ASTM E2980-15

Standard Test Methods for Estimating Average Particle Size of Powders Using Air Permeability

SIGNIFICANCE AND USE
4.1 These test methods provide procedures for determining the envelope-specific surface area of powders, from which is calculated an “average” particle diameter, assuming the particles are monosize, smooth surface, nonporous, spherical particles. For this reason, values obtained by these test methods will be reported as an average particle size. The degree of correlation between the results of these test methods and the quality of powders in use will vary with each particular application and has not been fully determined.  
4.2 These test methods are generally applicable to all powders, including metals (see Test Methods B330 for specific metal powder requirements), ceramics, and organic materials, for particles having diameters between 0.2 and 75 µm. They should not be used for powders composed of particles whose shape is too far from equiaxed - that is, flakes or fibers. In these cases, it is permissible to use the test methods described only by agreement between the parties concerned. These test methods shall not be used for mixtures of different powders, nor for powders containing binders or lubricants. When the powder contains agglomerates, the measured surface area may be affected by the degree of agglomeration. Methods of de-agglomeration such as that specified in Practice B859 may be used if agreed upon between the parties concerned.  
4.3 When an “average” particle size of powders is determined by these methods, it should be clearly kept in mind that this average size is derived from the determination of the specific surface area of the powder using a relationship that is true only for powders of uniform size and spherical shape. Thus, the results of these methods are only estimates of average particle size.  
4.4 Reported particle size measurement is a function of both the actual dimension and shape factor as well as the particular physical or chemical properties of the particle being measured. Caution is required when comparing data from instruments op...
SCOPE
1.1 These test methods use air permeability to determine an envelope-specific surface area and its associated average equivalent spherical diameter (from 0.2 to 75 µm) of powders. Two test methods are described: One test method for inorganic materials (Test Method 1), and another test method for organic materials (Test Method 2). The values obtained are not intended to be absolute but are generally useful on a relative basis for control purposes.  
1.2 Units—With the exception of the values for density and the mass used to determine density, for which the use of the gram per cubic centimetre (g/cm3) and gram (g) units is the longstanding industry practice; and the units for pressure, cm H2O—also long-standing practice; the values in SI units are to be regarded as standard.  
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.

General Information

• Status: Historical
• Publication Date: 30-Nov-2015
• ICS: 19.120 - Particle size analysis. Sieving
• Technical Committee: E29 - Particle and Spray Characterization
• Drafting Committee: E29.02 - Non-Sieving Methods

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: E2980 − 15
Standard Test Methods for
Estimating Average Particle Size of Powders Using Air
1
Permeability
This standard is issued under the fixed designation E2980; 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* and Screening Media
E2589 Terminology Relating to Nonsieving Methods of
1.1 These test methods use air permeability to determine an
Powder Characterization
envelope-specific surface area and its associated average
3
2.2 ISO Documents:
equivalent spherical diameter (from 0.2 to 75 µm) of powders.
ISO 10070 Metallic Powders: Determinations of Envelope-
Two test methods are described: One test method for inorganic
Specific Surface Area from Measurements of the Perme-
materials (Test Method 1), and another test method for organic
ability to Air of a Powder Bed Under Steady-State Flow
materials (Test Method 2). The values obtained are not
Conditions
intended to be absolute but are generally useful on a relative
basis for control purposes.
3. Terminology
1.2 Units—With the exception of the values for density and
3.1 Definitions—Many terms used in this test method are
the mass used to determine density, for which the use of the
defined in Terminologies E1638 and E2589.
3
gram per cubic centimetre (g/cm ) and gram (g) units is the
3.2 Definitions of Terms Specific to This Standard:
longstanding industry practice; and the units for pressure, cm
3.2.1 air permeability, n—measurement of air pressure drop
H O—also long-standing practice; the values in SI units are to
2
across a packed bed of powder.
be regarded as standard.
3.2.2 average particle size, n—for the purposes of these test
1.3 This standard does not purport to address all of the
methods only, an estimate of the equivalent average spherical
safety concerns, if any, associated with its use. It is the
particle diameter, calculated from the measured envelope-
responsibility of the user of this standard to establish appro-
specific surface area, assuming that all the powder particles are
priate safety and health practices and determine the applica-
spherical and that all are exactly the same size.
bility of regulatory limitations prior to use.
3.2.3 de-agglomeration, n—process used to break up ag-
2. Referenced Documents
glomerates of particles.
2
2.1 ASTM Standards:
3.2.4 envelope-specific surface area, n—specific surface
B330 Test Methods for Estimating Average Particle Size of
area of a powder as determined by gas permeametry in
Metal Powders and Related Compounds Using Air Per-
accordance with ISO 10070.
meability
3.2.5 MIC Sub-Sieve AutoSizer (MIC SAS), n—a commer-
B859 Practice for De-Agglomeration of Refractory Metal
cially available permeability instrument for measuring
Powders and Their Compounds Prior to Particle Size
envelope-specific surface area and estimating average particle
Analysis
size from 0.2 to 75 µm.
E29 Practice for Using Significant Digits in Test Data to
3.2.6 porosity of a bed of powder, n—ratio of the volume of
Determine Conformance with Specifications
the void space in the powder bed to that of the overall volume
E1638 Terminology Relating to Sieves, Sieving Methods,
of the powder bed.
4. Significance and Use
1
These test methods are under the jurisdiction of ASTM Committee E29 on
Particle and Spray Characterization and is the direct responsibility of Subcommittee
4.1 These test methods provide procedures for determining
E29.02 on Non-Sieving Methods.
the envelope-specific surface area of powders, from which is
Current edition approved Dec. 1, 2015. Published January 2016. Originally
calculated an “average” particle diameter, assuming the par-
approved in 2014. Last previous edition approved in 2014 as E2980 – 14. DOI:
10.1520/E2980-15. ticles are monosize, smooth surface, nonporous, spherical
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
*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
1

