1、Designation: D7867 13Standard Test Methods forMeasurement of the Rotational Viscosity of Paints, Inks andRelated Liquid Materials as a Function of Temperature1This standard is issued under the fixed designation D7867; the number immediately following the designation indicates the year oforiginal ado
2、ption 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 These test methods cover the use of rotational viscom-eters to determin
3、e the dependence of apparent viscosity ofpaints, inks and related liquid materials on temperature. Thefirst method uses a standard rotational viscometer with con-centric cylinder geometry running at a fixed rotational speed asthe temperature is increased or decreased. The second methoduses a rotatio
4、nal viscometer with cone and plate geometryrunning at a fixed rotational speed as the temperature isincreased or decreased. The third method uses concentriccylinder or cone/plate geometry operated with a shear rateramp at several discrete temperatures.1.2 The values stated in SI units are to be rega
5、rded asstandard. No other units of measurement are included in thisstandard.1.3 This standard may involve hazardous materials, opera-tions and equipment. This standard does not purport to addressall of the safety concerns, if any, associated with its use. It isthe responsibility of the user of this
6、standard to establishappropriate safety and health practices and determine theapplicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D3925 Practice for Sampling Liquid Paints and RelatedPigmented Coatings3. Terminology3.1 Definitions:3.1.1 apparent viscosity,
7、 nviscosity that is not a trueproperty of the fluid, but a variable depending on the shear rate.3.1.2 shear thinning fluidfluid in which the apparentviscosity decreases with increasing shear rate.3.1.3 thixotropic fluid, nfluid whose viscosity is timedependent, that is, its viscosity decreases with
8、the time it issubjected to shear.3.1.4 viscosity, nthe ratio between an applied shear stressto the resulting shear rate (velocity gradient) is defined as thedynamic viscosity; it is a measure of the resistance to flow ofa fluid.4. Summary of Test Methods4.1 Test Method A is run with a viscometer wit
9、h concentric(coaxial) cylinder capability, either built-in or as an accessorythat allows use of small specimen size (2 to 20 mL). This testis used for measuring apparent viscosity as a function oftemperature at low to medium shear rates. The viscosity-temperature profile of the paint, ink or other m
10、aterial may bedetermined at a fixed shear rate or the viscosity-shear rateprofile may be determined at several discrete temperatures.4.2 Test Method B is accomplished with a viscometer thathas cone/plate test geometry. It is used to measure apparentviscosity as a function of temperature at low to me
11、dium shearrates (high shear rates may cause shear heating that interfereswith temperature control). Shear heating is more likely withcone/plate geometry because it permits use of a wider range ofshear rates than does the concentric cylinder instrumentation inMethod A. The upper limit of shear rate w
12、ill depend on thematerial and its viscosity. The viscosity-temperature profile ofthe paint/coating may be determined at a fixed shear rate or theviscosity-shear rate profile may be determined at severaldiscrete temperatures. The smaller specimen size compared toMethod A permits better temperature co
13、ntrol and more rapidcharacterization of the viscosity-temperature profile.4.3 Test Method C is used for determining apparent viscos-ity as a function of a shear rate ramp at multiple discreettemperatures. This method can be used with either coaxialcylinder geometry or cone/plate geometry. A shear ra
14、te ramp isdefined and run at a discreet temperature; the viscosity valuesat each shear rate are recorded. The shear rate ramp is thenrepeated at a series of discreet temperatures and the viscosityvalues are measured to characterize the viscosity-temperatureprofile for the sample specimen.1These test
15、 methods are under the jurisdiction ofASTM Committee on Paint andRelated Coatings, Materials, and Applications and are the direct responsibility ofSubcommittee D01.24 on Physical Properties of Liquid Paints and Paint Materials.Current edition approved June 1, 2013. Published July 2013. DOI: 10.1520/
16、D7867-13.2For 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.Copyright ASTM International, 100 Barr Harbor Drive,
17、 PO Box C700, West Conshohocken, PA 19428-2959. United States14.4 Temperature control for Test Methods A, B, and Crequires use of an apparatus that maintains test sample tem-perature within 60.2C of the specified set point. Control towithin 60.1C is preferred if achievable.5. Significance and Use5.1
18、 The viscosity of paint, inks and many related liquidmaterials is dependent on temperature. It is useful to know theextent of this dependence. One use of such information is toprepare a viscosity-temperature table or curve. Then, if ambi-ent conditions do not allow the measurement of viscosity at th
19、eexact temperature stated in a specification or regulation, theviscosity measured at ambient temperature can be used todetermine the viscosity at the temperature of interest throughthe use of the previously prepared table or curve. Viscositymeasurements that cover a range of shear rates as well aste
20、mperatures could include shear rates associated with paintapplication or allow extrapolation to such shear rates. Thisinformation would enable a producer or user to estimate theeffect on application of heating the paint.6. Apparatus6.1 Multi-speed Rotational Viscometer, either with coaxial(concentri
21、c) cylinder geometry (either built-in or as an attach-ment) or cone/plate geometry.7. Sampling7.1 Take a representative sample of the product to be testedin accordance with Practice D3925. If the sample has atendency to settle or separate on standing, it must be stirred orshaken until homogeneous be
22、fore a test specimen is taken fromit. The specimen must be free of any foreign matter or airbubbles.TEST METHOD ACONCENTRIC CYLINDER8. Procedure8.1 Make all measurements at agreed upon temperatures ortemperature increments.8.2 Verify calibration of the viscometer according to themanufacturers instru
