Tiêu chuẩn iso 04666 3 2016

© ISO 2016 Rubber, vulcanized — Determination of temperature rise and resistance to fatigue in flexometer testing — Part 3 Compression flexometer (constant strain type) Caoutchouc vulcanisé — Détermin[.]

Rubber, vulcanized — Determination

Part 3:

Ca utch uc v lca isé — Déte mination de l’élé ation de temp ratur

et de la résista c à la ftigue da s le s essais a x fle xomètre s —

Partie 3: Fle xomètr à compre ssion (ty e à déormation co sta te)

COPYRIGHT PROTECTED DOCUMENT

© ISO 2016, P blshed in Sw itz rlan

A ll rig hts r eserved Unles otherw ise spe ified, nopar of this p blc tion ma y be r epr od c d or utilz d otherw ise in an form

or b an me ns, ele tr onic or me hanic l, inclu in p oto opying , or postin on the internet or an intranet , w ithout prior

written permis ion Permis ion c n be req esed from either ISO at the ad r es below or ISO’s member bod y in the c u try of

F reword i v

Introduction v

1 Sc ope 1

2 Nor mati ve r eferenc es 1

3 Terms and definitions 1

4 Principle 2

5 A pparatus 2

5.1 Flex mete 2

5.1.1 General desc iption 2

5.1.2 Detaied desc iption 2

5.2 Measuring gaug e 4

5.3 Time 4

6 Calbratio 4

7 Test piec e 4

8 Test c onditio s 5

9 Proc ed re .6

9.1 Pr eparation of flex mete 6

9.2 Tes pr oc d re 6

9.2.1 General

6 9.2.2 Dete mination of temperatur e risean of compr es ion set 7

9.2.3 Dete mination of fatig ue r esis anc 7

9.2.4 Dete mination of creep 7

10 Ex pres io of r esults 8

1 1 Temperatur e rise 8

1 2 Cr eep 8

1 3 Compr es ion set 9

1 4 Fatig ue lfe 9

11 Test rep r t 9

A nne x A (informative)Precisio

11 A nne x B (informative)Guidanc e for using pr ecisio results 13

A nne x C (normative) Calbration s hedule 14

Biblog raphy 17

ISO (he Int ernational Org nization for Stan ardization) is a worldwidefede ation of national s an ards

b dies (ISO membe b dies) The work of pr p ring Int ernational Stan ards is normaly car ied out

through ISO t ech ical committ ees Each membe b dy int er st ed in a subje t for w hich a t ech ical

committ ee has be n es a lshed has the right t o be r pr sent ed on that committ ee Int ernational

org nizations, g ove nmental an non-g ove nmental, in laison with ISO, also take part in the work

ISO cola orat es closely with the Int ernational Ele trot ech ical C mmis ion (IEC) on al matt ers of

ele trot ech ical s an ardization

The proc d r s used t o develo this document an those int en ed for it furthe maint enanc ar

desc ibed in the ISO/IEC Dir ctives, Part 1 In p rticular the dife ent a pro al c it eria ne ded for the

dife ent ty es of ISO document should be not ed This document was draft ed in ac ordanc with the

edit orial rules of the ISO/IEC Dir ctives, Part 2 ( e www.iso.org dir ctives)

A tt ention is drawn t o the p s ibi ity that some of the element of this document ma be the subje t of

p t ent right ISO shal not be held r sponsible for identifying any or al such p t ent right Detais of

any p t ent right identified d ring the develo ment of the document wi be in the Introd ction an / r

on the ISO ls of p t ent de larations r c ived ( e www.iso.org p t ent )

Any trade name used in this document is information given for the convenienc of use s an does not

cons itut e an en orsement

For an ex lanation on the meaning of ISO spe ific t erms an ex r s ions r lated to conformity as es ment,

as wel as information a out ISO’s adhe enc to the Wor ld Trade Org nization (WTO) principles in the

Te h ical Bar ie s to Trade (TBT) se the folowing URL: www.iso.org/ iso/for word.html

The committ ee r sp nsible for this document is ISO/TC 45, R ub e a d ru be produc ts , Subcommitt ee

