ASTM D4040-99

Standard Test Method for Viscosity of Printing Inks and Vehicles by the Falling-Rod Viscometer

SCOPE
1.1 This test method covers the procedure for determining the falling-rod viscosity of printing inks, vehicles, and similar liquids that are essentially nonvolatile and unreactive under ordinary room conditions.  
1.2 For printing inks, which are typically non-Newtonian, this test method is applicable in the apparent viscosity range of about 10 to 300 P at a shear rate of 2500 s -1 . For Newtonian liquids, the applicable viscosity range is about 10 to 1000 P (1 P = 0.1 Pa[dot]s).
1.3 This standard does not purport to address all of the safety concerns, 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. For specific hazard statements, see Section 8.

General Information

• Status: Historical
• Publication Date: 09-Jun-1999
• ICS: 87.080 - Inks. Printing inks
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.56 - Printing Inks

Relations

• Replaced By: ASTM D4040-05 - Standard Test Method for Rheological Properties of Paste Printing and Vehicles by the Falling-Rod Viscometer
• Effective Date: 15-May-2005
• Referred By: ASTM D7394-18(2023) - Standard Practice for Rheological Characterization of Architectural Coatings using Three Rotational Bench Viscometers
• Effective Date: 10-Jun-1999
• Referred By: ASTM D6336-11(2021) - Standard Practice for Evaluation of Flushing Vehicles for Pigment Wetting Using a Vacuum Modified Sigma Blade Mixer
• Effective Date: 10-Jun-1999
• Referred By: ASTM D5165-12(2020) - Standard Practice for Laboratory Preparation of Gelled Vehicles Using a Resin Kettle
• Effective Date: 10-Jun-1999
• Referred By: ASTM D7188-05(2019) - Standard Terminology for Printing Inks, Materials, and Processes
• Effective Date: 10-Jun-1999

