Standard Test Method for Column Crush Properties of Blown Thermoplastic Containers

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 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.

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Historical
Publication Date
31-Dec-2000
Technical Committee
Drafting Committee
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ASTM D2659-95(2001) - Standard Test Method for Column Crush Properties of Blown Thermoplastic Containers
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D2659–95 (Reapproved 2001)
Standard Test Method for
Column Crush Properties of Blown Thermoplastic
Containers
This standard is issued under the fixed designation D 2659; 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 (e) indicates an editorial change since the last revision or reapproval.
a decrease in the crush load, followed by resumption of the normal crush
1. Scope
load change with deflection. This phenomenon cannot be ignored in the
1.1 Thistestmethodcoversthedeterminationofmechanical
evaluation of the column crush properties of a blown thermoplastic
properties of blown thermoplastic containers when loaded
container, since it may be a very useful designated failure point for the
under columnar crush conditions at a constant rate of compres-
application under consideration. The load at which this abrupt change
sive deflection.Any container, whether blown commercially or occurs may be chosen as a crushing yield load for study. In such a case,
the report of results should be accompanied by a proper description of the
in the laboratory, may be used as the test specimen.
crushing yield load selected.
1.2 The values stated in SI units are to be regarded as the
standard.
3.1.2 crushing load at failure—the crushing load applied to
a blown thermoplastic container that produces a failure by
NOTE 1—There is no similar or equivalent ISO standard.
fracture or parting of the material in any portion of said
1.3 This standard does not purport to address all of the
container. It is expressed in kilograms (or pounds).
safety concerns, if any, associated with its use. It is the
3.1.3 deflection at crushing yield load—the decrease in
responsibility of the user of this standard to establish appro-
lengthofthecontainerspecimenproducedatthecrushingyield
priate safety and health practices and determine the applica-
load along the center line of testing (axis of crushing, see Fig.
bility of regulatory limitations prior to use.
1). It is expressed in millimetres (or inches).
3.1.4 apparent crushing stiffness—the ratio of the crushing
2. Referenced Documents
load to the corresponding deflection at a point on the linear
2.1 ASTM Standards:
portion of the crushing load deflection curve. It is expressed in
D 618 Practice for Conditioning Plastics for Testing
newtons per metre (or pounds per inch).
D 1248 Specification for Polyethylene Plastics Extrusion
Materials for Wire and Cable 4. Significance and Use
E 4 Practices for Force Verification of Testing Machines
4.1 Columncrushtestsprovideinformationaboutthecrush-
E 83 Practice for Verification and Classification of Exten-
ing properties of blown thermoplastic containers when em-
someters
ployed under conditions approximating those under which the
tests are made.
3. Terminology
4.2 The column crush properties include the crushing yield
3.1 Definitions:
load, deflection at crushing yield load, crushing load at failure,
3.1.1 crushing yield load—the first load at which an in-
and apparent crushing stiffness. Blown thermoplastic contain-
crease of deflection occurs with no increase in load in a
ers made from materials that possess a low order of ductility
compressive crushing test. It is expressed in units of kilograms
may fail in crushing by brittle fracture. In such cases, the
(or pounds) of load.
crushing yield load is equivalent to the crushing load at failure.
Blown thermoplastic containers made of ductile materials may
NOTE 2—In some cases, usually as a result of design or styling features,
or both, of a specific container, multiple values of the crushing yield load not exhibit a crushing load at failure although they will
may be observed, a small deflection may occur with no increase or with
normally provide a crushing yield load value.
4.3 Column crush tests provide a standard method of
obtaining data for research and development, applications,
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
design, quality control, acceptance or rejection under specifi-
and is the direct responsibility of Subcommittee D20.20 on Plastic Products.
cations, and special purposes. The tests cannot be considered
Current edition approved Nov. 10, 1995. Published January 1996. Originally
published as D 2659 – 67. Last previous edition D 2659 – 89.
significant for engineering design in applications differing
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
widely from the load - time scale of the standard test. Such
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
applications require additional tests such as impact, creep, and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. fatigue.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D2659–95 (2001)
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 63.6°F)and50 65 %relativehumidityfornotless
than 40 h prior to test in accordance with Procedure A of
Practice D 618, for those tests where conditioning is required.
In cases of disagreement, the tolerances shall be 61°C
(61.8°F) and 62 % relative humidity.
7.2 Test Conditions—Conduct tests in the standard labora-
FIG. 1 Typical Crushing Axes
tory atmosphere of 23 6 2°C (73.4 6 3.6°F) and 50 6 5%
relative humidity, unless otherwise specified in the test meth-
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
materials specification shall take precedence over those men-
be conditioned at the Standard LaboratoryTemperature of 23 6 2°C (73.4
tioned in this test method. If there are no material specifica- 6 3.6°F) for a period of 24 h, unless otherwise specified.
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 E 4.
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 crushing load on the test
specimen.Theinstrumentshallbeessentiallyfreeofinertia-lag
NOTE 5
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