ASTM D7744/D7744M-20

Standard Test Methods for Tensile Testing of High Performance Polyethylene Films

SIGNIFICANCE AND USE
5.1 The levels of tensile properties obtained when testing high performance polyethylene films are dependent on the age and history of the specimen and on the specific conditions used during the test. Among these conditions are rate of stretching, type of clamps, gauge length of specimen, temperature and humidity of the atmosphere, rate of airflow across the specimen, and temperature and moisture content of the specimen. Testing conditions accordingly are specified precisely to obtain reproducible test results on a specific sample.  
5.2 Breaking force is used in engineering calculations when designing various types of products. When needed to compare intrinsic strength characteristics, films of different sizes or different types of film, breaking tenacity is very useful because, for a given type of film, breaking force is approximately proportional to linear density.  
5.3 Elongation of film is taken into consideration in the design and engineering of reinforced products because of its effect on uniformity of the finished product and its dimensional stability during service.  
5.4 The FASE is used to monitor changes in characteristics of the material during the various stages involved in the processing.  
5.5 Modulus is a measure of the resistance of film to extension as a force is applied. Although modulus may be determined at any specified force, initial modulus is the value most commonly used.  
5.6 Work-to-break is dependent on the relationship of force to elongation. It is a measure of the ability of a textile structure to absorb mechanical energy. Toughness at break is work-to-break per unit mass.  
5.7 Shape, size, and internal construction of the end-product can have appreciable effect on product performance. It is not possible, therefore, to evaluate the performance of end product in terms of the reinforcing material alone.  
5.8 If there are differences of practical significance between reported test results for two laboratories (or more), comparat...
SCOPE
1.1 These test methods cover the tensile testing of high performance polyethylene films. The methods include testing procedure only and include no specifications or tolerances.  
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
1.3 This standard includes the following test methods:    
Section  
Breaking Force  
11  
Breaking Tenacity  
12  
Toughness at Break  
17  
Elongation at Break  
13  
Force at Specified Elongation (FASE)  
14  
Linear Density  
10  
Modulus  
15  
Work-to-Break  
16  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 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: 14-Mar-2020
• ICS: 83.180 - Adhesives
• Technical Committee: D13 - Textiles
• Drafting Committee: D13.19 - Industrial Fibers and Metallic Reinforcements

Relations

• Replaces: ASTM D7744/D7744M-11 - Standard Test Methods for Tensile Testing of High Performance Polyethylene Tapes
• Effective Date: 15-Mar-2020
• 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 D7269/D7269M-20 - Standard Test Methods for Tensile Testing of Aramid Yarns
• Effective Date: 01-Feb-2020
• 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 D4848-98(2018) - Standard Terminology Related to Force, Deformation and Related Properties of Textiles
• Effective Date: 01-Sep-2018
• Refers: ASTM D883-17 - Standard Terminology Relating to Plastics
• Effective Date: 15-Aug-2017
• Refers: ASTM D7269/D7269M-17 - Standard Test Methods for Tensile Testing of Aramid Yarns
• Effective Date: 15-Jul-2017
• Refers: ASTM D123-17 - Standard Terminology Relating to Textiles
• Effective Date: 01-Mar-2017
• Refers: ASTM D123-15b - Standard Terminology Relating to Textiles
• Effective Date: 15-Sep-2015

Overview

ASTM D7744/D7744M-20: Standard Test Methods for Tensile Testing of High Performance Polyethylene Films establishes the procedures for assessing the tensile properties of high performance polyethylene (HPPE) films. Developed by ASTM International, this standard is crucial for industries relying on the reliable mechanical characterization of HPPE materials, including ultra-high molecular weight polyethylene (UHMWPE) and high modulus polyethylene (HMPE), under controlled testing conditions. The standard is widely recognized for ensuring consistent, reproducible, and internationally comparable testing results in both research and manufacturing settings.

Key Topics

ASTM D7744/D7744M details several key tensile properties and the corresponding test methods for HPPE films:

• Breaking Force: Measures the maximum force a film can withstand before breaking, providing essential data for product engineering.
• Breaking Tenacity: Expresses the film’s strength relative to its linear density, enabling comparative analysis across film types or sizes.
• Elongation at Break: Assesses ductility, with direct implications for reinforced product design and dimensional stability.
• Force at Specified Elongation (FASE): Used to monitor material property changes during processing stages.
• Modulus: Indicates the film’s resistance to extension, with the “initial modulus” most commonly reported.
• Work-to-Break: Calculates the energy a film can absorb before breaking, important for evaluating material toughness.
• Breaking Toughness: Represents work-to-break per unit mass, providing a normalized measure of film toughness.
• Linear Density: Essential for calculating specific tensile properties.

