ASTM D3826-98(2008)
(Practice)Standard Practice for Determining Degradation End Point in Degradable Polyethylene and Polypropylene Using a Tensile Test
Standard Practice for Determining Degradation End Point in Degradable Polyethylene and Polypropylene Using a Tensile Test
SIGNIFICANCE AND USE
The tensile elongation property determined by this practice is of value for the characterization of degradable materials. The tensile elongation property may vary with specimen thickness, method of preparation, speed of testing, type of grips used, and manner of measuring test extension. Consequently, where precise comparative results are desired, these factors must be carefully controlled.
The tensile elongation property may be utilized to provide data for research and development and engineering design as well as quality control specifications. However, data from such tests cannot be considered significant for applications differing widely from the load-time scale of the test employed.
Materials that fail by tearing give anomalous data that cannot be compared with those from normal failure.
Before proceeding with this test method, reference should be made to the specifications of the material being tested. Any test specimen preparation, conditioning, dimensions, or testing parameters or a combination thereof, covered in the material specifications shall take precedence over those mentioned in this test method. If there are no material specifications, then the default conditions apply.
SCOPE
1.1 This practice covers the determination of a degradation-end point (a brittle point) for degradable polyethylene/polypropylene films and sheeting less than 1.0 mm (0.04 in.) thick. This practice is not intended for determination of the rate of degree of degradation of a polyethylene/polypropylene film or sheet, but rather, to assess when in the course of its degradation under some condition, a brittle point is reached. If one wishes to monitor tensile elongation during the degradation process (such as when the tensile elongation is significantly greater than 5 %), Test Method D 882 is recommended. This practice should not be considered the only way of determining a degradation-end point.
1.2 Tensile properties of plastics 1.0 mm (0.04 in.) or greater in thickness shall be determined in accordance with Test Method D 638.
1.3 Use a static weighing-constant rate of grip separation test. This procedure employs a constant rate of separation of the grips holding the sample and a static load cell.
Note 1—This procedure is based on the use of grip separation as a measure of extension; however, the desirability of using extension indicators accurate to ±1.0 % or better as specified in Test Method D 638 is recognized, and a provision for the use of such instrumentation is incorporated in the procedure.
1.4 This procedure has been successful for determining the degradation end point of ethylene-carbon-monoxide copolymers and has screened successfully two other additive-type polyethylenes in a round robin test.
1.5 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.6 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.
1.7 There is no equivalent ISO standard.
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Designation: D3826 − 98(Reapproved 2008)
Standard Practice for
Determining Degradation End Point in Degradable
Polyethylene and Polypropylene Using a Tensile Test
This standard is issued under the fixed designation D3826; 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 1.7 There is no equivalent ISO standard.
1.1 This practice covers the determination of a degradation-
2. Referenced Documents
end point (a brittle point) for degradable polyethylene/
2.1 ASTM Standards:
polypropylene films and sheeting less than 1.0 mm (0.04 in.)
D374 Test Methods for Thickness of Solid Electrical Insu-
thick.This practice is not intended for determination of the rate
lation
of degree of degradation of a polyethylene/polypropylene film
D618 Practice for Conditioning Plastics for Testing
or sheet, but rather, to assess when in the course of its
D638 Test Method for Tensile Properties of Plastics
degradation under some condition, a brittle point is reached. If
D882 Test Method for Tensile Properties of Thin Plastic
one wishes to monitor tensile elongation during the degrada-
Sheeting
tion process (such as when the tensile elongation is signifi-
D5208 Practice for Fluorescent Ultraviolet (UV) Exposure
cantly greater than 5 %), Test Method D882 is recommended.
of Photodegradable Plastics
This practice should not be considered the only way of
E691 Practice for Conducting an Interlaboratory Study to
determining a degradation-end point.
Determine the Precision of a Test Method
1.2 Tensile properties of plastics 1.0 mm (0.04 in.) or
greater in thickness shall be determined in accordance with
3. Terminology
Test Method D638.
3.1 Definitions:
1.3 Use a static weighing-constant rate of grip separation
3.1.1 Definitions of terms and symbols relating to tension
test. This procedure employs a constant rate of separation of
testing of plastics appear in the Annex to Test Method D638.
the grips holding the sample and a static load cell.
