Lecture 3 Rubber Processing Ch14

7/25/2019 Lecture 3 Rubber Processing Ch14

1/41

Lecture # 3

RUBBER PROCESSING

TECHNOLOGY

1. Rubber Processing n! S"ing

$. %nu&cture o& Tires n! Ot"er Rubber Pro!ucts

3. Pro!uct 'esign Consi!ertions


2/41

O(er(ie) o& Rubber Processing

%n* o& t"e ro!uction +et"o!s use! &or ,stics re

,so ,icb,e to rubbers

Ho)e(er- rubber rocessing tec"no,og* is !i&&erent incertin resects- n! t"e rubber in!ustr* is ,rge,*

serte &ro+ t"e ,stics in!ustr*

T"e rubber in!ustr* n! goo!s +!e o& rubber re

!o+inte! b* one ro!uct tires Tires re use! in ,rge nu+bers on uto+obi,es-

truc/s- ircr&t- n! bic*c,es


3/41

T)o Bsic Stes in

Rubber Goo!s Pro!uction

1. Pro!uction o& t"e rubber itse,&

Ntur, rubber 0NR is n gricu,tur, cro

S*nt"etic rubbers is bse! on etro,eu+

$. Processing into &inis"e! goo!s

Co+oun!ing

%i2ing S"ing

u,cni4ing


4/41

T"e Rubber In!ustries

Pro!uction o& r) NR is n gricu,tur, in!ustr*

becuse latex- t"e strting ingre!ient- is gro)n on

,nttions in troic, c,i+tes B* contrst- s*nt"etic rubbers re ro!uce! b* t"e

etroc"e+ic, in!ustr*

5in,,*- rocessing into tires n! ot"er ro!ucts occurs

t rocessor 0&brictor ,nts- co++on,* /no)n st"e rubber in!ustr*


5/41

Pro!uction o& Ntur, Rubber

Ntur, rubber is te! &ro+ rubber trees 0Hevea

brasiliensis s ,te2

In Sout"est 6si n! ot"er rts o& t"e )or,! Lte2 is co,,oi!, !isersion o& so,i! rtic,es o& t"e

o,*+erpolyisoprenein )ter

Po,*isorene 0C7H8nis t"e c"e+ic, substnce

t"t co+rises NR- n! its content in t"e e+u,sionis bout 39:


6/41

Reco(ering t"e Rubber

Pre&erre! +et"o! to reco(er rubber &ro+ ,te2

in(o,(es cogu,tion ; !!ing n ci! suc" s &or+ic

ci! 0HCOOH Cogu,tion t/es bout 1$ "ours

T"e cogu,u+- no) so&t so,i! s,bs- is t"en s


7/41

Gr!es o& Ntur, Rubber

T"e resu,ting rubber- no) in &or+ c,,e! ribbed

smoked sheet- is &o,!e! into ,rge b,es &or s"i+ent

to t"e rocessor In so+e cses- t"e s"eets re !rie! in "ot ir rt"er

t"n s+o/e"ouses- n! t"e ter+ air dried sheet is

use!

T"is is consi!ere! better gr!e o& rubber

6 sti,, better gr!e- c,,e!pale creperubber- in(o,(es

t)o cogu,tion stes- &o,,o)e! b* )r+ ir !r*ing


8/41

S*nt"etic Rubber

%ost s*nt"etic rubbers re ro!uce! &ro+ etro,eu+

b* t"e s+e o,*+eri4tion tec"ni


9/41

Co+oun!ing

Rubber is ,)*s co+oun!e! )it" !!iti(es

Co+oun!ing !!s c"e+ic,s &or (u,cni4tion-

suc" s su,&ur 6!!iti(es inc,u!e &i,,ers t"t eit"er en"nce t"e

rubber>s +ec"nic, roerties 0rein&orcing&i,,ers or e2ten! t"e rubber to re!uce cost