All procedures call for precise specification and documentation of testing conditions-such as clamping methods, gauge length, crosshead travel rate, environmental temperature, and humidity-to ensure reliable and repeatable results.

Applications

Tensile testing according to ASTM D7744/D7744M-20 is critical across diverse industries:

• Industrial Textiles: For quality assurance of HPPE films in ropes, nets, webbing, and composite reinforcements.
• Packaging: To verify mechanical integrity and resistance to breakage during handling and transport.
• Medical: For devices and products where mechanical reliability of HPPE films is vital, such as sutures and protective barriers.
• Automotive and Aerospace: Ensures HPPE films employed as reinforcement or lightweight components meet stringent safety standards.
• Quality Control and R&D: Laboratories and manufacturers depend on these methods to benchmark new HPPE film formulations or production lots, identifying performance trends or process-induced variations.

Related Standards

To facilitate comprehensive material testing and reporting, ASTM D7744/D7744M-20 references several related ASTM standards:

• ASTM D76: Specification for tensile testing machines for textiles.
• ASTM D123: Terminology relating to textiles.
• ASTM D883: Terminology relating to plastics.
• ASTM D1776: Practice for conditioning and testing textiles.
• ASTM D1907: Test method for linear density of yarn by the skein method.
• ASTM D4848: Terminology related to force, deformation, and related properties of textiles.
• ASTM D5947: Test methods for physical dimensions of solid plastics specimens.
• ASTM D3800: Test method for density of high-modulus fibers.
• ASTM E177/E691: Practices for use and assessment of precision and bias in ASTM test methods.

Conclusion

ASTM D7744/D7744M-20 provides robust, standardized methods for tensile testing of high performance polyethylene films. Implementing these test procedures ensures product safety, quality, and performance consistency in critical applications. Users of HPPE films-whether in manufacturing, research, or quality control-rely on this ASTM standard to deliver precise mechanical characterizations, facilitate product development, and comply with regulatory and industry benchmarks.