SC 2, Tes tin a d a alys i s

This third edition canc ls an r plac s the se on edition (ISO 466 -3:2 1 ), 5.1.2 of w hich has be n

t ech icaly r vised

A l s of al p rt in theISO 46 6 se ies can be fou d on the ISO websit e

One major conseq enc of the int ernal heat g ene ation of rub e u de a flexing compr s ion is the

develo ment of an elev t ed t empe atur in the rub e This document pro ides for the measur ment of

the t empe atur rise

Un e particularly sever heat g ene ation an t empe atur rise con itions, int ernal ruptur of the t es

pie e can oc ur with fatigue faiur Pro ision is also made for the measur ment of r sis anc t o this

ty e of fatigue

The t es is con uct ed un e con itions of a sele t ed s atic pr -s r s or compr s ion an a sele t ed

cyclc s rain of cons ant ma imum ampltu e imp sed up n thepr -s r s ed t es pie e

Rubber, vulcanized — Determination oftemperature rise

and resistanc e to fatig ue in flexometer testing —

Part 3:

WARNING 1 — Per o s using this document sho ld be fami iar with n rmal laboratory practice

This document d es not purport to addres al of the safety pro lems, if any, as ociated with its

use It is the respo sibi ity of the use to establsh appropriate safety and he lth practices and to

ensure complance with any natio al re ulatory co ditio s

WARNING 2— Certain procedures specified in this document might inv lve the use or g eneration

of substances, or the g eneratio of waste, that co ld constitute a local enviro mental hazard

Reference sho ld be made to appro riate d cumentatio o safe handl ng and disposal after use

This document spe if ies the flex omet er t es with cons ant-s rain ampltu e for the det ermination of

the t empe atur rise and r sis anc t o fatigue of vulcaniz d rub e The flex omet er spe if ied is k own

as the Go drich flex omet er, but any othe a p ratus giving eq iv lent pe formanc can be used

This document gives dir ctions for car ying out measur ment w hich make p s ible pr dictions

r g rding the d ra i ty of rub e s in f inished articles subje t t o dynamic flexing in se vic , such as

tyr s, bearings, sup ort , V-belt , an ca le-puley inse t rings Howeve , owing t o the wide v riations

in se vic con itions, no simple cor elation betwe n the ac ele at ed t es s desc ibed in the v rious

p rt of this document an se vic pe formanc can be as umed

The method isnot r commen ed for rub e ha ing a hardnes gr at er than 8 IRHD

2 Normati ve r eferences

The folowing document ar r fe r d t o in the t ext in such a wa that some or al of their cont ent

cons itut es r q ir ment of this document F or dat ed r fe enc s, only the edition cit ed a ples F or

un at ed r fe enc s, the lat es edition of the r fe enc d document ( inclu ing any amen ment ) a ples

ISO 48, Ru be , v ulc ani zed or the mo las tic — Dete min tio o h rdnes s (h rdnes s bet we n 10 IRHD a d

10 IRHD)

ISO 2 5 9, R ub e r — Ge ne ral procedur s fr pre parin a d c onditio in tes t pieces fr p ysic al tes t meth ds

ISO 1 89 :2 1 , R ub e — Guide to the c albratio o tes t eq ipment

3 Terms and definitions

F or the purposes of this document, the t erms an def initions given in ISO 46 6-1 a ply

ISO an IEC maintain t erminolo ical data ases for use in s an ardization at the folowing ad r s es:

— IECEle tro edia: a aia le at ht p:/ www.ele tro edia.org

— ISO Onlne brow sing plat orm:a ai a le at ht p:/ www.iso.org o p

4 Principle

A spe ified compr s ive lo d is a pled t o a t es pie e through a leve sy st em ha ing high ine tia, w hie

imp sing on the t es pie e an ad itional high-fr q ency cyclc compr s ion of spe ified ampltu e

Measur ment ar made of the inc ease in t empe atur at the base of the t es pie e with a the mocouple

w hich pro idesa r lative in ication of the heat g ene at ed in flexing the t es pie e an of the n mbe of

cycles w hich prod c s fatigue br akdown

W ith the t es pie e subje t t o a cons ant a pled lo d or t o a cons ant initial compr s ion d ring the

t es , contin ous measur ment is made of the chang e in height of the t es pie e The compr s ion set of

the t es pie e is measur d aft er t es ing

5.1 Fle xometer

5.1.1 General des ription

The es ential p rt of the a p ratus ar shown in Figur 1

The t es pie e is plac d betwe n anvis fac d with a the mal insulating mat erial The t op anvi is

conne t ed t o an adjus a le e c ntric usual y driven at an osci lation rat e of 3 Hz ± 0,2 Hz

