ASTM_D_6905_-_03_2012.pdf

Designation:D690503(Reapproved 2012)Standard Test Method forImpact Flexibility of Organic Coatings1This standard is issued under the fixed designation D6905;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 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 a procedure for determining theability of a coating film and its substrate to resist shattering,cracking,or chipping when the film and substrate are distendedbeyond their original form by impact.1.2 This test method does not measure impact resistance butuses rapid impact to improve Test Methods D522,another testmethod for flexibility.Since the impact of the coating is almostinstantaneous,all of the problems associated with time vari-ables in the mandrel tests are eliminated.1.3 This test method is similar in content but not technicallyequivalent to Test Method D2794.1.4 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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D522 Test Methods for Mandrel Bend Test of AttachedOrganic CoatingsD609 Practice for Preparation of Cold-Rolled Steel Panelsfor Testing Paint,Varnish,Conversion Coatings,andRelated Coating ProductsD823 Practices for Producing Films of Uniform Thicknessof Paint,Varnish,and Related Products on Test PanelsD1186 Test Methods for Nondestructive Measurement ofDry Film Thickness of Nonmagnetic Coatings Applied toa Ferrous Base(Withdrawn 2006)3D1400 Test Method for Nondestructive Measurement of DryFilm Thickness of Nonconductive Coatings Applied to aNonferrous Metal Base(Withdrawn 2006)3D2240 Test Method for Rubber PropertyDurometer Hard-nessD2794 Test Method for Resistance of Organic Coatings tothe Effects of Rapid Deformation(Impact)3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 impact flexibility,nof a coating,the percent areaincrease required to produce cracking in the deformed coating.4.Summary of Test Method4.1 The organic coating under test is applied to suitable thinmetal panels.After the coating has cured,a standard weight/indenter is dropped from a measured distance so as to strike thesubstrate which deforms the coating and the substrate.Thepercent elongation is the highest area of distensibility in whichthere is no film breaks that the film can stand.5.Significance and Use5.1 Coatings attached to substrates are subjected to damag-ing impacts during the manufacture of articles and their use inservice.This impact resistance test method has been found tobe useful in predicting the performance of organic coatings fortheir ability to resist cracking caused by impacts.6.Apparatus6.1 Impact Flexibility Tester4,assembly illustrated in Figs.1and 2.The instrument contains a 1.63 kg(3.6 lb)weight/indenter,a rubber pad and an aluminum pad,Fig.3.The roundrod weight/indenters two spherical ends(Marked“A”and“B”)are shown in Figs.4 and 5.The dimensions for theSpherical weight/indenter are shown in Table 1.The rod slides1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.23 on Physical Properties of Applied Paint Films.Current edition approved Nov.1,2012.Published November 2012.Originallyapproved in 2003.Last previous edition approved in 2008 as D6905 03(2008).DOI:10.1520/D6905-03R12.2For referenced ASTM standards,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.3The last approved version of this historical standard is referenced onwww.astm.org.4The sole source of supply of the apparatus known to the committee at this timeis the IM-172-GE Impact Tester,available from the Paul N.Gardner Company,Inc.,316 N.E.First Street,Pompano Beach,FL 33060.If you are aware of alternativesuppliers,please provide this information to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,1which you may attend.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 in a vertical,slotted guide and serves as a falling weight toimpact a test panel with the“embossed”end.When positionedproperly,the lifting knob on the weight/indenter coincides withthe bottom of the guide tube.7.Test Specimens7.1 Apply uniform coatings of the material to be tested