ASTM D1975-95(2006)
(Test Method)Standard Test Method for Environmental Stress Crack Resistance of Plastic Injection Molded Open Head Pails
Standard Test Method for Environmental Stress Crack Resistance of Plastic Injection Molded Open Head Pails
SIGNIFICANCE AND USE
These procedures provide an indication of the environmental stress-crack resistance of injection molded open head pails, covers, and components from a selected group or lot. Provided the thermal history of each container is constant, this test method may be used for determining the applicability of various plastic resins and mold designs for injection molding of open head pails and covers.
The environmental stress-crack that occurs is indicative of what results when a container is exposed to agents such as soaps, organics, or any surface active solutions while under environmental conditions of stress.
Environmental stress-cracking is the mechanism of chemical attack that is highly dependent upon the test reagent, resin, container molding history, exposure temperature, applied stress, and other factors. The combination of these factors may result in eventual stress-crack failure.
Procedure A minimizes the potential for test variability by providing the user with rigidly defined test conditions. This test method may be used for production quality control of injection molded open head containers.
Procedure B allows the user to select and evaluate extreme individual elements or the interaction of several test levels on container performance. These conditions are established based on laboratory experience and available knowledge of the distribution environment. This test method may be used for identifying critical stresses which could aid in container design or help in minimizing the occurrence of these stresses during distribution.
This test method is intended only as a pass/fail procedure in accordance with the user’specification, or as agreed upon between the user and the supplier. It is not intended as a predictor or indicator of field performance regarding time to failure.
SCOPE
1.1 This test method provides procedures for an indication of the environmental stress crack resistance of plastic injection molded open head pails, covers, and components as a summation of the effects of container design, resin, manufacturing conditions, field performance, and other factors.
1.2 This test method may be used to evaluate a container's resistance to mechanical failure by cracking when in the presence of chemical and physical stresses.
1.3 Two procedures are provided as follows:
1.3.1 Procedure A, Specified Stress-Crack Resistance Test Method This procedure is particularly useful for quality control since the conditions of the test are specified.
1.3.2 Procedure B, User Selected Stress-Crack Resistance Test Method This procedure allows individual selection of test levels and is particularly useful as a design and development tool.
1.4 These procedures are not designed to test the ability of the cover gasketing material or closure to retain the test reagent. Loss or leakage of the reagent through these openings does not constitute container failure. However, this may indicate an internal pressure loss that might affect test results.
1.5 The values stated in inch-pound units are to be regarded as the standard. The SI units given in parentheses are for information only.
This standard does not purport to address all of the safety problems, 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 warning statements are given in 6.2, 10.2.3, 10.2.4, 10.2.6, and 10.2.8.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D1975–95 (Reapproved 2006)
Standard Test Method for
Environmental Stress Crack Resistance of Plastic Injection
Molded Open Head Pails
This standard is issued under the fixed designation D1975; 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 2. Referenced Documents
1.1 This test method provides procedures for an indication 2.1 ASTM Standards:
of the environmental stress crack resistance of plastic injection D996 Terminology of Packaging and Distribution Environ-
molded open head pails, covers, and components as a summa- ments
tion of the effects of container design, resin, manufacturing D4332 Practice for Conditioning Containers, Packages, or
conditions, field performance, and other factors. Packaging Components for Testing
1.2 This test method may be used to evaluate a container’s E122 Practice for Calculating Sample Size to Estimate,
resistance to mechanical failure by cracking when in the With Specified Precision, the Average for a Characteristic
presence of chemical and physical stresses. of a Lot or Process
1.3 Two procedures are provided as follows:
3. Terminology
1.3.1 Procedure A, Specified Stress-Crack Resistance Test
Method—This procedure is particularly useful for quality 3.1 Definitions—Reference Terminology D996 for defini-
tions applicable to this test method.
control since the conditions of the test are specified.
1.3.2 Procedure B, User Selected Stress-Crack Resistance 3.2 Definitions of Terms Specific to This Standard:
3.2.1 environmental stress crack—an external or internal
Test Method—This procedure allows individual selection of
test levels and is particularly useful as a design and develop- crack that develops when a container is exposed to chemical or
physical stresses, or both.
ment tool.
1.4 These procedures are not designed to test the ability of 3.2.2 stress crack failure—any environmental stress crack
that causes a loss or leakage of the test reagent shall be
the cover gasketing material or closure to retain the test
interpreted as container failure.
reagent. Loss or leakage of the reagent through these openings
does not constitute container failure. However, this may
4. Summary of Test Method
indicate an internal pressure loss that might affect test results.
