ASTM_D_1986_-_14.pdf

Designation:D198614Standard Test Method forDetermining the Apparent Viscosity of Polyethylene Wax1This standard is issued under the fixed designation D1986;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 describes the determination of theviscosity of polyethylene wax using small-volume,concentriccylinder,rotational viscometer and a temperature bath at140C.1.2 The values stated in SI units are to be regarded asstandard.The units in parentheses are provided for userconvenience and are not standard.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:2E1970 Practice for Statistical Treatment of ThermoanalyticalData3.Terminology3.1 Definitions:3.1.1 polyethylene waxpolymerized ethylene with a mo-lecular weight 2,000 to 10,000 g/mol and a density of 0.9 to 1.0g/cm3.These polymers may be oxidized or copolymerized butshould have a melt point lower than 140C.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.3.1.2.1 DiscussionThe unit of viscosity is the pascalsecond(Pas).For a Newtonian liquid,the viscosity is constantat all shear rates.For a non-Newtonian liquid,viscosity willvary depending on shear rate.3.1.3 apparent viscositythe viscosity determined by thistest method and expressed in millipascal seconds(mPas orcentipoises(cP).(1 cP=1 mPas).Its value may vary with thespindle and rotational speed selected because many waxes arenon-Newtonian.4.Significance and Use4.1 This test method is used to determine a physicalproperty of a wax and may determine the utility of the wax,aswell as being a significant quality control test.5.Apparatus5.1 Small-volume,Coaxial Rotational Viscometer3Theessential instrumentation required providing the minimal rota-tional viscometer analytical capabilities for this method in-clude:5.1.1 Drive Motor,to apply an unidirectional rotationaldisplacement to the specimen at a rate of 0.05 to 6.0 rad/s(0.5to 60 r/min)constant to 61%.5.1.2 Force Sensor,to measure the torque up to 0.6 mNmdeveloped by the specimen to the rotational displacement ofthe rotational element.5.1.3 Coupling Shaft,or other means to transmit the rota-tional displacement from the motor to the specimen.5.1.4 Rotational Element,Spindle or Tool,to fix the speci-men between the drive shaft and a stationary position.Acoaxial spindle with the dimensions shown in Fig.1 is suitablefor this test method.5.1.5 Data Collection Device,to acquire and display mea-sured or calculated signals from the test.The minimum outputsignals required for apparent viscosity are torque,rotationalspeed,temperature and time.5.1.6 Stand,to support,level and adjust the height of thedrive motor,shaft and rotational element.5.1.7 Auxiliary Instrumentation,useful in conducting thistest method includes:5.1.7.1 Data Analysis Capability,to provide viscosity,stressor other useful parameters derived from measured signals.5.1.7.2 Level,to indicate the vertical plumb of the drivemotor and shaft geometry.1This test method is under the jurisdiction ofASTM Committee D21 on Polishesand is the direct responsibility of Subcommittee D21.02 on Raw Materials.Current edition approved Sept.1,2014.Published October 2014.Originallyapproved in 1991.Last previous edition approved in 2013 as D1986-13.DOI:10.1520/D1986-14.2For 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 most manufacturers of precision laboratory instruments.Manyversions have an integral controlled temperature bath and other specified apparatus.The product literature or sales information usually specifies that the instrument issuitable for use in ASTM D1986.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.2 Temperature Sensor,to provide an indication of thespecimen temperature over the range of 130 to 160C to within60.1C.5.3 Temperature Bath,to provide a controlled isothermaltemperature environment for the specimen.5.4 Temperature Controller,capable of operating the tem-perature bath at an isothermal temperature over the range of130 to 160C,constant to within 60.5C.5.5 Small Volume Container,with Insulating Cap,with acapacity of 9 to 10 mL to hold the test specimen in thetemperature bath during testing.6.Calibration6.1 The viscometer is