ASTM_D_5179_-_16.pdf

Designation:D517916Standard Test Method forMeasuring Adhesion of Organic Coatings in the Laboratoryby Direct Tensile Method1This standard is issued under the fixed designation D5179;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.Scope*1.1 This test method covers the laboratory determination oforganic coating adhesion to plastic substrates by mounting andremoving a metal stud from the surface of the coating andmeasuring the force required to break the coating/substratebond with a tensile tester.This test method may also be appliedto substrates other than plastic.1.2 This test method requires that the metal stud be adhereddirectly to the surface of a coated,cured panel(Fig.1).1.3 This test method is used to compare the adhesion ofcoatings to plastic or other substrates,thus allowing for aquantitative comparison of various coating/substrate combina-tions in laboratory conditions.1.4 Other tensile test methods are Test Methods D4541,D7234,D7522,and ISO 4624(but are not technically equiva-lent).1.5 The values stated in SI units are to be regarded asstandard.The values given in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.1.6 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:2D4541 Test Method for Pull-Off Strength of Coatings UsingPortable Adhesion TestersD7234 Test Method for Pull-Off Adhesion Strength of Coat-ings on Concrete Using Portable Pull-Off Adhesion Tes-tersD7522 Test Method for Pull-Off Strength for FRP LaminateSystems Bonded to Concrete Substrate2.2 Other Standard:ISO 4624 Paints and VarnishesPull-off test for adhesion33.Summary of Test Method3.1 A metal stud is bonded directly to a coated cured panel.The adhesive is allowed to cure according to manufacturersrecommendations.The specimen is then subjected to test on atensile tester equipped with an upper coupling adapter(Fig.2),and a restraining device(Fig.3).3.2 If a coating is to fulfill its function of protecting ordecorating a substrate,it must adhere to it for the expectedservice life.Because the substrate and its surface preparation(or lack of it)has a drastic effect on the adhesion of coatings,a method of evaluating the adhesion of a coating to differentsubstrates or surface treatments,or of different coatings to thesame substrate and treatment,is of considerable usefulness inthe industry.4.Significance and Use4.1 The pull-off strength(commonly referred to as adhe-sion)of a coating is an important performance property that hasbeen used in specifications.This test method serves as a meansfor uniformly preparing and testing organic coatings on plasticor other substrates.4Further information may be found inAppendix X1.5.Apparatus and Materials5.1 Tensile TesterA properly calibrated testing machinethat can be operated at constant rates of crosshead motion,andin which the error in the load measuring system shall notexceed 61%of the maximum load expected to be measured.NOTE1A computer-controlled machine is preferable.1This 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 April 1,2016.Published June 2016.Originallyapproved in 1991.Last previous edition approved in 2008 as D5179 02(2008).DOI:10.1520/D5179-16.2For 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.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.4Gray,K.N.,Buckley,S.E.,and Nelson,G.L.,“Accessing MeasurementStandards for Coating Adhesion to Plastics,”Modern Paint and Coatings Journal,Vol 75,No.10,October 1985,p.160.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.2 Metal StudThe shape and dimensions of the stud areshown in Fig.1.If aluminum studs are used,the surface forbonding may require treatment to improve adhesion.Suchaluminum treatments are commercially available.5.3 Upper Coupling AdaptorThe apparatus is shown inFig.2.The adaptor is 94 mm 334in.long,31 mm 114in.in diameter at the top,and 25 mm 1 in.in diameter at thebottom.The