1、Designation: D 6677 07Standard Test Method forEvaluating Adhesion by Knife1This standard is issued under the fixed designation D 6677; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parenthes
2、es indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the procedure for assessing theadhesion of coating films to substrate by using a knife.1.2 This test method is used to establish
3、whether theadhesion of a coating to a substrate or to another coating (inmulti-coat systems) is at a generally adequate level.NOTE 1The term “substrate” relates to the basic surface on which acoating adheres (may be steel, concrete, etc. or other coating).1.3 This method can be used in the laborator
4、y and field.1.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to e
5、stablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 2197 Test Method for Adhesion of Organic Coatings byScrape AdhesionD 3359 Test Methods for Measuring Adhesion by Tape TestD 4541 Test
6、 Method for Pull-Off Strength of CoatingsUsing Portable Adhesion TestersD 7234 Test Method for Pull-Off Adhesion Strength ofCoatings on Concrete Using Portable Pull-Off AdhesionTesters3. Summary of Test Method3.1 Adhesion is determined by making an “X” cut into thecoating film to the substrate and b
7、y lifting the coating with aknife. Adhesion is evaluated qualitatively ona0to10scale.4. Significance and Use4.1 Coatings, to perform satisfactorily, must adhere to thesubstrates on which they are applied. This test method has beenfound useful as a simple means of assessing the adhesion ofcoatings. A
8、lthough this method is a qualitative and a subjectivetest it has been used in industry for many years and can providevaluable information.4.2 Other adhesion test methods may be useful in obtainingquantitative results. See D 2197, D 3359, D 4541, and D 7234.4.3 The Performance Evaluation Scale (see 7
9、.4, Table 1)isbased on both the degree of difficulty to remove the coatingfrom the substrate and the size of removed coating.4.4 This test method does not have a known correlation toother adhesion test methods (pull-off, tape, etc.).4.5 A coating that has a high degree of cohesive strengthmay appear
10、 to have worse adhesion than one that is brittle andhence fractures 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 utilityknife in one stroke.5. Apparatus and Materials5.1 Cutting ToolSharp utility knife.5.2 Cu
11、tting GuideSteel or other hard metal straight edgeto ensure straight cuts.6. Test Specimen6.1 When this test method is used in the field, the specimenis the coated substrate on which the adhesion is to be evaluated.6.2 For laboratory use, apply the materials to be tested topanels of the composition
12、and surface conditions on which it isdesired to determine adhesion.NOTE 2If desired or specified, the coated test panels may be subjectedto a preliminary exposure such as water immersion, salt spray, or highhumidity before conducting the knife adhesion test.7. Procedure7.1 Select an area free of ble
13、mishes and surface imperfec-tions.7.2 Using a sharp knife and cutting guide, make two cutsinto the coating with a 30 to 45 angle between legs and downto the substrate which intersects to form an “X.” Make each leg1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related C
14、oatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.46 on Industrial Protective Coatings.Current edition approved July 1, 2007. Published August 2007. Originallyapproved in 2001. Last previous edition approved in 2001 as D 6677 - 01.2For referenced ASTM standards
15、, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19
16、428-2959, United States.of the angle a minimum of 38.1 mm (112 in.) in length.Disregard coating removed during cutting process.7.3 Employing the point of the knife and beginning at thevertex of the angle, attempt to lift up the coating from thesubstrate or from the coating below. Rate according to T
17、able 1.7.4 Repeat the test in two other locations on each test panel.For large structures make sufficient tests to ensure that theadhesion evaluation is representative of the whole surface.7.5 After making several cuts examine the cutting edge and,if necessary, replace the blade.8. Report8.1 Report
18、the following information:8.1.1 Report the number of tests, their mean and range, andwhere the failure (if any) occurred (between first coat andsubstrate, between first and second coat, or within the coating,etc.).8.1.2 For field test, report the structure or article tested, thelocation and the envi
19、ronmental conditions at the time oftesting.8.1.3 For test panels, report the substrate employed, the typeof coatings, the dry film thickness and cure of each coat, andthe environmental conditions at the time of testing.9. Precision and Bias9.1 No precision statement has been established for this tes
20、tmethod 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 asserted in connection with any item mentionedin this standard. Users of this standard a
21、re 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 by the responsible technical committee and must be reviewed every five years andif not
22、 revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which y
23、ou may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,Unite
24、d States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).TABLE 1 Rating SystemRating Description10 Coating i
25、s extremely difficult to remove; fragments no larger thanapproximately 0.8 by 0.8 mm (132 in. by132 in.) removed with greatdifficulty.8 Coating is difficult to remove; chips ranging from approximately 1.6by 1.6 mm (116 by116 in.) to 3.2 by 3.2 mm (18 by18 in.) can beremoved with difficulty.6 Coating
26、 is somewhat difficult to remove; chips ranging fromapproximately 3.2 by 3.2 mm (18 by18 in.) to 6.3 by 6.3 mm (14 by14 in.) can be removed with slight difficulty.4 Coating is somewhat difficult to remove; chips in excess of 6.3 by6.3mm(14 by14 in.) can be removed by exerting light pressure withthe knife blade.2 Coating is easily 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 length greaterthan 6.3 mm (14 in.).D6677072