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: D7744/D7744M − 20
Standard Test Methods for
Tensile Testing of High Performance Polyethylene Films
This standard is issued under the fixed designation D7744/D7744M; 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 D123 Terminology Relating to Textiles
D883 Terminology Relating to Plastics
1.1 These test methods cover the tensile testing of high
D1776 Practice for Conditioning and Testing Textiles
performance polyethylene films. The methods include testing
D1907 Test Method for Linear Density of Yarn (Yarn Num-
procedure only and include no specifications or tolerances.
ber) by the Skein Method
1.2 The values stated in either SI units or inch-pound units
D2258 Practice for Sampling Yarn for Testing
are to be regarded separately as standard. The values stated in
D3800 Test Method for Density of High-Modulus Fibers
each system are not necessarily exact equivalents; therefore, to
D4848 Terminology Related to Force, Deformation and
ensure conformance with the standard, each system shall be
Related Properties of Textiles
used independently of the other, and values from the two
D5947 Test Methods for Physical Dimensions of Solid
systems shall not be combined.
Plastics Specimens
1.3 This standard includes the following test methods:
D7269/D7269M Test Methods forTensileTesting ofAramid
Section
Yarns
Breaking Force 11
E177 Practice for Use of the Terms Precision and Bias in
Breaking Tenacity 12
ASTM Test Methods
Toughness at Break 17
Elongation at Break 13
E691 Practice for Conducting an Interlaboratory Study to
Force at Specified Elongation 14
Determine the Precision of a Test Method
(FASE)
Linear Density 10
Modulus 15
3. Terminology
Work-to-Break 16
3.1 Definitions:
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3.1.1 high-performance polyethylene, n—a manufactured
responsibility of the user of this standard to establish appro- fiber or film made of a polymer prepared by the polymerization
priate safety, health, and environmental practices and deter-
of ethylene as the sole monomer which has a minimum of
mine the applicability of regulatory limitations prior to use.
tenacity at break of 20 gpd.
1.5 This international standard was developed in accor-
3.1.1.1 Discussion—General–The following acronyms are
dance with internationally recognized principles on standard-
used to describe this category of fibers:
ization established in the Decision on Principles for the
UHMWPE – Ultra high molecular weight polyethylene
Development of International Standards, Guides and Recom-
HMPE – High modulus polyethylene
HPPE – High performance polyethylene
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. Specific–For other definitions related to polyethylene
refer to Terminology D883.
2. Referenced Documents
3.1.2 film, n—in plastics, an optional term for sheeting
2.1 ASTM Standards:
havinganominalthicknessnotgreaterthan0.25mm[0.01in.].
D76 Specification for Tensile Testing Machines for Textiles
3.2 For definitions of terms related to force and deformation
in textiles, refer to Terminology D4848.
This test method is under the jurisdiction ofASTM Committee D13 on Textiles
and is the direct responsibility of Subcommittee D13.19 on Industrial Fibers and
3.3 The following terms are relevant to this standard:
Metallic Reinforcements.
Current edition approved March 15, 2020. Published April 2020. Originally
breaking force, breaking tenacity, elongation, force at specified
approved in 2011. Last previous edition approved in 2011 as D7744/D7744M–11.
elongation (FASE), force-elongation curve, force-extension
DOI: 10.1520/D7744_D7744M-20.
2 curve, modulus, toughness at break, and work-to-break.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3.4 For definitions of other terms related to textiles, refer to
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Terminology D123.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7744/D7744M − 20
4. Summary of Test Method found, either its cause must be found and corrected, or future
test results must be adjusted in consideration of the known
4.1 A conditioned high performance polyethylene film is
bias.
clamped in a constant rate of extension tensile testing machine
(CRE) and then stretched or loaded until broken.
6. Apparatus
4.2 Breaking force, elongation, and force at specified elon-
6.1 Tensile Testing Machine—Asingle-strand tensile testing
gation (FASE) are determined directly. Modulus and work-to-
machine of the constant rate of extension (CRE) type. The
break are calculated from the force-elongation curve.
specifications and methods of calibration and verification of
these machines shall conform to Specification D76.The tensile
5. Significance and Use
testing machines shall be equipped with a data acquisition and
5.1 The levels of tensile properties obtained when testing
a data evaluation system.
high performance polyethylene films are dependent on the age
6.2 Clamps—Side action grips with flat jaw faces shall be