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D4040–99
Standard Test Method for
Viscosity of Printing Inks and Vehicles by the Falling-Rod
Viscometer
This standard is issued under the fixed designation D4040; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope* shear rate is inversely proportional to fall time F per unit
distance L over which a unit thickness x of the liquid is
1.1 This test method covers the procedure for determining
stressed: D= L/xF.
the falling-rod viscosity of printing inks, vehicles, and similar
3.1.4 Newtonian—refers to a liquid whose viscosity is
liquids that are essentially nonvolatile and unreactive under
constant at all shear rates.
ordinary room conditions.
3.1.5 non-Newtonian—refers to a liquid whose viscosity
1.2 For printing inks, which are typically non-Newtonian,
varies with shear rate. Such liquids may be either shear-
this test method is applicable in the apparent viscosity range
−1
thinning (pseudoplastic) or shear-thickening (dilatant). Most
from about 10 to 300 P at a shear rate of 2500 s . For
printing inks are shear-thinning.
Newtonianliquids,theapplicableviscosityrangeisabout10to
3.1.6 apparent viscosity, V —the viscosity of a non-
1000 P (1 P=0.1 Pa·s). D
Newtonian fluid at a particular shear rate D. A shear rate of
1.3 This standard does not purport to address all of the
−1
2500 s has been found useful for printing inks and is
safety concerns, if any, associated with its use. It is the
specified in this test method.
responsibility of the user of this standard to establish appro-
3.1.7 yield stress, S —the minimum shear stress required to
o
priate safety and health practices and determine the applica-
initiate motion in a non-Newtonian liquid.
bility of regulatory limitations prior to use. For specific hazard
3.2 Definitions of Terms Specific to This Standard:
statements, see Section 8.
3.2.1 power law—a mathematical model that presumes that
2. Referenced Documents the viscosity of a liquid varies with shear rate in accordance
with a power function as follows:
2.1 ASTM Standards:
D445 Test Method for Kinematic Viscosity of Transparent
S
k 5 (1)
N
and Opaque Liquids
D
3. Terminology
where:
k = a constant related to the viscosity of the liquid and
3.1 Definitions:
N = a constant describing the rate at which shear stress
3.1.1 viscosity, V—theratioofshearstresstoshearrate.The
varies with shear rate.
viscosity of a liquid is a measure of the internal friction of the
The value of N is precisely 1.0 for a Newtonian fluid, less
liquid in motion. The cgs unit of viscosity is 1 g/cm·s (1
2 2
than 1.0 for a shear-thinning liquid, and greater than 1.0 for a
dyne·s/cm ) and is called a poise.The SI unit is 1 N·s/cm and
shear-thickening liquid.
is equal to 10 P.
3.2.2 power law plot—a logarithmic plot of shear stress
3.1.2 shear stress, S—shearing force per unit area; the unit
2 2
versusshearratebasedontheexpandedformofthepowerlaw
is 1 g/cm·s (1 dyne/cm ). In the falling-rod viscometer, shear
equation:
stressisproportionaltototalweight Wperunitofshearingarea
A times the gravitational constant g, in accordance with the ln S 5ln k 1 Nln D (2)
equation: S= Wg/A.
3.1.3 shear rate, D—velocity gradient through the stressed
For liquids conforming to the power law, the logarithmic
−1
liquid; the unit is 1/s or 1 s . In the falling-rod viscometer,
plotof Sversus Dislinearovertheshearraterangeofinterest.
The slope of the line is the power law constant N.
3.2.3 shortness—thepropertyofanon-Newtonianfluidthat
This test method is under the jurisdiction of ASTM Committee D-1 on Paint
prevents it from being drawn into a filament.
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.56 on Printing Inks. 3.3 Symbols: (for Power-Law Calculations):
Current edition approved June 10, 1999. Published August 1999. Originally
published as D4040–81. Last previous edition D4040–96.
Annual Book of ASTM Standards, Vol 05.01.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D4040–99
6.1.1 Falling-Rod Viscometer, equipped with a swinging
B = intercept of a straight line.
platform and automatic timing device accurate to at least 0.1
F = measured fall time, s.
s, preferably 0.01 s. A special lightweight rod is useful for
F = corrected fall time, s.
c
−1
F = fall time equivalent to a shear rate of 2500 s ,s. liquids in the 10-P range.
−1 −1 −1
K = apparent viscosity constant at 2500 s ,cm s .
6.1.2 Set of Tapped or Slotted Weights—Weights of 50 or
N = slope of the power law plot, a measure of
100 to 500 g are usually provided with the instrument. Extra
non-Newtonianism, cm /dyne·s.
500-g weights, approximately 4, totaling about 2000 g are
−1
SF = shortness factor, s .
requiredtohandlefluidsattheupperendofthepracticalrange.
S8 = pseudo yield value, dyne/cm
o
A25-g weight is useful for liquids in the 10-P range.
