ASTM D7540-09(2019)

Standard Practice for Dispersion of Chromatic Pigments with a Mechanical Muller

SIGNIFICANCE AND USE
5.1 The results obtained with a mechanical muller do not necessarily correlate directly with an industrial situation where different dispersing conditions exist. However, dispersion with a mechanical muller is a quick and inexpensive way to prepare specimens for testing the color and strength of a pigment for routine quality control.  
5.2 By following the procedure described in Appendix X1, the conditions for achieving the maximum practical degree of dispersion with a mechanical muller may be determined. Any color and strength tests done with the dispersions should be carried out under these conditions.
SCOPE
1.1 This practice is intended to be used to disperse a chromatic pigment for subsequent testing.  
1.2 This practice does not apply to white pigments.
Note 1: The dispersion portion of Test Method D3022 is similar to this practice, but it utilizes a miniature sandmill rather than a mechanical muller, to disperse the chromatic pigment.
Note 2: The dispersion portions of Test Methods D332 and D2745 are similar to this practice, but they are intended for use with white pigments, rather than chromatic pigments.  
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in Section 8.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Mar-2019
• ICS: 87.060.10 - Pigments and extenders
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.24 - Physical Properties of Liquid Paints & Paint Materials

Relations

• Replaces: ASTM D7540-09(2013) - Standard Practice for Dispersion of Chromatic Pigments with a Mechanical Muller
• Effective Date: 01-Apr-2019
• Refers: ASTM D332-87(2020) - Standard Test Method for Relative Tinting Strength of White Pigments by Visual Observation
• Effective Date: 01-Jun-2020
• Refers: ASTM D332-87(2015) - Standard Test Method for Relative Tinting Strength of White Pigments by Visual Observation
• Effective Date: 01-Dec-2015
• Refers: ASTM E284-13b - Standard Terminology of Appearance
• Effective Date: 01-Nov-2013
• Refers: ASTM E284-13a - Standard Terminology of Appearance
• Effective Date: 01-Jun-2013
• Refers: ASTM E284-13 - Standard Terminology of Appearance
• Effective Date: 01-Jan-2013
• Refers: ASTM E284-12 - Standard Terminology of Appearance
• Effective Date: 01-Jul-2012
• Refers: ASTM D3022-84(2011) - Standard Test Method for Color and Strength of Color Pigments by Use of a Miniature Sandmill (Withdrawn 2020)
• Effective Date: 01-Jun-2011
• Refers: ASTM D332-87(2011) - Standard Test Method for Relative Tinting Strength of White Pigments by Visual Observation
• Effective Date: 01-Feb-2011
• Refers: ASTM E284-09a - Standard Terminology of Appearance
• Effective Date: 01-Jun-2009
• Refers: ASTM E284-09 - Standard Terminology of Appearance
• Effective Date: 01-Jan-2009
• Refers: ASTM E284-08 - Standard Terminology of Appearance
• Effective Date: 01-Aug-2008
• Refers: ASTM D2745-00(2008) - Standard Test Method for Relative Tinting Strength of White Pigments by Reflectance Measurements
• Effective Date: 01-Feb-2008
• Refers: ASTM E284-07 - Standard Terminology of Appearance
• Effective Date: 15-Jul-2007
• Refers: ASTM E284-06b - Standard Terminology of Appearance
• Effective Date: 01-Dec-2006

Overview

ASTM D7540-09(2019): Standard Practice for Dispersion of Chromatic Pigments with a Mechanical Muller is an internationally recognized method for preparing chromatic pigment dispersions suitable for subsequent color and strength testing. Issued by ASTM International, this standard provides guidance for routine quality control in laboratories and production environments involved with colored pigments for paints, inks, and related products. By prescribing a reliable, reproducible method utilizing a mechanical muller, it enables comparison of pigment characteristics such as shade and tinting strength under controlled conditions.

Key Topics

• Scope: This practice is specifically intended for dispersing chromatic pigments. It is not applicable to white pigments. The process prepares pigment specimens for testing their hue, intensity, and pigment strength after dispersion.
• Mechanical Muller Use: The standard details the procedure for using a mechanical muller to disperse pigments in a consistent manner using set forces and a prescribed number of revolutions.
• Reproducibility: Dispersion by mechanical muller allows for rapid, inexpensive, and repeatable specimen preparation, supporting effective pigment quality control.
• Limitations: The results from mechanical muller dispersion may not exactly replicate conditions from industrial dispersing equipment or real-world manufacturing processes.
• Optimization: Appendix X1 describes how to determine optimal dispersing conditions - including force applied, number of revolutions, and pigment-vehicle ratios - to achieve maximum practical tinting strength.
• Testing and Comparisons: After dispersion, prepared specimens can be evaluated visually or instrumentally for color and tinting strength against standards.

Applications

• Quality Control: Routine pigment quality assurance in paint, ink, and coatings production laboratories. Standardizes sample preparation for color and strength comparisons.
• Product Development and R&D: Assessment of new pigment formulations by ensuring uniform dispersion prior to testing color characteristics.
• Material Certification: Preparation of standardized dispersions for certification of chromatic pigments against industry requirements.
• Comparative Testing: Enables consistent evaluation of chromatic pigments from different suppliers or batches by minimizing variables introduced by dispersion techniques.