and history of the specimen and on the specific conditions used
during the test. Among these conditions are rate of stretching, used. The test specimen shall be held in such a way that
slippage relative to the grips is prevented insofar as possible.
type of clamps, gauge length of specimen, temperature and
humidity of the atmosphere, rate of airflow across the Flat faced grips were found to fulfill this requirement. The
widthofthejawfacesshouldbeequalorlargerthanthesample
specimen, and temperature and moisture content of the speci-
men. Testing conditions accordingly are specified precisely to width. The use of paper has been found to reduce slippage.
Air-actuated or hydraulic grips have been found advantageous.
obtain reproducible test results on a specific sample.
In cases where samples frequently fail at the edge of the grips,
5.2 Breaking force is used in engineering calculations when
it may be advantageous to increase slightly the radius of
designing various types of products. When needed to compare
curvature of these edges where the grips come in contact with
intrinsic strength characteristics, films of different sizes or
the test area of the specimen.
differenttypesoffilm,breakingtenacityisveryusefulbecause,
for a given type of film, breaking force is approximately
6.3 Gauge Length—The gauge length shall be the total
proportional to linear density.
length between the jaw faces.
5.3 Elongation of film is taken into consideration in the
6.4 The compliance of the total testing system (tensile
design and engineering of reinforced products because of its
tester, loadcell and clamping system) shall be less than 0.2 µm
-6
effect on uniformity of the finished product and its dimensional
[10 in.] per Newton.
stability during service.
6.5 Useacrossheadtravelrateinmm/min[in./min]ofeither
5.4 The FASE is used to monitor changes in characteristics
50 or 100 % of the nominal gauge length in millimeters
of the material during the various stages involved in the
[inches] of the specimen. The rate used must be reported.
processing.
NOTE 1—The selected testing equipment (tester, clamp) and gauge
length are known to have an influence on the properties measured. When
5.5 Modulus is a measure of the resistance of film to
required, the influences introduced by the selected testing equipment can
extension as a force is applied. Although modulus may be
beeliminatedusingthemethodasgiveninTestMethodsD7269/D7269M,
determined at any specified force, initial modulus is the value
Appendix X1.
most commonly used.
5.6 Work-to-break is dependent on the relationship of force 7. Sampling
to elongation. It is a measure of the ability of a textile structure
7.1 Film:
to absorb mechanical energy. Toughness at break is work-to-
7.1.1 For acceptance testing, sample each lot as directed in
break per unit mass.
Practice D2258. Take the number of specimens for testing
5.7 Shape, size, and internal construction of the end-product
specified for the specific property measurement to be made.
can have appreciable effect on product performance. It is not
possible, therefore, to evaluate the performance of end product
8. Conditioning
in terms of the reinforcing material alone.
8.1 Bring all specimens to equilibrium in the atmosphere
5.8 If there are differences of practical significance between
prior to testing as directed in Practice D1776.
reported test results for two laboratories (or more), compara-
tive tests should be performed to determine if there is a
9. Sample Preparation
statistical bias between them, using competent statistical assis-
tance. As a minimum, test samples should be used that are as 9.1 The width and the thickness of the samples are deter-
homogeneous as possible, that are drawn from the material mined in accordance with Practice D5947, Option C. The
-3
from which the disparate test results were obtained, and that thickness must be equal or less than 250 µm [10 in.]. The
are randomly assigned in equal numbers to each laboratory for width of the samples should not exceed 150 mm [6 in.]. Due to
testing. Other materials with established test values may be constraints of the tensile equipment, the test cannot be used for
used for this purpose.The test results from the two laboratories filmswiderthanthatlimit.Ifthewidthexceeds150mm[6in.],
should be compared using a statistical test for unpaired data, at the sample must be cut to width so that it fulfills this
a probability level chosen prior to the testing series. If a bias is requirement.
D7744/D7744M − 20
10. Linear Density 11.3.2.1 Use a tensioning device that applies a pretension
corresponding to 20 6 1 mN/tex [0.20 6 0.01 gf/den] for high
10.1 Scope—This test method was issued to determine the
performance PE films. This device may be a weight, a spring,
linear density of film for use in the calculation of tensile
or an air-actuated mechanism. Place one end of the specimen
properties such as modulus and tenacity.
between the jaws of the clamp connected to the loading cell
