ASTM D2659-95(2005)
(Test Method)Standard Test Method for Column Crush Properties of Blown Thermoplastic Containers
Standard Test Method for Column Crush Properties of Blown Thermoplastic Containers
SIGNIFICANCE AND USE
Column crush tests provide information about the crushing properties of blown thermoplastic containers when employed under conditions approximating those under which the tests are made.
The column crush properties include the crushing yield load, deflection at crushing yield load, crushing load at failure, and apparent crushing stiffness. Blown thermoplastic containers made from materials that possess a low order of ductility may fail in crushing by brittle fracture. In such cases, the crushing yield load is equivalent to the crushing load at failure. Blown thermoplastic containers made of ductile materials may not exhibit a crushing load at failure although they will normally provide a crushing yield load value.
Column crush tests provide a standard method of obtaining data for research and development, applications, design, quality control, acceptance or rejection under specifications, and special purposes. The tests cannot be considered significant for engineering design in applications differing widely from the load - time scale of the standard test. Such applications require additional tests such as impact, creep, and fatigue.
Before proceeding with this test method, reference should be made to the specification of the material being tested. Any test specimen preparation, conditioning, dimensions, or testing parameters, or combination thereof, covered in the materials specification 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 test method covers the determination of mechanical properties of blown thermoplastic containers when loaded under columnar crush conditions at a constant rate of compressive deflection. Any container, whether blown commercially or in the laboratory, may be used as the test specimen.
1.2 The values stated in SI units are to be regarded as the standard.
Note 1—There is no similar or equivalent ISO standard.
1.3 his 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.
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Designation:D2659–95 (Reapproved 2005)
Standard Test Method for
Column Crush Properties of Blown Thermoplastic
Containers
This standard is issued under the fixed designation D2659; 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.
or both, of a specific container, multiple values of the crushing yield load
1. Scope
may be observed, a small deflection may occur with no increase or with
1.1 Thistestmethodcoversthedeterminationofmechanical
a decrease in the crush load, followed by resumption of the normal crush
properties of blown thermoplastic containers when loaded
load change with deflection. This phenomenon cannot be ignored in the
under columnar crush conditions at a constant rate of compres-
evaluation of the column crush properties of a blown thermoplastic
sive deflection.Any container, whether blown commercially or container, since it may be a very useful designated failure point for the
application under consideration. The load at which this abrupt change
in the laboratory, may be used as the test specimen.
occurs may be chosen as a crushing yield load for study. In such a case,
1.2 The values stated in SI units are to be regarded as the
the report of results should be accompanied by a proper description of the
standard.
crushing yield load selected.
NOTE 1—There is no known ISO equivalent to this standard.
3.1.2 crushing load at failure—the crushing load applied to
1.3 This standard does not purport to address all of the a blown thermoplastic container that produces a failure by
safety concerns, if any, associated with its use. It is the
fracture or parting of the material in any portion of said
responsibility of the user of this standard to establish appro- container. It is expressed in kilograms (or pounds).
priate safety and health practices and determine the applica-
3.1.3 deflection at crushing yield load—the decrease in
bility of regulatory limitations prior to use. lengthofthecontainerspecimenproducedatthecrushingyield
load along the center line of testing (axis of crushing, see Fig.
2. Referenced Documents
1). It is expressed in millimetres (or inches).
2.1 ASTM Standards:
3.1.4 apparent crushing stiffness—the ratio of the crushing
D618 Practice for Conditioning Plastics for Testing
load to the corresponding deflection at a point on the linear
D4976 Specification for Polyethylene Plastics Molding and
portion of the crushing load deflection curve. It is expressed in
Extrusion Materials
newtons per metre (or pounds per inch).
E4 Practices for Force Verification of Testing Machines
4. Significance and Use
E83 Practice for Verification and Classification of Exten-
someter Systems
4.1 Column crush tests provide information about the crush-
ing properties of blown thermoplastic containers when em-
3. Terminology
ployed under conditions approximating those under which the
3.1 Definitions:
tests are made.
3.1.1 crushing yield load—the first load at which an in-
4.2 The column crush properties include the crushing yield
crease of deflection occurs with no increase in load in a
load, deflection at crushing yield load, crushing load at failure,
compressive crushing test. It is expressed in units of kilograms
and apparent crushing stiffness. Blown thermoplastic contain-
(or pounds) of load.
ers made from materials that possess a low order of ductility
may fail in crushing by brittle fracture. In such cases, the
NOTE 2—In some cases, usually as a result of design or styling features,
crushing yield load is equivalent to the crushing load at failure.
