Tiêu chuẩn iso 04628 4 2016

© ISO 2016 Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity and size of defects, and of intensity of uniform changes in appearance — Part 4 Assessment of degree o[.]

Paints and varnishes — Evaluation

defects, and ofintensity ofuniform

Part 4:

Peinture s et ve nis — Év lu tion de la dé radation de s r vê tement

— Désign tion de la q a tité et de la dimension de s déa ts, et de

l’intensité de s ch n ement u iforme s d’aspect —

Partie 4 : Év lu tion du degré de cra ue la e

T ir d edition

2 16-0 -1

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

the r eq eser

ISO c pyrig ht ofic

C de Blan on et 8 • C 4 1

CH-1 14 Vernier, Geneva, Sw itzerlan

F reword i v

1 Sc ope 1

2 Nor mati ve r eferenc es 1

3 Terms and definitio s 1

4 A sses ment 1

5 Ex pres io of r esults 2

6 Test rep rt 3

A nne x A (informative)Examples for types of cracking 6

Biblog raphy 15

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

F or an ex lanation on the meaning of ISO spe ific t erms an ex r s ions r lat ed t o conformity

as es ment, as wel as information a out ISO’ s adhe enc t o the WTO principles in the Te h ical

Bar ie s t o Trade (TBT) se the fol owing URL: F or word - Sup lementary information

The committ ee r sp nsible for this document is ISO/TC 3 , Paint a d v rni shes , Subcommitt ee SC 9,

G ene al tes t meth ds fr p ints a d v rni shes

This third edition canc ls an r plac s the se ond edition (ISO 46 8-4:2 0 ), w hich has be n t ech icaly

r vised with the folowing chang es:

a) lowe l mit for visual as es ment of defe t has be n introd c d in Ta le 2;

b) a normative r fe enc t o ISO 1 076 for i lumination for the as es ment has be n ad ed

ISO 46 8 consis s of the folowing part , un e the g ene al title Paints a d v rni shes — Ev lu tion o

degradatio o c oatin s — Des ig ation o q a tit y a d s i ze o defec ts, a d o intens it y o u ifrm cha ges

in a peara c e:

— Part 1: G ene al introduc tio a d des ig atio sys tem

— Part 2 : As ses s ment o degr e o bli s terin

— Part 3 : As s es s ment o degr e o rus tin

— Part 4 : As s es s ment o degr e o c rackin

— Part 5: As s es s ment o degr e o flakin

— Part 6 : As s es s ment o degr e o chalkin b ta e meth d

— Part 7: As ses s ment o degr e o chalkin b velvet meth d

— Part 8: As s es s ment o degr e o delamin tion a d c or os io  aro nd a s c ribe or othe  artific ial defec t

— Part 10: As ses s ment o degr e o fi frm c or os ion

P aints and varnishes — Evaluation ofdeg radation of

Part 4:

This p rt of ISO 46 8 spe if ies a method for as es ing the degr e of c acking of co tings b comp rison

with pict orial s an ards

ISO 46 8-1 defines the sy st em used for designating the q antity an siz of defe t an the int ensity

of chang es in a pearanc of co tings an outl nes the g ene al principles of the sy st em This sy st em is

int en ed t o be used, in p rticular, for defe t caused b ag eing an weathe ing, an for u iform chang es

such as colour chang es, for ex mple yelowing

2 Normati ve r eferences

The folowing document , in w hole or in p rt, ar normatively r fe enc d in this document an ar

in ispensa le for it a pl cation F or dat ed r fe enc s, only the edition cit ed a pl es F or u dat ed

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

ISO 1 07 6, Paints a d v rni shes — Lig tin a d proc edur fr v i s ual as ses s ment o c oatin s

3 Terms and definitions

F or the purposes of this document, the folowing t ermsand definitions a ply

3.1

de re of c acking

rating charact erizing c acks in a co ting in t erms of q antity, siz , an depth

As es the q antity of c acking b r fe enc t o Ta le 1 an using as ex mple Figur 1 or Figur 2,

depending on the ty e of c acking

NOTE Figure 1 shows c acking without preferential direction an Figure 2 shows c acking in one preferential

direction, which oc ur with substrat es such as wood (“anisotropic” substrates) Other forms of c acking oc ur,

but the principles of as es ing the q antity remain the same

Table 1 — Rating s heme for designating the q antity of c acks

0 none, i.e no detecta le c acks

1 very few, i.e.smal,b rely signif icant n mb r of c acks

2 few, i.e smal but signif icant n mb r of c acks

4 considera le n mb r of c acks

5 dense patt ern of c acks

If spe if ied, as es the a e ag e siz of the c acks in ac ordanc with Ta le 2

Table 2 — Rating s heme for designating the size of c acks

0 not visible u der × 1 ma nif ication

1 only visible u der ma nif ication u to × 0

2 just visible with normal cor ect ed vision (u to 0,2 mm)

a

3 cle rly visible with normal cor ected vision (larg r than 0,2 mm u t o

0,5 mm)

