© 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 7 Assessment of degree o[.]
INTERNATIONAL STANDARD ISO 4628-7 Second edition 2016-01-15 Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity and size of defects, and of intensity of uniform changes in appearance — Part 7: Assessment of degree of chalking by velvet method Peintures et vernis — Évaluation de la dégradation des revêtements — Désignation de la quantité et de la dimension des défauts, et de l’intensité des changements uniformes d’aspect — Partie 7: Évaluation du degré de farinage selon la méthode du morceau de velours Reference number ISO 4628-7:2016(E) © ISO 2016 ISO 4628-7:2016(E) COPYRIGHT PROTECTED DOCUMENT © ISO 2016, Published in Switzerland All rights reserved Unless otherwise specified, no part o f this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission Permission can be requested from either ISO at the address below or ISO’s member body in the country o f the requester ISO copyright o ffice Ch de Blandonnet • CP 401 CH-1214 Vernier, Geneva, Switzerland Tel +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org ii © ISO 2016 – All rights reserved ISO 4628-7:2016(E) Contents Page Foreword iv Scope Normative references Terms and definitions Principle Materials Assessment Test report Bibliography © ISO 2016 – All rights reserved iii ISO 4628-7:2016(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work o f preparing International Standards is normally carried out through ISO technical committees Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters o f electrotechnical standardization The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part In particular the different approval criteria needed for the di fferent types o f ISO documents should be noted This document was dra fted in accordance with the editorial rules of the ISO/IEC Directives, Part (see www.iso.org/directives) Attention is drawn to the possibility that some o f the elements o f this document may be the subject o f patent rights ISO shall not be held responsible for identi fying any or all such patent rights Details o f any patent rights identified during the development o f the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents) Any trade name used in this document is in formation given for the convenience o f users and does not constitute an endorsement For an explanation on the meaning o f ISO specific terms and expressions related to formity assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary in formation The committee responsible for this document is ISO/TC 35, Paints and varnishes, Subcommittee SC 9, General test method for paints and varnishes This second edition cancels and replaces the first edition (ISO 4628-7:2003), which has been technically revised with the following changes: a) the pictorial reference standard for numerical chalking ratings to have been copied from ISO 4628-6:2011; b) a normative reference to ISO 13076 for illumination for the assessment has been added ISO 4628 consists of the following parts, under the general title Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity and size of defects, and of intensity of uniform changes in appearance: — Part 1: General introduction and designation system — Part 2: Assessment of degree of blistering — Part 3: Assessment of degree of rusting — Part 4: Assessment of degree of cracking — Part 5: Assessment of degree of flaking — Part 6: Assessment of degree of chalking by tape method — Part 7: Assessment of degree of chalking by velvet method — Part 8: Assessment of degree of delamination and corrosion around a scribe or other artificial defect — Part 10: Assessment of degree of filiform corrosion iv © ISO 2016 – All rights reserved INTERNATIONAL STANDARD ISO 4628-7:2016(E) Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity and size of defects, and of intensity of uniform changes in appearance — Part 7: Assessment of degree of chalking by velvet method Scope T h i s p ar t o f I S O 62 s p e ci fie s a me tho d s u itable, i n p ar tic u la r, for rati ng the de gre e o f cha l ki ng on wh ite or coloure d ex terior co ati ngs and co ati ng s ys tem s on rough s ur face s (i e tho s e havi ng a roughness greater than segment of the reference comparator G as described in ISO 8503-1) T he te s t me tho d s p e c i fie d c a n a l s o b e u s e d fo r the a s s e s s ment o f the de g re e o f ch a l ki ng o f co ati ngs a nd co ati ng s ys tem s o n s mo o th s u r face s , b ut the me tho d s p e c i fie d i n this purpose ISO 4628-6:2011 is preferable for T he te s t me tho d i s ap p l ic ab le to co ati ngs a nd co ati ng s ys tem s o n m i nera l s ub s trate s , e g fib re cement, brick, concrete, and renderings, independent of the structure of the surface The method can be used ff f f site evaluation qu ite e e c ti vely b y e xp er ience d op erato rs a nd i s re com mende d o r l ab o rato r y u s e a s wel l a s o r o n- NO TE When a re ference to th i s te s t me tho d i s i nclude d i n s p e c i fic atio n s , the te s t cond itio n s (i e we ather i ng NO TE Re fer to I S O 62 -1 method and substrate) have to be agreed between the interested parties NOTE The method described in this part of ISO 4628 is a relative