Designation:D3121–94(Reapproved1999)StandardTestMethodforTackofPressure-SensitiveAdhesivesbyRollingBall1ThisstandardisissuedunderthefixeddesignationD3121;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversmeasurementofthecompara-tivetackofpressure-sensitiveadhesivesbyarollingballandismostappropriateforlow-tackadhesives.Thistestmethodisonlyoneofseveralavailableforthemeasurementoftack.1.1.1Thistestmethodisnotrecommendedforthespecifi-cationofenduseproducts.1.2Thevaluesstatedininch-poundunitsaretoberegardedasthestandard.Thevaluesintheparenthesesaregivenforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:D907TerminologyofAdhesives2E171SpecificationforStandardAtmospheresforCondi-tioningandTestingFlexibleBarrierMaterials33.Terminology3.1Definitions—Severaltermsinthistestmethodarede-finedinaccordancewithTerminologyD907.3.2DescriptionofTermSpecifictoThisStandard:3.2.1tack—thepropertyofanadhesivethatenablesittoformabondofmeasurablestrengthimmediatelyafteradhesiveandadherendarebroughtintocontactunderlowpressure.4.SummaryofTestMethod4.1Inthedeterminationoftackbytherolling-ballmethod,asteelballisreleasedatthetopofanincline,allowedtoacceleratedowntheinclineandrollontoahorizontalsurfacecoveredwithapressure-sensitiveadhesive.Tackisdeterminedbymeasuringthedistancethattheballtravelsacrosstheadhesivebeforestopping.Therearetwomajorretardingforcesappliedbytheadhesivetotheball:(1)theadhesionbetweentheballandtheadhesive,oftencalled“grab,”and(2)the“plowingeffect”orenergyrequiredtopushtheadhesiveoutoftheball...