An anvi is sometimes caled a “ plat e” However, do not confuse “anvi ” with the plat e desc ibed in

Clause 7

The lo d is a pled b means of a leve r s ing on a k ife edg e The moment of ine tia of the leve

sy st em is inc eased an it natural fr q ency r d c d b suspen ing mas es of 24 kg at each en of

the leve sy st em The lowe anvi can be raised or lowe ed r lative t o the leve b means of a calbrat ed

mic omet er devic This devic pe mit the leve sy st em t o be maintained in a horizontal position

d ring the t es asdet ermined b a p int er an a r fe enc mark on the en of the bar

The inc ease in t empe atur at the b se of the t es pie e is det ermined b means of a the mocouple

plac d at the c ntr of the b tt om anvi

5.1.2 Detaied des r iption

The a paratus( e Figur 1) consis s of a b lanc beam (6) w hich can be locked in it horizontal position

b means of a st eel pin The beam is pro ided with mas es of 24 kg ( 8) at b th en s The dis anc

betwe n the k ife edg e sup orting the beam an the edg es sup orting the mas es is 2 8 mm ± 0,5 mm

An eq iv lent ine tial sy st em can be used

The t es pie e (2) is plac d upon an anvi (3) on one arm of the b lanc beam The dis anc of the

t es pie e sup ort (1 ) from the fulc um is 1 7 mm ± 0,5 mm On the othe side of the b lanc beam,

ad itional mas es (7)ar plac d in orde t o a ply a lo d t o the t es pie e The desir d weight ar 1 kg

or 2 kg w hich cor espon t o a pr -s r s of 1,0 MPa ± 0,0 MPa or 2,0 MPa ± 0,0 MPa, r spe tively

The t es pie e(2) is plac d betwe n the anvis(1 and 3), w hich ar made of a the mal insulating mat erial

ha ing a the mal con uctivity of not mor than 0,2 W/(m∙K) or, eq iv lently, 0,24 kcal/(h∙m °C)

P enolc hardpa e can be used for this purp se In the c ntr of the lowe anvi, a the mocouple,

for ex mple, iron-cons antan, is at ached for t empe atur measur ment The sensing p int of the

the mocouple shal be in contact with the t es pie e The sensitivity of the the mocouple shal be

± ,5 °C

Dimensions in milimetr es

Key

Figure 1 — C mpres io flexometer (constant-strain type) — General ar ang ement

Means shal be pro ided for measuring the de r ase in height of the t es pie e, as the t es proc eds,

with an ac uracy of 0,1 mm F or this purp se, the dis anc between the lowe and up e anvi s can be

v ried b means of a calbrat ed mic omet er devic u ti it r turns t o the horizontal position, w hich can

be r co niz d b a mark on the balanc beam and a p int er (5) on the casing The adjus ment devic

consis s of a mic omet er sc ew (4 ) w hich, b means of a chain an sprocket-w he l drive, mo es the

sc ew (9) up or down without rotating the lowe anvi (3) The degr e of adjus ment is r ad from the

mic omet er sc ew (4 ) The c ntr p int of the up e anvi (1) r mains in the same p sition The up e

anvi (1) is con e t ed through a guide bearing t o an e c ntric w hich can be set t o the desir d s roke in

a rang e from 4,45 mm t o 6,3 mm an is driven b a mot or at 3 Hz ± 0,2 Hz

Figur 2 shows a heating chambe The t es pie e (7) with the sup orting anvis is locat ed in the

chambe , the t empe atur of w hich can be maintained t o within ± °C of a t es t empe atur g ene aly in

the rang e 40 °C t o 1 0 °C The chambe shal ha e the folowing dimensions:

— width 1 0 mm t o 2 0 mm;

— depth 1 0mm t o 2 0 mm;

— height a pro imat ely 2 0 mm

The b tt om of the chambe shal be situat ed 2 mm ± 2mm a o e the b lanc beam ( 9)

