ASTM D4212-99(2005)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D4212–99(Reapproved2005)
Standard Test Method for
Viscosity by Dip-Type Viscosity Cups
This standard is issued under the fixed designation D4212; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope E1 Specification for ASTM Liquid-in-Glass Thermometers
1.1 This test method covers the determination of viscosity
3. Terminology
of paints, varnishes, lacquers, inks, and related liquid materials
3.1 Definitions:
by dip-type viscosity cups. This test method is recommended
3.1.1 near-Newtonian liquid, n—a liquid in which the
for viscosity control work within one plant or laboratory and
variation of viscosity with shear rate is small and the effect on
should be used to check compliance with specifications only
viscosity of mechanical disturbances such as stirring is negli-
when sufficient controls have been instituted to ensure ad-
gible.
equate comparability of results.
3.1.2 Newtonian liquid, n—aliquidinwhichtheviscosityis
1.2 Viscosity cups are designed for testing of Newtonian
independent of the shear stress or shear rate. If the ratio of
and near-Newtonian liquids. If the test material is non-
shear stress to shear rate is not constant, the liquid is non-
Newtonian, for example, shear-thinning or thixotropic, another
Newtonian.
method, such as Test Methods D2196, should be used. Under
controlled conditions, comparisons of the viscosity of non-
4. Summary of Test Method
newtonian materials may be helpful, but viscosity determina-
4.1 The cup is completely immersed in the material to be
tion methods using controlled shear rate or shear stress are
tested,withdrawn,andthetimeforthematerialtoflowthrough
preferred.
a hole in the base of the cup is measured.
1.3 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
5. Significance and Use
only.
5.1 Viscosity is a measure of the fluidity of a material.
1.4 This standard does not purport to address all of the
Viscosity data are useful in the determination of the ease of
safety concerns, if any, associated with its use. It is the
stirring, pumping, dip coating, or other flow-related properties
responsibility of the user of this standard to establish appro-
of paints and related fluids.
priate safety and health practices and determine the applica-
5.2 This type of cup is used to measure viscosity because it
bility of regulatory limitations prior to use.
is easy to use, robust, and may be used in tanks, reservoirs, and
reactors.
2. Referenced Documents
2 5.3 There are other types of apparatus for measuring vis-
2.1 ASTM Standards:
cosity in the laboratory that provide better precision and bias,
D1200 Test Method for Viscosity by Ford Viscosity Cup
including the Ford viscosity cup (Test Method D1200), and the
D2196 Test Methods for Rheological Properties of Non-
Brookfield viscometer (Test Methods D2196).
Newtonian Materials by Rotational (Brookfield type) Vis-
5.4 Certain higher shear rate devices such as cone/plate
cometer
viscometers (Test Method D4287) provide more information
D4287 Test Method for High-Shear Viscosity Using a
about sprayability, roll coatability, and other high-shear rate
Cone/Plate Viscometer
related properties of coatings.
6. Apparatus
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of
6.1 Zahn Viscosity Cup—No. 1 through No. 5 Zahn viscos-
Subcommittee D01.24 on Physical Properties of Liquid Paints and Paint Materials.
ity cups made of corrosion- and solvent-resistant materials.
Current edition approved May 15, 2005. Published June 2005. Originally
The nominal capacity of the cup is 44 mL, but may vary from
approved in 1982. Last previous edition approved in 1999 as D4212 – 99. DOI:
10.1520/D4212-99R05.
43 to 49 mL, depending on the manufacturer. A diagram of a
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ZahncupisgiveninFig.1.Thedimensions,includingorifices,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
are only approximate because the cups are not made to a
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. uniform specification. Each manufacturer produces a different
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D4212–99 (2005)
NOTE 1—Dimensions are approximate only and may vary with the manufacturer and from batch to batch
FIG. 1 Zahn Cup Nominal Dimensions
cup and considerable variation between batches from some viscous paints and inks (No. 3 for manufacturing of flexo-
manufacturers has been noted in the past. This is a major graphic inks); and cup No. 5 is used for silk screen inks.