4 larg c acks, larg r than 0,5 mm u to 1mm wide

5 very larg c acks g neraly more than 1 mm wide

a

Ty ic ly, defe t larger than 0,2 mm are visible with normal c r e ted vision

Whe e the t es ar a exhibit c acks of v rious siz s, q ot e as the siz rating that of the larg es c acks

w hich ar n me ous enough t o be ty ical of the t es ar a

If pos ible, in icat e the depth of c acking b r fe enc t o the level in the co ting sy st em t o w hich the

c ackspenetrat e A dis inction is made betwe n thr e main ty es of faiur b c acking:

a) surfac c acks w hich do not fuly penetrat e the t op co t ( i.e che king);

b) c acks w hich penetrat e the t op co t, the un e lying co t (s) being subs antialy unafe t ed;

c) c acks w hich penetrat e the w hole co ting sy st em

Car y out the as es ment u de g ood i lumination, as spe if ied in ISO 1 076

5 Ex pres ion of results

Ex r s the n me ical ratings of the q antity an , ifspe ified, siz of the c acks, t og ethe with the

depth of c acking (a, b, or c), shown in Figur s 1 an 2 t og ethe with the a pro imat e dimensions of the

ar a conc rned, or it pro ortion t o the t otal ar a, ex r s ed as a pe c ntag e

F or ex mple, for q antity 2, siz 3 with the c acks penetrating the t op co t an the un e lying co t (s)

ar subs antialy unafe t ed, r port the r sult as

— c acking;degr e of c acking 2( S3)b

If ne es ary, the as es ment ma be ampl fied in words, for ex mple “c acking in one pr fe ential

dir ction”an b using the desc iptions given in An ex A

6 Test r eport

The t es r p rt hal contain at leas the folowing information:

a) al detais ne es ary t o identify the co ting ex mined;

b) a r fe enc t o this p rt of ISO 46 8, i.e ISO 46 8-4;

c) thety e of surfac ex mined, it siz an , if a pro riat e, it location;

d) ther sult of the ex mination in ac ordanc with Clause 5;

e) an indication of the i lumination u de w hich the as es ment was car ied ou

f) any u usual featur s (anomales)o se ved d ring the as es men

g) thedat e of the ex mination

a) Quantity (density) 1 b) Quantity (density) 2 c)Quantity (density) 3

Figure 1 — Cracking with ut preferential direction (panels of are 1 0 cm

2

to 20 cm

2

)

a) Quantity (density) 1 b) Quantity (density) 2 c)Quantity (density) 3

Figure 2 — Cracking in o e preferential direction (for example due to brush marks or wo d

grain)(panels of are 1 0 cm

2

to 200 cm

2

)

A nnex A

ASTM — Ame ican Society for Tes ing an Mat erials

TNO — Nede lan se Org nisatie v or Toeg ep s Natu rwet enscha peljk Onde zoek (Nethe lan s

Org nization for Ap led S ientif ic R esear h)

ASTM 8

ASTM 6

TNO 6

TNO 8

Figure A.1 — Ir e ular

ASTM 8

TNO 2

ASTM 6

TNO 4

ASTM 2

TNO 8 ASTM 4

TNO 6

Figure A.2— Lo g l ne

TNO 4 ASTM 8

TNO 2

ASTM2

TNO 8 TNO 6

ASTM 4

Figure A.3— Short paralel

TNO 2 ASTM 8

ASTM 4

TNO 6

TNO 4 ASTM 6

ASTM 2

TNO 8

Figure A.4 — Switch

ASTM 6

TNO 4

ASTM 2

TNO 8 TNO 6

ASTM 4

ASTM 8

TNO 2

Figure A.5 — Crow foot

TNO 2

TNO 4

ASTM 2

TNO 8 ASTM 4

TNO 6

Figure A.6 — Mosaic

ASTM 8

TNO 2

ASTM 6

TNO 4

ASTM 2

TNO 8 TNO 6

ASTM 4

Figure A 7 — Shrinkag e

ASTM 8

ASTM 6

TNO 6

TNO 8

Figure A.8 — Short, random

TNO 8 ASTM 2

TNO 6 ASTM 4

ASTM 8

TNO 2

ASTM 6

TNO 4

Figure A 9 — Sigmoid

Bibl og raphy

[1] ISO 46 8-1, Paints a d v rni shes — Ev lu tion o degradatio o c oatin s — Des ig ation o

q a tit y a d s i ze o defec ts, a d o intens it y o u ifrm ch n es in a peara c e — Part 1: G ene al

introduc tion a d des ig ation sys tem