ASTM D5419-95(2003)
(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
SIGNIFICANCE AND USE
This test method compares closures for ESCR. Suitable variables are: closure materials, closure designs, processes, applied torque, and stress-crack agents.
Results can be used for estimating shelf life of closures in terms of ESCR. This requires that the user has calibrated failure time in this test to failure time in the field for actual packaging systems.
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.
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.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D5419–95 (Reapproved 2003)
Standard Test Method for
Environmental Stress Crack Resistance (ESCR) of Threaded
Plastic Closures
This standard is issued under the fixed designation D5419; 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 D3198 Test Method forApplication and RemovalTorque of
Threaded or Lug-Style Closures
1.1 This test method determines the susceptibility of
E145 Specification for Gravity-Convection and Forced-
threaded plastic closures to failure due to environmental stress
Ventilation Ovens
cracking (ESC).
E691 Practice for Conducting an Interlaboratory Study to
1.2 Threaded plastic closures in use may contact agents that
Determine the Precision of a Test Method
appreciably reduce the stress at which cracks form. Examples
of such agents are: soaps, detergents, oils, and liquid bleaches.
3. Terminology
1.3 Other major factors that influence environmental stress
3.1 Definitions—Except for those terms below, see Termi-
crack resistance (ESCR) of threaded plastic closures are the
nologies D883 and D1600.
closure material(s), closure design, molded-in stress, and
3.2 Definitions of Terms Specific to This Standard:
applied stress.
3.2.1 assembly—closure applied to a bottle finish.
1.4 This procedure applies particularly to closures made
3.2.2 failure—during this test, any visible crack.
from plastics based on polypropylene (PP) or polystyrene (PS).
3.2.2.1 Discussion—A crack does not have to penetrate the
It may also apply to other polymers.
closure wall to be considered a failure.
1.5 The values stated in SI units are to be regarded as the
3.2.3 finish—fixturerepresentingthethreadedportionofthe
standard.
bottle.
1.6 This standard does not purport to address all of the
3.2.4 threaded closure—part applied to seal bottle as speci-
safety concerns, if any, associated with its use. It is the
fied in Specification D2911.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4. Summary of Test Method
bility of regulatory limitations prior to use. Specific precau-
4.1 This test method consists of applying closures at a
tionary statements are given in Section 8 and Note 2.
specified application torque to rigid finishes (of polysulfone or
NOTE 1—There are no ISO standards covering the primary subject of
other appropriate resin), immersing the assembly in a potential
this test method.
stress-cracking agent, and observing and reporting time-to-
failure.
2. Referenced Documents
2.1 ASTM Standards:
5. Significance and Use
D618 Practice for Conditioning Plastics for Testing
5.1 This test method compares closures for ESCR. Suitable
D883 Terminology Relating to Plastics
variables are: closure materials, closure designs, processes,
D1600 Terminology for Abbreviated Terms Relating to
applied torque, and stress-crack agents.
Plastics
5.2 Results can be used for estimating shelf life of closures
D2911 Specification for Dimensions and Tolerances for
in terms of ESCR. This requires that the user has calibrated
Plastic Bottles
failure time in this test to failure time in the field for actual
packaging systems.
This test method is under the jurisdiction ofASTM Committee D20 on Plastics 6. Apparatus
and is the direct responsibility of Subcommittee D20.19 on Film and Sheeting.
6.1 Wide-Mount Gallon Jars, glass, PET, or other suitable
Current edition approved July 10, 2003. Published September 2003. Originally
material. Must have lined closures to ensure air-tight seal. Use
approved in 1993. Last previous edition approved in 1995 as D5419 – 95. DOI:
10.1520/D5419-95R03.
one jar per sample.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.2 Circulating-Air Oven, capable of maintaining a tem-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
perature of 50 6 1°C (critical in this application). See
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Specification E145 for a procedure for confirming satisfactory
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5419–95 (2003)
NOTE 1—Tolerances for Dimensions T, E, and S shall be in accordance with Specification D2911.
FIG. 1 Typical Fixture
uniformity of temperature within the oven.There is no air-flow 8. Hazards
requirement in this application. An environmental room with
8.1 Always wear protective equipment appropriate to the
these properties is also suitable.
product hazard when setting up or inspecting closures. This
may include goggles, gloves, and aprons.
NOTE 2—Caution: A high-temperature safety switch is highly recom-
mended on this oven. Some test liquids can cause extreme pressure to
9. Test Specimens
build up upon heating. Under these conditions the test jars may rupture
with explosive force. The override cutoff switch should be set to turn off
9.1 Normal sample size is 20 closures, typical of lots to be
the oven if the test temperature is exceeded by 10°C or more.
tested. It is strongly advisable to run the test in duplicate (two
6.3 Tongs, for sample removal and inspection.
sets of 20) or to sample more than one lot.
6.4 Bottle Finishes, polysulfone or other material of equiva-
9.2 Visually inspect each closure to be tested. Replace any
lent stiffness and thermal coefficient of expansion, to which
that appear defective or irregular.
closures are applied. May be made by injection molding or by
10. Conditioning
machining rod stock. See Fig. 1 for drawing of typical fixture.
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 D618. Condition test
specifications.PP-basedclosuresshouldbeatleast3weeksold
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
instructed otherwise.
NOTE 3—To convert lbf-in. torque to Nm torque, multiply by 0.113.
7. Reagents and Materials 11. Procedure
7.1 Test Solution—Use solution for which the closure is 11.1 Apply closures to bottle finishes (see Test Method
intended. D3198). Application torque should be either of the following:
D5419–95 (2003)
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 any test
solution from jar-finish area. Cap jars and hand tighten.
11.4 Place jars on test at 50 6 2°C. Check temperature of
test area daily and maintain within limits. Record the tempera-
ture of the oven or room.
11.5 Inspe
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.