0non rein&orcing &i,,ers

It is t"roug" co+oun!ing t"t t"e seci&icrubber is !esigne! to stis&* gi(en ,ictionin ter+s o& roerties- cost- n! rocessbi,it*


10/41

Crbon B,c/ in Rubber

T"e sing,e +ost i+ortnt rein&orcing &i,,er in rubber

is carbon black- co,,oi!, &or+ o& crbon obtine!

b* t"er+, !eco+osition o& "*!rocrbons 0soot It increses tensi,e strengt" n! resistnce to

brsion n! tering o& t"e &in, rubber ro!uct

Crbon b,c/ ,so ro(i!es rotection &ro+

u,tr(io,et r!ition %ost rubber rts re b,c/ in co,or becuse o&

t"eir crbon b,c/ content


11/41

Ot"er 5i,,ers n! 6!!iti(es in

Rubber

C"in c,*s "*!rous ,u+inu+ si,ictes06,$Si$O70OH? rein&orce ,ess t"n crbon b,c/ but re

use! )"en t"e co,or b,c/ is not ccetb,e Ot"er o,*+ers- suc" s st*rene- PC- n! "eno,ics

Rec*c,e! rubber !!e! in so+e rubber ro!ucts- butusu,,* 19: or ,ess

6ntio2i!nts@ &tigue n! o4one rotecti(e c"e+ic,s@

co,oring ig+ents@ ,stici4ers n! so&tening oi,s@b,o)ing gents in t"e ro!uction o& &o+e! rubber@ +o,!re,ese co+oun!s


12/41

%i2ing

T"e !!iti(es +ust be t"oroug",* +i2e! )it" t"e

bse rubber to c"ie(e uni&or+ !isersion o&

ingre!ients Uncure! rubbers "(e "ig" (iscosit* so +ec"nic,

)or/ing o& t"e rubber cn increse its te+erture u

to 179C 03995

I& (u,cni4ing gents )ere resent &ro+ t"e strt o&+i2ing- re+ture (u,cni4tion )ou,! resu,t t"e

Arubber rocessor>s nig"t+re


13/41

%i2ers in Rubber Processing

0 T)o;ro,, +i,, n!

0b Bnbur*;t*e

intern, +i2er


14/41

T)o;Stge %i2ing

To (oi! re+ture (u,cni4tion- t)o stge +i2ing

rocess is usu,,* e+,o*e!

Stge 1 ; crbon b,c/ n! ot"er non (u,cni4ing

!!iti(es re co+bine! )it" t"e r) rubber

T"is stge 1 +i2ture is c,,e! t"e +ster btc"

Stge $ ; &ter stge 1 +i2ing is co+,ete!- n!

coo,ing ti+e "s been ,,o)e!- stge $ +i2ing is

crrie! out in )"ic" (u,cni4ing gents re !!e!


15/41

5i,+ent Rein&orce+ent in

Rubber

%n* ro!ucts re


16/41

S"ing n! Re,te! Processes

&or Rubber Pro!ucts

5our bsic ctegories o& s"ing rocesses

1. E2trusion

$. C,en!ering

3. Coting

?. %o,!ing n! csting

So+e ro!ucts re


17/41

E2trusion

Scre) e2tru!ers re gener,,* use!

T"e L=' rtio o& t"e e2tru!er brre, is ,ess t"n &or

t"er+o,stics T*ic, rnge 19 to 17

Re!uces ris/ o& re+ture cross ,in/ing

'ie s)e,, occurs in rubber e2tru!tes

T"e "ig",* ,stic o,*+er e2"ibits A+e+or*

T"e rubber "s not *et been (u,cni4e!


