ASTM D5861-07(2017)

Standard Guide for Significance of Particle Size Measurements of Coating Powders

SIGNIFICANCE AND USE
4.1 This guide describes the need to specify the measuring technique used whenever quoting the particle size distribution of a coating powder.  
4.2 This guide is for use by manufacturers of coating powders and by specifiers for process control and product acceptance.
SCOPE
1.1 This guide covers the significance of referencing the techniques used whenever specifying the particle size distribution of a coating powder.  
1.2 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-May-2017
• ICS: 77.160 - Powder metallurgy
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.51 - Powder Coatings

Relations

• Refers: ASTM D3451-06(2017) - Standard Guide for Testing Coating Powders and Powder Coatings
• Effective Date: 01-Jun-2017

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: D5861 −07 (Reapproved 2017)
Standard Guide for
Significance of Particle Size Measurements of Coating
1
Powders
This standard is issued under the fixed designation D5861; 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 4.2 This guide is for use by manufacturers of coating
powders and by specifiers for process control and product
1.1 This guide covers the significance of referencing the
acceptance.
techniques used whenever specifying the particle size distribu-
tion of a coating powder.
5. Particle Size of Coating Powders
1.2 This international standard was developed in accor-
5.1 The size of the particles comprising a coating powder
dance with internationally recognized principles on standard-
plays a critical role in the fluidization, application, and recla-
ization established in the Decision on Principles for the
mation of the powder, and in the final appearance of the coated
Development of International Standards, Guides and Recom-
part. Coating powders are comprised of particles of widely
mendations issued by the World Trade Organization Technical
differing sizes, from as low as about 1 µm to as high as about
Barriers to Trade (TBT) Committee.
150 µm. Collectively, the individual particles form a size
2. Referenced Documents distribution, defined by the percentages of particles present of
2 a given size or within a given size range. There are generally
2.1 ASTM Standards:
few particles at the low and high ends of the distribution, the
D1921 Test Methods for Particle Size (Sieve Analysis) of
majority being in the 25 to 65-µm range. The distribution can
Plastic Materials
be described by an actual plot of the particle size distribution,
D3451 Guide for Testing Coating Powders and Powder
or by numerical attributes of the distribution, such as the
Coatings
calculated values of its mean, median, mode, and span. The
3. Terminology mean represents the average particle size (the sum of all the
particle sizes divided by the number of particles). The median
3.1 Definitions:
represents a size such that half the particles are larger than it
3.1.1 coating powders, n—these are finely divided particles
and half the particles are smaller than it. The mode represents
of organic polymer that generally contain pigments, fillers, and
the most frequently occurring particle size. For all coating
additives and that remain finely divided during storage under
powders these three figures are numerically different. The span
suitable conditions.
is an indication of the width of the particle size distribution.
3.1.2 powder coatings, n—these are coatings that are
Referring to Table A1.1, the span is calculated by subtracting
protective, decorative, or both; and that are formed by the
the d10 from the d90 and then dividing by the d50 or median
application of a coating powder to a substrate and fused into
particle size.
continuous films by the application of heat or radiant energy.
5.2 The particle size distribution is generally chosen by the
4. Significance and Use
coating powder manufacturer from knowledge of the applica-
tion technique, the required cured film thickness, surface
4.1 This guide describes the need to specify the measuring
appearance, and performance. Once the desired particle size
technique used whenever quoting the particle size distribution
distribution has been selected, it needs to be monitored to
of a coating powder.
ensure consistency from batch to batch and, indeed, within
each batch. Occasionally the coating powder applicator may
1
This guide is under the jurisdiction of ASTM Committee D01 on Paint and
specify the particle size from knowledge of the specific
Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.51 on Powder Coatings.
application equipment or customer requirements, or both.
Current edition approved June 1, 2017. Published June 2017. Originally
5.3 It is important for all involved to understand that the
approved in 1995. Last previous edition approved in 2013 as D5861 – 07 (2013).
DOI: 10.1520/D5861-07R17.
numerical data comprising a particle size distribution are
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
significantlydependentonthetechniqueusedtoobtainthem.It
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
is, therefore, of little use to quote or specify a particle size
Standards volume information, refer to the standard’s
...