ASTM_D_3808_-_01_2013.pdf

Designation:D380801(Reapproved 2013)Standard Test Method forQualitative Determination of Adhesion of Adhesives toSubstrates by Spot Adhesion1This standard is issued under the fixed designation D3808;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 simple qualitative procedurefor quickly screening whether an adhesive will,under recom-mended application conditions,bond to a given substratewithout actually making bonded assemblies.1.2 The values stated in SI units are to be regarded as thestandard.The values in parentheses are for information only.1.3 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:2D907 Terminology of AdhesivesE171 Practice for Conditioning and Testing Flexible BarrierPackaging3.Terminology3.1 DefinitionsMany of the terms used in this test methodare defined in Terminology D907.3.1.1 spot adhesion,na qualitative method of determiningadhesion by attempting to pry a“spot”of cured adhesive froma substrate.4.Summary of Test Method4.1 Spots of adhesive(size can vary,but generally about 6mm(14in.)in diameter)are placed onto a substrate using theapplication procedure and curing conditions acceptable to bothuser and supplier of the adhesive.4.2 The substrate preparation and environmental exposureof the spot of adhesive after cure or setting can be varied asdesired.4.3 The determination of whether an adhesive bonds to thesubstrate is made by simply trying to pry the spot of adhesivefrom the substrate.4.4 The mode of failure is readily evident by examiningwhether the bond separated adhesively or cohesively,either inthe adhesive or substrate.5.Significance and Use5.1 This is a quick,simple,and inexpensive test method forqualitatively determining,without the need to prepare bondedtest specimens,whether the adhesive under consideration willbond to a particular substrate.If the results are acceptable,thenstandard quantitative adhesive test procedures can be used toobtain quantitative measurements of the adhesives perfor-mance.5.2 This test method can also be used to compare relativeadhesion of several adhesives to given substrates.5.3 It can be used to determine whether an adhesive willcontinue to adhere to the substrate under specified environmen-tal conditions.5.4 It can be used to evaluate adhesion of a particularadhesive to a variety of substrates.5.5 It can be used to obtain“subjective”comparative databetween several adhesives on a given substrate by noting therelative ease of inducing failure between the adhesives tested.5.6 It should be most applicable to adhesives that cure or setwhen exposed to“air”(ambient,heated,etc.)and could beused for anaerobic adhesives if testing is carried out in anoxygen-free atmosphere.6.Apparatus6.1 No special equipment is needed for application of theadhesive to the test substrate(s).When using hot-meltadhesives,for example,it would be desirable to have ahand-gun applicator or equivalent apparatus to allow deposi-tion of the hot-melt at a recommended application temperature.The use of such equipment is not mandatory as a hot plate can1This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is the direct responsibility of Subcommittee D14.40 on Adhesives forPlastics.Current edition approved July 1,2013.Published July 2013.Originally approvedin 1979.Last previous edition approved in 2007 as D3808 01(2007).DOI:10.1520/D3808-01R13.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 be used to melt a quantity of the hot melt to the applicationtemperature in a deformable container such as an aluminumweighing dish.Upon reaching proper temperature,the hot meltcan be poured onto the substrate after forming a pouring spoutin the container.6.2 For some applications it is desirable to preheat thesubstrate.For this reason an oven or other heat source would beuseful.6.3 To test adhesion of the adhesive spot,a thin stainlesssteel spatula or similar probe is needed to pry or lift the spotfrom the substrate.7.Test Specimen7.1 Any form or shape of the substrate is acceptable.It isadvisable to place several spots of the same adhesive onto thesubstrate.7.2 In most cases,it is most efficient to test severaladhesives on the same substrate