L 2
S = Lehman yield value, dyne/cm .
o
6.1.3 A Thermostatically Controlled Cabinet or a Special
T = measured specimen temperature,° C.
Collar, through which water is circulated from a constant-
T = reference temperature, °C.
R
temperature bath (both are optional if room conditioning is not
−1
V = apparent viscosity at 2.5 s ,P.
2.5
−1 available).
V = apparent viscosity at 2500 s ,P.
6.1.4 Thermistor, spanning the specified test temperature
W = total weight, g.
(usually 25°C), accurate to 0.01°C, and equipped with a probe
W = added weight, g.
A
having a response time of 3 to 6 s.
W = weight of rod, g.
R
−1
6.1.5 Ring Stand and Clamp,orotherdeviceforholdingthe
W = weightrequiredtoobtainashearrateof2500s ,
thermistor probe in a suitable position.
g.
6.1.6 Small Plastic Spatula—Metal spatulas are not suit-
able.
4. Summary of Test Method
6.1.7 Plastic Scraper, consisting of a piece of flexible
4.1 This test method is based on measurements of the time
plastic, approximately 30 by 70 mm, having a semicircle cut
required for a weighted rod to fall through an aperture
out at one end; semicircle should fit the rod.
containing the test specimen.
6.2 Instrument Calibration:
4.2 Fall times are corrected to a reference temperature of 6.2.1 Balance, weighing to 0.1 g.
6.2.2 Metric Rule or Scale, at least 100 mm in length.
25°C (or other mutually agreed-upon temperature). The test
6.2.3 Vernier Caliper, accurate to 0.01 mm, having a capac-
method specifies precise measurement of actual specimen
ity of at least 30 mm.
temperature in order to detect fluctuations due to cooling by
6.3 Graphical Solutions:
metal, heat of friction during shearing, and body heat of the
6.3.1 Chart Paper, logarithmic 2 32to2 33 cycles.
operator.
6.3.2 Triangle,45°,withahypotenuselengthofatleast100
4.3 Each specific instrument must be calibrated in order to
mm (approximately 8 in.).
establish the fall time that is equivalent to a shear rate of 2500
6.3.3 Protractor.
−1
s .
7. Materials
4.4 Fall times as a function of weight are extrapolated to
−1 5
2500 s by means of the power law (logarithmic) relationship 7.1 ASTM Standard Viscosity Oils, a minimum of two,
betweenshearstressandshearrate.Apparentviscosityat2500 preferablythree,spanningthepracticalrangeofthefalling-rod
−1
viscometer (used for calibration purposes only).
s and the degree of non-Newtonianism are determined by
7.2 Lithographic Varnish or similar vehicle having a vis-
calculation or graphically.The calculation of several low shear
cosity of about 200 P (for use in 12.3, if needed).
parameters is also covered.
7.3 Lint-and-Metal-Free Rags or Tissues.
7.4 Naphtha or other low-boiling solvent in a wash bottle
5. Significance and Use
or closed metal container.
5.1 Apparent viscosity at the relatively high shear rate of
−1
8. Hazards
2500 s does not completely define the rheological properties
of printing inks but is useful in the practical control of ink
8.1 Safety Precautions—Since solvents may be hazardous
viscosity during production and the specification acceptance
to the skin and eyes, in addition to other precautions, wear
between supplier and purchaser.
5.2 Theslopeofthepowerlawplotisthepreferredmeasure
Platform and timing device are standard on newer viscometer models. For
of non-Newtonianism. The yield value, which is obtained by
equipping older models, see Bassemir, R., “Evaluation of the Laray Viscometer,”
American Ink Maker, Vol 39, No. 4, April 1961, pp. 24–26 and 60.
extrapolation of high-shear measurements to a shear rate
Collars are available as accessories from the respective manufacturers of
approachingzero,doesnotconformtothedefinitionofthetrue
falling-rod viscometers.
yield stress (see 3.1.7). The yield value and other low shear
The sole source of supply of the certified standard viscosity oil known to the
committee at this time is Cannon Instrument Company, P.O. Box 16, State College,
parameters are also subject to a high degree of variability (see
PA16801. If you are aware of alternative suppliers, please provide this information
the precision table in Section 16).
to ASTM Headquarters. Your comments will receive careful consideration at a
meetingoftheresponsibletechnicalcommittee, whichyoumayattend.TableA1.2
in Test Method D445 shows satisfactory oils including S-600 (16 P at 25°C),
6. Apparatus
S-2000 (56 P), S-8000 (230 P), and S-30 000 (810 P). Viscosity at various
6.1 Fall-Time Runs: temperatures is indicated on the label of each container.
D4040–99
rubber gloves and safety glasses during cleanup to avoid 11.1.2 Prior to the run, a portion of the sample may be
solvent contact with skin and eyes. In case of contact, wash transferred to a slab and gently spread out in order to remove
skin with water; flush eyes for 15 min with water and call a bubbles, skin, or other debris.