Related Standards

• ASTM D3022: Test Method for Color and Strength of Color Pigments by Use of a Miniature Sandmill - similar in purpose but utilizes a sandmill instead of a mechanical muller.
• ASTM D332 and ASTM D2745: Both relate to the dispersion and tinting strength of white pigments, not chromatic, but offer procedures comparable in approach for other pigment types.
• ASTM E284: Terminology of Appearance, which defines relevant appearance and colorimetric terms used in pigment dispersion testing.

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Keywords: chromatic pigments dispersion, mechanical muller, pigment quality control, color testing, pigment strength, ASTM D7540, laboratory pigment testing, standard pigment dispersion method

Note: For safety, health, and environmental considerations, always refer to manufacturer recommendations and review Section 8 of the standard. This practice was developed in compliance with international standardization principles established by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D7540 − 09 (Reapproved 2019)
Standard Practice for
Dispersion of Chromatic Pigments with a Mechanical
Muller
This standard is issued under the fixed designation D7540; 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 D3022 Test Method for Color and Strength of Color Pig-
ments by Use of a Miniature Sandmill
1.1 This practice is intended to be used to disperse a
E284 Terminology of Appearance
chromatic pigment for subsequent testing.
1.2 This practice does not apply to white pigments.
3. Terminology
NOTE1—ThedispersionportionofTestMethodD3022issimilartothis
3.1 Definitions—Definitions of appearance terms used in
practice, but it utilizes a miniature sandmill rather than a mechanical
this practice may be found in Terminology E284.
muller, to disperse the chromatic pigment.
NOTE 2—The dispersion portions ofTest Methods D332 and D2745 are
similar to this practice, but they are intended for use with white pigments,
4. Summary of Practice
rather than chromatic pigments.
4.1 Pigments are dispersed in a suitable vehicle with a
1.3 The values stated in SI units are to be regarded as the
mechanical muller. Test and standard pigments are treated
standard. The values given in parentheses are for information
identically. Opaque drawdowns may be made from the disper-
only.
sions and compared for color and strength differences either
1.4 This standard does not purport to address all of the
visually or instrumentally.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5. Significance and Use
priate safety, health, and environmental practices and deter-
5.1 The results obtained with a mechanical muller do not
mine the applicability of regulatory limitations prior to use.
necessarily correlate directly with an industrial situation where
Specific hazard statements are given in Section 8.
different dispersing conditions exist. However, dispersion with
1.5 This international standard was developed in accor-
a mechanical muller is a quick and inexpensive way to prepare
dance with internationally recognized principles on standard-
specimens for testing the color and strength of a pigment for
ization established in the Decision on Principles for the
routine quality control.
Development of International Standards, Guides and Recom-
5.2 By following the procedure described in Appendix X1,
mendations issued by the World Trade Organization Technical
the conditions for achieving the maximum practical degree of
Barriers to Trade (TBT) Committee.
dispersion with a mechanical muller may be determined. Any
color and strength tests done with the dispersions should be
2. Referenced Documents
carried out under these conditions.
2.1 ASTM Standards:
D332 Test Method for Relative Tinting Strength of White
6. Apparatus
Pigments by Visual Observation
6.1 Balances—(1) A balance sensitive to 10 mg, and (2)an
D2745 Test Method for Relative Tinting Strength of White
analytical balance sensitive to 1.0 mg.
Pigments by Reflectance Measurements
6.2 Muller, Mechanical, equipped with ground-glass plates
to which a variable but known force may be added in 220-N
(50-lbf) increments. The driven glass plate shall have a speed
This practice is under the jurisdiction of ASTM Committee D01 on Paint and
ofrotationofbetween70and120r/minandtheapparatusshall
Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.24 on Physical Properties of Liquid Paints & Paint Materials.
have an arrangement for pre-setting the number of revolutions
Current edition approved April 1, 2019. Published April 2019. Originally
in multiples of 50. See Fig. 1 for an example of such a device.
approved in 2009. Last previous edition approved in 2013 as D7540 – 09 (2013).
DOI: 10.1520/D7540-09R19.
6.3 Rubbing Surfaces—The rubbing surfaces of the ground-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
glass plates shall be kept sharp by removing them from the
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
muller and grinding them face-to-face with No. 303 optical
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. emery, or its equivalent, and water.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7540 − 09 (2019)
9. Dispersing Conditions
9.1 The conditions for dispersing the pigment on the me-
chanical muller should be such that the maximum tinting
strength is developed. For each pigment and each dispersing
vehicle the development of tinting strength by the mechanical
muller is influenced by the force applied, the number of
revolutions, the mass of the pigment, and the mass of the
vehicle. The conditions for obtaining the maximum tinting
strength with the mechanical muller can be determined by
following the procedure in Appendix X1.
9.2 If these conditions are known for a particular pigment
with a particular vehicle, or if the purchaser and seller agree
upon a particular set of conditions, there is no need to carry out
the procedure in Appendix X1.
10. Dispersion Procedure
10.1 Decide, by agreement or by experimentation, as dis-
cussed in Section 9, the following dispersing conditions:
10.1.1 Force applied to the muller plates;
10.1.2 Number of revolutions;
10.1.3 Mass of the pigment; and
10.1.4 Mass of the vehicle.
10.2 Applying these decisions, prepare a dispersion of the
FIG. 1 A Muller-Type Laboratory Grinder/Disperser (Courtesy of reference standard pigment. Weigh onto a glass slab to within
Paul N. Gardner Company, Inc.)
2 mg, the appropriate quantities of the standard pigment and
the dispersing vehicle. Mix the pigment and vehicle together
6.4 Small Glass Slab or other nonabsorbent material, suit-
thoroughly with the spatula and transfer the mixture to the
ab
...