A the mocouple of the same ty e as that used in the lowe anvi ( 8) shal be used for measur ment of

the t empe atur in the chambe The the mocouple shal be p sitioned at a dis anc of6 mm t o 9 mm

t owards the right-han side behin the r ar edg e of the anvi an at a height midwa betwe n the

anvis A length of at leas 1 0mm of the the mocouple wir shal be within the chambe

The air cir ulation within the chambe is pro ided b a radial fan (4 ) of 7 mm diamet er, o e ating at a

rotational fr q ency of 2 Hz t o 2 Hz Theair intake shal ha e a diamet er of 6 mm The air outlet (5)

shal measur 40 mm × 45 mm Thegrid shelf for sup orting the t es pie e d ring con itioning (2) shal

be fitt ed 1 mm ± 2 mm a o e the b tt om of the chambe

Dimensions in milimetr es

Key

1 he ting chamb r w ith do r 6 cr os b r w ith lifing rods an u per anvil

2 g rid shelf for su porting test pieces d ring con itioning 7 test piece

Figure 2 — Example of a he ting chamber

5.2 Measur ing gaug e

The g ug e for measuring the height an diamet er of t es pie es shal conform t o the r q ir ment of

The s an ard method of pr p ring the t es pie e shal be the dir ct moulding of the cy lin e It is

sugg est ed, for the purp se of u iformity an close t ole anc in the moulded t es pie e, that the

dimensions of the mould be spe if ied and shrinkag e compensat ed for the ein A plat e ca ity of thick es

2 ,4 mm ± 0,0 mm an diamet er 1 ,0 mm ± 0,0 mm, ha ing o e flow ca ities at b th t op an b tt om

w hen combined with two en plat es, pro idesone ty e of suita le mould

An alt ernative method of pr p ring the t es pie e is t o cut from a vulcaniz d sla of the r q ir d

thicknes The vulcaniz d thicknes shal besuch that buff ing is not r q ir d

The cir ular die used for cut ing the t es pie e shal ha e an inside diamet er of 1 ,8 mm ± 0,0 mm In

cut ing the t es pie e, the die shal be suita ly rotat ed in a dri l pr s or simi ar devic an lubricat ed b

means ofa so p solution A minimum dis anc of 1 mm shal be maintained between the cut ing edg e

of the die an the edg e of thesla The cut ing pr s ur shal be as lght as pos ible t o minimiz cup ing

or ta e in the diamet er of the t es pie e

It should be r co niz d that eq al time an tempe atur used for b th moulded an sla t es pie es

do not prod c an eq iv alent s at e ofvulcanization in the two ty es of tes pie e A highe degr e of

vulcanization is o tained in the moulded t es pie e A djus ment , pr fe a ly in the time of cur , should be

taken into conside ation if comp risons betwe n the two ty es of t es pie e ar to be conside ed v ald

8 Test conditions

The conditions spe if ied in Ta le 1 ar normal y emplo ed in flex omet er t es s with cons ant-s rain

ampl tu e

Table 1 — Test con itio s

C amb r temperature 5 °C ± 1°C or 1 0 °C ±1 °C

Stroke (double amplitu e) 4,45 mm, 5,71mm or 6,3 mm

Pre-stres on test piece

a

1,0 MPa or 2,0MPa

a

A pre-s res of 1,0 MPa is eq ivalent to a weig t on the balanc be m of

1 k ;a pre-s res of 2,0 MPa is eq ivalent oa w eig t of 2 k

Tes s with the heating chambe r mo ed ar r fe r d t o as “ ro m t empe atur ” t es s, or t es s at

s an ard la orat ory t empe atur The s an ard la orat ory t empe atur used shal be spe if ied in the

t es r p rt

F or the measur ment of t empe atur rise, a chambe t empe atur of eithe 5 °C or 1 0 °C shal be

sele t ed with a s roke of 4,45 mm or 5,7 mm Any of these choic s of t empe atur an s roke can be

used with a pr -s r s of eithe 1,0 MPa or 2,0 MPa on the t es pie e These choic s ordinari y give a

t empe atur rise that is es ential y at eq i brium aft er the normal t es d ration of 2 min Howeve ,

t es times long er than 2 min can be sele t ed, if desir d, for spe ial t es purp ses