ranking method and is therefore not suitable for use in agreements between parties See, however, the Note to Table fo r the de s ign ation s ys tem for qu a ntity a nd s i z e o f de fe c ts a nd the i nten s ity o f ch a n ge s i n app e a nce o f co ati ngs , a s wel l a s genera l p r i nc ip le s o f the s ys tem Normative references T he fol lowi ng i nd i s p en s able c u ments , i n whole or i n p ar t, are normatively re ference d i n th i s c u ment a nd are for its appl ic ation For date d re ference s , on ly the e d ition cite d appl ie s For u ndate d re ference s , the late s t e d ition o f the re ference d c u ment (i nclud i ng any amend ments) appl ie s ISO 13076, Paints and varnishes — Lighting and procedure for visual assessments of coatings Terms and definitions For the pu r p o s e s o f th i s c u ment, the fol lowi ng term s and defi n ition s apply 3.1 chalking app e ara nce o f a lo o s ely ad herent fi ne p owder on the s u r face o f a fi l m a ri s i ng one or more of its constituents from the degradation o f Principle L o o s ely ad herent p owder i s remove d from the co ati ng u nder te s t, u s i ng a s u itable chalking is assessed with reference to a rating scale © ISO 2016 – All rights reserved fabric T he degre e o f ISO 4628-7:2016(E) Materials 5.1 Fabric, as agreed between the interested parties, to rub against the surface being tested Black wool felt, velvet, and velveteen have proven particularly e ffective for light coatings and a white fabric for dark coatings Assessment Carry out the assessment under good illumination, as specified in ISO 13076 Carry out the assessment in duplicate, unless otherwise agreed Using the index finger, press the fabric against the coating being tested with firm pressure Rotate the fabric once through an angle of 180° Remove the fabric and assess the degree of chalking under diffuse light in reference to the rating scheme shown in Table A mechanical apparatus should be pre ferred i f comparable results are obtained; the coating may also be wiped once with the fabric Table — Rating scheme for designating the degree of chalking (derived from ISO 4628-1:2016, Table 3) Rating NOTE Degree of chalking unchanged, i.e no perceptible chalking very slight, i.e just perceptible chalking slight, i.e clearly perceptible chalking moderate, i.e very clearly perceptible chalking considerable, i.e pronounced chalking severe, i.e intense chalking I f specified or agreed, a simpler rating system can be used However, in such cases, the meanings o f the ratings in this table which are used shall not be changed in order to avoid confusion Examples of pictorial standards for assessing the degree of chalking are given in Figure The figure is obtained with the tape method specified in ISO 4628-6:2011, but the degrees o f chalking to are comparable to those specified in this part o f ISO 4628 The amount o f powder may vary over a given area There fore, the test shall be carried out at an average location on the coating On large surfaces, the assessment shall be made at several locations, and the mean and range reported Ratings obtained with coatings exposed to natural weathering shall be treated with caution, as dirt rom the atmosphere deposited on the sur face can give abnormally high values o f the degree o f chalking f © ISO 2016 – All rights reserved ISO 4628-7:2016(E) NOTE The right-hand end of each tape corresponds to chalking rating of Figure — Pictorial reference standards for numerical chalking ratings to Test report The test report shall contain at least the following information: a) a l l de ta i l s ne ce s s a r y to identi fy the co ati ng te s te d; b) a reference to this part of ISO 4628, i.e ISO 4628-7; c) the typ e o f s u r face exam i ne d, its s i z e a nd, i f appropriate , its lo c ation; © ISO 2016 – All rights reserved ISO 4628-7:2016(E) d) the numerical rating of the degree of chalking in accordance with Clause (mean value, range, and number of assessments); e) a l l de tai l s ne ce s s ar y to identi fy the fabric f) whe ther the re s u lt wa s ob tai ne d u s i ng the i nde x fi nger or a p a r tic u l ar app aratus (de ta i l s to b e g) de tai l s o f any devi ation h) any u nus ua l u s e d; indicated); fe ature s from the pro ce du re s p e ci fie d; (a noma l ie s) ob s er ve d du ri ng the as s e s s ment; i) the date of the examination © ISO 2016 – All rights reserved ISO 4628-7:2016(E) Bibliography [1] ISO 4628-1, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity and size of defects, and of intensity of uniform changes in appearance — Part 1: General introduction and designation system [2] ISO 4628-6, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity and size ofdefects, and ofintensity ofuniform changes in appearance — Part 6: Assessment of degree of chalking by tape method [3] ISO 8503-1, Preparation of steel substrates before application of paints and related products — Surface roughness characteristics of blast-cleaned steel substrates — Part 1: Specifications and definitions for ISO surface pro file comparators for the assessment of abrasive blast-cleaned surfaces © ISO 2016 – All rights reserved ISO 4628-7:2016(E) ICS 87.040 Price based on pages © ISO 2016 – All rights reserved