ASTM_D_4498_-_07.pdf

Designation:D449807Standard Test Method forHeat-Fail Temperature in Shear of Hot Melt Adhesives1This standard is issued under the fixed designation D4498;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 is intended to determine the tempera-ture at which specimens bonded with hot melt adhesivedelaminate under static load in shear.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.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 AdhesivesE28 Test Methods for Softening Point of Resins Derivedfrom Pine Chemicals and Hydrocarbons,by Ring-and-Ball ApparatusE145 Specification for Gravity-Convection and Forced-Ventilation OvensE171 Practice for Conditioning and Testing Flexible BarrierPackagingE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 DefinitionsMany of the terms found in this testmethod are defined in Terminology D907.3.2 Definitions of Terms Specific to This Standard:3.2.1 heat-fail temperature,nthe temperature at whichdelamination occurs under static loading in shear.4.Significance and Use4.1 Heat-fail temperature establishes a limiting temperatureabove which the adhesive is not to be exposed in service undershear load.5.Apparatus5.1 A device capable of producing adhesive films of uni-form thickness with 625.4 m(61 mil)tolerances.5.2 Standard SubstrateNIST Standard Reference Material1810(Liner-Board)35.3 Heat Sealing DeviceSentinel heat sealer or equivalentcapable of maintaining selected sealing temperature within62.5C(65F).5.4 Forced-Ventilation Oven,manual or programmed.Ovenshall be capable of maintaining selected temperatures within61%of the differential between oven and ambient tempera-tures in accordance with Specification E145,with the program-mable oven capable of attaining smooth temperature increasesof 30C/h over a range of 25 to 150C.5.5 Thermometric Device,for monitoring oven tempera-tures.5.6 TFE-fluorocarbon Cloth,silicone release paper,500 gweights and clamping devices for suspending weights andspecimens in the oven.6.Sampling,Test Specimens,and Test Units6.1 The test sample is to be representative of the adhesivebeing tested.6.2 Prepare test specimen films of representative adhesive ata thickness of 76 6 25 m(3 6 1 mil).Inspect the cooled filmsand reject any containing voids or other imperfections.Cut thefilms into pieces measuring 25.4 by 25.4 mm 6 1.6 mm(1 by1 in.6 0.0625 in.).Measure the thickness of the adhesive filmto the nearest 0.013 mm(0.0005 in.).Cut strips of standardsubstrate measuring 25.4 6 1.6 by 76 mm(1 6 0.0625 by 3in.)with 76-mm(3-in.)dimension in the machine direction.6.3 Prepare a lap joint measuring 25.4 by 25.4 mm(1 by 1in.)inside two strips of standard substrate.Place this assembly1This test method is under the jurisdiction of ASTM Committee D10 onPackaging and is the direct responsibility of Subcommittee D10.14 on Tape andLabels.Current edition approved May 1,2007.Published June 2007.Originallyapproved in 1985.Last previous edition approved in 2000 as D4498 00.DOI:10.1520/D4498-07.2For 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 National Institute of Standards and Technology(NIST),100Bureau Dr.,Stop 1070,Gaithersburg,MD 20899-1070,http:/www.nist.gov.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 between a folded sheet of silicone-coated release paper orTeflon cloth(Note 1).Insert the assembly between the platensof the heat sealer having only the upper platen heated.Makethe seal under the following conditions and seal at least 6specimens of each adhesive for test.6.3.1 TemperatureAs needed to activate hot-melt adhesive(Note 2).6.3.2 Pressure103.4 kPa(15 psi).6.3.3 Dwell Time1.5 s.NOTE1Use of the coated release paper or TFE-fluorocarbon clothmay require a higher than expected sealing temperature because ofthermal insulating effects.NOTE2The operator should test at least two bonds after cooling toroom temperature to ensure that adequate adhesion has been obtained.Adjust sealing temperature to obtain that adhesion.6.4 Measure the thickness of the two pieces of substrate,calculate,and record the adhesive thickness,which is