18/41

Rubber stoc/ is sse!

t"roug" series o& gs

o& !ecresing si4e b* stn! o& rotting ro,,s

Rubber s"eet t"ic/ness

is s,ig"t,* greter t"n

&in, ro,, g !ue to !ies)e,,

C,en!ering


19/41

Co+bintion o& e2trusion n! c,en!ering t"t resu,tsin better


20/41

I+ortnt in!ustri, rocess &or ro!ucing tires-con(e*or be,tsin&,tb,e r&ts- n! )terroo& c,ot"

Coting or I+regnting 5brics

)it" Rubber


21/41

%o,!e! Rubber Pro!ucts

%o,!e! rubber ro!ucts inc,u!e s"oe so,es n!

"e,s- gs/ets n! se,s- suction cus- n! bott,e

stos 6,so- +n* &o+e! rubber rts re ro!uce! b*

+o,!ing

In !!ition- +o,!ing is n i+ortnt rocess in tire

ro!uction


22/41

%o,!ing Processes &or Rubber

Princi, +o,!ing rocesses &or rubber re

1. Co+ression +o,!ing

$. Trns&er +o,!ing

3. Inection +o,!ing

Co+ression +o,!ing is t"e +ost i+ortnt becuse

o& its use in tire +nu&cture


23/41

%o,!ing Processes &or Rubber

Curing 0(u,cni4ing is cco+,is"e! in t"e +o,! in ,,

t"ree +o,!ing rocesses

T"is reresents !erture &ro+ re(ious s"ing+et"o!s

Ot"er s"ing +et"o!s use serte

(u,cni4ing ste


24/41

D"t is u,cni4tion

T"e tret+ent t"t cco+,is"es cross ,in/ing o&

e,sto+er +o,ecu,es

%/es t"e rubber sti&&er n! stronger but retine2tensibi,it*

T"e ,ong c"in +o,ecu,es beco+e oine! t certin

tie oints- )"ic" is re!uces t"e bi,it* to &,o)

So&t rubber "s 1 or $ cross ,in/s er 1999 +ers

6s t"e nu+ber o& cross ,in/s increses- t"e

o,*+er beco+es sti&&er 0e.g.- "r! rubber


25/41

01 r) rubber- n! 0$ (u,cni4e! 0cross ,in/e! rubber

0 so&t rubber n! 0b "r! rubber

E&&ect o& u,cni4tion on

Rubber %o,ecu,es


26/41

u,cni4tion C"e+ic,s n!

Ti+es

D"en &irst in(ente! b* Goo!*er in 183F- (u,cni4tion

use! su,&ur 0bout 8 rts b* )eig"t o& S +i2e! )it"

199 rts o& NR t 1?9C 0$89

5 &or bout 7 "ours

u,cni4tion )it" su,&ur ,one is no ,onger use!-

!ue to ,ong curing ti+es

rious ot"er c"e+ic,s 0e.g.- 4inc o2i!e- steric ci!

re co+bine! )it" s+,,er !oses o& su,&ur to cce,erten! strengt"en t"e tret+ent

Resu,ting cure ti+e is 17 $9 +inutes


27/41

Tires n! Ot"er Rubber Pro!ucts

Tires re bout 7: o& tot, rubber tonnge

Ot"er i+ortnt ro!ucts

5oot)er Se,s

S"oc/ bsorbing rts

Con(e*or be,ts

Hose 5o+e! rubber ro!ucts

Sorts e


28/41

Pneu+tic Tires

5unctions o& neu+tic tires on (e"ic,e

Suort t"e )eig"t o& t"e (e"ic,e- ssengers-

n! crgo Trns+it t"e +otor tor


29/41

Tire Construction

6 tire is n sse+b,* o& +n* co+onents

6bout 79 &or ssenger cr tire

Lrge ert"+o(er tire "s s +n* s 17

T"e intern, structure o& t"e tire- /no)n s t"e

carcass- consists o& +u,ti,e ,*ers o& rubber;cote!

