ASTM D4212-99
(Test Method)Standard Test Method for Viscosity by Dip-Type Viscosity Cups
Standard Test Method for Viscosity by Dip-Type Viscosity Cups
SCOPE
1.1 This test method covers the determination of viscosity of paints, varnishes, lacquers, and related liquid materials by dip-type viscosity cups. This test method is recommended only for viscosity control work within one plant or laboratory and should not be used to check compliance with specifications.
1.2 Viscosity cups are designed for testing of Newtonian and near-Newtonian liquids. If the test material is non-Newtonian, that is, shear-thinning or thixotropic, another method, such as Test Methods D2196, should be used.
1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation:D4212–99
Standard Test Method for
Viscosity by Dip-Type Viscosity Cups
This standard is issued under the fixed designation D 4212; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.1 near-Newtonian liquid—a liquid in which the varia-
tion of viscosity with shear rate is small and the effect on
1.1 This test method covers the determination of viscosity
viscosity of mechanical disturbances such as stirring is negli-
of paints, varnishes, lacquers, inks, and related liquid materials
gible.
by dip-type viscosity cups. This test method is recommended
3.1.2 Newtonian liquid—a liquid in which the viscosity is
for viscosity control work within one plant or laboratory and
independent of the shear stress or shear rate. If the ratio of
should be used to check compliance with specifications only
shear stress to shear rate is not constant, the liquid is non-
when sufficient controls have been instituted to ensure ad-
Newtonian.
equate comparability of results.
1.2 Viscosity cups are designed for testing of Newtonian
4. Summary of Test Method
and near-Newtonian liquids. If the test material is non-
4.1 The cup is completely immersed in the material to be
Newtonian, for example, shear-thinning or thixotropic, another
tested,withdrawn,andthetimeforthematerialtoflowthrough
method, such as Test Methods D 2196, should be used. Under
a hole in the base of the cup is measured.
controlled conditions, comparisons of the viscosity of non-
newtonian materials may be helpful, but viscosity determina-
5. Significance and Use
tion methods using controlled shear rate or shear stress are
5.1 Viscosity is a measure of the fluidity of a material.
preferred.
Viscosity data are useful in the determination of the ease of
1.3 This standard does not purport to address all of the
stirring, pumping, dip coating, or other flow-related properties
safety concerns, if any, associated with its use. It is the
of paints and related fluids.
responsibility of the user of this standard to establish appro-
5.2 This type of cup is used to measure viscosity because it
priate safety and health practices and determine the applica-
is easy to use, robust, and may be used in tanks, reservoirs, and
bility of regulatory limitations prior to use.
reactors.
5.3 There are other types of apparatus for measuring vis-
2. Referenced Documents
cosity in the laboratory that provide better precision and bias,
2.1 ASTM Standards:
2 includingtheFordviscositycup(TestMethodD 1200),andthe
D 1200 Test Method for Viscosity by Ford Viscosity Cup
Brookfield viscometer (Test Methods D 2196).
D 2196 Test Methods for Rheological Properties of Non-
5.4 Certain higher shear rate devices such as cone/plate
Newtonian Materials by Rotational (Brookfield) Viscom-
2 viscometers (Test Method D 4287) provide more information
eter
about sprayability, roll coatability, and other high-shear rate
D 4287 TestMethodforHighShearViscosityUsingtheICI
2 related properties of coatings.
Cone/Plate Viscometer
E 1 Specification for ASTM Thermometers
6. Apparatus
3. Terminology 6.1 Zahn Viscosity Cup—No. 1 through No. 5 Zahn viscos-
ity cups made of corrosion- and solvent-resistant materials.
3.1 Definitions:
The nominal capacity of the cup is 44 mL, but may vary from
43 to 49 mL, depending on the manufacturer. A diagram of a
This test method is under the jurisdiction of ASTM Committee D-1 on Paint
Zahn cup is given in Fig. 1.The dimensions, including orifices,
and Related Coatings, Materials, andApplications and is the direct responsibility of
are only approximate because the cups are not made to a
Subcommittee D01.24 on Physical Properties of Liquid Paints and Paint Materials.
