1、Designation:D509908(Reapproved 2013)Standard Test Methods forRubberMeasurement of Processing Properties UsingCapillary Rheometry1This standard is issued under the fixed designation D5099;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revisio
2、n,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 These test methods describe how capillary rheometrymay be used to measure the rheological characteristics ofr
3、ubber(raw or compounded).Two methods are addressed:Method Ausing a piston type capillary rheometer,andMethod Busing a screw extrusion type capillary rheometer.The two methods have important differences,as outlined in 7 10 and 11 14,respectively.1.2 These test methods cover the use of a capillary rhe
4、om-eter for the measurement of the flow properties of thermoplas-tic elastomers,unvulcanized rubber,and rubber compounds.These material properties are related to factory processing.1.3 Since piston type capillary rheometers impart only asmall amount of shearing energy to the sample,these measure-men
5、ts directly relate to the state of the compound at the time ofsampling.Piston type capillary rheometer measurements willusually differ from measurements with a screw extrusion typerheometer,which imparts shearing energy just before therheological measurement.1.4 Capillary rheometer measurements for
6、plastics are de-scribed in Test Method D3835.1.5 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the u
7、ser 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:2D1349 Practice for RubberStandard Conditions for Test-ingD1418 PracticeforRubberandRubberLaticesNomenclatureD14
8、85 Practice for Rubber from Natural SourcesSampling and Sample PreparationD3182 Practice for RubberMaterials,Equipment,and Pro-cedures for Mixing Standard Compounds and PreparingStandard Vulcanized SheetsD3835 Test Method for Determination of Properties ofPolymeric Materials by Means of a Capillary
9、RheometerD3896 Practice for Rubber From Synthetic SourcesSamplingD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 The following terms appear in logical order fo
10、r thesake of clarity:3.1.2 capillary rheometeran instrument in which rubbercan be forced from a reservoir through a capillary die;thetemperature,pressure entering the die,and flow rate throughthe die can be controlled and accurately measured.3.1.3 die entrance pressure(P)the pressure in the reser-vo
11、ir at the die entrance,in Pa.3.1.4 volumetric flow rate(Q)the flow rate through thecapillary die,in mm3/s.3.1.5 apparent(uncorrected)shear rate(a)shear strainrate(or velocity gradient)of the rubber extrudate as it passesthrough the capillary die(Eq 1),in s1.1These test methods are under the jurisdic
12、tion of ASTM Committee D11 onRubber and are the direct responsibility of Subcommittee D11.12 on ProcessabilityTests.Current edition approved Nov.1,2013.Published January 2014.Originallyapproved in 1993.Last previous edition approved in 2008 as D5099 08.DOI:10.1520/D5099-08R13.2For referenced ASTM st
13、andards,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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428
14、-2959.United States1 3.1.5.1 DiscussionThis velocity gradient is not uniformthrough the cross-section of the capillary die.The shear rate iscalculated for the region of highest shear,at the wall of thecapillary.By selecting a die diameter and controlling thevolumetric flow rate(Q)through the die,a s
15、pecific level ofapparent shear rate may be achieved.Alternately,the shearstress(die entrance pressure,P)may be controlled,and theapparent shear rate measured.Mathematically,the apparent shear rate for a Newtonianfluid at the wall is given as follows:a532 Q D3(1)where:a=apparent shear rate,s1,Q=volum
16、etric flow rate,mm3/s,=the constant pi,approximately 3.142,andD=diameter of the capillary die,mm.3.1.6 apparent shear stress(a)the measured resistance toflow through a capillary die(Eq 2).a5P4L/D!(2)where:a=apparent shear stress,Pa,P=pressure at the entrance to the capillary die,Pa,L=length of the capillary die,mm,andD=diameter of the capillary die,mm.3.1.7 apparent viscosity(a)ratio of apparent shear stressto apparent shear rate,in Pa-s.3.1.7.1 DiscussionFor a capillary rheometer,the apparentvi