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 25-mm (1-in.) 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
between different kinds of cups, that is, a No. 2 Zahn cup has no
relationship whatsoever with a No. 2 Shell cup.
6.1.1 Nominal Zahn cup orifice diameters are listed inTable
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
X2.1. Cup No. 1 with the smallest orifice is used for determin-
having properties similar enough to the Shell cup to be included in this test method.
ing the viscosity of thin-bodied materials. Cup No. 2 is for use
If you have knowledge of a cup that should be considered, please provide details to
with clears, lacquers, enamels, and press-side adjustment of
ASTM International Headquarters. Your comments will receive careful consider-
flexographic inks; cups Nos. 3 and 4 are for use with more ation at a meeting of the responsible technical committee, which you may attend.
D4212–99 (2005)
FIG. 2 Shell Cup
inks; Nos. 3 through 4 are used for industrial enamels, viscosity determined at one measured temperature may be
lacquers, flexographic, and gravure inks; Nos. 5 and 6 are used converted quickly to a viscosity at another temperature.
for heavy materials.
NOTE 2—When dip cups are used for original purposes, that is thinning
6.3 Calibration Thermometer—ASTM Saybolt Viscosity
or monitoring of materials in tanks, coaters, etc., temperature is not
Thermometer 17F having a range of 66 to 80°F and subdivi-
important. This is because the key to good operation is to maintain the
sions of 0.2°F, or 17C having a range of 19 to 27°C and fluid within a certain range of dip cup-seconds regardless of the tempera-
ture of the fluid.
subdivisions of 0.1°C, both conforming to the requirements of
Specification E1. Thermometers having subdivisions other
9. Checking and Calibration of Cups
than these may be used depending on the sensitivity of the
9.1 Cups should be checked in accordance with the proce-
material to be tested, the demands of the application, and the
dure described inAppendix X2. The frequency of this depends
agreement between the purchaser and seller.
upon the amount of use and care that the individual cup
6.4 Timer—Any timing device may be used provided that
receives, and the level of precision required.
the readings can be taken with a discrimination of 0.1 s or
9.2 Cups may be calibrated with standard fluids according
better.
to the procedure in Appendix X3. However, because the
viscosity of standard fluids can vary significantly with tem-
7. Test Materials
peratureandduetodifficultyinobtainingadequatetemperature
7.1 The material to be tested should be visibly homoge-
control with dip cups, calibration is a difficult procedure that
neous and free from any foreign material or air bubbles.
must be done with great care and knowledge.
8. Temperature of Testing
10. Procedure
8.1 Measurements should be made at 25°C (77°F) unless 10.1 Choose the proper cup so that the time of efflux will be
otherwise specified.Temperature drift during the test should be
between 20 and 80 s. See Table 1 for viscosity ranges for the
kept to a minimum. The viscosities of paints and related various cups.
materials are highly dependent on temperature. Differences in
NOTE 3—The formulas used in this test method to describe the
temperature between measurements can give substantially
conversionfromZahnsecondstostokesarelinear,theactualcupresponse
different viscosities (up to 5 % per °F). For careful work, the
is not. The range of 20 to 80 s covers the most linear portion of each cup.
temperature should be taken in the efflux stream, but for
In addition, below 20 s, turbulent flow may cause additional inconsisten-
process control (such as monitoring a dip tank), this is not cies.Above 80 s, factors that may impact on the precision include; loss of
solvent (and therefore varying viscosity), “skinning” of the liquid in the
necessary.
cup, intermittent flow.
