BS EN ISO 4628-6-2011 Paints and varnishes Evaluation of degradation of coatings Designation of quantity and size of defects and of intensity of uniform changes in appearance Asses.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 4628-6:2011Paints and varnishes Evaluation of degradation of coatings Designation of quantity and size of defects, and of intensity of uniform changes in appearancePart

2、 6: Assessment of degree of chalking by tape methodBS EN ISO 4628-6:2011 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 4628-6:2011. It is identical to . It supersedes BS EN ISO 4628-6:2007, which is withdrawn.The UK participation in its preparation was ent

3、rusted to T e c h n i c a l C o m m i t t e e S T I / 1 0 , T e s t m e t h o d s f o r p a i n t s .A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are re

4、sponsible for its correct application. BSI 2011 ISBN 978 0 580 68544 6 ICS 87.040 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2011.Amendments is

5、sued since publicationDate T e x t a f f e c t e dEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 4628-6 September 2011 ICS 87.040 Supersedes EN ISO 4628-6:2007English Version Paints and varnishes - Evaluation of degradation of coatings - Designation of quantity and size of defects, and of

6、intensity of uniform changes in appearance - Part 6: Assessment of degree of chalking by tape method (ISO 4628-6:2011) Peintures et vernis - valuation de la dgradation des revtements - Dsignation de la quantit et de la dimension des dfauts, et de lintensit des changements uniformes daspect - Partie

7、6: valuation du degr de farinage par la mthode du ruban adhsif (ISO 4628-6:2011) Beschichtungsstoffe - Beurteilung von Beschichtungsschden - Bewertung der Menge und der Gre von Schden und der Intensitt von gleichmigen Vernderungen im Aussehen - Teil 6: Bewertung des Kreidungsgrades nach dem Klebeban

8、dverfahren (ISO 4628-6:2011) This European Standard was approved by CEN on 31 August 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date l

9、ists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation und

10、er the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,

11、 Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NO

12、RMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 4628-6:2011: EBS EN ISO 4628-6:2011 EN ISO 4628-6:2011 (E) 3 Foreword This document (EN ISO 4628-6:2011) has been p

13、repared by Technical Committee ISO/TC 35 “Paints and varnishes“ in collaboration with Technical Committee CEN/TC 139 “Paints and varnishes” the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or

14、by endorsement, at the latest by March 2012, and conflicting national standards shall be withdrawn at the latest by March 2012. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for i

15、dentifying any or all such patent rights. This document supersedes EN ISO 4628-6:2007. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech

16、Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 4628-6:2011

17、has been approved by CEN as a EN ISO 4628-6:2011 without any modification. BS EN ISO 4628-6:2011ISO 4628-6:2011(E) ISO 2011 All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of

18、 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

19、, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main

20、task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Atten

21、tion is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 4628-6 was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee SC 9, General

22、 test methods for paints and varnishes. This third edition cancels and replaces the second edition (ISO 4628-6:2007), which has been technically revised. The main changes are as follows: a) the pictorial standards (photographic pictures) used in the first edition (ISO 4628-6:1990) have been re-inser

23、ted because the computer-generated chalking scale used in the second edition (ISO 4628-6:2007) did not always give the same rating as that given by the scale used in the first edition (for more details, see the Introduction); b) a limiting value of the transmittance of the tape below which chalking

24、is considered to have taken place has been added (see 5.2). 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 in

25、troduction 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 ve

26、lvet method Part 8: Assessment of degree of delamination and corrosion around a scribe or other artifical defect Part 10: Assessment of degree of filiform corrosion BS EN ISO 4628-6:2011ISO 4628-6:2011(E) iv ISO 2011 All rights reservedIntroduction ISO 4628-1 defines the system for designating the q

27、uantity and size of defects and the intensity of uniform changes of coatings and outlines the general principles of the system. This system is intended to be used, in particular, for defects caused by ageing and weathering, and for uniform changes such as colour changes, for example yellowing. The o

28、ther parts of ISO 4628 provide pictorial standards or other means for evaluating particular types of defect. As far as possible, already existing evaluation schemes have been used as the basis. The chalking scale used in the first (1990) edition and in this third edition of ISO 4628-6 consists of ph

29、otographic pictures of adhesive tapes with different amounts of pigment particles adhering to them. The pigment particles are not evenly distributed over each tape. The lower ratings in particular (i.e. 1 to 3) give the impression of cloudiness. All five ratings in the scale used in the first (1990)

30、 edition and in this edition are sufficiently different for visual-assessment purposes, however. The scale used in the second (2007) edition was computer-generated. Thus the white dots representing the pigment particles were distributed very evenly over the tape, with the result that not all the rat

31、ings differed sufficiently well from each other for visual assessment to be carried out. While ratings 0,5 to 3,0 on the black background on the 2007 scale could be differentiated sufficiently well from each other, it was hardly possible to differentiate visually between ratings above 3,0, especiall