cor!s- c,,e!plies

T"e cor!s re strn!s o& n*,on- o,*ester- &iber

g,ss- or stee,- )"ic" ro(i!e ine2tensibi,it* to

rein&orce t"e rubber in t"e crcss


30/41

T"ree Tire constructions 0 !igon,

,*- 0b be,te! bis- n! 0c r!i, ,*


31/41

Tire Pro!uction Se


32/41

Pre&or+ing o& Co+onents

Crcss consists o& +u,ti,e co+onents- +ost o&

)"ic" re rubber or rein&orce! rubber

T"ese co+onents n! ot"ers re ro!uce! b*continuous rocesses

T"e* re t"en re cut to si4e n! s"e &or

subse


33/41

Prior to +o,!ing n! curing- t"e crcss is

sse+b,e! on building drum- )"ose +in e,e+ent

is c*,in!ric, rbor t"t rottes

Bui,!ing t"e Crcss


34/41

%o,!ing n! Curing

01 Uncure! tire ,ce! o(er e2n!b,e !i"rg+-0$ s,it +o,! is c,ose! n! !i"rg+ is e2n!e!

to &orce uncure! rubber ginst c(it* )it" tre!ttern@ +o,! !i"rg+ re "ete! to cure rubber


35/41

Ot"er Rubber Pro!ucts

Rubber Be,ts

Di!e,* use! in con(e*ors n! u,,e* s*ste+s

Rubber is i!e, &or t"ese ro!ucts !ue to its &,e2ibi,it*-

but t"e be,t +ust "(e ,itt,e or no e2tensibi,it* 6ccor!ing,*- it is rein&orce! )it" &ibers- co++on,*

o,*ester or n*,on

5brics o& t"ese o,*+ers re usu,,* cote! b*

c,en!ering- sse+b,e! toget"er to obtin re


36/41


Hose

T)o bsic t*es

1. P,in "ose 0no rein&orce+ent is e2tru!e! tubing

$. Rein&orce! tube- )"ic" consists o&

Inner tube ; e2tru!e! o& rubber co+oun!e!

&or rticu,r ,i


37/41


5oot)er

Rubber co+onents in &oot)er so,es- "ee,s- rubber

o(ers"oes- n! certin uer rts

%o,!e! rts re ro!uce! b* inection +o,!ing-co+ression +o,!ing- n! certin seci, +o,!ing

tec"ni


38/41

Processing o& T"er+o,stic

E,sto+ers

6 t"er+o,stic e,sto+er 0TPE is t"er+o,stic

o,*+er t"t ossesses t"e roerties o& rubber

TPEs re rocesse! ,i/e t"er+o,stics- but t"eir,ictions re t"ose o& n e,sto+er

%ost co++on s"ing rocesses re inection

+o,!ing n! e2trusion

Gener,,* +ore econo+ic, n! &ster t"n t"etr!ition, rocesses &or rubbers t"t +ust be

(u,cni4e!


39/41

TPE Pro!ucts

%o,!e! ro!ucts s"oe so,es- t",etic &oot)er- n!

uto+oti(e co+onents suc" s &en!er e2tensions

n! corner ne,s E2tru!e! ite+s insu,tion coting &or e,ectric, )ire-

tubing &or +e!ic, ,ictions- con(e*or be,ts- s"eet

n! &i,+ stoc/

No tires o& TPE


40/41

Pro!uct 'esign Consi!ertions

Econo+ic Pro!uction Juntities

Rubber rts ro!uce! b* co+ression +o,!ing 0t"e

tr!ition, rocess cn o&ten be ro!uce! in


41/41

Pro!uct 'esign Consi!ertions

'r&t

'r&t is usu,,* unnecessr* &or +o,!e! rts o&

rubber- becuse its &,e2ibi,it* ,,o)s it to !e&or+ &orre+o(, &ro+ t"e +o,!

S",,o) un!ercuts- ,t"oug" un!esirb,e- re

ossib,e )it" rubber +o,!e! rts &or t"e s+e

reson T"e ,o) sti&&ness n! "ig" e,sticit* o& t"e +teri,

er+its re+o(, &ro+ t"e +o,!

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Lecture 3 Rubber Processing Ch14