ASTM D5419-95
(Test Method)Standard Test Method for Environmental Stress Crack Resistance (ESCR) of Threaded Plastic Closures
Standard Test Method for Environmental Stress Crack Resistance (ESCR) of Threaded Plastic Closures
SCOPE
1.1 This test method determines the susceptibility of threaded plastic closures to failure due to environmental stress cracking (ESC).
1.2 Threaded plastic closures in use may contact agents that appreciably reduce the stress at which cracks form. Examples of such agents are: soaps, detergents, oils, and liquid bleaches.
1.3 Other major factors that influence environmental stress crack resistance (ESCR) of threaded plastic closures are the closure material(s), closure design, molded-in stress, and applied stress.
1.4 This procedure applies particularly to closures made from plastics based on polypropylene (PP) or polystyrene (PS). It may also apply to other polymers.
1.5 The values stated in SI units are to be regarded as the standard.
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. Specific precautionary statements are given in Section 8 and Note 2. Note 1-There are no ISO standards covering the primary subject of this test method.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 5419 – 95
Standard Test Method for
Environmental Stress Crack Resistance (ESCR) of Threaded
Plastic Closures
This standard is issued under the fixed designation D 5419; 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.
1. Scope of Threaded or Lug-Style Closures
E 145 Specification for Gravity-Convection and Forced-
1.1 This test method determines the susceptibility of
Ventilation Ovens
threaded plastic closures to failure due to environmental stress
E 691 Practice for Conducting an Interlaboratory Study to
cracking (ESC).
Determine the Precision of a Test Method
1.2 Threaded plastic closures in use may contact agents that
appreciably reduce the stress at which cracks form. Examples
3. Terminology
of such agents are: soaps, detergents, oils, and liquid bleaches.
3.1 Definitions—Except for those terms below, see Termi-
1.3 Other major factors that influence environmental stress
nologies D 883 and D 1600.
crack resistance (ESCR) of threaded plastic closures are the
3.2 Definitions of Terms Specific to This Standard:
closure material(s), closure design, molded-in stress, and
3.2.1 assembly—closure applied to a bottle finish.
applied stress.
3.2.2 failure—during this test, any visible crack.
1.4 This procedure applies particularly to closures made
3.2.2.1 Discussion—A crack does not have to penetrate the
from plastics based on polypropylene (PP) or polystyrene (PS).
closure wall to be considered a failure.
It may also apply to other polymers.
3.2.3 finish—fixture representing the threaded portion of the
1.5 The values stated in SI units are to be regarded as the
bottle.
standard.
3.2.4 threaded closure—part applied to seal bottle as speci-
1.6 This standard does not purport to address all of the
fied in Specification D 2911.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Summary of Test Method
priate safety and health practices and determine the applica-
4.1 This test method consists of applying closures at a
bility of regulatory limitations prior to use. Specific precau-
specified application torque to rigid finishes (of polysulfone or
tionary statements are given in Section 8 and Note 2.
other appropriate resin), immersing the assembly in a potential
NOTE 1—There are no ISO standards covering the primary subject of
stress-cracking agent, and observing and reporting time-to-
this test method.
failure.
2. Referenced Documents
5. Significance and Use
2.1 ASTM Standards:
5.1 This test method compares closures for ESCR. Suitable
D 618 Practice for Conditioning Plastics and Electrical
variables are: closure materials, closure designs, processes,
Insulating Materials for Testing
applied torque, and stress-crack agents.
D 883 Terminology Relating to Plastics
5.2 Results can be used for estimating shelf life of closures
D 1600 Terminology for Abbreviated Terms Relating to
in terms of ESCR. This requires that the user has calibrated
Plastics
failure time in this test to failure time in the field for actual
D 2911 Specification for Dimensions and Tolerances for
packaging systems.