10.2 Number of Specimens—Five specimens of 1 m [40 in.]
and close it. Place the other end through the jaw of the second
length of film.
clamp and fix a pretension weight to the unclamped end or pull
the thread such that the specified pretension in the test
10.3 Procedure—Determine linear density form weighing
specimen is applied. Close the second clamp and operate the
the five individual films as directed in Option 1 ofTest Method
testing machine at the rate specified in 6.1.
D1907 except condition the film as specified in Section 8.
11.3.2.2 Place the sample between the clamps and close
10.4 Calculate the average linear density of the sample.
them. Move the crosshead until the pretension has been
reached. Correct the gauge length for the displacement neces-
11. Breaking Force of Conditioned Films
sarytoachievethepretension.Whenthespecimenbreaks,read
thebreakingforce(BF)(maximumforce)inNewtons[pounds-
11.1 Scope—This test method is used to determine the
force]. Discard specimens that do not break within the free
breaking force of films.
length between the clamps. If the clamps are of the air-actuated
11.2 Number of Specimens—Test five specimens.
type, adjust the air pressure so that specimens will not slip in
the jaws, but keep air pressure below the level that will cause
11.3 Procedure—Make all tests on the conditioned films in
specimens to break at the edge of the jaws.
the atmosphere for high performance polyethylene. Select a
loading cell and the settings of the tensile tester such that the 11.4 The velocity of conditioned air flowing across a
estimated breaking force of the specimen will fall in the range specimen while determining tensile properties can have a
from 10 to 90 % of the full-scale force effective at the time of
measurableeffectonthebreakingforceandelongationatbreak
the specimen break. This selection of the full scale force may becauseoftheGough-Jouleeffect.Themagnitudeofthiseffect
be done manually by the operator before the start of the test or
depends on the type of film, air velocity, and sample history.
by electronic means or computer control during the test by Interlaboratory testing of nylon, polyester, and rayon cords
automatically adjusting the amplification of the loading cell
indicates that air velocities of less than 250 mm/s [50 ft/min]
amplifier.Adjustthedistancebetweentheclampsonthetesting across the specimen will not significantly bias the comparison
machine so that the nominal gauge length of the specimen,
of cord properties between laboratories.
measured as stated in 6.2 is:
11.5 Calculation—Calculate the average breaking force and
300 61mm @12.0 6 0.05 in.#
the standard deviation from the observed breaking forces of
NOTE 2—As stated in the procedures in 11.3.1 and 11.3.2, a test result
specimens.
is valid when the specimen breaks within the free length between the
11.6 Report results as stated in Section 18.
clamps.
11.7 Precision and Bias:
Remove the specimen from the sample and handle it to
11.7.1 See Section 19.
preventanychangeinconfigurationpriortoclosingthejawsof
the clamps on the specimen. Avoid any damage to the film.
12. Breaking Tenacity of Conditioned Films
Depending on the equipment being used and the availability of
12.1 Scope—This test method is used to determine the
online computer control and data processing, either can be
breaking tenacity of high performance polyethylene films after
used: Slack start procedure(preferredprocedure;see11.3.1)or
conditioning in the atmosphere.
Pretension-start procedure (see 11.3.2).
11.3.1 Slack Start Procedure—Thread one end of the speci-
12.2 Calculation—Calculate the breaking tenacity of the
men between the jaws of one of the clamps and close it. Place
sample in terms of milliNewton per tex (mN/tex) (grams-force
the other end of the specimen through the jaws of the second
per denier (gf/den)) from the breaking force and the linear
clamp and keep the specimen just slack (zero tension) and
density using Eq 1 or Eq 2.
close the clamp, taking care that the film is positioned in the
BF · 1000
n
centerline of the jaws of the clamp. Operate the testing
BT 5 (1)
n
LD
t
machine at the rate as specified in 6.1 and stretch the specimen
BF · 454
until it ruptures. When the specimen breaks, read the breaking l
BT 5 (2)
g
LD
d
force (BF) (maximum force) in Newtons [pounds-force].
Discard specimens that do not break with the free length
where:
between the clamp. If the clamps are of the air-actuated type,
BT = breaking tenacity, mN/tex,
n
adjust the air pressure to prevent specimens slipping in the
BT = breaking tenacity, gf/den,
g
jaws, but keep the air pressure below the level that will cause
BF = breaking force, N,
n
specimens to break at the edge of the jaws. This slack start
procedure has the effect that the nominal gauge length of the
specimen will be slightly greater as specified in 11.3.
Jones, R. E. and Desson, M. J, “Adiabatic Effects on Tensile Testing,” Journal
11.3.2 Pretension-Start Procedure: of the I.R.I, Jun
...

