ASTM D2839-16

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 and health 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.

General Information

• Status: Historical
• Publication Date: 30-Sep-2016
• ICS: 83.080.20 - Thermoplastic materials
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.15 - Thermoplastic Materials

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D2839 − 16
Standard Practice for
Use of a Melt Index Strand for Determining Density of
1
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* 4. Significance and Use
1.1 This practice covers the preparation of a sample for 4.1 This practice has been found to be very useful for
polyethylene density determination in accordance with Test preparing polyethylene samples suitable for determination of
Method D1505. The sample consists of a strand produced by density by Test Method D1505, for quality control purposes,
extrusion of the polyethylene in accordance with Test Method especially in a resin manufacturing facility where fast,
D1238, Condition 190/2.16 (Melt Index). reproducible, comparative results are needed. It is not neces-
sarily recommended for resin specifications that are part of a
1.2 The values stated in SI units are to be regarded as the
sales contract between the buyer and the seller.
standard. The values given in parentheses are for information
only. 4.2 The density of a polyethylene sample is highly depen-
dent on the preparation and thermal history of the specimens.
1.3 This standard does not purport to address all of the
The level of density results obtained by this practice of sample
safety concerns, if any, associated with its use. It is the
preparation differs from that obtained by other methods as
responsibility of the user of this standard to establish appro-
described in Practice D4703, Annex A1.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
4.3 Before proceeding with this practice, reference shall be
made to the specification of the material being tested. Any test
NOTE 1—There is no known ISO equivalent to this standard.
specimen preparation, conditioning, dimensions, or testing
NOTE 2—The precision data on densities measured using this sample
preparation practice is listed in Test Method D1505. parameters, or some combination thereof, covered in the
materials specification shall take precedence over those men-
2. Referenced Documents
tioned in this practice. If there are no material specifications,
2
the default conditions apply.
2.1 ASTM Standards:
D1238 Test Method for Melt Flow Rates of Thermoplastics
5. Apparatus
by Extrusion Plastometer
D1505 Test Method for Density of Plastics by the Density-
5.1 Extrusion Plastometer, as described in Test Method
Gradient Technique
D1238.
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
3. Terminology
covers.
3.1 Definitions:
6. Sample
3.1.1 melt index strand—the extrudate produced when poly-
ethylene is extruded in accordance with Test Method D1238, 6.1 Polyethylene, in any form suitable for test in accordance
Condition 190/2.16. with Test Method D1238.
7. Procedure
1
This practice is under the jurisdiction of ASTM Committee D20 on Plastics and
7.1 Prepare a Melt Index Strand by extruding the sample in
is the direct responsibility of Subcommittee D20.15 on Thermoplastic Materials
(D20.15.01). accordance with Test Method D1238, Condition 190/2.16,
Current edition approved Oct. 1, 2016. Published October 2016. Originally
dropping the strand on a cool metal plate after cutting off.
approved in 1969. Last previous edition approved in 2010 as D2839 - 10. DOI:
When Procedure B of Test Method D1238 is used, cut off the
10.1520/D2839-16.
2
extrudate at about the time the timer is actuated and discard.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Save the portion extruded during the timed interval.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. NOTE 3—It has been shown that the measured density of an extruded
*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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D2839 − 16
strand is significantly affected by changes in the localized air velocity due
7.4 Remove the strand from the water and cut off a 5-mm
to external drafts, location in relation to HVAC outlets, and so forth. It is
1
( ⁄4-in.) length from the thicker end of the strand. Discard this
advisable to minimize any external airflow and to recognize this when
1
po
...

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: D2839 − 10 D2839 − 16
Standard Practice for
Use of a Melt Index Strand for Determining Density of
1
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*
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 and health 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D1238 Test Method for Melt Flow Rates of Thermoplastics by Extrusion Plastometer
D1505 Test Method for Density of Plastics by the Density-Gradient Technique
D4703 Practice for Compression Molding Thermoplastic Materials into Test Specimens, Plaques, or Sheets
3. Terminology
3.1 Definitions:
3.1.1 melt index strand—the extrudate produced when polyethylene is extruded in accordance with Test Method D1238,
Condition 190/2.16.
4. 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.
1
This practice is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.15 on Thermoplastic Materials
(D20.15.01).
Current edition approved Aug. 1, 2010Oct. 1, 2016. Published September 2010October 2016. Originally approved in 1969. Last previous edition approved in 20052010
as D2839 - 05.D2839 - 10. DOI: 10.1520/D2839-10.10.1520/D2839-16.
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.
*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 ----------------------
D2839 − 16
5. Apparatus
5.1 Extrusion Plastometer, as described in Test Method D1238.
5.2 Hot Plate, to boil water.
5.3 Beakers, 250-mL low form, graduated, with watch-glass covers.
6. Sample
6.1 Polyethylene, in any form suitable for test in accordance with Test Method D1238.
7. Procedure
7.1 Prepare a Melt Index Strand by extruding the sample in accordance with Test Method D1238, Condition 190/2.16, dropping
the strand on a cool metal plate after cutting off. When Procedure B of Test Method D1238 is used, cut off the extrudate at about
the time the timer is actuated and discard. Save the portion extruded during the timed interval.
NOTE 3—It has been shown that the measured density of an extruded strand can be is significan
...