Plastic Bottles
D 3198 Test Method for Application and Removal Torque
6. Apparatus
6.1 Wide-Mount Gallon Jars, glass, PET, or other suitable
material. Must have lined closures to ensure air-tight seal. Use
This test method is under the jurisdiction of ASTM Committee D-20 on Plastics
one jar per sample.
and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.
The following sections have been changed in this revision: 4.1, 6.2, 6.4, 6.5, 6.6,
6.2 Circulating-Air Oven, capable of maintaining a tem-
9.1, 11.4, 11.5, 11.6, 11.8, 12.1, 12.2.1, 12.2.2, 13.1.1, 13.1.5, 14.1, and 14.2.
perature of 50 6 1°C (critical in this application). See
Current edition approved Nov. 10, 1995. Published January 1996. Originally
published as D 5419 – 93. Last previous edition D 5419 – 93.
Annual Book of ASTM Standards, Vol 08.01.
3 4
Annual Book of ASTM Standards, Vol 15.09. Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 5419
Specification E 145 for a procedure for confirming satisfactory 7. Reagents and Materials
uniformity of temperature within the oven. There is no air-flow
7.1 Test Solution—Use solution for which the closure is
requirement in this application. An environmental room with
intended.
these properties is also suitable.
8. Hazards
NOTE 2—Caution: A high-temperature safety switch is highly recom-
8.1 Always wear protective equipment appropriate to the
mended on this oven. Some test liquids can cause extreme pressure to
product hazard when setting up or inspecting closures. This
build up upon heating. Under these conditions the test jars may rupture
may include goggles, gloves, and aprons.
with explosive force. The override cutoff switch should be set to turn off
the oven if the test temperature is exceeded by 10°C or more. 9. Test Specimens
9.1 Normal sample size is 20 closures, typical of lots to be
6.3 Tongs, for sample removal and inspection.
tested. It is strongly advisable to run the test in duplicate (two
6.4 Bottle Finishes, polysulfone or other material of equiva-
sets of 20) or to sample more than one lot.
lent stiffness and thermal coefficient of expansion, to which
9.2 Visually inspect each closure to be tested. Replace any
closures are applied. May be made by injection molding or by
that appear defective or irregular.
machining rod stock. See Fig. 1 for drawing of typical fixture.
10. Conditioning
Use appropriate size based on closure and bottle specifications.
10.1 Conditioning—After aging in accordance with 6.6,
6.5 Torque Meter, with capacity of at least 5 torque Nm,
condition closures and bottle finishes at 23 6 2°C and 50 6
calibrated or verified within the past 12 months.
5 % relative humidity for not less than 40 h prior to test, in
6.6 Plastic Test Closures, lined or unlined closure based on
accordance with Procedure A of Practice D 618. Condition test
specifications. PP-based closures should be at least 3 weeks old
solution at 50 6 2°C until it reaches 50 6 2°C (16 h normally
before testing, and PS closures at least 16 h old. This is to
required).
ensure that full crystallization has essentially been achieved.
10.2 Test Conditions—Conduct all tests at 50 6 2°C, unless
NOTE 3—To convert lbf-in. torque to Nm torque, multiply by 0.113. instructed otherwise.
NOTE 1—Tolerances for Dimensions T, E, and S shall be in accordance with Specification D 2911.
FIG. 1 Typical Fixture
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 5419
11. Procedure indicated at the intersection of the data line with the 50 %
failure level probability line shall be reported as the F failure
11.1 Apply closures to bottle finishes (see Test Method
time. See Fig. 2 for example.
D 3198). Application torque should be either of the following:
11.1.1 That corresponding to the upper limit of immediate
removal torque in production (rule of thumb: application
torque = 1.05 3 immediate removal torque), or
11.1.2 A nominal value based on the closure diameter (rule
of thumb: torque, Nm = closure diameter, mm 3 0.08), or
11.1.3 A value agreed upon between the laboratory and the
customer.
11.2 Tolerance for the torque should be 65%.
11.3 Place 20 assemblies in jars. Fill jars with enough test
solution at 50 6 2°C to cover all assemblies. Wipe a
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.