ASTM_D_3236_-_15.pdf

Designation:D323615Standard Test Method forApparent Viscosity of Hot Melt Adhesives and CoatingMaterials1This standard is issued under the fixed designation D3236;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 determination of the appar-ent viscosity of hot melt adhesives and coating materialscompounded with additives and having apparent viscosities upto 200 000 millipascal second(mPas)(Note 3)at temperaturesup to 175 C(347 F).NOTE1Although precision has not been studied,this procedure maybe adaptable to viscosities higher than the present 200 000 mPas limit andtemperatures above 175 C(347 F).Equipment described in this testmethod permits testing of materials having viscosities as high as 16 106mPas and provides temperatures up to 260 C(500 F).NOTE2For petroleum waxes and their blends having apparentviscosities below 15 mPas,Test Method D445 is especially applicable.NOTE3One pascal second(Pas)=1000 centipoise(cP);one milli-pascal-second=one centipoise.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:2D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids(and Calculation of Dynamic Viscos-ity)3.Terminology3.1 Definitions:3.1.1 apparent viscositythe viscosity determined by thistest method and expressed in millipascal seconds.Its valuemay vary with the spindle and rotational speed selectedbecause many hot melts are non-Newtonian.3.1.2 viscositythe ratio of shear stress to shear rate.Theviscosity of a liquid is a measure of the internal friction of theliquid in motion.The unit of dynamic viscosity is the pascalsecond.For a Newtonian liquid,the viscosity is constant at allshear rates.For a non-Newtonian liquid,viscosity will varydepending on shear rate.4.Summary of Test Method4.1 A representative sample of the molten material to betested is maintained in a thermally controlled sample chamber.Apparent viscosity is determined under temperature equilib-rium conditions using a precision rotating spindle type viscom-eter.Data obtained at several temperatures can be plotted onappropriate semi-logarithmic graph paper and apparent viscos-ity at intermediate temperatures can be estimated.5.Significance and Use5.1 This test method distinguishes between hot melts havingdifferent apparent viscosities.It is believed that apparentviscosity determined by this procedure is related to flowperformance in application machinery operating under condi-tions of low shear rate.Apparent viscosity as determined bythis test method may not correlate well with end-use applica-tions where high shear rates are encountered.5.2 Materials of the type described in this procedure may bequite non-Newtonian and as such,the apparent viscosity willbe a function of shear rate under the conditions of test.Although the viscometer described in this test method gener-ally operates under conditions of relatively low shear rate,differences in shear effect can exist depending upon the spindleand rotational speed conditions selected for the test program.Maximum correlation between laboratories,therefore,dependsupon testing under conditions of equivalent shear.6.Apparatus6.1 Viscometer,Concentric Cylinder RotationalThe es-sential instrumentation required providing the minimum ratio-nal viscometer analytical capabilities include:6.1.1 Drive motor,to apply a unidirectional rotational dis-placement to the specimen at a rate of 0.5 r min to 60 r minconstant to 61%.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.10.0A on Physical/Chemical Properties.Current edition approved April 1,2015.Published May 2015.Originallyapproved in 1973.Last previous edition approved in 2014 as D3236 88(2014).DOI:10.1520/D3236-15.2For 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.*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 6.1.2 Force sensor,to measure the torque developed by thespecimen in response to the rotational displacement.6.1.3 Coupling shaft,or other means to transmit t