ASTM D5870-95
(Practice)Standard Practice for Calculating Property Retention Index of Plastics
Standard Practice for Calculating Property Retention Index of Plastics
SCOPE
1.1 This practice covers procedures for the calculation of a property retention index (PRI) of thermoplastic and thermoset plastics after exposure to thermal aging, natural or artificial accelerated weathering, or chemical exposures.
1.2 This practice is not intended to establish a fixed procedure for conducting the exposure test, but it is intended to provide a set of specific procedures used to calculate the retention index of a characteristic property of the material after it has been exposed. Selection of the specific exposure test conditions depends on the material being tested and the property being measured. It is up to the user to determine which exposure test conditions are most relevant to the specific material and the service condition being used. The exposure test used must be conducted according to conditions described in specific exposure standards.
1.3 This practice does not describe procedures for sampling the materials to be tested. These procedures are described in the standards and specifications applicable to the material being evaluated.
1.4 The procedure used to calculate the PRI depends on whether the test used to characterize the materials being exposed is destructive or nondestructive. The PRI can be useful in describing short-term mechanical, electrical, and other properties of plastics at specified temperatures after the materials have been subjected to an exposure test.
1.5 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. Note 1-There is no similar or equivalent ISO standard. ISO DIS 11248 is significantly different since it pertains only to thermosetting resins.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.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 5870 – 95
Standard Practice for
Calculating Property Retention Index of Plastics
This standard is issued under the fixed designation D 5870; 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 D 618 Practice for Conditioning Plastics and Electrical
Insulating Materials for Testing
1.1 This practice covers procedures for the calculation of a
D 883 Terminology Relating to Plastics
property retention index (PRI) of thermoplastic and thermoset
D 1435 Practice for Outdoor Weathering of Plastics
plastics after exposure to thermal aging, natural or artificial
D 1499 Practice for Operating Light- and Water-Exposure
accelerated weathering, or chemical exposures.
Apparatus (Carbon-Arc Type) for Exposure of Plastics
1.2 This practice is not intended to establish a fixed proce-
D 1898 Practice for Sampling of Plastics
dure for conducting the exposure test, but it is intended to
D 2565 Practice for Operating Xenon Arc-Type Light Ex-
provide a set of specific procedures used to calculate the
posure Apparatus With and Without Water for Exposure of
retention index of a characteristic property of the material after
Plastics
it has been exposed. Selection of the specific exposure test
D 3045 Practice for Heat Aging of Plastics Without Load
conditions depends on the material being tested and the
D 4329 Practice for Operating Light- and Water-Exposure
property being measured. It is up to the user to determine
Apparatus (Fluorescent UV-Condensation Type) for Expo-
which exposure test conditions are most relevant to the specific
sure of Plastics
material and the service condition being used. The exposure
D 4364 Practice for Performing Accelerated Outdoor
test used must be conducted according to conditions described
Weathering of Plastics Using Concentrated Natural Sun-
in specific exposure standards.
light
1.3 This practice does not describe procedures for sampling
D 4459 Practice for Operating an Accelerated Lightfastness
the materials to be tested. These procedures are described in the
Xenon-Arc-Type (Water Cooled) Light-Exposure Appara-
standards and specifications applicable to the material being
tus for the Exposure of Plastics for Indoor Applications
evaluated.
D 4674 Test Method for Accelerated Testing for Color
1.4 The procedure used to calculate the PRI depends on
Stability of Plastics Exposed to Indoor Fluorescent Light-
whether the test used to characterize the materials being
ing and Window-Filtered Daylight
exposed is destructive or nondestructive. The PRI can be useful
G 113 Terminology Relating to Natural and Artificial
in describing short-term mechanical, electrical, and other
Weathering Test of Nonmetallic Materials
properties of plastics at specified temperatures after the mate-
2.2 ISO Standards:
rials have been subjected to an exposure test.