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: D7744/D7744M − 11 D7744/D7744M − 20
Standard Test Methods for
Tensile Testing of High Performance Polyethylene
TapesFilms
This standard is issued under the fixed designation D7744/D7744M; 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 TheThese test method coversmethods cover the tensile testing of high performance polyethylene tapes.films. The method
includesmethods include testing procedure only and includesinclude no specifications or tolerances.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system mayare not benecessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used
independently of the other. Combiningother, and values from the two systems may result in non-conformance with the
standard.shall not be combined.
1.3 This standard includes the following test methods:
Section
Breaking Strength (Force) 11
Breaking Force 11
Breaking Tenacity 12
Breaking Toughness 17
Toughness at Break 17
Elongation at Break 13
Force at Specified Elongation 14
(FASE)
Linear Density 10
Modulus 15
Work-to-Break 16
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 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.
2. Referenced Documents
2.1 ASTM Standards:
D76 Specification for Tensile Testing Machines for Textiles
D123 Terminology Relating to Textiles
D883 Terminology Relating to Plastics
D1776 Practice for Conditioning and Testing Textiles
D1907 Test Method for Linear Density of Yarn (Yarn Number) by the Skein Method
D2258 Practice for Sampling Yarn for Testing
D3800 Test Method for Density of High-Modulus Fibers
D4848 Terminology Related to Force, Deformation and Related Properties of Textiles
D5947 Test Methods for Physical Dimensions of Solid Plastics Specimens
D7269/D7269M Test Methods for Tensile Testing of Aramid Yarns
This test method is under the jurisdiction of ASTM Committee D13 on Textiles and is the direct responsibility of Subcommittee D13.19 on Industrial Fibers and Metallic
Reinforcements.
Current edition approved July 15, 2011March 15, 2020. Published September 2011April 2020. Originally approved in 2011. Last previous edition approved in 2011 as
D7744/D7744M–11. DOI: 10.1520/D7744_D7744M–11.10.1520/D7744_D7744M-20.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7744/D7744M − 20
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions:
3.1.1 high-performance polyethylene, n—a polyethylene yarn or tape with a manufactured fiber or film made of a polymer
prepared by the polymerization of ethylene as the sole monomer which has a minimum of tenacity at break of minimally 1000
mN/tex [11 gpd].20 gpd.
3.1.1.1 Discussion—
General–The following acronyms are used to describe this category of fibers:
UHMWPE – Ultra high molecular weight polyethylene
HMPE – High modulus polyethylene
HPPE – High performance polyethylene
Specific–For other definitions related to polyethylene refer to Terminology D883.
3.1.2 tape,film, n—in highplastics, performance end-uses,an optional a flat, highly-oriented strip of polymer material.term for
sheeting having a nominal thickness not greater than 0.25 mm [0.01 in.].
3.2 Definitions:For definitions of terms related to force and deformation in textiles, refer to Terminology D4848.
3.2 For definitions of terms related to force and deformation in textiles, refer to Terminology D4848.
3.3 The following terms are relevant to this standard: breaking force, breaking strength, breaking tenacity, breaking toughness,
modulus, force-extension curve, force-elongation curve, tenacity, elongation, force at specified elongation (FASE), tensile strength,
force-elongation curve, force-extension curve, modulus, toughness at break, and work-to-break.
3.4 For definitions of other terms related to textiles, refer to Terminology D123.
4. Summary of Test Method
4.1 A conditioned high performance polyethylene tapefilm is clamped in a constant rate of extension tensile testing machine
(CRE) and then stretched or loaded until broken.
4.2 Breaking force, elongation, and force at specified elongation (FASE) are determined directly. Modulus and work-to-break
are calculated from the force-elongation curve.
5. Significance and Use
5.1 The levels of tensile properties obtained when testing high performance polyethylene tapesfilms are dependent on the age
and history of the specimen and on the specific conditions used during the test. Among these conditions are rate of stretching, type
of clamps, gauge length of specimen, temperature and humidity of the atmosphere, rate of airflow across the specimen, and
temperature and moisture content of the specimen. Testing conditions accordingly are specified precisely to obtain reproducible
test results on a specific sample.
5.2 Breaking strengthforce is used in engineering calculations when designing various types of products. When needed to
compare intrinsic strength characteristics tapescharacteristics, films of different sizes or different types of tape,film, breaking
tenacity is very useful because, for a given type of tape,film, breaking force is approximately proportional to linear density.
5.3 Elongation of tapefilm is taken into consideration in the design and engineering of reinforced products because of its effect
on uniformity of the finished product and its dimensional stability during service.
5.4 The FASE is used to monitor changes in characteristics of the material during the various stages involved in the processing.
5.5 Modulus is a measure of the resistance of tapefilm to extension as a force is applied. Although modulus may be determined
at any specified force, initial modulus is the value most commonly used.
5.6 Work-to-break is dependent on the relationship of force to elongation. It is a measure of the ability of a textile structure to
absorb mechanical energy. Breaking toughnessToughness at break is work-to-break per unit mass.
5.7 Shape, size, and internal construction of the end-product can have appreciable effect on product performance. It is not
possible, therefore, to evaluate the performance of end product in terms of the reinforcing material alone.
5.8 If there are differences of practical significance between reported test results for two laboratories (or more), comparative
tests should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a
minimum, test samples should be used that are as homogeneous as possible, that are drawn from the material from which the
disparate test results were obtained, and that are randomly assigned in equal numbers to each laboratory for testing. Other materials
with established test values may be used for this purpose. The test results from the two laboratories should be compared using a
D7744/D7744M − 20
statistical test for unpaired data, at a probability level chosen prior to the testing series. If a bias is found, either its cause must be