4.1 The environmental stress-crack resistance is determined
1.5 The values stated in inch-pound units are to be regarded
by subjecting an injection molded open head pail and cover
as the standard. The SI units given in parentheses are for
that is filled and sealed with a stress-crack reagent to a
information only.
mechanical top load at elevated temperatures. The time to
1.6 This standard does not purport to address all of the
stress-crack failure is observed.
safety problems, if any, associated with its use. It is the
4.1.1 ProcedureAexposesaminimumofthreecontainersto
responsibility of the user of this standard to establish appro-
specified levels of chemical and physical stresses.
priate safety and health practices and determine the applica-
4.1.2 Procedure B exposes containers to varying chemical
bility of regulatory limitations prior to use. Specific warning
and physical stresses based on the user’s knowledge and
statements are given in 6.2, 10.2.3, 10.2.4, 10.2.6, and 10.2.8.
objectives.
5. Significance and Use
5.1 These procedures provide an indication of the environ-
mental stress-crack resistance of injection molded open head
This test method is under the jurisdiction of ASTM Committee D10 on
Packaging and is the direct responsibility of Subcommittee D10.21 on Shipping
Containers and Systems - Application of Performance Test Methods. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2006. Published November 2006. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
´1
approved in 1991. Last previous edition approved in 2001 as D1975 – 95 (2001) Standards volume information, refer to the standard’s Document Summary page on
. DOI: 10.1520/D1975-95R06. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D1975–95 (2006)
NOTE 1—Due to the viscosity of the stress-cracking agent, it is helpful
pails, covers, and components from a selected group or lot.
to prepare the solution at an elevated temperature. A maximum tempera-
Provided the thermal history of each container is constant, this
ture of 122°F (50°C) is an acceptable level provided caution is used to
test method may be used for determining the applicability of
avoid prolonged heating and eventual volume losses.
variousplasticresinsandmolddesignsforinjectionmoldingof
open head pails and covers. 7.2 Procedure B—Any reagent or proprietary product (liq-
5.2 The environmental stress-crack that occurs is indicative uid, solid, etc.) that is potentially a stress-cracking agent.
of what results when a container is exposed to agents such as
soaps, organics, or any surface active solutions while under 8. Sampling
environmental conditions of stress.
8.1 Aminimum of three containers are required for this test
5.3 Environmental stress-cracking is the mechanism of
method. When possible for direct comparison, the test contain-
chemical attack that is highly dependent upon the test reagent,
ers should be produced in the same mold and molding
resin, container molding history, exposure temperature, applied
conditions. It is suggested that test container resin, machine,
stress, and other factors. The combination of these factors may
mold, and molding conditions be thoroughly documented to
result in eventual stress-crack failure.
improve statistical reliability of the test data. (Practice E122.)
5.4 Procedure A minimizes the potential for test variability
by providing the user with rigidly defined test conditions. This
9. Conditioning
test method may be used for production quality control of
9.1 Condition empty test containers at 73 6 2°F (23 6
injection molded open head containers.
1.3°C) 50 6 3 % relative humidity for 48 h prior to testing (see
5.5 Procedure B allows the user to select and evaluate
Practice D4332).
extreme individual elements or the interaction of several test
levels on container performance. These conditions are estab-
10. Procedure
lished based on laboratory experience and available knowledge
of the distribution environment. This test method may be used
10.1 Procedure A—Specified Stress-Crack Resistance
for identifying critical stresses which could aid in container
Method:
design or help in minimizing the occurrence of these stresses
10.1.1 Place the oven set point control at 122 6 2°F (50 6
during distribution.
1.3°C) and allow it to reach equilibrium. Fill each test
5.6 This test method is intended only as a pass/fail proce-
specimen to 98 % of the container’s total volumetric capacity
dure in accordance with the user’s specification, or as agreed
with the test reagent. Apply the cover to the pail firmly and
upon between the user and the supplier. It is not intended as a
evenly using a method similar to the assembly technique used
predictor or indicator of field performance regarding time to
during actual production.
failure.
10.1.2 Place test specimens in the oven on an even horizon-
tal surface. Place an identical pail filled to rated capacity with
6. Apparatus
sand or water on top of each test specimen. Apply additional
6.1 Oven—The oven should be capable of maintaining a
weight to the top of the pail filled with sand or water to bring
temperature control of 62.5°F (61.4°C) of set point. For best
the total top load weight (sand or water pail plus weight) up to
circulation and a constant temperature throughout, a forced air
the values specified in Table 1. Record the time and date the
system is recommended.
test was started.
6.2 Top Load—Requires a pail identical to the test pail be
10.1.3 Inspect the test pails and covers daily for any
filled to rated capacity or weight and then nested above the test
evidence of stress-crack failure. Inspection is performed with-
pail. Free weights are then placed above in amounts necessary
out removing the top load from the test container. Stress crack
to equal the specified top load. A calib
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