3.1.2 line grips, n—in tensile testing machines, grips having
faces designed to concentrate the entire gripping force along a
NOTE 1—This procedure is based on the use of grip separation as a
measure of extension; however, the desirability of using extension
single line perpendicular to the direction of testing stress.
indicators accurate to 61.0 % or better as specified in Test Method D638
3.1.3 tear failure, n—in tensile testing of films, a failure
is recognized, and a provision for the use of such instrumentation is
characterized by fracture initiating at one edge of the specimen
incorporated in the procedure.
and progressing across the specimen at a rate slow enough to
1.4 This procedure has been successful for determining the
produce an anomalous load-deformation curve.
degradation end point of ethylene-carbon-monoxide copoly-
3.2 Definitions of Terms Specific to This Standard:
mers and has screened successfully two other additive-type
3.2.1 film, n—for the purpose of this practice, a piece of
polyethylenes in a round robin test.
material not exceeding 0.250 mm (0.01 in.) in thickness.
1.5 The values stated in SI units are to be regarded as the
3.2.2 brittle point, n—in degradable polyethylene/
standard. The values in parentheses are for information only.
polypropylene film, that point in the history of a material when
1.6 This standard does not purport to address all of the 75 % of the specimens tested have a tensile elongation at break
of 5 % or less.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Significance and Use
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
4.1 The tensile elongation property determined by this
practice is of value for the characterization of degradable
This practice is under the jurisdiction ofASTM Committee D20 on Plastics and
isthedirectresponsibilityofSubcommitteeD20.96onEnvironmentallyDegradable
Plastics and Biobased Products. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Aug. 1, 2008. Published September 2008. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1991. Last previous edition approved in 2002 as D3826 – 98 (2002). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D3826-98R08. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3826 − 98 (2008)
materials. The tensile elongation property may vary with precision-ground base shear-block (similar to a paper cutter)
specimen thickness, method of preparation, speed of testing, has proved satisfactory. The use of striking dies is not
type of grips used, and manner of measuring test extension. recommended because poor and inconsistent specimen edges
Consequently, where precise comparative results are desired, maybeproduced.Itisimperativethatthecuttingedgesbekept
these factors must be carefully controlled. sharp and free from visible scratches or nicks.
4.2 The tensile elongation property may be utilized to 5.6 Extension Indicators—Ifemployed,extensionindicators
provide data for research and development and engineering shall conform to requirements specified in Test Method D638.
design as well as quality control specifications. However, data In addition, such apparatus shall be so designed as to minimize
from such tests cannot be considered significant for applica- stressonthespecimenatthecontactpointsofthespecimenand
tions differing widely from the load-time scale of the test the indicator.
employed.
NOTE 3—A high-response speed in the recording system is desirable,
particularly when relatively high strain rates are employed for rigid
4.3 Materials that fail by tearing give anomalous data that
materials. The speed of pen response for recorders is supplied by
cannot be compared with those from normal failure.
manufacturers of this equipment. Take care to conduct tests at conditions
4.4 Before proceeding with this test method, reference suchthatresponsetime(abilityofrecordertofollowactualload)produces
less than 2 % error.
should be made to the specifications of the material being
tested. Any test specimen preparation, conditioning, dimen-
6. Test Specimen
sions, or testing parameters or a combination thereof, covered
in the material specifications shall take precedence over those 6.1 Cut test specimens prior to exposure. Take utmost care
mentioned in this test method. If there are no material in cutting specimens to prevent nicks and tears that are likely
specifications, then the default conditions apply. to cause premature failures (see Note 4). The edges shall be
parallel to within 5 % of the width over the length of the
5. Apparatus specimen between the grips.
5.1 Testing Machines: NOTE 4—A microscopic examination of the specimen may be used to
detect flaws due to sample or specimen preparation.
5.1.1 Use a testing machine of the constant rate-of-jaw-
separation type. The machine shall be equipped with a weigh-
6.2 Prepare the test specimen with uniform width and
ing system that moves a maximum distance of 2 % of the
length. Examples of typical lengths and widths are:
specimen extension within the range being measured. Also,
Width, mm Length, mm
there should be a device for recording the tensile load and the 13 (0.5 in.) 152 (6 in.)