32、y ratings 4 and 5. On the white background, the difference between ratings 0,5, 1,0 and 1,5 was not easy to discern. The differences between ratings 1,5 to 5,0 were more evident, however. Comparing the 1990 scale with the 2007 scale, it would appear that rating 1 on the 1990 scale corresponded to 0,

33、5 on the 2007 scale, and rating 2 on the 1990 scale corresponded to 1 on the 2007 scale. It was therefore decided that the 2007 scale was unsuitable for use in the visual assessment of the degree of chalking of paints over the whole rating scale from 0,5 to 5,0. BS EN ISO 4628-6:2011INTERNATIONAL ST

34、ANDARD ISO 4628-6:2011(E) ISO 2011 All rights reserved 1Paints and varnishes Evaluation of degradation of coatings Designation of quantity and size of defects, and of intensity of uniform changes in appearance Part 6: Assessment of degree of chalking by tape method IMPORTANT For the assessment of th

35、e degree of chalking by the tape method, it is necessary to use the pictorial reference standards contained in this part of ISO 4628. Owing to the fact that electronic copies of these standards are subject to change when viewed on screen or printed, it is recommended that only the pictorial standard

36、s contained in printed copies of this part of ISO 4628 purchased from ISO member bodies or their distributors be used when comparing test results. 1 Scope This part of ISO 4628 provides pictorial reference standards for designating the degree of chalking of paint coatings. It also describes a method

37、 by which the degree of chalking is rated. In using this method, it is essential that care be taken to distinguish between true degradation products and adhering dirt, particularly when chalking is slight. 2 Terms and definitions For the purposes of this document, the following terms and definitions

38、 apply. 2.1 chalking appearance of a loosely adherent fine powder on the surface of a paint coating, arising from the degradation of one or more of its constituents 3 Principle The chalking is removed from the coating under test using an adhesive tape. The chalking adhering to the tape is examined a

39、gainst a contrasting background (either black or white, whichever gives the greater contrast) and the degree of chalking is assessed with reference to a rating scale. 4 Materials 4.1 Self-adhesive transparent tape, of width at least 15 mm. Commercially available flexible tapes, transparent and witho

40、ut perceptible colour, have been found to be satisfactory. However, the quality of the tape affects the rating obtained. The type of tape shall therefore be agreed on between the interested parties and shall be stated in the test report. 4.2 Background, black or white, with matt finish, for example

41、card or velvet having a short pile without a tendency to be crushed. BS EN ISO 4628-6:2011ISO 4628-6:2011(E) 2 ISO 2011 All rights reserved5 Procedure 5.1 Allow the surface to dry at room temperature before carrying out the test. Place a piece of the adhesive tape (4.1) on the dry coating by applyin

42、g firm pressure and rubbing with a finger. The length of the tape should be at least 40 mm. Remove the tape perpendicularly to the surface and lay it on a background (4.2) of the appropriate colour to give the greater contrast, with the adhesive in contact with the background. Assess light-coloured

43、coatings on the black background and dark-coloured coatings on the white background. Under consistent illumination, immediately assess (see 5.5) the degree of chalking by comparing the amount of chalk on the tape with the pictorial reference standards in Figure 1. The more background that is visible

44、, the lower the rating. Report the illumination in the test report. 5.2 The degree of chalking may also be determined quantitatively using a suitable photoelectric instrument to compare the transmittance of the chalked tape with that of unused tape. In this procedure, the adhesive tape shall not be

45、placed on a background (4.2) but on a clean glass slide or open support, which is placed in the optical beam of the instrument2,3. A transmittance of less than 70 % of that of the unused tape indicates chalking. This instrumental method shall only be used if the pattern of chalking residues on the t

46、ape is homogeneous. 5.3 The degree of chalking can vary over a given area. On large areas with a uniform surface (no texture), the determination should preferably be made at several locations and the mean and range reported. Apply the tape to an area of the panel that has not been used for previous

47、measurements to avoid false readings. 5.4 Ratings obtained with coatings exposed to natural weathering shall be treated with caution as dirt deposited on the surface from the atmosphere can give false values of chalking. 5.5 After removing the chalking from the coating under test, the assessment of

48、each piece of adhesive tape shall be carried out without delay because the appearance of the chalking residues on the adhesive tape and the transmittance of the tape might change with time. 5.6 When testing low-gloss paint coatings, a certain amount of loosely adherent material might be observed, ev

49、en with unweathered panels. A blank test, carried out on an unweathered panel, is therefore recommended for such coatings. 6 Rating Rate the degree of chalking by reference to the pictorial standards shown in Figure 1. NOTE The numerical values given correspond to those in ISO 4628-1. For textured surfaces, the rating shall be based on the observations of the most intensively chalked parts of the tape. BS EN ISO 4628-6:2011ISO 4628-6:2011(E) ISO 2011 All rights reserved 37 Test report The test report shal