found and corrected, or future test results must be adjusted in consideration of the known bias.
6. Apparatus
6.1 Tensile Testing Machine—A single-strand tensile testing machine of the constant rate of extension (CRE) type. The
specifications and methods of calibration and verification of these machines shall conform to Specification D76. The tensile testing
machines shall be equipped with a data acquisition and a data evaluation system.
6.2 Tensile Testing Machine—Clamps—A single-strand tensile testing machine of the constant rate of extension (CRE) type. The
specifications and methods of calibration and verification of these machines shall conform to SpecificationSide action grips with
flat jaw faces shall be used. The test specimen shall be held in such a way that slippage relative to the grips is prevented insofar
as possible. Flat faced grips were found to fulfill this requirement. The width of the jaw faces should be equal or larger than the
sample width. The use of paper has been found to reduce D76. The testing machine shall be equipped with an autographic recorder
(rectilinear coordinates preferred). It is permissible to use tensile testing machines that have a means for calculating and displaying
the required results without the use of an autographic recorder.slippage. Air-actuated or hydraulic grips have been found
advantageous. In cases where samples frequently fail at the edge of the grips, it may be advantageous to increase slightly the radius
of curvature of these edges where the grips come in contact with the test area of the specimen.
6.1.1 Clamps—Side action grips with flat jaw faces. The test specimen shall be held in such a way that slippage relative to the
grips is prevented insofar as possible. Flat faced grips were found to fulfill this requirement. The width of the jaw faces should
be equal or larger than the sample width. The use of paper has been found to reduce slippage. Air-actuated or hydraulic grips have
been found advantageous. In cases where samples frequently fail at the edge of the grips, it may be advantageous to increase
slightly the radius of curvature of these edges where the grips come in contact with the test area of the specimen.
-6
6.1.2 The compliance of the total testing system (tensile tester, loadcell and clamping system) shall be less than 0.2 μm [10
in.] per Newton.
6.1.3 Gauge Length—The gauge length shall be the total length between the jaw faces.
6.1.4 Use a crosshead travel rate in mm/min [in./min] of preferably 50 or 100 % of the nominal gauge length in millimeters
[inches] of the specimen. The rate used must be reported.
6.3 Gauge Length—The gauge length shall be the total length between the jaw faces.
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6.4 The compliance of the total testing system (tensile tester, loadcell and clamping system) shall be less than 0.2 μm [10 in.]
per Newton.
6.5 Use a crosshead travel rate in mm/min [in./min] of either 50 or 100 % of the nominal gauge length in millimeters [inches]
of the specimen. The rate used must be reported.
NOTE 1—The selected testing equipment (tester, clamp) and gauge length are known to have an influence on the properties measured. When required,
the influences introduced by the selected testing equipment can be eliminated using the method as given in Test Methods D7269/D7269M, Appendix X1.
7. Sampling
7.1 Tape:Film:
7.1.1 For acceptance testing, sample each lot as directed in Practice D2258. Take the number of specimens for testing specified
for the specific property measurement to be made.
8. Conditioning
8.1 Bring all specimens to equilibrium in the atmosphere prior to testing for at least 3 h as directed in Practice D1776 (UHMW
Polyethylene).
9. Sample Preparation
9.1 The width and the thickness of the samples are determined in accordance with Practice D5947, Option C. The thickness
-3
must be equal or less than 250 μm [10 in.]. The width of the samples must be in the range of 2 to 150 mm [0.1 to 6 should not
exceed 150 mm [6 in.]. Due to constraints of the tensile equipment, the test cannot be used for tapesfilms wider than that limit.
If the width exceeds 150 mm [6 in.], the sample must be cut to width so that it fulfills this requirement.
10. Linear Density
10.1 Scope—This test method was issued to determine the linear density of tapefilm for use in the calculation of tensile
properties such as modulus and tenacity.
10.2 Number of Specimens—Five specimens of 1 m [40 in.] length of tape.film.
10.3 Procedure—Determine linear density form weighing the five individual tapesfilms as directed in Option 1 of Test Method
D1907 except condition the tapefilm as specified in Section 8.
10.4 Calculate the average linear density of the sample.
D7744/D7744M − 20
11. Breaking Strength (Force) Force of Conditioned TapesFilms
11.1 Scope—This test method is used to determine the breaking strength (force) of tapes after conditioning in the atmosphere
for testing (UHMW Polyethylene).force of films.
11.2 Number of Specimens—Test five specimens.
11.3 Procedure—Make all tests on the conditioned films in the atmosphere for high performance polyethylene. Select a loading
cell and the settings of the tensile tester such that the estimated breaking force of the specimen will fall in the range from 10 to
90 % of the full-scale force effective at the time of the specimen break. This selection of the full scale force may be done manually
by the operator before the start of the test or by electronic means or computer control during the test by automatically adjusting
the amplification of the loading cell amplifier. Adjust the distance between the clamps on the testing machine so that the nominal
gauge length of the specimen, measured between the jaws faces of the clamps, is preferably 300 6 2 mm [12 6 0.10 in.]. Make
all tests on the conditioned tapes in theas stated in 6.2 atmosphere is:
300 61mm @12.0 6 0.05 in.#
for
NOTE 2—As stated in the procedures in 11.3.1 and 11.3.2, a test result is valid when the specimen breaks within the free length between the clamps.
UHMW Polyethylene. Remove the specimen from the sample and handle it to prevent any change in configuration prior to closing
the jaws of the clamps on the specimen. Avoid any damage to the tape. Depending on the equipment being used and the availability
of on-line computer control and data processing, either can be used:
Pretension-start procedure (see 11.3.1) or
Slack start procedure (see 11.3.2).
Remove the specimen from the sample and handle it to prevent any change in configuration prior to closing the jaws of the
clamps on the specimen. Avoid any damage to the film. Depending on the equipment being used and the availability of online