F or measur ment of the fatigue pro e ties of rub e , mor seve e t es con itions ar ne ded Spe ificaly,

s rokes of 5,7 mm and 6,3 mm ar r commen ed with the highe pr -s r s on the b lanc beam

S le tion of the mor seve e con itions a oids ex ces ive t es d rations for each t es pie e

In g ene al, for medium hardnes rub e s that ha e ordinary t empe atur rise charact eris ics, a pr

-s r s of 1,0 MPa, a s roke of 5,7 mm an a chambe t empe atur of 5 °Cor 1 0 °C is r commen ed

The same t es con itions shal be maintained throughout a se ies of t es s int en ed for comparison of a

groupof comp u ds

9 Proc edure

9.1 Preparation of fle ometer

L cat e the machine on a f irm fou dation A djus the levelng sc ew in the b se t o bring the machine int o

a level position in al dir ctions at a p int jus t o the r ar of the fulc um of the lo ding leve W ith the

lo ding leve locked in plac with the pin, plac a level on the leve b r an ve ify the level set ing

A djus the e c ntric t o give a s roke or a double ampltu e of 4,45 mm ± 0,0 mm This is bes

ac ompl shed b means of a dial mic omet er r s ing on eithe the c os b r of the up e anvi or b

means of ada t ers at ached t o the lo ding arm of the e c ntric

The 4,45 mm s roke is sele t ed as the s an ard for calbration purposes When s rokes othe than

4,45mm ar t o be used, the displac ment of the lowe anvi should be maintained within the t ole anc

spe ified for it height a o e the lo ding leve

Raise the t op anvi as far as the e c ntric pe mit b it rotation Plac a cal brating block of height

2 ,0 mm ± 0,0 mm on thelowe anvi

A suita le block ma be made from bras ha ing a diamet er of 1 ,8 mm The en t o be plac d on the

lowe anvi should be count er-b r d for clearanc of the the mocouple disc

Raise the anvi b means of the mic omet er unti the b tt om side of the metal cup holding the

the mocouple is 6 mm ± 3 mm a o e the t op of the lo ding leve The lo ding leve shal be in the

locked position

A djus the c os b r of the up e anvi, maintaining a paralel set ing with the lowe anvi an a

firm contact with the calbrating block The mic omet er shal now be set at z ro This could r q ir

diseng g ement of the g ear train near s the ve nie scale of the mic omet er

R emo e the calbrating block an r che k the s roke or double ampltu e for the 4,45 mm set ing S t

the p int er on the mark at the en of the leve bar This es a lshes the level p sition

R emo e the locking pin from the lo ding leve an g ently osci at e the leve sy st em t o det ermine the

p int of r s If the b r does not come t o r s in a pro imat ely the level p sition, slow ly r turn it t o it

level position an r lease If mo ement from the level p sition is o se ved, ad or r mo e a mas t o or

from the r q ir d ine tia mas t o o tain a b lanc

9.2 Test proc edure

9.2.1 General

Che k the machine for pro e adjus ment se 9.1) an the r q ir d t es con itions ( e Clause 8) Plac

the ne es ary mas es on the r ar hang er t o give the desir d lo d

lf a s roke othe than 4,45 mm is desir d, a new z ro set ing is r q ir d on the mic omet er aft er

adjus ing the e c ntric t o the new s roke Proc ed as outl ned in 9.1t o o tain the z ro set ing

F or elev t ed t empe atur s r q iring the use of the heating chambe , alow a minimum of 2 h for

pr heating of the a p ratus an the at ainment of eq i brium prior t o the s art of t es Maintain the

lowe anvi at the z ro set ing, that is, 6 mm a o e the lo ding leve d ring the con itioning pe iod

Measur an r cord the height of the t es pie e Then measur it hardnes in ac ordanc with ISO 48

When the heating chambe is t o be used, plac the t es pie e in the chambe on the grid shelf an

con ition for a minimum of 3 min befor the s art of t es

Befor s arting the t es , the lowe anvi t empe atur an the ambient t es t empe atur shal be in

eq i brium W ith the up e anvi or c os b r in it highes position, lowe the b tt om anvi an q ickly

p sition the t es pie e the eon, inve ting it position from that used d ring the con itioning pe iod