ASTM D4212-1999(2005) Standard Test Method for Viscosity by Dip-Type Viscosity Cups《浸渍型粘度杯测定粘度的试验方法》.pdf

1、Designation: D 4212 99 (Reapproved 2005)Standard Test Method forViscosity by Dip-Type Viscosity Cups1This standard is issued under the fixed designation D 4212; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis

2、ion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of viscosityof paints, varnishes, lacquers, inks, and related liquid materialsby dip-

3、type viscosity cups. This test method is recommendedfor viscosity control work within one plant or laboratory andshould be used to check compliance with specifications onlywhen sufficient controls have been instituted to ensure ad-equate comparability of results.1.2 Viscosity cups are designed for t

4、esting of Newtonianand near-Newtonian liquids. If the test material is non-Newtonian, for example, shear-thinning or thixotropic, anothermethod, such as Test Methods D 2196, should be used. Undercontrolled conditions, comparisons of the viscosity of non-newtonian materials may be helpful, but viscos

5、ity determina-tion methods using controlled shear rate or shear stress arepreferred.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety concerns, if any, associated

6、 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:D 1200 Test Method for Viscosity by Ford Viscosity Cup2D 2196 Te

7、st Methods for Rheological Properties of Non-Newtonian Materials by Rotational (Brookfield type) Vis-cometerD 4287 Test Method for High Shear Viscosity Using aCone/Plate ViscometerE1 Specification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 Definitions:3.1.1 near-Newtonian liquid, na liqu

8、id in which thevariation of viscosity with shear rate is small and the effect onviscosity of mechanical disturbances such as stirring is negli-gible.3.1.2 Newtonian liquid, na liquid in which the viscosity isindependent of the shear stress or shear rate. If the ratio ofshear stress to shear rate is

9、not constant, the liquid is non-Newtonian.4. Summary of Test Method4.1 The cup is completely immersed in the material to betested, withdrawn, and the time for the material to flow througha hole in the base of the cup is measured.5. Significance and Use5.1 Viscosity is a measure of the fluidity of a

10、material.Viscosity data are useful in the determination of the ease ofstirring, pumping, dip coating, or other flow-related propertiesof paints and related fluids.5.2 This type of cup is used to measure viscosity because itis easy to use, robust, and may be used in tanks, reservoirs, andreactors.5.3

11、 There are other types of apparatus for measuring vis-cosity in the laboratory that provide better precision and bias,including the Ford viscosity cup (Test Method D 1200), and theBrookfield viscometer (Test Methods D 2196).5.4 Certain higher shear rate devices such as cone/plateviscometers (Test Me

12、thod D 4287) provide more informationabout sprayability, roll coatability, and other high-shear raterelated properties of coatings.6. Apparatus6.1 Zahn Viscosity CupNo. 1 through No. 5 Zahn viscos-ity cups made of corrosion- and solvent-resistant materials.The nominal capacity of the cup is 44 mL, b

13、ut may vary from43 to 49 mL, depending on the manufacturer. A diagram of aZahn cup is given in Fig. 1. The dimensions, including orifices,are only approximate because the cups are not made to auniform specification. Each manufacturer produces a different1This test method is under the jurisdiction of

14、 ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.24 on Physical Properties of Liquid Paints and Paint Materials.Current edition approved May 15, 2005. Published June 2005. Originallyapproved in 1982. Last previous editi

15、on approved in 1999 as D 4212 99.2For 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.1Copyright ASTM Internationa

16、l, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.cup and considerable variation between batches from somemanufacturers has been noted in the past. This is a majorreason why Zahn cups should not be referenced in specifica-tions between producer and user only when

17、 controls sufficientto ensure adequate cup-to-cup and operator-to-operator com-parison are included. (See Appendix X1 for additional infor-mation on Zahn Cups.)NOTE 1The various cup numbers are for identification of the viscosityranges within the series only and should not be used for comparisonbetw

18、een different kinds of cups, that is, a No. 2 Zahn cup has norelationship whatsoever with a No. 2 Shell cup.6.1.1 Nominal Zahn cup orifice diameters are listed in TableX2.1. Cup No. 1 with the smallest orifice is used for determin-ing the viscosity of thin-bodied materials. Cup No. 2 is for usewith

19、clears, lacquers, enamels, and press-side adjustment offlexographic inks; cups Nos. 3 and 4 are for use with moreviscous paints and inks (No. 3 for manufacturing of flexo-graphic inks); and cup No. 5 is used for silk screen inks.6.2 Shell Viscosity Cup3No. 1 through No. 6 Shell vis-cosity cups made