Current edition approved May 10, 1999. Published July 1999. Originally uniform specification. Each manufacturer produces a different
published as D 4212 – 82. Last previous edition D 4212 – 93.
cup and considerable variation between batches from some
Annual Book of ASTM Standards, Vol 06.01.
manufacturers has been noted in the past. This is a major
Annual Book of ASTM Standards, Vol 14.03.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D4212
NOTE 1—Dimensions are approximate only and may vary with the manufacturer and from batch to batch
FIG. 1 Zahn Cup Nominal Dimensions
reason why Zahn cups should not be referenced in specifica- 6.2 Shell Viscosity Cup —No. 1 through No. 6 Shell vis-
tions between producer and user only when controls sufficient cosity cups made of stainless steel with a capacity of 23 mL
to ensure adequate cup-to-cup and operator-to-operator com- and a 1-in. (25-mm) long capillary in the bottom and conform-
parison are included. (See Appendix X1 for additional infor- ing to the dimensions shown in Fig. 2.
mation on Zahn Cups.) 6.2.1 Nominal Shell cup orifice diameters are listed inTable
X2.1. Cup Nos. 1 through 2 ⁄2 are recommended for use with
NOTE 1—Thevariouscupnumbersareforidentificationoftheviscosity
reduced rotogravure inks; No. 2 is for use with flexographic
ranges within the series only and should not be used for comparison
inks; Nos. 3 through 4 are used for industrial enamels,
between different kinds of cups, that is, a No. 2 Zahn cup has no
lacquers, flexographic, and gravure inks; Nos. 5 and 6 are used
relationship whatsoever with a No. 2 Shell cup.
for heavy materials.
6.1.1 Nominal Zahn cup orifice diameters are listed inTable
X2.1. Cup No. 1 with the smallest orifice is used for determin-
ing the viscosity of thin-bodied materials. Cup No. 2 is for use
Shell cups may be obtained from the Norcross Corp., 255 Newtonville Ave.,
Newton, MA02158. This committee is not aware of any other source for flow cups
with clears, lacquers, enamels, and press-side adjustment of
having properties similar enough to the Shell cup to be included in this test method.
flexographic inks; cups Nos. 3 and 4 are for use with more
If you have knowledge of a cup that should be considered, please provide details to
viscous paints and inks (No. 3 for manufacturing of flexo-
ASTMHeadquarters.Yourcommentswillreceivecarefulconsiderationatameeting
graphic inks); and cup No. 5 is used for silk screen inks.
of the responsible technical committee, which you may attend.
D4212
FIG. 2 Shell Cup
important. This is because the key to good operation is to maintain the
6.3 Calibration Thermometer—ASTM Saybolt Viscosity
fluid within a certain range of dip cup-seconds regardless of the tempera-
Thermometer 17F having a range of 66 to 80°F and subdivi-
ture of the fluid.
sions of 0.2°F, or 17C having a range of 19 to 27°C and
subdivisions of 0.1°C, both conforming to the requirements of
9. Checking and Calibration of Cups
Specification E 1. Thermometers having subdivisions other
9.1 Cups should be checked in accordance with the proce-
than these may be used depending on the sensitivity of the
dure described inAppendix X2. The frequency of this depends
material to be tested, the demands of the application, and the
upon the amount of use and care that the individual cup
agreement between the purchaser and seller.
receives, and the level of precision required.
6.4 Timer—Any timing device may be used provided that
9.2 Cups may be calibrated with standard fluids according
the readings can be taken with a discrimination of 0.1 s or
to the procedure in Appendix X3. However, because the
better.
viscosity of standard fluids can vary significantly with tem-
peratureandduetodifficultyinobtainingadequatetemperature
7. Test Materials
control with dip cups, calibration is a difficult procedure that
7.1 The material to be tested should be visibly homoge-
must be done with great care and knowledge.
neous and free from any foreign material or air bubbles.
10. Procedure
8. Temperature of Testing
10.1 Choose the proper cup so that the time of efflux will be
8.1 Measurements should be made at 77°F (25°C) unless
between 20 and 80 s. See Table 1 for viscosity ranges for the
otherwise specified.Temperature drift during the test should be
various cups.
kept to a minimum. The viscosities of paints and related
NOTE 3—The formulas used in this test method to describe the
materials are highly dependent on temperature. Differences in
conversionfromZahnsecondstostokesarelinear,theactualcupresponse
temperature between measurements can give substantially
different viscosities (up to 5 % per °F). For careful work, the
TABLE 1 Approximate Viscosity Ranges, cST (mm /s) (Roughly
temperature should be taken in the efflux stream, but for
Corresponding to 20 to 80 s Flow Time)
process control (such as monitoring a dip tank), this is not
Cup Number Zahn Cup Shell Cup
necessary.
A
1 5–60 2–20
8.2 A temperature correction curve may be constructed for
2 20–250 10–50
each liquid by plotting viscosity (seconds) against temperature
2 ⁄2 . 20–80
over the expected temperature range. With this curve, a
3 100–800 30–120
viscosity determined at one measured temperature may be 3 ⁄2 . 40–170
4 200–1200 70–270
converted quickly to a viscosity at another temperature.
5 400–1800 125–520
6 . 320–1300
NOTE 2—When dip cups are used for original purposes, that is thinning
A
or monitoring of materials in tanks, coaters, etc., temperature is not The lower limit for the Zahn No. 1 cup is 35 s rather than 20 s.