25 (1.0 in.) 102 (4 in.)
amount of separation of the grips; both of these measuring
systems shall be accurate to 62 %. The rate of separation of
the grips shall be uniform and capable of adjustment from
6.2.1 The test specimen thickness is contingent upon the
approximately 1.3 to 500 mm/min (0.05 to 20 in./min) in
thickness of the end-use application. The test specimen thick-
increments necessary to produce the strain rates specified in
ness should be the same as that for the specific end-use
9.2.
application.
5.2 Grips—Use a gripping system that minimizes both
6.3 Wherever possible, select test specimen so that thick-
slippage and uneven stress distribution with the test specimen.
ness is uniform to within 10 % of the thickness over the le
...
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.
´1
Designation:D3826–91 Designation:D 3826–98 (Reapproved 2008)
Standard Practice for
Determining Degradation End Point in Degradable
Polyethylene and Polypropylene Using a Tensile Test
This standard is issued under the fixed designation D 3826; 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. ´ NOTE—The title was changed editorially in
August 1991.
1. Scope
1.1This practice covers the determination of a degradation-end point (a brittle point) for degradable polyethylene/polypropylene
films and sheeting less than 1.0 mm (0.04 in.) thick. This practice is not intended for determination of the rate of degree of
degradation of a polyethylene/polypropylene film or sheet, but rather, to assess when in the course of its degradation under some
condition, a brittle point is reached. If one wishes to monitor tensile elongation during the degradation process (such as when the
tensile elongation is significantly greater than 5%), Test Method D882 is recommended. This practice should not be considered
the only way of determining a degradation-end point. Other degradation-end-point procedures are currently being evaluated and
developed by Subcommittee D20.96 for polyolefins and other plastics such as polystyrene. For example, Test Method D1922 is
being considered as a test for determining a degradation-end point in polyethylene/polypropylene films. Practice D1435 may be
used for determining outdoor weathering of polyethylene/polypropylene films and sheeting.
1.2Tensile properties of plastics 1.0 mm (0.04 in.) or greater in thickness shall be determined in accordance with Test Method
D638
1.1 This practice covers the determination of a degradation-end point (a brittle point) for degradable polyethylene/
polypropylene films and sheeting less than 1.0 mm (0.04 in.) thick. This practice is not intended for determination of the rate of
degree of degradation of a polyethylene/polypropylene film or sheet, but rather, to assess when in the course of its degradation
under some condition, a brittle point is reached. If one wishes to monitor tensile elongation during the degradation process (such
as when the tensile elongation is significantly greater than 5 %), Test Method D 882 is recommended. This practice should not be
considered the only way of determining a degradation-end point.
1.2 Tensile properties of plastics 1.0 mm (0.04 in.) or greater in thickness shall be determined in accordance with Test Method
D 638.
1.3Use1.3 Use a static weighing-constant rate of grip separation test. This procedure employs a constant rate of separation of
the grips holding the sample and a static load cell.
NOTE 1—This procedure is based on the use of grip separation as a measure of extension; however, the desirability of using extension indicators
accurate to 61.0 % or better as specified in Test Method D 638 is recognized, and a provision for the use of such instrumentation is incorporated in the
procedure.
1.4This procedure has been successful for determining the degradation end point of ethylene-carbon-monoxide copolymers, but
its utility for other polymers is yet to be determined by round-robin testing.
1.4 Thisprocedurehasbeensuccessfulfordeterminingthedegradationendpointofethylene-carbon-monoxidecopolymersand
has screened successfully two other additive-type polyethylenes in a round robin test.
1.5 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.6 This standard does not purport to address all of the safety problems,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.
1.7 There is no equivalent ISO standard.
This practice is under the jurisdiction of ASTM Committee D-20 on Plastics and is the direct responsibility of Subcommittee D20.96 on Environmentally Degradable
Plastics.
Current edition approved May 15, 1991. Published July 1991.
This practice is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.96 on Environmentally Degradable
Plastics and Biobased Products.
