IST-40.2

StandardTestMethodforElectrostaticDecayofNonwovenFabricsAnumberinParenthesesindicatestheyearoflastrevision.1.Scope1.1Thismethoddeterminestheelectrostaticpropertiesofamaterialinfilmorsheetformbymeasuringthetimerequiredtodissipateachargefromthesurfaceofthematerial.2.ReferencedDocuments2.1ASTMStandards:D123TerminologyRelatingtoTextiles1D1776PracticeforConditioningTextilesforTesting12.1OtherStandards:NFPA-99-92Sec.12-4.1.3.8(f)(3)2FederalTestMethodSTDNo.101C,Method4046,ElectrostaticPropertiesofMaterials33Terminology3.1Definitions:3.1.1electrostaticdecay,n–theabilityofamaterialwhengroundedtodissipateachargewhichhasbeeninducedonthesurfaceofthematerial.3.1.2decaytime,n–thetimeinsecondsfortheinducedchargetodissipateto10%ofitsoriginallevel.4.SummaryoftheMethod4.1Aflatsheetmaterialistestedtodetermineitsabilitytodissipateanelectrostaticchargebymountingsamplesofthematerial,subsequentlychargingthematerialto5000Vandthentimingthechargedissipation.5.SignificanceandUse5.1Fabrics,films,nonwovens,orothermaterialswhichmaybeusedinsituationswhereelectrostaticchargeisobjectionablemaybetestedusingthismethod.Thesesituationsmaybesafetyrelatedsuchasusearoundflammablematerialsorpracticalsuchashandlingthefabricorfilmonautomatedequipment.6.Apparatus6.1StaticDecayMeter(1)–Thestaticdecaymetershallbecapableofimpartingahighvoltagechargeofatleast5000voltspositiveandnegative,andhaveavoltmeterandtimecapableofmeasuringthechargeandtimingitsdecaytoapresentlimit.Themetershouldbeequippedwithasetofelectrodescapableofsupportingsamples89x140mm(3.5x5.5in.)andmakinggoodelectricalcontact.6.2Gloves–latexorcottonknitgloveswhichwillpreventcontaminationoffabricsurfaces.7.Sampling,TestSpecimensandTestUnits7.1Takethebulkandlaboratorysamplesaccordingtoanyapplicablematerialspecifications,orintheirabsence,takethelaboratorysampleinsuchamannerthatitisrepresentativeofthelottobetested.7.2Takenospecimennearertheedgethan1/10thewidthofthefabric.7.3Fivespecimensshouldbetakenineachdirectionpersample.7.4Ifitisdeterminedthatasignificantdifferenceinperformanceexistsbetweenfaceandbackthenadoublesetofspecimensshouldberuntoevaluateperformanceofeachsurface.8.PreparationofApparatus8.1Thetestunitshouldbeinstalledinaconditionedenvironmentidenticaltotheenvironmentusedtoconditionthespecimens.8.2Theapparatusshouldbeturnedonand“warmed-up”foratleast30minutespriortocalibrationortesting.8.3Calibratetheinstrumentusingmanufacturersinstructionsfortheunit.Thiscalibrationshouldbedonedailyoralternately,priortoeachroundoftesting.Calibrationresultsshouldberecordedaspartofatotalqualitysystem.8.4Besuretheinstrumentisclean,andthatthecut-offswitchforthetimerissetproperly.8.5Besuretheinstrumentisclean,andthatthecutoffswitchforthetimerissetproperly.9.Conditioning9.1Samplesshouldbeconditionedat50%R.H.and23°+1°Cfor24hourspriortotesting.Testingshouldbecarriedoutattheseconditions.SamplesshouldbeexposedtotheseconditionsfollowingguidelinesinASTMD1776.9.2Otherconditionsmayberequiredbyproductspecificationsandorstandards.IftestconditionsaredifferentfromthosementionedabovetheresultsarenotincompliancewithNFPA99.Theseconditionsshouldbereportedalongwiththetestresults.9.3\\\\\\\INDA,AssociationoftheNonwovenFabricsIndustry1300CrescentGreen,Suite135Cary,NC27512Copyright2001,INDA1AnnualBookofASTMStandards,Vol.07.01.2NationalFireProtectionAssociation,1BatterymarchParkP.O.Box9101,Quincy,MA02269-9101.3GeneralServicesAdministrationBuilding197,WashingtonNavyYard,Washington,DC20407.®STANDARDTEST:IST40.2(01)10.PreparationofSpecimens10.1PreparetheMDandCDspecimensbydieorscissorcuttingtothedimensionsspecifiedinSection6.1,beingcarefulnottocontaminatethespecimensduringhandling.11.Procedure11.1Turnthetestdeviceonandallow30minutestowarmup.11.2DepressZero/Standardswitch.Besurecut-offsettingison10%.Samplechargemetershouldread0.11.3Calibratethemeteraccordingtomanufactureinstructions.11.4SetmanualmodeandsetHighVoltageto“off”.11.5Loadthetestsampleintotheelectrodes.Besuresampleisstraightandmakesgoodcontactateachpoint.Donottouchsampleswithunglovedhands.11.6Depresschargebutton.Ifthesampleregistersacharge,itmaynotbeantistatic.11.7DepressHiVoltage(+)andadjustto5KV.11.8DepressZero/STBYandadjustifnecessary.11.9DepressCHGButton.Thesamplechargemetershouldinstantlymovetofullscale.Ifthesample-chargingstopisslowthesampleisprobablynotantistaticorisweaklyantistatic.11.10Oncechargedfull-scale(5KV)pressthetestbutton.Decaytimewillbedisplayedinseconds.Recordthisvalue.11.11Turnoffhighvoltage.Removesample.11.12Repeat11.7–11.11forhighvoltage(-).12.Calculation12.1Calculatetheaverageforeachdirection/face.13.Report13.1Reportboththeaverageandindividualmaximumforeachdirection/face.13.2Ifthematerialisnotchargeable,reportatnotchargeable,underthismethod.13.3Ifdecaytimeexceedsoneminutereportas(1min).13.4ReporttemperatureandR.H.valuesforthistestiftheydifferfromthosespecified.14.PrecisionandBias14.1Precision–Theprecisionofthismethodhasnotbeendetermined.14.2Bias–Theaccuracyofthistestmethodistobedetermined.15.Keywords15.1electrostaticdecay,nonwovenfabrics,charge,dissip