8.2 A temperature correction curve may be constructed for
each liquid by plotting viscosity (seconds) against temperature 10.2 Immerse the cup in the container, which may be a can
over the expected temperature range. With this curve, a or beaker, but is more likely to be a thinning or mixing tank or
D4212–99 (2005)
TABLE 1 Approximate Viscosity Ranges, cST (mm /s) (Roughly
cups from the same manufacturer must be used or other action
Corresponding to 20 to 80 s Flow Time)
taken to ensure compatibility of results. The following criteria
Cup Number Zahn Cup Shell Cup
can be used for judging the acceptability of results at the 95 %
A
1 5–60 2–20
confidence level:
2 20–250 10–50
13.1.1 Zahn Cups—Precision was determined on the basis
2 ⁄2 . 20–80
of an interlaboratory test in which six laboratories used new
3 100–800 30–120
3 ⁄2 . 40–170 Zahn cups (all from the same set from the same manufacturer)
4 200–1200 70–270
to test eight paints covering a broad range of viscosities. The
5 400–1800 125–520
within-laboratory coefficient of variation was 3.7 % and the
6 . 320–1300
A between-laboratories coefficient of variation was 11.5 %.
The lower limit for the Zahn No. 1 cup is 35 s rather than 20 s.
Based on these coefficients the following criteria should be
used for judging the acceptability of results at the 95 %
even a resin reactor. Stir or agitate the fluid well to give
confidence level:
uniform temperature and density. Allow the cup to remain in
13.1.1.1 Repeatability—Two results, each the mean of two
the fluid for 1 to 5 min to attain thermal equilibrium. (Because
measurements, obtained by the same operator should be
of their greater mass, Shell cups should remain in the fluid for
considered suspect if they differ by more than 11 % of their
the full 5 min.)
mean value.
NOTE 4—Dip cups are not recommended for use with thixotropic (time 13.1.1.2 Reproducibility—Two results, each the mean of
dependent) materials but if used for them (such as gravure or flexographic
two measurements, obtained by operators in different labora-
inks), more vigorous agitation will be necessary to break up the structure
tories should be considered suspect if they differ by more than
before the measurement is made.
33 % of their mean value.
10.3 Lift the cup vertically out of the material in a quick,
NOTE 6—The values used to determine the precision were obtained
steady motion. As the top edge of the cup breaks the surface,
underidealconditions(asinglesetofcups),reproducibilityinpracticecan
start the timer. During the time of flow, hold the cup vertically
be just as good, by employing strict controls and good techniques.
no more than 15.2 cm (6 in.) above the level of the liquid. Stop
13.1.1.3 Bias—Bias does not apply to this test method as no
the timer at the first definite break in the stream at the base of
acceptable standards exist.
the cup. The efflux time in seconds constitutes the viscosity. It
is common to make only a single measurement, but for greater NOTE 7—Since the precision values were obtained under ideal condi-
tions (a single set of cups), reproducibility in practice probably is poorer
precision and accuracy the mean of two or more measurements
than that given (perhaps as bad as 50 %).
should be taken.
13.1.2 Shell Cups—Precision was determined on the basis
NOTE 5—The cup should not be held by the loop handle during the
of an interlaboratory test in which four laboratories tested
measurement process. Most manufacturers equip the cup with a ring
seven paints covering a broad range of viscosities. The
through the loop handle. Holding the cup by this ring will help to ensure
that the cup hangs vertically.
within-laboratory coefficient of variation was 3.2 % and the
between-laboratories coefficient of variation was 6.3 %. Based
11. Care of Cups
on these coefficients the following criteria should be used for
11.1 Following each determination, clean the cup with a
judging the acceptability of results at the 95 % confidence
suitable solvent and a soft brush. Use no metal tools in contact
level:
with the instrument as nicks or wear of the drilled orifice affect
13.1.2.1 Repeatability—Two results, each the mean of two
the accuracy of the cup.
measurements, obtained by the same operator should be
considered suspect if they differ by more than 9 % of their
12. Report
mean value.
12.1 Report the efflux time to the nearest 0.2 s for Zahn or
13.1.2.2 Reproducibility—Two results, each the mean of
Shell cup No. ___, manufactured by _____, (in the case of
two measurements, obtained by operators in different labora-
Zahn cups) the temperature of the fluid (where measured), and
tories should be considered suspect if they differ by more than
whether the result is from a single measurement or the mean of
18 % of their mean value.
two of more measurements.
13.1.2.3 Bias—Bias does not apply to this test method as no
acceptable standards exist.
13. Precision and Bias
...