Current edition approved Aug. 1, 2008. Published September 2008. Originally approved in 1991. Last previous edition approved in 2002 as D 3826 – 98 (2002).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 3826–98 (2008)
2. Referenced Documents
2.1 ASTM Standards:
D 374 Test Methods for Thickness of Solid Electrical Insulation
D 618Practice for Conditioning Plastics and Electric Insulating Materials for Testing Practice for Conditioning Plastics for
Testing
4 3
D 638Test Method for Tensile Properties of Plastics 638M Standard Test Method for Tensile Properties of Plastics (Metric)
D 882 Test MethodsMethod for Tensile Properties of Thin Plastic Sheeting
D1435Practice for Outdoor Weathering of Plastics
5208 Practice for Fluorescent Ultraviolet (UV) Exposure of Photodegradable Plastics
D1922Test Method for Propagation Tear Resistance of Plastic Film and Thin Sheeting by Pendulum Methods
E691Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method 691 Discontinued 1981;
Specification for Compound Powdered Soap (Granulated, with Rosin)
3. Terminology
3.1 Definitions:
3.1.1 Definitions of terms and symbols relating to tension testing of plastics appear in theAnnex to Test Method D638D 638.
3.1.2line grips, n—in3.1.2 line grips, n—in tensile testing machines, grips having faces designed to concentrate the entire
gripping force along a single line perpendicular to the direction of testing stress.
3.1.3tear failure, n—in3.1.3 tear failure, n—in tensile testing of films, a failure characterized by fracture initiating at one edge
of the specimen and progressing across the specimen at a rate slow enough to produce an anomalous load-deformation curve.
3.2 DefinitionsDescription of Terms Specific to This Standard:
3.2.1 film, n—for the purpose of this practice, a piece of material not exceeding 0.250 mm (0.01 in.) in thickness.
3.2.2 brittle point, n—in degradable polyethylene/polypropylene film, that point in the history of a material when 75 % of the
specimens tested have a tensile elongation at break of 5 % or less.
4. Significance and Use
4.1 The tensile elongation property determined by this practice is of value for the characterization of degradable materials. The
tensile elongation property may vary with specimen thickness, method of preparation, speed of testing, type of grips used, and
manner of measuring test extension. Consequently, where precise comparative results are desired, these factors must be carefully
controlled.
4.2 Thetensileelongationpropertymaybeutilizedtoprovidedataforresearchanddevelopmentandengineeringdesignaswell
as quality control specifications. However, data from such tests cannot be considered significant for applications differing widely
from the load-time scale of the test employed.
4.3 Materials that fail by tearing give anomalous data that cannot be compared with those from normal failure.
4.4 Before proceeding with this test method, reference should be made to the specifications of the material being tested. Any
test specimen preparation, conditioning, dimensions, or testing parameters or a combination thereof, covered in the material
specifications shall take precedence over those mentioned in this test method. If there are no material specifications, then the
default conditions apply.
5. Apparatus
5.1 Testing Machines:
5.1.1 Use a testing machine of the constant rate-of-jaw-separation type.The machine shall be equipped with a weighing system
that moves a maximum distance of 2 % of the specimen extension within the range being measured.Also, there should be a device
forrecordingthetensileloadandtheamountofseparationofthegrips;bothofthesemeasuringsystemsshallbeaccurateto 62%.
The rate of separation of the grips shall be uniform and capable of adjustment from approximately 1.3 to 500 mm/min (0.05 to
20 in./min) in increments necessary to produce the strain rates specified in 9.2.
5.2 Grips—Use a gripping system that minimizes both slippage and uneven stress distribution with the test specimen.
NOTE 2—Grips lined with thin rubber, crocus-cloth, or pressure-sensitive tape as well as file-faced or serrated grips have been successfully used for
many materials. The choice of grip surface depends on the material tested and thickness. More recently, line grips padded on the round face with 1.0 mm
(40 mil) blotting paper have been found superior.Air-actuated grips have been found advantageous, particularly in the case of materials that tend to neck
into the grips, since pressure is maintained at all times. In cases where samples frequently fail at the edge of the grips, it may be advantageous to increase
slightly the radius of curvature of the edges where the grips come in contact with the test area of the specimen.
Accelerated exposure practices to appropriately degrade polyethylene/polypropylene films and sheeting are also being developed by Subcommittee D20.96. When these
practices are approved, they will be referenced in this document.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Withdrawn.
...
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