ASTM D4883-18

Standard Test Method for Density of Polyethylene by the Ultrasound Technique

SIGNIFICANCE AND USE
4.1 The density of polyethylene is a conveniently measurable property which is frequently useful as a means of following physical changes in a sample, as an indication of uniformity among samples, and as a means of identification.  
4.2 This test method is designed to yield results with a precision of ±0.08 % or better.
SCOPE
1.1 This test method covers the determination of the density of polyethylene through the utilization of ultrasound equipment.  
1.2 This test method is based on the distinct behaviors of the amorphous and crystalline phases of polyethylene in response to ultrasound. Polyethylene shall be viewed as a composite structure where high-density crystalline regions are connected by lower-density amorphous material. The ratio of crystalline to amorphous material determines the final density of the material. The amorphous and crystalline phases exhibit very distinct behaviors with regard to the propagation of sound waves. The propagation characteristics in the composite will depend on the relative amount of the two phases (the degree of crystallinity).  
1.3 Inorganic materials increase density as measured by Test Methods D792 and D1505, but they have little or no effect on ultrasonic density. The ultrasonic measurement is basically a base resin density.  
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.5 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.  
1.6 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-Oct-2018
• ICS: 83.080.20 - Thermoplastic materials
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.70 - Analytical Methods

Relations

• Replaces: ASTM D4883-08 - Standard Test Method for Density of Polyethylene by the Ultrasound Technique (Withdrawn 2017)
• Effective Date: 01-Nov-2018
• Refers: ASTM D883-24 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2024
• Refers: ASTM D883-23 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2023
• Refers: ASTM D883-20 - Standard Terminology Relating to Plastics
• Effective Date: 01-Jan-2020
• Refers: ASTM D883-19c - Standard Terminology Relating to Plastics
• Effective Date: 01-Aug-2019
• Refers: ASTM D883-19a - Standard Terminology Relating to Plastics
• Effective Date: 15-Apr-2019
• Refers: ASTM D883-19 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2019
• Refers: ASTM D883-18a - Standard Terminology Relating to Plastics
• Effective Date: 01-Dec-2018
• Refers: ASTM D883-18 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2018
• Refers: ASTM E2935-17 - Standard Practice for Conducting Equivalence Testing in Laboratory Applications
• Effective Date: 01-Oct-2017
• Refers: ASTM D883-17 - Standard Terminology Relating to Plastics
• Effective Date: 15-Aug-2017
• Refers: ASTM E2935-16 - Standard Practice for Conducting Equivalence Testing in Laboratory Applications
• Effective Date: 15-Nov-2016
• Refers: ASTM D1248-16 - Standard Specification for Polyethylene Plastics Extrusion Materials for Wire and Cable
• Effective Date: 15-Nov-2016
• Refers: ASTM E2935-15 - Standard Practice for Conducting Equivalence Testing in Laboratory Applications
• Effective Date: 01-Oct-2015
• Refers: ASTM E2935-14 - Standard Practice for Conducting Equivalence Testing in Laboratory Applications
• Effective Date: 01-Oct-2014

Overview

ASTM D4883-18: Standard Test Method for Density of Polyethylene by the Ultrasound Technique establishes a reliable procedure for determining the density of polyethylene using ultrasonic equipment. This standard supports the identification, quality control, and tracking of changes in polyethylene samples by measuring density, a key indicator of material properties such as uniformity and crystallinity. The ultrasound method is particularly valued for its precision (typically ±0.08% or better), effectiveness in distinguishing base resin density, and its relevance where traditional gravimetric techniques may be influenced by additives or inorganic fillers.

Key Topics

• Fundamental Principle: The test leverages differences in the propagation of ultrasonic waves through the amorphous and crystalline phases of polyethylene. The proportion of these phases directly affects the density measurement and provides insights into the polymer’s composition and degree of crystallinity.
• Sample Requirements: Specimens must be free of foreign material and surface defects, with recommended dimensions and thicknesses (typically 1.9 ± 0.2 mm for compliance with related polyethylene specifications).
• Calibration: Accurate calibration is essential for reliable results. Calibration samples should be prepared and measured using established ASTM density methods (such as D792 or D1505) before creating an instrument-specific calibration curve.
• Testing Conditions: All specimens should be conditioned at standardized temperatures and humidity before testing. Ultrasound measurements are conducted in a controlled water bath, ensuring consistency and repeatable results.
• Reporting: Results should include full material identification, specimen preparation, conditioning details, average density, and indication of result precision (standard deviation, number of determinations, and test date).

