ASTM D6677-2018 red 6250 Standard Test Method for Evaluating Adhesion by Knife.pdf

1、Designation: D6677 07 (Reapproved 2012)D6677 18Standard Test Method forEvaluating Adhesion by Knife1This standard is issued under the fixed designation D6677; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio

2、n. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the procedure for assessing the adhesion of coating films to substrate by using a knife.1.2 This test meth

3、od is used to establish whether the adhesion of a coating to a substrate or to another coating (in multi-coatsystems) is at a generally adequate level.NOTE 1The term “substrate” relates to the basic surface on which a coating adheres (may be steel, concrete, etc. or other coating).1.3 This method ca

4、n be used in the laboratory and field.1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof t

5、he user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardizationes

6、tablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D2197 Test Method for Adhesion of Organic Coatings by Scrape

7、 AdhesionD3359 Test Methods for Rating Adhesion by Tape TestD4138 Practices for Measurement of Dry Film Thickness of Protective Coating Systems by Destructive, Cross-SectioningMeansD4541 Test Method for Pull-Off Strength of Coatings Using Portable Adhesion TestersD6132 Test Method for Nondestructive

8、 Measurement of Dry Film Thickness of Applied Organic Coatings Using an UltrasonicCoating Thickness GageD7091 Practice for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to Ferrous Metalsand Nonmagnetic, Nonconductive Coatings Applied to Non-Ferrous MetalsD7234 Test

9、 Method for Pull-Off Adhesion Strength of Coatings on Concrete Using Portable Pull-Off Adhesion Testers3. Summary of Test Method3.1 Adhesion is determined by makingscribing an “X” cut into the coating film to the substrate and by lifting the coating witha the point of a utility knife. Adhesion is ev

10、aluated qualitatively on a 0 to 10 scale.4. Significance and Use4.1 Coatings, to perform satisfactorily, must adhere to the substrates on which they are applied. This test method has been founduseful as a simple means of assessing the adhesion of coatings. Although this method is a qualitative and a

11、 subjective (subjective)test it has been used in industry for many years and can provide valuable information.1 This test method is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.46 on Indust

12、rial Protective Coatings.Current edition approved Nov. 1, 2012June 1, 2018. Published November 2012June 2018. Originally approved in 2001. Last previous edition approved in 20072012 asD6677 07.D6677 07 (2012). DOI: 10.1520/D6677-07R12.10.1520/D6677-18.2 For referencedASTM standards, visit theASTM we

13、bsite, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standardsstandards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard a

14、n indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is t

15、o be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.2 Other adhesion test methods may be useful in obtaining quantitative results. See Test Methods D2197, D3359, D4541, andD7234.4.3 The Performance

16、Evaluation Scale (see 7.4, Table 1) is based on both the degree of difficulty to remove the coating fromthe substrate and the size of removed coating.coating chip.4.4 This test method does not have a known correlation to other adhesion test methods (pull-off, tape, etc.).4.5 A coating that has a hig

17、h degree of cohesive strength may appear to have worse adhesion than one that is brittle and hencefractures easily when probed.4.6 This method is not to be used on overly thick coatings, that is, those which cannot be cut to the substrate with a utility knifein one stroke.5. Apparatus and Materials5

18、.1 Cutting ToolSharp utility knife.5.2 Cutting GuideSteel or other hard metal straight edge to ensure straight cuts.5.3 Dry Film Thickness Gage.6. Test Specimen6.1 When this test method is used in the field, the specimen is the coated substrate on which the adhesion is to be evaluated.6.2 For labora

19、tory use, apply the materials to be tested to panels of the composition and surface conditions on which it is desiredto determine adhesion.NOTE 2If desired or specified, the coated test panels may be subjected to a preliminary exposure such as water immersion, salt spray, or high humiditybefore cond

20、ucting the knife adhesion test.7. Procedure7.1 Select an area free of blemishes and surface imperfections.7.2 Measure the dry film thickness at, or near, the location where adhesion assessment will be performed. Appropriateprocedures are found in Practices D4138, Test Method D6132, or Practice D7091

21、.7.3 Using a sharp knife and cutting guide, make two cuts into the coating with a 30 to 45 angle between legs and down to thesubstrate which intersects to form an “X.” Make each leg of the angle a minimum of 38.1 mm (112 in.) in length. Disregard coatingremoved during cutting process.7.4 Employing t

22、he point of the knife and beginning at the vertex of the angle, attempt to lift up the coating from the substrateor from the coating below. Rate according to Table 1.7.5 Repeat the test in two other locations on each test panel. For large structures make sufficient tests to ensure that the adhesione

23、valuation is representative of the whole surface.7.6 After making several cuts examine the cutting edge and, if necessary, replace the blade.8. Report8.1 Report the following information:8.1.1 The number of tests,TABLE 1 Rating SystemRating Description10 Coating is extremely difficult to remove; fra

24、gments no larger thanapproximately 0.8 by 0.8 mm (132 in. by 132 in.) removed withgreat difficulty.8 Coating is difficult to remove; chips ranging from approximately1.6 by 1.6 mm (116 by 116 in.) to 3.2 by 3.2 mm (18 by 18 in.) canbe removed with difficulty.6 Coating is somewhat difficult to remove;

25、 chips ranging fromapproximately 3.2 by 3.2 mm (18 by 18 in.) to 6.3 by 6.3 mm (14by 14 in.) can be removed with slight difficulty.4 Coating is somewhat difficult to remove; chips in excess of 6.3by 6.3 mm (14 by 14 in.) can be removed by exerting lightpressure with the knife blade.2 Coating is easi

26、ly removed; once started with the knife blade, thecoating can be grasped with ones fingers and easily peeled to alength of at least 6.3 mm (14 in.).0 Coating can be easily peeled from the substrate to a lengthgreater than 6.3 mm (14 in.).D6677 1828.1.2 The mean and range of the tests,8.1.3 Report th

27、e number of tests, their mean and range, and where the Where the failure (if any) occurred (between first coatand substrate, between first and second coat, or within the coating, etc.).etc., and8.1.4 The coating dry film thickness.8.1.5 For field test, report the structure or article tested, the loc

28、ation and the environmental conditions at the time of testing.report:8.1.5.1 The structure or article tested,8.1.5.2 The location on the article where the test(s) were performed, and8.1.5.3 The environmental conditions at the time of testing.8.1.6 For test panels, report the substrate employed, the

29、type of coatings, the dry film thickness and cure of each coat, and theenvironmental conditions at the time of testing.report:8.1.6.1 The substrate employed,8.1.6.2 The type of coatings,8.1.6.3 The dry film thickness and cure of each coat, and8.1.6.4 The environmental conditions at the time of testi

30、ng.9. Precision and Bias9.1 No precision statement has been established for this test method due to its subjective character.10. Keywords10.1 adhesion; coating; intercoat adhesion; knife adhesion; paint; wet adhesionASTM International takes no position respecting the validity of any patent rights as

31、serted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time

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