D4212
is not. The range of 20 to 80 s covers the most linear portion of each cup.
13.1.1 Zahn Cups—Precision was determined on the basis
In addition, below 20 s, turbulent flow may cause additional inconsisten-
of an interlaboratory test in which six laboratories used new
cies.Above 80 s, factors that may impact on the precision include; loss of
Zahn cups (all from the same set from the same manufacturer)
solvent (and therefore varying viscosity), “skinning” of the liquid in the
to test eight paints covering a broad range of viscosities. The
cup, intermittent flow.
within-laboratory coefficient of variation was 3.7 % and the
10.2 Immerse the cup in the container, which may be a can
between-laboratories coefficient of variation was 11.5 %.
or beaker, but is more likely to be a thinning or mixing tank or
Based on these coefficients the following criteria should be
even a resin reactor. Stir or agitate the fluid well to give
used for judging the acceptability of results at the 95 %
uniform temperature and density. Allow the cup to remain in
confidence level:
the fluid for 1 to 5 min to attain thermal equilibrium. (Because
13.1.1.1 Repeatability—Two results, each the mean of two
of their greater mass, Shell cups should remain in the fluid for
measurements, obtained by the same operator should be
the full 5 min.)
considered suspect if they differ by more than 11 % of their
NOTE 4—Dip cups are not recommended for use with thixotropic (time
mean value.
dependent) materials but if used for them (such as gravure or flexographic
13.1.1.2 Reproducibility—Two results, each the mean of
inks), more vigorous agitation will be necessary to break up the structure
two measurements, obtained by operators in different labora-
before the measurement is made.
tories should be considered suspect if they differ by more than
10.3 Lift the cup vertically out of the material in a quick,
33 % of their mean value.
steady motion. As the top edge of the cup breaks the surface,
start the timer. During the time of flow, hold the cup vertically
NOTE 6—The values used to determine the precision were obtained
no more than 15.2 cm (6 in.) above the level of the liquid. Stop
underidealconditions(asinglesetofcups),reproducibilityinpracticecan
be just as good, by employing strict controls and good techniques.
the timer at the first definite break in the stream at the base of
the cup. The efflux time in seconds constitutes the viscosity. It
13.1.1.3 Bias—Bias does not apply to this test method as no
is common to make only a single measurement, but for greater
acceptable standards exist.
precision and accuracy the mean of two or more measurements
should be taken.
NOTE 7—Since the precision values were obtained under ideal condi-
tions (a single set of cups), reproducibility in practice probably is poorer
NOTE 5—The cup should not be held by the loop handle during the
than that given (perhaps as bad as 50 %).
measurement process. Most manufacturers equip the cup with a ring
through the loop handle. Holding the cup by this ring will help to ensure
13.1.2 Shell Cups—Precision was determined on the basis
that the cup hangs vertically.
of an interlaboratory test in which four laboratories tested
seven paints covering a broad range of viscosities. The
11. Care of Cups
within-laboratory coefficient of variation was 3.2 % and the
11.1 Following each determination, clean the cup with a
between-laboratories coefficient of variation was 6.3 %. Based
suitable solvent and a soft brush. Use no metal tools in contact
on these coefficients the following criteria should be used for
with the instrument as nicks or wear of the drilled orifice affect
judging the acceptability of results at the 95 % confidence
the accuracy of the cup.
level:
12. Report
13.1.2.1 Repeatability—Two results, each the mean of two
measurements, obtained by the same operator should be
12.1 Report the efflux time to the nearest 0.2 s for Zahn or
Shell cup No. ___, manufactured by _____, (in the case of considered suspect if they differ by more than 9 % of their
mean value.
Zahn cups) the temperature of the fluid (where measured), and
whether the result is from a single measurement or the mean of
13.1.2.2 Reproducibility—Two results, each the mean of
two of more measurements.
two measurements, obtained by operators in different labora-
tories should be considered suspect if they differ by more than
13. Precision and Bias
18 % of their mean value.
13.1 The most satisfactory results when using dip cups are
13.1.2.3 Bias—Bias does not apply to this test method as no
obtained when viscosity is being controlled at a single location
acceptable standards exist.
only.However,whencomparisonsbetweenlocationsaremade,
cups from the same manufacturer must be used or other action
14. Keywords
taken to ensure compatibility of results. The following criteria
can be used for judging the acceptability of results at the 95 % 14.1 dip cup(s); flow cup(s); Shell cup(s); viscosity; Zahn
confidence level: cup(s)
D4212
APPENDIXES
(Nonmandatory Information)
X1. ZAHN CUP DESIGN, MANUFACTURE, AND US
...
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