Applications

• Product Quality Control: Manufacturers utilize this ultrasound density test method to ensure uniformity across polyethylene production batches, rapidly identify variability, and facilitate process optimization in both extrusion and molding processes.
• Material Identification: The method provides a quick and reliable means of identifying polyethylene resin types by their characteristic density, assisting in the verification of shipments or compliance with customer specifications.
• Crystallinity Assessment: By leveraging the distinct ultrasound responses of crystalline and amorphous regions, laboratories can monitor changes in polymer structure due to processing, recycling, or environmental exposure.
• Research and Development: R&D teams benefit from precision density measurements to assess the effect of new formulations, additives, or processing techniques on polyethylene performance.
• Regulatory Compliance: The standard’s adherence to internationally recognized principles (including WTO TBT Committee decisions) supports its use in global markets where harmonized testing protocols are required.

Related Standards

• ASTM D792 - Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement: Frequently referenced for calibration of ultrasound instruments.
• ASTM D1505 - Test Method for Density of Plastics by the Density-Gradient Technique: Another technique used in calibration and quality control.
• ASTM D618 - Practice for Conditioning Plastics for Testing: Specifies conditioning parameters to ensure uniform test conditions.
• ASTM D4703 - Practice for Compression Molding Thermoplastic Materials: Describes plaque preparation procedures for test specimens.
• ASTM D1248, D3350, D4976 - Specifications related to polyethylene materials, often referenced for compliant specimen preparation.
• ASTM E494, E691, E2935 - Standards covering ultrasonic measurement practices, conducting interlaboratory studies, and laboratory equivalence testing for ensuring consistency and reproducibility.

Note: There is currently no ISO equivalent for ASTM D4883-18, making this an essential reference for organizations and labs requiring validated ultrasound-based polyethylene density determination.

By adopting ASTM D4883-18, stakeholders in the plastics industry can ensure precision, consistency, and compliance in the measurement of polyethylene density, supporting both production integrity and international trade.

