ASTM D6619-00(2006)
(Practice)Standard Practice for Incorporating Pigments by High Speed Dispersion
Standard Practice for Incorporating Pigments by High Speed Dispersion
SIGNIFICANCE AND USE
High speed dispersion is a commonly used dispersion method in the coatings industry. For the purpose of this practice, “high speed” would normally be understood to be a range of RPM between 3 000 and 10 000. This practice provides a reference for its use, so that a producer and user can standardize on an incorporation technique. This will minimize differences in the millbase, and allow the interested parties to concentrate on the physical, chemical, or optical methods to be run.
SCOPE
1.1 This practice covers the dispersion of pigments using a laboratory size high-speed impeller mill. It is similar in technical content to ISO 8780-3.Note 1
This practice is restricted to mill bases of moderately high viscosity due to either high vehicle concentration or high pigment concentration, or both, which can produce high shear force. It is not intended to provide a means of formulating either pilot plant or full-scale mill base compositions (scaling up the process from laboratory equipment to factory mills is not simple).
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.
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Standards Content (Sample)
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Designation:D6619–00(Reapproved2006)
Standard Practice for
1
Incorporating Pigments by High Speed Dispersion
This standard is issued under the fixed designation D6619; 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 4.1.1 Drive Unit—The power rating of the drive unit shall
be sufficient to maintain the peripheral speed of the disk at an
1.1 This practice covers the dispersion of pigments using a
agreed value. A reduced rotational speed shall be available for
laboratory size high-speed impeller mill. It is similar in
pre-mixing in accordance with 6.2. The motor of the drive unit
technical content to ISO 8780-3.
shall be mounted on a stand together with the impeller shaft so
NOTE 1—This practice is restricted to mill bases of moderately high
thatitsheightcanbeadjusted.Thereshallbeaclampingdevice
viscosity due to either high vehicle concentration or high pigment
for the vessel at the foot of the stand, such that the impeller
concentration, or both, which can produce high shear force. It is not
shaft is concentric with the vessel.
intended to provide a means of formulating either pilot plant or full-scale
4.1.2 Disk and Vessel:
mill base compositions (scaling up the process from laboratory equipment
4.1.2.1 The diameters of the vessel and the disk shall be
to factory mills is not simple).
such that there is adequate clearance between the disk periph-
1.2 This standard does not purport to address all of the
ery and the walls of the vessel (see Fig. 1). If the disk is
safety concerns, if any, associated with its use. It is the
serrated, it shall be mounted so that the direction of movement
responsibility of the user of this standard to establish appro-
of the serrations is such that the mill base flows in the
priate safety and health practices and determine the applica-
directions shown in Fig. 1.
bility of regulatory limitations prior to use.
4.1.2.2 The degree of dispersion achieved will depend on
2. Referenced Documents the type of disk used. Fig. 1 shows only one type.
4.1.2.3 The type and diameter of the disk, the geometry of
2.1 ISO Standards:
the vessel, and the speed of the disk shall be agreed upon and
ISO 8780-3 Pigments and Extenders—Methods of Disper-
recorded in the test report.
sion for Assessment of Dispersion Characteristics—
2
Dispersion Using a High Speed Impeller Mill
NOTE 2—Avessel with a double wall to allow circulation of a liquid to
control the temperature should be employed, if necessary. A lid with a
3. Significance and Use
central aperture may also be provided.
NOTE 3—The diameter of a vessel used in an industrial scale mill is
3.1 High speed dispersion is a commonly used dispersion
normally two to three times the diameter of the impeller, or sometimes
method in the coatings industry. For the purpose of this
even greater. The vessel/disk geometry and the disk speed specified make
practice, “high speed” would normally be understood to be a
allowance for the small diameter of a laboratory disk.
range of RPM between 3 000 and 10 000. This practice
provides a reference for its use, so that a producer and user can 5. Vehicle System
standardize on an incorporation technique. This will minimize
5.1 The vehicle system shall be agreed upon between the
differences in the millbase, and allow the interested parties to
interested parties.Agreement will be necessary on the vehicle,
concentrate on the physical, chemical, or optical methods to be
the solvent, the concentration of the vehicle in the solvent, as
run.
well as any critical temperature sensitivity or rheological
properties (for example viscosity) of the vehicle system. The
4. Apparatus
same batch of vehicle system shall be used for all tests in the
4.1 High-speed Impeller Mill, consisting of a cylindrical
same series.
vessel and a horizontal disk stirrer blade driven by a motor. A
disk with a serrated edge is commonly used. 6. Mill Base Composition
6.1 General Requirements:
1
This practice is under the jurisdiction of ASTM Committee D01 on Paint and
6.1.1 It is essential that the mill base assume a pattern in the
Related Coatings, Materials, and Applications and is the direct responsibility of
form of a toroid (or doughnut). The concentrations of pigment
Subcommittee D01.24 on Physical Properties of Liquid Paints and Paint Materials.
and vehicle system required to give this pattern shall be
Current edition approved April 1, 2006. Published April 2006. Originally
approved in 2000. Last previous edition approved in 2000 as D6619 - 00. DOI: determined by prior experiment.
10.1520/D6619-00R06.
2
Available from American National St
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