20、of stainless steel with a capacity of 23 mLand a 25-mm (1-in.) long capillary in the bottom and conform-ing to the dimensions shown in Fig. 2.6.2.1 Nominal Shell cup orifice diameters are listed in TableX2.1. Cup Nos. 1 through 212 are recommended for use withreduced rotogravure inks; No. 2 is for u

21、se with flexographicinks; Nos. 3 through 4 are used for industrial enamels,lacquers, flexographic, and gravure inks; Nos. 5 and 6 are usedfor heavy materials.3Shell cups may be obtained from the Norcross Corp., 255 Newtonville Ave.,Newton, MA 02158. This committee is not aware of any other source fo

22、r flow cupshaving properties similar enough to the Shell cup to be included in this test method.If you have knowledge of a cup that should be considered, please provide details toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible techni

23、cal committee,1which you may attend.NOTE 1Dimensions are approximate only and may vary with the manufacturer and from batch to batchFIG. 1 Zahn Cup Nominal DimensionsD 4212 99 (2005)26.3 Calibration ThermometerASTM Saybolt ViscosityThermometer 17F having a range of 66 to 80F and subdivi-sions of 0.2

24、F, or 17C having a range of 19 to 27C andsubdivisions of 0.1C, both conforming to the requirements ofSpecification E1. Thermometers having subdivisions otherthan these may be used depending on the sensitivity of thematerial to be tested, the demands of the application, and theagreement between the p

25、urchaser and seller.6.4 TimerAny timing device may be used provided thatthe readings can be taken with a discrimination of 0.1 s orbetter.7. Test Materials7.1 The material to be tested should be visibly homoge-neous and free from any foreign material or air bubbles.8. Temperature of Testing8.1 Measu

26、rements should be made at 25C (77F) unlessotherwise specified. Temperature drift during the test should bekept to a minimum. The viscosities of paints and relatedmaterials are highly dependent on temperature. Differences intemperature between measurements can give substantiallydifferent viscosities

27、(up to 5 % per F). For careful work, thetemperature should be taken in the efflux stream, but forprocess control (such as monitoring a dip tank), this is notnecessary.8.2 A temperature correction curve may be constructed foreach liquid by plotting viscosity (seconds) against temperatureover the expe

28、cted temperature range. With this curve, aviscosity determined at one measured temperature may beconverted quickly to a viscosity at another temperature.NOTE 2When dip cups are used for original purposes, that is thinningor monitoring of materials in tanks, coaters, etc., temperature is notimportant

29、. This is because the key to good operation is to maintain thefluid within a certain range of dip cup-seconds regardless of the tempera-ture of the fluid.9. Checking and Calibration of Cups9.1 Cups should be checked in accordance with the proce-dure described in Appendix X2. The frequency of this de

30、pendsupon the amount of use and care that the individual cupreceives, and the level of precision required.9.2 Cups may be calibrated with standard fluids accordingto the procedure in Appendix X3. However, because theviscosity of standard fluids can vary significantly with tem-perature and due to dif

31、ficulty in obtaining adequate temperaturecontrol with dip cups, calibration is a difficult procedure thatmust be done with great care and knowledge.10. Procedure10.1 Choose the proper cup so that the time of efflux will bebetween 20 and 80 s. See Table 1 for viscosity ranges for thevarious cups.NOTE

32、 3The formulas used in this test method to describe theconversion from Zahn seconds to stokes are linear, the actual cup responseFIG. 2 Shell CupTABLE 1 Approximate Viscosity Ranges, cST (mm2/s) (RoughlyCorresponding to 20 to 80 s Flow Time)Cup Number Zahn Cup Shell Cup1A560 2202 20250 1050212 . 208

33、03 100800 30120312 . 401704 2001200 702705 4001800 1255206 . 3201300AThe lower limit for the Zahn No. 1 cup is 35 s rather than 20 s.D 4212 99 (2005)3is not. The range of 20 to 80 s covers the most linear portion of each cup.In addition, below 20 s, turbulent flow may cause additional inconsisten-ci

34、es. Above 80 s, factors that may impact on the precision include; loss ofsolvent (and therefore varying viscosity), “skinning” of the liquid in thecup, intermittent flow.10.2 Immerse the cup in the container, which may be a canor beaker, but is more likely to be a thinning or mixing tank oreven a re