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: D4883 − 18
Standard Test Method for
Density of Polyethylene by the Ultrasound Technique
This standard is issued under the fixed designation D4883; 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* 2. Referenced Documents
1.1 This test method covers the determination of the density
2.1 ASTM Standards:
of polyethylene through the utilization of ultrasound equip-
D618 Practice for Conditioning Plastics for Testing
ment.
D792 Test Methods for Density and Specific Gravity (Rela-
tive Density) of Plastics by Displacement
1.2 Thistestmethodisbasedonthedistinctbehaviorsofthe
D883 Terminology Relating to Plastics
amorphous and crystalline phases of polyethylene in response
D1248 Specification for Polyethylene Plastics Extrusion
to ultrasound. Polyethylene shall be viewed as a composite
Materials for Wire and Cable
structure where high-density crystalline regions are connected
by lower-density amorphous material. The ratio of crystalline D1505 Test Method for Density of Plastics by the Density-
to amorphous material determines the final density of the Gradient Technique
material. The amorphous and crystalline phases exhibit very
D3350 Specification for Polyethylene Plastics Pipe and Fit-
distinct behaviors with regard to the propagation of sound
tings Materials
waves. The propagation characteristics in the composite will
D4703 Practice for Compression Molding Thermoplastic
depend on the relative amount of the two phases (the degree of
Materials into Test Specimens, Plaques, or Sheets
crystallinity).
D4976 Specification for Polyethylene Plastics Molding and
Extrusion Materials
1.3 InorganicmaterialsincreasedensityasmeasuredbyTest
E494 Practice for Measuring Ultrasonic Velocity in Materi-
Methods D792 and D1505, but they have little or no effect on
als
ultrasonic density. The ultrasonic measurement is basically a
base resin density. E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.4 The values stated in SI units are to be regarded as the
E2935 Practice for Conducting Equivalence Testing in
standard. The values given in parentheses are for information
Laboratory Applications
only.
1.5 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
3.1 Definitions—The definitions given in Terminology
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter- D883, as well as in Test Methods D792 and D1505, are
mine the applicability of regulatory limitations prior to use. applicable to this test method.
NOTE 1—There is no known ISO equivalent to this standard.
4. Significance and Use
1.6 This international standard was developed in accor-
4.1 The density of polyethylene is a conveniently measur-
dance with internationally recognized principles on standard-
able property which is frequently useful as a means of
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- following physical changes in a sample, as an indication of
uniformity among samples, and as a means of identification.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4.2 This test method is designed to yield results with a
precision of 60.08 % or better.
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
and is the direct responsibility of Subcommittee D20.70 on Analytical Methods.
Current edition approved Nov. 1, 2018. Published November 2018. Originally For referenced ASTM standards, visit the ASTM website, www.astm.org, or
approved in 1989. Last previous edition approved in 2008 as D4883–08, which was contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
withdrawn January 2017 and reinstated in November 2018. DOI: 10.1520/D4883- Standards volume information, refer to the standard’s Document Summary page on
18. 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
D4883 − 18
5. Apparatus 6.6 Use demineralized water for the testing equipment’s
water bath.
5.1 Use an instrument which utilizes a sonic technique to
evaluate the density of polyethylene. The DS 500 instrument
7. Conditioning
utilizes a sonic sensing head (transducer) which measures the
7.1 Conditioning—Condition the test specimens at
velocity of sound in a molded specimen. Because sonic
23 6 2°C (73.4 6 3.6°F) for not less than 40 h prior to test in
velocity is positively correlated to density in polyethylene, a
accordance with Procedure A of Practice D618, for those tests
measurement of this velocity is used to determine specimen
where conditioning is required. In cases of disagreement,
density. The information from this transducer then must be
specimens shall be conditioned at 23 6 1°C and 50 65%
electronically evaluated; in the DS 500 instance this is done
relative humidity.
with a computer, and the result is reported either through a
display or printout.
7.2 Test Conditions—Conduct tests in instrument’s water
bath at a temperature of 23 6 2°C (73.4 6 3.6°F) unless
5.2 Equipment specified in Test Method D1505.
otherwise specified. In cases of disagreement, the tolerances
5.3 Equipment specified in Test Methods D792.
shall be 61°C (1.8°F).
5.4 Equipment specified in Practice D618.
7.3 Testing in normal plant operations frequently calls for
5.5 Equipment specified in Practice D4703, Annex 1.
testing before the sample has become fully conditioned. It will
benecessarytoestablishacorrelationbetweenapredetermined
NOTE2—Theequipmentspecifiedin5.2or5.3isrequiredfortheinitial
conditioning time (that is, 30 minutes in a water bath at
calibration of the sonic equipment. Once the equipment is calibrated, this
additional equipment is no longer required. It is recommended that the
23 6 2°C (73.4 6 3.6°F)) and measured density and the mea-
standards used for the initial calibration be retained for any additional
sured density when fully conditioned in accordance with
calibration when needed. It is also recommended that one or more of the
Procedure A of Practice D618 and to apply the correlation to
calibration standards be evaluated on a routine basis for calibration
obtain the predicted density. Retain the sample and retest once
verification.Theabsoluteaccuracyofdataproducedwillnotbebetterthan
the sample has been fully conditioned. If the measured density
this initial calibration and continued verification. Samples for initial
calibration are available from various sources (such as the National
of the retained specimen does not fall within 60.0004 of the
InstituteofStandardsandTechnology(NIST),resinmanufacturers,andso
predicted density then the conditioning time will need to be
forth).
adjusted and a new correlation between measured and pre-
dicted density will need to be created.
6. Test Specimens and Materials
6.1 Test plaques shall be prepared in accordance to the
8. Calibration
molding procedure specified in Practice D4703, Annex 1,
8.1 Refer to instrument’s operating manual for details on
Procedure C.
operating the instrument.
6.2 Thetestspecimenshallconsistofapieceofthematerial
8.2 The cleanliness of the demineralized water used in the
under test. Mold or cut the sample specimen to the specified
water bath shall be monitored and the water be replaced on a
dimensions.When a sample piece is cut from a molded plaque,
regular basis to avoid erroneous testing results.
care must be taken to avoid change in density resulting from
compressive stress. 8.3 Resins to be utilized for calibration shall be molded into
plaques in accordance with Practice D4703 Annex 1, Proce-
Specimen Dimensions, mm (in.)
Length 80–100 (3.15–3.94)
dure C and be conditioned in accordance with Procedure A of
Width 35–45 (1.38–1.77)
Practice D618. Specimens to be used for calibration shall
Thickness 1.5–3 (0.06–0.12)
undergo full conditioning.
A minimum thickness of 1.5 mm is re
...