ASTM D1921-01

Standard Test Methods for Particle Size (Sieve Analysis) of Plastic Materials

SCOPE
1.1 These test methods cover the measurement of the particle size of plastic materials in the powdered, granular, or pelleted forms in which they are commonly supplied. As these test methods utilize dry sieving, the lower limit of measurement is considered to be about 38 microns (No. 400 sieve). For smaller particle sizes, sedimentation methods are recommended.  
1.2 Two test methods are described:  
1.2.1 Test Method A—This test method uses multiple sieves selected to span the particle size of the material. The mean particle diameter and distribution can be determined by this test method.  
1.2.2  Test Method B—This test method is an abbreviated version of Test Method A conducted with a few specific sieves. This test method determines "percent passing" or "percent retained" on a given sieve. Test Method B is applicable to materials which do not have a normal particle size distribution such as pellets and cubes.  
1.3 The values as stated in inch-pound units are to be regarded as the standard. The values given in parentheses are given 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 and health practices and determine the applicability of regulatory limitations prior to use.
Note 1-—There is no technically equivalent ISO standard.

General Information

• Status: Historical
• Publication Date: 09-Aug-2001
• ICS: 19.120 - Particle size analysis. Sieving
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.70 - Analytical Methods

Relations

• Replaces: ASTM D1921-96 - Standard Test Methods for Particle Size (Sieve Analysis) of Plastic Materials
• Effective Date: 10-Aug-2001
• Replaced By: ASTM D1921-06 - Standard Test Methods for Particle Size (Sieve Analysis) of Plastic Materials
• Effective Date: 01-Apr-2006
• Referred By: ASTM D4020-18 - Standard Specification for Ultra-High-Molecular-Weight Polyethylene Molding and Extrusion Materials
• Effective Date: 10-Aug-2001
• Referred By: ASTM D5861-07(2017) - Standard Guide for Significance of Particle Size Measurements of Coating Powders
• Effective Date: 10-Aug-2001
• Referred By: ASTM E1229-21 - Standard Specification for Calcium Hypochlorite
• Effective Date: 10-Aug-2001
• Referred By: ASTM D3451-06(2017) - Standard Guide for Testing Coating Powders and Powder Coatings
• Effective Date: 10-Aug-2001
• Referred By: ASTM D8424-21 - Standard Guide for Retroreflective Composite Optics Laboratory Procedures
• Effective Date: 10-Aug-2001
• Referred By: ASTM D8402-23 - Standard Practice for Development of Microplastic Reference Samples for Calibration and Proficiency Evaluation in All Types of Water Matrices with High to Low Levels of Suspended Solids
• Effective Date: 10-Aug-2001
• Referred By: ASTM D7486-22 - Standard Test Method for Measurement of Fines and Dust Particles on Plastic Pellets by Wet Analysis
• Effective Date: 10-Aug-2001
• Referred By: ASTM D1755-21 - Standard Specification for Poly(Vinyl Chloride) Resins
• Effective Date: 10-Aug-2001
• Referred By: ASTM D3218-07(2018) - Standard Specification for Polyolefin Monofilaments
• Effective Date: 10-Aug-2001

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:D1921–01
Standard Test Methods for
1
Particle Size (Sieve Analysis) of Plastic Materials
This standard is issued under the fixed designation D 1921; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope* 2. Referenced Documents
1.1 These test methods cover the measurement of the 2.1 ASTM Standards:
particle size of plastic materials in the powdered, granular, or E11 Specification for Wire-Cloth Sieves for Testing Pur-
2
pelleted forms in which they are commonly supplied.As these poses
test methods utilize dry sieving, the lower limit of measure- E 691 Practice for Conducting an Interlaboratory Study to
2
ment is considered to be about 38 µm (No. 400 sieve). For Determine the Precision of a Test Method
smaller particle sizes, sedimentation test methods are recom-
3. Summary of Test Methods
mended.
3.1 A dry mass of plastic material is placed on a series of
1.2 Two test methods are described:
1.2.1 Test Method A—This test method uses multiple sieves sieves arranged in order of increasing fineness and the mass is
divided into fractions corresponding to the sieve opening.
selected to span the particle size of the material. The mean
particlediameteranddistributioncanbedeterminedbythistest
4. Significance and Use
method.
4.1 These test methods can be used to determine particle
1.2.2 Test Method B—This test method is an abbreviated
size distribution and therefore are useful for determining
version ofTest MethodAconducted with a few specific sieves.
lot-to-lot uniformity.
This test method determines “percent passing” or “percent
4.2 The particle sizes of plastic materials affect the handling
retained” on a given sieve. Test Method B is applicable to
characteristics and may affect the processing characteristics of
materials which do not have a normal particle size distribution
some polymers.
such as pellets and cubes.
1.3 The values stated in SI units shall be considered
5. Interferences
standard for dimensions of the wire cloth openings and the
5.1 Some materials develop a static charge during sieving.
diameter of the wires used in the wire cloth. The values stated
This charge interferes with the sieving process and results in a
in inch-pound units shall be considered standard with regard to
coarse bias. Use of an antistat is necessary to obtain meaning-
the sieve frames.
ful results.
1.4 This standard does not purport to address all of the
5.2 The choice of antistat (or slip agent) will affect the
safety concerns, if any, associated with its use. It is the
coarse bias. Some materials are more effective in aiding the
responsibility of the user of this standard to establish appro-
fines to separate from the mass.
priate safety and health practices and determine the applica-
5.3 Too much material on a sieve causes mass blinding and
bility of regulatory limitations prior to use.
results in a coarse bias. The sieve selection and charge weight
NOTE 1—There is no technically equivalent ISO standard.
must be chosen to avoid overloading any sieve.
5.4 Wavy, improperly stretched wire-cloth may allow wires
1 to separate without being visually damaged. Sieves with wavy
These test methods are under the jurisdiction of ASTM Committee D20 on
or torn wires should be discarded, as they no longer conform to
Plastics and are the direct responsibility of Subcommittee D20.70 on Analytic
Methods (Section D20.70.01).
SpecificationE11.
Current edition approved August 10, 2001. Published October 2001. Originally
published as D 1921 – 61 T. Last previous edition D 1921 – 96.
This revision adds an ISO equivalency statement, includesTable 1 showing sieve
2
size openings, and has wording changes in Sections 10, 12, 13, and 15. Annual Book of ASTM Standards, Vol 14.02.
*A Summary of Changes section appears at the end of this standard.
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D1921–01
6. Apparatus TEST METHOD A
6.1 Balance, 500-g minimum capacity with the capability of
12. Procedure
reading to the nearest 0.1 g.
12.1 Selectsievesinsufficientnumbertocovertheexpected
6.2 Mechanical Sieving Device and Time Switch—A me-
range of particle sizes, and nest them together in order of
chanical sieve-shaking device equipped with an automatic time
diminishing opening with the coarsest sieve on top and the pan
switch. This device shall be capable of imparting uniform
on the bottom.
rotary motion and a tapping action at a rate of 150 6 10
taps/min.
NOTE 2—Select sieves in sufficient number to have significan
...