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E2980 − 15
all plug heights when new plugs are purchased and periodically thereafter
particles.Forthisreason,valuesobtainedbythesetestmethods
to make sure all are equal in height.
will be reported as an average p
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E2980 − 14 E2980 − 15
Standard Test Methods for
Estimating Average Particle Size of Powders Using Air
1
Permeability
This standard is issued under the fixed designation E2980; 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 Scope*
1.1 These test methods use air permeability to determine an envelope-specific surface area and its associated average equivalent
spherical diameter (from 0.2 to 75 μm) of powders. Two test methods are described: One test method for inorganic materials (Test
Method 1), and another test method for organic materials (Test Method 2). The values obtained are not intended to be absolute
but are generally useful on a relative basis for control purposes.
1.2 Units—With the exception of the values for density and the mass used to determine density, for which the use of the gram
3
per cubic centimetre (g/cm ) and gram (g) units is the longstanding industry practice; and the units for pressure, cm H O—also
2
long-standing practice; the values in SI units are to be regarded as standard.
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.
2. Referenced Documents
2
2.1 ASTM Standards:
B330 Test Methods for Estimating Average Particle Size of Metal Powders and Related Compounds Using Air Permeability
B859 Practice for De-Agglomeration of Refractory Metal Powders and Their Compounds Prior to Particle Size Analysis
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E1638 Terminology Relating to Sieves, Sieving Methods, and Screening Media
E2589 Terminology Relating to Nonsieving Methods of Powder Characterization
3
2.2 ISO Documents:
ISO 10070 Metallic Powders: Determinations of Envelope-Specific Surface Area from Measurements of the Permeability to Air
of a Powder Bed Under Steady-State Flow Conditions
3. Terminology
3.1 Definitions—Many terms used in this test method are defined in Terminologies E1638 and E2589.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 air permeability, n—measurement of air pressure drop across a packed bed of powder.
3.2.2 average particle size, n—for the purposes of these test methods only, an estimate of the equivalent average spherical
particle diameter, calculated from the measured envelope-specific surface area, assuming that all the powder particles are spherical
and that all are exactly the same size.
3.2.3 de-agglomeration, n—process used to break up agglomerates of particles.
3.2.4 envelope-specific surface area, n—specific surface area of a powder as determined by gas permeametry in accordance with
ISO 10070.
1
These test methods are under the jurisdiction of ASTM Committee E29 on Particle and Spray Characterization and is the direct responsibility of Subcommittee E29.02
on Non-Sieving Methods.
Current edition approved Dec. 1, 2014Dec. 1, 2015. Published January 2015January 2016. Originally approved in 2014. Last previous edition approved in 2014 as E2980
– 14. DOI: 10.1520/E2980-14.10.1520/E2980-15.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
*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
1

---------------------- Page: 1 ----------------------
E2980 − 15
3.2.5 HELMIC Sub-Sieve AutoSizer (HEL(MIC SAS), n—a commercially available permeability instrument for measuring
envelope-specific surface area and estimating average particle size from 0.2 to 75 μm.
3.2.6 porosity of a bed of powder, n—ratio of the volume of the void space in the powder bed to that of the overall volume of
the powder bed.
4. Significance and Use
4.1 These test methods provide procedures for determining the envelope-specific surface area of powders, fro
...