physician. See supplier’s Material Safety Data Sheets for
NOTE 2—Caution: Do not work the sample vigorously; this practice
further information on each solvent used.
causes a significant increase in sample temperature. Be sure to close the
8.2 Instrument Cautions:
container immediately after removing the desired portion.
8.2.1 Avoid any operation that will scratch the rod. Do not
12. Conditioning
use a metal spatula. Never drop the rod through an empty
aperture.
12.1 The temperature of the room (cabinet or collar) should
8.2.2 Weight loads in excess of 3000 g may cause bending
be set at 23 6 1°C (or 2°C below the reference temperature).
of the rod.
NOTE 3—In accordance with Note 8, the allowable range for specimen
8.2.3 To minimize heat buildup from body temperature
temperatureis 62°Cfromthereferencetemperature.However,duringthe
during a run, avoid contacting the viscometer block with bare
course of testing, heat of shearing and body heat of the operator both
hands. When instructions call for holding the block steady,
contribute to continuous temperature rises in test specimens, notwith-
wear a glove or place a small cloth in the palm of the hand. standing room, cabinet, or collar conditions. To allow for inevitable
temperature rises, temperature controls are set at the lower end of the
8.2.4 When making fall-time measurements, work quickly
allowable range.
and without interruption so that the entire run is completed
within 5 to 10 min.
12.2 Equilibration of test samples is not necessary. Speci-
mensizesaresmall(lessthan2mL);whenspreadoutonaslab
NOTE 1—Many modern printing inks and vehicles contain some sol-
and applied to the viscometer, both hot and cold samples
vent, and volatile loss during a run can seriously bias test results unless
quickly reach the temperature of the metal.
rigorous control of exposure time is exercised. Volatile loss can be
detected if successive drops of the rod with the same weight result in 12.3 If the viscometer has been idle for more than an hour,
increasingly longer fall times.
it may be necessary to bring it into equilibrium with the
conditioning temperature (23°C or other specified in 12.1).
9. Preparation of Apparatus
Make preparations for an exploratory run (13.2-13.5) using a
9.1 Set the viscometer on a sturdy bench located in an area
varnish if the test specimen contains volatiles. Read specimen
free of direct drafts, direct sunlight, and other sources of heat. temperature; if too low (a possibility considering that metal
Level the viscometer, using the adjustable feet.
servesasaheatsink),adda1000-gweighttotherodandmake
9.2 Pass a hand over the upper and lower photocells to a few drops (13.7-13.9 but without recording time) until the
assure that the timer is activated and deactivated.
specimen temperature reaches that of conditioning. Continue
9.3 Attach the clamp to the ring stand and place next to or the run or, if a varnish was used, clean up.
behind the viscometer. Drape the thermistor probe over the
clamp; reset the clamp so that the probe end falls close to the
13. Procedure for Fall-Time Runs
viscometer block.
13.1 Ifrequired,prepare,level,andconditiontheinstrument
9.4 Clean the block and rod thoroughly with tissues wetted
as described in 9.1 and 12.3.
with naphtha. Remove residual solvent with clean dry tissue.
13.2 Withtheproperendofthecleanroddown,holdtherod
Roll the clean dry rod over a flat surface to check for
vertically over the clean aperture and gently lower until it rests
straightness.Ifrodisbent,discardandobtainanewrod/orifice
on the swinging platform.
set.
13.3 Transfer a uniform specimen to the tip of a clean
9.5 Examine the markings at the ends of the rod. Select one
plasticspatula.Thespecimensizeshouldbesufficienttofillthe
marking as an indication of the “proper” end to be always
well of the viscometer.
inserted into the aperture first.
13.4 Hold the rod with the fingertips and carefully raise
about20mm.Transferthespecimenfromthespatulatotherod
10. Calibration
as close as possible to the bottom of the well. Rotate the rod
slowlytodistributethespecimenaroundthewell,ensuringthat
10.1 Determineinstrumentconstantsinaccordancewiththe
procedure given in Annex A1. the well is full. Allow the rod to fall to the platform.
13.5 Place the thermistor probe in the well close to but not
10.2 Optional—If a graphical method is to be used for
direct conversion of test results to viscosity, prepare Master touching the rod. The probe can remain in the well throughout
the run. Turn the thermistor on.
Sliding Scale Calibration Graph as in Annex A2.
10.3 Periodically check calibration as in A1.2. 13.6 Using experience or the information in Table 1 as a
guide,selectawe
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