35、sin reactor. Stir or agitate the fluid well to giveuniform temperature and density. Allow the cup to remain inthe fluid for 1 to 5 min to attain thermal equilibrium. (Becauseof their greater mass, Shell cups should remain in the fluid forthe full 5 min.)NOTE 4Dip cups are not recommended for use wit

36、h thixotropic (timedependent) materials but if used for them (such as gravure or flexographicinks), more vigorous agitation will be necessary to break up the structurebefore the measurement is made.10.3 Lift the cup vertically out of the material in a quick,steady motion. As the top edge of the cup

37、breaks the surface,start the timer. During the time of flow, hold the cup verticallyno more than 15.2 cm (6 in.) above the level of the liquid. Stopthe timer at the first definite break in the stream at the base ofthe cup. The efflux time in seconds constitutes the viscosity. Itis common to make onl

38、y a single measurement, but for greaterprecision and accuracy the mean of two or more measurementsshould be taken.NOTE 5The cup should not be held by the loop handle during themeasurement process. Most manufacturers equip the cup with a ringthrough the loop handle. Holding the cup by this ring will

39、help to ensurethat the cup hangs vertically.11. Care of Cups11.1 Following each determination, clean the cup with asuitable solvent and a soft brush. Use no metal tools in contactwith the instrument as nicks or wear of the drilled orifice affectthe accuracy of the cup.12. Report12.1 Report the efflu

40、x time to the nearest 0.2 s for Zahn orShell cup No. _, manufactured by _, (in the case ofZahn cups) the temperature of the fluid (where measured), andwhether the result is from a single measurement or the mean oftwo of more measurements.13. Precision and Bias13.1 The most satisfactory results when

41、using dip cups areobtained when viscosity is being controlled at a single locationonly. However, when comparisons between locations are made,cups from the same manufacturer must be used or other actiontaken to ensure compatibility of results. The following criteriacan be used for judging the accepta

42、bility of results at the 95 %confidence level:13.1.1 Zahn CupsPrecision was determined on the basisof an interlaboratory test in which six laboratories used newZahn cups (all from the same set from the same manufacturer)to test eight paints covering a broad range of viscosities. Thewithin-laboratory

43、 coefficient of variation was 3.7 % and thebetween-laboratories coefficient of variation was 11.5 %.Based on these coefficients the following criteria should beused for judging the acceptability of results at the 95 %confidence level:13.1.1.1 RepeatabilityTwo results, each the mean of twomeasurement

44、s, obtained by the same operator should beconsidered suspect if they differ by more than 11 % of theirmean value.13.1.1.2 ReproducibilityTwo results, each the mean oftwo measurements, obtained by operators in different labora-tories should be considered suspect if they differ by more than33 % of the

45、ir mean value.NOTE 6The values used to determine the precision were obtainedunder ideal conditions (a single set of cups), reproducibility in practice canbe just as good, by employing strict controls and good techniques.13.1.1.3 BiasBias does not apply to this test method as noacceptable standards e

46、xist.NOTE 7Since the precision values were obtained under ideal condi-tions (a single set of cups), reproducibility in practice probably is poorerthan that given (perhaps as bad as 50 %).13.1.2 Shell CupsPrecision was determined on the basisof an interlaboratory test in which four laboratories teste

47、dseven paints covering a broad range of viscosities. Thewithin-laboratory coefficient of variation was 3.2 % and thebetween-laboratories coefficient of variation was 6.3 %. Basedon these coefficients the following criteria should be used forjudging the acceptability of results at the 95 % confidence

48、level:13.1.2.1 RepeatabilityTwo results, each the mean of twomeasurements, obtained by the same operator should beconsidered suspect if they differ by more than 9 % of theirmean value.13.1.2.2 ReproducibilityTwo results, each the mean oftwo measurements, obtained by operators in different labora-tor

49、ies should be considered suspect if they differ by more than18 % of their mean value.13.1.2.3 BiasBias does not apply to this test method as noacceptable standards exist.14. Keywords14.1 dip cup(s); flow cup(s); Shell cup(s); viscosity; Zahncup(s)D 4212 99 (2005)4APPENDIXES(Nonmandatory Information)X1. ZAHN CUP DESIGN, MANUFACTURE, AND USEX1.1 Zahn cups were designed (and manufactured byGeneral Electric) as simple flow property devices for use in diptanks, flow coat reservoirs, etc. They were not designed to beviscometers or to b