computer control and data processing, either can be used: Slack start procedure (preferred procedure; see 11.3.1) or
Pretension-start procedure (see 11.3.2).
11.3.1 Slack Start Procedure—Thread one end of the specimen between the jaws of one of the clamps and close it. Place the
other end of the specimen through the jaws of the second clamp and keep the specimen just slack (zero tension) and close the
clamp, taking care that the tapefilm is positioned in the centerline of the jaws of the clamp. Operate the testing machine at the rate
as specified in 6.1.36.1 and stretch the specimen until it ruptures. When the specimen breaks, read the breaking force (BF)
(maximum force) in Newtons [pounds-force] from the force-elongation curve, from the dial, from the display, or by electronic
means. [pounds-force]. Discard specimens that do not break in the jaws or within 10 mm [with the free length between ⁄8 in.] of
the edge of the jaws. the clamp. If the clamps are of the air-actuated type, adjust the air pressure to prevent specimens slipping
in the jaws, but keep the air pressure below the level that will cause specimens to break at the edge of the jaws. This slack start
procedure has the effect that the nominal gauge length of the specimen is not exactly 300 mm [12 in.] will be slightly greater as
specified in 10.311.3, but always will be somewhat more due to slack in the specimen after closing the clamps.
11.3.2 Pretension-Start Procedure—Procedure: Use a tensioning device that applies a pretension corresponding to 20 6 1
mN/tex [0.20 6 0.01 gf/den] for high performance PE tapes. This device may be a weight, a spring, or an air-actuated mechanism.
Place one end of the specimen between the jaws of the clamp connected to the loading cell and close it. Place the other end through
the jaw of the second clamp and fix a pretension weight to the unclamped end or pull the thread such that the specified pretension
in the test specimen is applied. Close the second clamp and operate the testing machine at the rate specified in 6.1.4. When the
specimen breaks (ruptures), read the breaking force (maximum force) in Newtons [pounds-force] from the force-extension curve
on the chart, from the dial, from the display, or by electronic means. Discard specimens that break in the jaws or within 10 mm
[ ⁄8 in.] of the nip of the jaws. If the clamps are of the air-actuated type, adjust the air pressure so that specimens will not slip in
the jaws, but keep air pressure below the level that will cause specimens to break at the edge of the jaws.
11.3.2.1 Use a tensioning device that applies a pretension corresponding to 20 6 1 mN/tex [0.20 6 0.01 gf/den] for high
performance PE films. This device may be a weight, a spring, or an air-actuated mechanism. Place one end of the specimen
between the jaws of the clamp connected to the loading cell and close it. Place the other end through the jaw of the second clamp
and fix a pretension weight to the unclamped end or pull the thread such that the specified pretension in the test specimen is applied.
Close the second clamp and operate the testing machine at the rate specified in 6.1.
11.3.2.2 Place the sample between the clamps and close them. Move the crosshead until the pretension has been reached.
Correct the gauge length for the displacement necessary to achieve the pretension. When the specimen breaks, read the breaking
force (BF) (maximum force) in Newtons [pounds-force]. Discard specimens that do not break within the free length between the
clamps. If the clamps are of the air-actuated type, adjust the air pressure so that specimens will not slip in the jaws, but keep air
pressure below the level that will cause specimens to break at the edge of the jaws.
D7744/D7744M − 20
11.4 The velocity of conditioned air flowing across a specimen while determining tensile properties can have a measurable
effect on the breaking force and elongation at break because of the Gough-Joule effect. The magnitude of this effect depends on
the type of tape,film, air velocity, and sample history. Interlaboratory testing of nylon, polyester, and rayon cords indicates that air
velocities of less than 250 mm/s [50 ft/min] across the specimen will not significantly bias the comparison of cord properties
between laboratories.
11.5 Calculation—Calculate the average breaking force and the standard deviation from the observed breaking forces of
specimens.
11.6 Report: Report results as stated in Section 18.
11.6.1 State that the specimens were tested as directed in Section 10 of Test Methods D7744. Describe the material or product
sampled and the method of sampling used.
11.6.2 Report the option or procedure used; then number of specimens tested; and the breaking force for the sample as the
breaking strength.
11.7 Precision and Bias:
11.7.1 See Section 19.
12. Breaking Tenacity of Conditioned TapesFilms
12.1 Scope—This test method is used to determine the breaking tenacity of high performance polyethylene tapesfilms after
conditioning in the atmosphere for testing UHMW Polyethylene.atmosphere.
12.2 Calculation—Calculate the breaking tenacity of the sample in terms of milliNewtonsmilliNewton per tex (mN/tex)
(grams-force per denier (gf/den)) from the breaking strengthforce and the linear density using Eq 1 or Eq 2.
BF ·1000
n
BT 5 (1)
n
LD
t
BF · 1000
n
BT 5 (1)
n
LD
t
BF ·454
l
BT 5 (2)
g
LD
d
BF · 454
l
BT 5 (2)
g
LD
d
where:where:
BT = breaking tenacity, mN/tex,
n
BT = breaking tenacity, gf/den,
g
BF = average breaking force, N,
n
BF = breaking force, N,
n
BF = average breaking force, lbf,
l
BF = breaking force, lbf,
l
LD = measured linear density, tex, and
t
LD = average linear density of the sample, tex, and
t
LD = measured linear density, denier.
d
LD = average linear density of the sample, denier.
d
12.3 Calculate the average and standard deviation of the breaking tenacity.
12.4 Report: Report results as stated in Section 18.
12.3.1 State that the specimens were tested as directed in Section 12 of Test Methods D7744. Describe the material or product
sampled and the method of sampling used.
12.3.2 Report the option or procedure used, the number of specimens tested, and the breaking tenacity for the sample.
12.5 Precision and Bias:
12.5.1 See Section 19.
13. Elongation at Break of Conditioned TapesFilms
13.1 Scope—This test method is used to determine the elongation at break of tapesfilms after conditioning in the atmosphere
for testing UHMW Polyethylene.high performance polyethylene.
13.2 Procedure—Determine the elongation at break of each conditioned specimen when determining its breaking force (see
Section 12). Read the extension at the breaking force from the autographic recorder or by electronic means. The general equation
f
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