uilding drum consists of a drum surrounded *y an e$panda*le *ladder.

2ladder can *e e$panded at the time of *ead application. Some holes are

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provided on the drum to introduce air *etween drum and *ladder. t the time

of tyre strip out the *ladder will deflate to promote the strip out operation.

( =i$g)r +ly -!.$ a"")m(ly

+his is an assem*ly of spring fingers mounted as an end to a ring.3hen the finger arrives at the drum edge they are opened to encircle the

overhanging plies.

' D*al (la--)r t*r$ *+ a"")m(ly

+hese *ladder turn up assem*ly is a pair of inflata*le ru**er tu*es one

side the other. +hey are clamped *y their edges in a spiral ring which forms an

air tight seal. +he ring assem*ly can move *ack and forth *y means of an air

cylinder. fter the *ead set operation the *ladder is inflated and eachassumes the shape of a donut with the ply portion to *e turn up. +hen the

push-can will push the inflated *ladder with plies end and stitches it around

the *ead.

- Stit'h)r *$it

In order to remove the trapped air *etween the plies they are stitched

well with a stitcher. +here are two types of stitchers in a first stage *uilding

machine. +hey are called *ottom stitchers and swan neck switchers. +he

*ottom stitchers consist of two rollers rotating at a specified rpm. It can stitch

the carcass at low pressure and side wall at high pressure. Swan neck rollers

are provided at *oth end of the drum. Swan neck switchers are used for final

tuck in operation. +o keep the plies in position during the application on the

drum a sponge roller is used. +hey can apply a small pressure.

) Car'a"" +li)" ")ri')r

+he cassette containing carcass ply and drum s4ueegee has separate

let off stations. +hey are provided with *reaking system to maintain the

tension during application. +he plies are centered using light sensors and cut

at specified length *y a rotating knife.

2 S)'!$- "tag) (*il-i$g ma'hi$)

a : T -r*m

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2 & + drum consists of a dou*le conical e$pansion cone which is fitted

*etween the drumCs side flanges. +he metallic flat rigid aluminum segments

among them num*er of segments form-*uilding deck is filled w

Inplant Traing

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