23、ctions.8.3 Select the correct inner cylinder.8.4 Place the proper amount of material in the cup of theinstrument. Make sure to introduce the sample in a consistentway (that is, via a syringe or by pouring).8.5 Allow the specimen and inner cylinder to equilibrate tothe first temperature. Verify the t
24、emperature at the instrument.8.6 Select proper rpm and allow the rotating cylinder torotate for an agreed upon time interval and taking a reading orwait until the reading stabilizes and note that value.8.7 Record viscosity reading, temperature and rotationalspeed. Record shear rate if measurable and
25、 needed.NOTE 1Many paints and inks are shear thinning and thixotropic. Theyhave structure that is broken down by shearing. By allowing the same timeinterval between readings for measurements on given product, viscositydifferences due to differences in the degree of break-down of structureshould be m
26、inimized.8.8 Turn off motor after data point is collected. Increasetemperature to next level. Allow the specimen and innercylinder to come to equilibrium. The time for thermal equili-bration will vary with the instrument and the size and mass ofthe cylinders.8.9 Repeat steps 8.4-8.8 as needed until
27、the desired tem-perature range had been covered.NOTE 2In the case of highly structured materials or those that dryrapidly, it may be necessary to change the specimen between eachtemperature change.9. Report9.1 Report the following information:9.1.1 Reference to this test method, the viscometer model
28、and specific concentric cylinder geometry used.9.1.2 The viscosity at each rotational speed/temperature.9.1.3 The time interval between measurements.TEST METHOD BCONE/PLATE VISCOMETER10. Procedure10.1 Make all measurements as agreed upon temperaturesor temperature increments.10.2 Select the cone nee
29、ded for the shear rate or rates ofinterest.10.3 Zero the viscometer and verify calibration according tothe manufacturers instructions.10.4 Make sure that the gap between the cone and the plateis set properly.NOTE 3If temperature is changed in increments of 10C or more, thenthe gap setting should be
30、rechecked.10.5 Place the correct amount of material on the plate. Makesure to introduce the sample in a consistent way (that is, via asyringe or by pouring).10.6 Allow the specimen and cone to equilibrate to the firsttemperature. Verify temperature at the instrument.10.7 Select proper rpm and allow
31、cone to rotate for anagreed upon time before taking a reading or wait until readingstabilizes.NOTE 4See Note 1.10.8 Record viscosity reading, temperature and rotationalspeed. Record shear rate if applicable.10.9 After taking a data point, turn off motor. Increasetemperature to next level. Allow prop
32、er amount of time forspecimen and cone to come to equilibrium.10.10 Repeat steps 10.5-10.9 as needed until the desiredtemperature range has been covered.NOTE 5Cone/plate specimens have a tendency to dry out around theedges, particularly if they contain volatile solvents. Heating makes thisworse. The
33、refore, it may be necessary to change the specimen betweeneach temperature change. If temperature is changed in increments of 10Cor more, then the gap setting should be rechecked.11. Report11.1 Report the following results:11.1.1 Reference to this test method and the viscometermodel and the cone use
34、d.D7867 13211.1.2 The viscosity at each rotational speed/temperature.11.1.3 The time interval between measurements.TEST METHOD CSHEAR RATE RAMP ATDISCRETE TEMPERATURES12. Procedure12.1 Make all measurements at agreed upon shear rate rampand discreet temperatures.12.2 Select the system (coaxial cylin
35、der or cone/plate)needed for the shear rate ramp of interest.12.3 Zero the viscometer and verify calibration according tothe manufacturers instructions.12.4 If using the cone/plate system, make sure that the gapbetween the cone and the plate is set properly.NOTE 6If temperature is increased by a tot
36、al change of 10C or more,the gap between the cone and plate should be reset.12.5 Place the correct amount of sample material into thechamber if using coaxial cylinder geometry. If using cone/plategeometry, place the proper amount of material on the plate.Make sure to introduce the sample in a consis
37、tent way (that is,via a syringe or by pouring).12.6 Allow the specimen and spindle to equilibrate to thetest temperature.12.7 Select the first rotational speed and allow the spindle torotate for an agreed upon time before taking a viscosity readingor wait until the viscosity reading stabilizes.NOTE
38、7Many paints and inks are shear thinning and thixotropic. Theyhave structure that is broken down by the shearing action. Allowing thesame time interval between viscosity readings at different shear rates mayprovide better repeatability of test data.12.8 Record viscosity readings at each rotational s
39、peed inthe shear rate ramp.12.9 After taking all data points in the shear rate ramp, turnoff motor. Increase temperature to next level. Allow properamount of time for specimen to come to equilibrium.12.10 Repeat steps 12.5-12.9 as needed until the desiredtemperature range has been covered and each t
40、emperature hasbeen tested at the shear rate ramp.NOTE 8Cone/plate specimens have a tendency to dry out around theedges, particularly if they contain volatile solvents. Heating makes thisworse. Therefore, it may be necessary to change the specimen betweeneach temperature change. If temperature is cha
41、nged in increments of 10Cor more, then the gap setting should be rechecked.NOTE 9If concentric cylinder geometry is being used and if thematerial is highly structured or may dry rapidly, it may be necessary tochange the specimen between each temperature change.13. Report13.1 Report the following res
42、ults:13.1.1 The viscometer model and geometry used.13.1.2 The viscosity at each rotational speed/temperature.13.1.3 The time interval between measurements.14. Precision and Bias14.1 PrecisionNo precision statement has yet been devel-oped.14.2 BiasSince there is no accepted reference materialsuitable
43、 for determining bias for the procedures in thisstandard, bias has not and will not be determined.15. Keywords15.1 coaxial cylinder viscometer; cone/plate viscometer;rotational viscosity; viscosity; viscosity as a function of tem-peratureASTM International takes no position respecting the validity o
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