ASTM_D_2196_-_15.pdf

Designation:D219615Standard Test Methods forRheological Properties of Non-Newtonian Materials byRotational Viscometer1This standard is issued under the fixed designation D2196;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 These test methods cover the determination of theapparent viscosity and the shear thinning and thixotropicproperties of non-Newtonian materials in the shear rate rangefrom 0.1 to 50 s1using a rotational viscometer operating in afluid of“infinite”dimensions.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 the safetyconcerns,if any,associated with its use.It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2.Summary of Test Method2.1 Test Method A consists of determining the apparentviscosity of coatings and related materials by measuring thetorque on a spindle rotating at a constant speed in the material.2.2 Test Methods B and C consist of determining the shearthinning and thixotropic(time-dependent)rheological proper-ties of the materials.2The viscosities of these materials aredetermined at a series of prescribed speeds of a rotational-typeviscometer operating in a fluid of“infinite”dimensions.Theagitation of the material immediately preceding the viscositymeasurements is carefully controlled.3.Significance and Use3.1 Test Method A is used for determining the apparentviscosity at a given rotational speed,although viscosities at twoor more speeds give better characterization of a non-Newtonianmaterial than does a single viscosity measurement.3.2 With Test Methods B and C,the extent of shear thinningis indicated by the drop in viscosity with increasing rotationalspeed.The degree of thixotropy is indicated by comparison ofviscosities at increasing and decreasing rotational speeds(TestMethod B),viscosity recovery(Test Method B),or viscositiesbefore and after high shear(combination of Test Methods Band C).The high-shear treatment in Test Method C approxi-mates shearing during paint application.The viscosity behaviormeasured after high shear is indicative of the characteristics ofthe paint soon after application.4.Apparatus4.1 Rotational ViscometerThe essential instrumentationrequired providing the minimum rotational viscometer analyti-cal capabilities for this method include:4.1.1 A drive motor,to apply a unidirectional rotationaldisplacement to the specimen at at least for rotational speedsbetween 0.05 and 6 rad/s(0.5 and 60 r/min)constant to within1%.4.1.2 Aforce sensor to measure the torque developed by thespecimen to the rotational displacement of the rotationalelement to within 1%.4.1.3 A coupling shaft,or other means,to transmit therotational displacement from the motor to the rotational ele-ment.4.1.4 A rotational element,spindle,or tool,such as thecylindrical shape shown in Fig.1,to fix the specimen betweenthe drive shaft and a stationary position.NOTE1Each rotational element covers a range of about 1.5 decadesof viscosity.The rotational element is selected so that the measuredviscosity(or torque)is between 10 and 90%of the range of the rotationalelement.4.1.5 A data collection device,to provide a means ofacquiring,storing,and displaying measured or calculatedsignals,or both.The minimum output signals required forrotational viscosity are torque,rotational speed,temperature,and time.NOTE2Manual observation and recording of data are acceptable.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings,Materials,and Applications and are the directresponsibility of Subcommittee D01.24 on Physical Properties of Liquid Paints&Paint Materials.Current edition approved Feb.15,2015.Published April 2015.Originallyapproved in 1963.Last previous edition approved in 2010 as D2196 10.DOI:10.1520/D2196-15.2Pierce,P.E.,“Measurement of Rheology of Thixotropic Organic Coatings andResins with the Brookfield Viscometer,”Journal of Paint Technology,Vol 43,No.557,1971,pp.3543.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.1.6 A stand,to support,level,and adjust the height of thedrive motor,shaft and rotational element.4.1.7 A level to indicate the vertical plumb of the drivemotor,shaft and rotational element.4.1.8 Auxiliary instrumentation considered useful in con-ducting this method includes:4.1.8.1 Data analysis capability to provide viscosity,stressor other useful parameters derived from the measured signals.4.2 A temperature me