ASTM D2839-16(2023)
(Practice)Standard Practice for Use of a Melt Index Strand for Determining Density of Polyethylene
Standard Practice for Use of a Melt Index Strand for Determining Density of Polyethylene
SIGNIFICANCE AND USE
4.1 This practice has been found to be very useful for preparing polyethylene samples suitable for determination of density by Test Method D1505, for quality control purposes, especially in a resin manufacturing facility where fast, reproducible, comparative results are needed. It is not necessarily recommended for resin specifications that are part of a sales contract between the buyer and the seller.
4.2 The density of a polyethylene sample is highly dependent on the preparation and thermal history of the specimens. The level of density results obtained by this practice of sample preparation differs from that obtained by other methods as described in Practice D4703, Annex A1.
4.3 Before proceeding with this practice, reference shall be made to the specification of the material being tested. Any test specimen preparation, conditioning, dimensions, or testing parameters, or some combination thereof, covered in the materials specification shall take precedence over those mentioned in this practice. If there are no material specifications, the default conditions apply.
SCOPE
1.1 This practice covers the preparation of a sample for polyethylene density determination in accordance with Test Method D1505. The sample consists of a strand produced by extrusion of the polyethylene in accordance with Test Method D1238, Condition 190/2.16 (Melt Index).
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
Note 1: There is no known ISO equivalent to this standard.
Note 2: The precision data on densities measured using this sample preparation practice is listed in Test Method D1505.
1.4 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
Relations
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: D2839 − 16 (Reapproved 2023)
Standard Practice for
Use of a Melt Index Strand for Determining Density of
Polyethylene
This standard is issued under the fixed designation D2839; 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* 3. Terminology
1.1 This practice covers the preparation of a sample for 3.1 Definitions:
polyethylene density determination in accordance with Test 3.1.1 melt index strand—the extrudate produced when poly-
Method D1505. The sample consists of a strand produced by ethylene is extruded in accordance with Test Method D1238,
extrusion of the polyethylene in accordance with Test Method Condition 190/2.16.
D1238, Condition 190/2.16 (Melt Index).
4. Significance and Use
1.2 The values stated in SI units are to be regarded as the
4.1 This practice has been found to be very useful for
standard. The values given in parentheses are for information
preparing polyethylene samples suitable for determination of
only.
density by Test Method D1505, for quality control purposes,
1.3 This standard does not purport to address all of the
especially in a resin manufacturing facility where fast,
safety concerns, if any, associated with its use. It is the
reproducible, comparative results are needed. It is not neces-
responsibility of the user of this standard to establish appro-
sarily recommended for resin specifications that are part of a
priate safety, health, and environmental practices and deter-
sales contract between the buyer and the seller.
mine the applicability of regulatory limitations prior to use.
4.2 The density of a polyethylene sample is highly depen-
NOTE 1—There is no known ISO equivalent to this standard.
dent on the preparation and thermal history of the specimens.
NOTE 2—The precision data on densities measured using this sample
The level of density results obtained by this practice of sample
preparation practice is listed in Test Method D1505.
preparation differs from that obtained by other methods as
1.4 This international standard was developed in accor-
described in Practice D4703, Annex A1.
dance with internationally recognized principles on standard-
4.3 Before proceeding with this practice, reference shall be
ization established in the Decision on Principles for the
made to the specification of the material being tested. Any test
Development of International Standards, Guides and Recom-
specimen preparation, conditioning, dimensions, or testing
mendations issued by the World Trade Organization Technical
parameters, or some combination thereof, covered in the
Barriers to Trade (TBT) Committee.
materials specification shall take precedence over those men-
2. Referenced Documents
tioned in this practice. If there are no material specifications,
the default conditions apply.
2.1 ASTM Standards:
D1238 Test Method for Melt Flow Rates of Thermoplastics
5. Apparatus
by Extrusion Plastometer
5.1 Extrusion Plastometer, as described in Test Method
D1505 Test Method for Density of Plastics by the Density-
D1238.
Gradient Technique
D4703 Practice for Compression Molding Thermoplastic
5.2 Hot Plate, to boil water.
Materials into Test Specimens, Plaques, or Sheets
5.3 Beakers, 250-mL low form, graduated, with watch-glass
covers.
This practice is under the jurisdiction of ASTM Committee D20 on Plastics and
6. Sample
is the direct responsibility of Subcommittee D20.15 on Thermoplastic Materials
(D20.15.01).
6.1 Polyethylene, in any form suitable for test in accordance
Current edition approved March 15, 2023. Published March 2023. Originally
with Test Method D1238.
approved in 1969. Last previous edition approved in 2016 as D2839 - 16. DOI:
10.1520/D2839-16R23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 7. Procedure
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
7.1 Prepare a Melt Index Strand by extruding the sample in
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. accordance with Test Method D1238, Condition 190/2.16,
*A Summary of Changes section appears at the end of
...
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