Blown thermoplastic containers made of ductile materials may
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
not exhibit a crushing load at failure although they will
and is the direct responsibility of Subcommittee D20.19 on Film and Sheeting.
normally provide a crushing yield load value.
Current edition approved July 15, 2005. Published August 2005. Originally
4.3 Column crush tests provide a standard method of
approved in 1967. Last previous edition approved in 2001 as D2659 - 1995 (2001).
DOI: 10.1520/D2659-95R05.
obtaining data for research and development, applications,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
design, quality control, acceptance or rejection under specifi-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
cations, and special purposes. The tests cannot be considered
Standards volume information, refer to the standard’s Document Summary page on
significant for engineering design in applications differing
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D2659–95 (2005)
free of obvious defects such as rocker bottoms or bent necks,
unless such defects constitute a variable to be studied. The
surfaces of the container that bear on the fixed and movable
members of the testing machine shall be parallel to each other.
NOTE 3—In the event that the bearing surface of the blown thermo-
plastic container deviates noticeably from the parallel relationship, the
construction and use of a suitable testing jig will be necessary. This jig
shall be attached to that crosshead member of the testing machine that
contacts the nonparallel surface of the container. Similarly, some blown
thermoplastic container designs may cause slippage on the machine
crushing surfaces. In this event, a nonslip material such as masking tape
should be applied to the slipping member of the testing machine.
7. Conditioning
7.1 Conditioning—Condition the test specimens at 23 6
2°C (73.4 6 3.6°F) and 50 6 5 % relative humidity for not less
than 40 h prior to test in accordance with Procedure A of
Practice D618, for those tests where conditioning is required.
In cases of disagreement, the tolerances shall be 61°C
FIG. 1 Typical Crushing Axes
(61.8°F) and 62 % relative humidity.
7.2 Test Conditions—Conduct tests in the standard labora-
widely from the load - time scale of the standard test. Such
tory atmosphere of 23 6 2°C (73.4 6 3.6°F) and 50 6 5%
applications require additional tests such as impact, creep, and
relative humidity, unless otherwise specified in the test meth-
fatigue.
ods. In cases of disagreement, the tolerances shall be 61°C
4.4 Before proceeding with this test method, reference
(61.8°F) and 62 % relative humidity.
shouldbemadetothespecificationofthematerialbeingtested.
Any test specimen preparation, conditioning, dimensions, or
NOTE 4—Blown thermoplastic container test specimens that are made
testing parameters, or combination thereof, covered in the of materials known to be insensitive to changes of relative humidity, may
be conditioned at the Standard LaboratoryTemperature of 23 6 2°C (73.4
materials specification shall take precedence over those men-
6 3.6°F) for a period of 24 h, unless otherwise specified.
tioned in this test method. If there are no material specifica-
tions, then the default conditions apply.
8. Number of Test Specimens
5. Apparatus
8.1 At least 20 specimens shall be tested for each sample on
5.1 Testing Machine—Any suitable testing machine capable
any given axis of crushing. If more than one axis of crushing
of control of constant-rate-of-crosshead movement and com-
is to be studied, at least 20 specimens shall be tested for each
prising essentially the following:
axis.
5.1.1 Drive Mechanism—A drive mechanism imparting the
8.2 Specimensthatfailatsomeobviousfortuitousflawshall
crosshead movable member of a uniform, controlled velocity
be discarded and retests made, unless such flaws constitute a
with respect to the fixed member, this velocity to be regulated
variable to be studied. The data should be discarded and the
as specified in Section 9.
number of rejected specimens noted.
5.1.2 Load Indicator—A load-indicating mechanism ca-
pable of showing the total crushing load carried by the test
9. Speed of Testing
specimen. The mechanism shall be essentially free from
9.1 Speed of testing shall be the relative rate of motion of
inertia-lag at the specified rate of testing and shall indicate the
the fixed and movable members of the testing machine during
crushing load with an accuracy of 61 %. The accuracy of the
the test. Rate of motion of the movable member, when the
testing machine shall be verified at least once a year, in
machineisrunningidle,maybeusedifitcanbeshownthatthe
accordance with Practices E4.
resulting speed of testing is within the limits of variation
5.2 Extensometer—A suitable instrument for determining
allowed.
the distance between the two surfaces of load application on
9.2 The speed of testing shall be constant within 610 %.
the test specimen at any time during the test. It is desirable that
9.3 The speed of testing shall be chosen in the range from
this instrument automatically record this distance, or any
12.5 mm (0.50 in.)/min to 50.0 mm (2.0 in.)/min.
change in it as a function of the c
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