ISO 291 Plastics—Standard Atmospheres for Conditioning
1.5 This standard does not purport to address all of the
and Testing
safety concerns, if any, associated with its use. It is the
ISO 877 Plastics—Methods of Exposure to Direct Weath-
responsibility of the user of this standard to establish appro-
ering, to Weathering Using Glass Filtered Daylight, and to
priate safety and health practices and determine the applica-
Intensified Weathering by Daylight Using Fresnel Mirrors
bility of regulatory limitations prior to use.
ISO 4892 Plastics—Methods of Exposure to Laboratory
NOTE 1—There is no similar or equivalent ISO standard. ISO DIS
Light Sources Part 1: General Guidance, Part 2: Xenon
11248 is significantly different since it pertains only to thermosetting
Arc Exposures, Part 3: Fluorescent UV Exposures, and
resins.
Part 4: Filtered Open Flame Carbon Arc Exposures
ISO DIS 11248 Plastics—Thermosetting Molding Materi-
2. Referenced Documents
als, Evaluation of Short-Term Performance at Elevated
2.1 ASTM Standards:
Temperatures
D 543 Test Method for Resistance of Plastics to Chemical
Reagents
Annual Book of ASTM Standards, Vol 08.02.
1 4
This practice is under the jurisdiction of ASTM Committee D20 on Plastics and Annual Book of ASTM Standards, Vol 08.03.
is the direct responsibility of Subcommittee D20.50 on Durability of Plastics. Annual Book of ASTM Standards, Vol 14.02.
Current edition approved December 10, 1995. Published February 1996. Available from American National Standards Institute, 11 W. 42nd St., 13th
Annual Book of ASTM Standards, Vol 08.01. Floor, New York, NY 10036.
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.
D5870–95
3. Terminology exposure; (4) complete description of the environment in
which the physical properties were determined (for example,
3.1 Definitions: The terminology given in Terminologies
temperature and relative humidity); (5) complete description of
D 883 and G 113 is applicable to this practice.
the procedure used to determine the physical properties tested,
including the rate at which specimens were tested, if appli-
4. Significance and Use
cable; (6) if applicable, void content of the specimens tested
4.1 The property retention index (PRI) determined by this
and the method used to measure void content.
practice is intended primarily to provide relative durability
performance information on materials for design engineers. It NOTE 2—It is not the intent of this practice to require users to divulge
proprietary information regarding composition. To avoid divulging pro-
is up to the user to ensure that appropriate sampling procedures
prietary information, generic descriptions may be used to provide infor-
are used for the selection of specimens to be exposed so that
mation on material composition.
the PRI data obtained is actually representative of the material
being evaluated.
4.6 When destructive tests are used to determine a physical
4.2 The PRI obtained depends on the material being tested,
or chemical change, or both, which occurs as a result of
property being evaluated, and exposure condition used. A PRI
exposure, the amount of change is expressed as a function of
obtained for one property will probably not be the same as the
the value obtained for the material tested at a specified test
PRI for a different property of the same material, even if the
environment (for example, temperature and humidity). The
same exposure test is used.
exposed and reference specimens are measured at the same
4.3 Plastics exposed to a combination of environmental and
time in the specified test environment.
thermal treatments may undergo a change in functional perfor-
4.7 When nondestructive tests are used to determine a
mance. Any laboratory-accelerated aging procedure, especially
physical or chemical change, or both, which occurs as a result
those that use only a single stress, may not realistically indicate
of exposure, the amount of change is expressed as a function of
the changes a plastic may undergo in actual use conditions.
the value obtained on the specimens prior to exposure. Prop-
This practice provides a means for expressing the changes in
erty measurement tests on the specimens before and after
properties as a function of time exposed in a wide variety of
exposure shall be conducted at the same conditions (for
tests. The PRI data obtained is best used for comparing the
example, temperature and humidity).
performance of materials subjected to the same exposure test
4.8 The property or properties to be measured may be
simultaneously.
specified in an ASTM, ISO, or other appropriate standard for
4.3.1 Both laboratory-accelerated and outdoor exposure
the material being tested, or by any prior agreement between
testing can be highly variable, and the PRI data will be
interested parties. If the method used to measure the property
influenced by this variability. For example, PRI data from
being evaluated is not described in an ASTM, ISO, or other
outdoor exposures can vary depending on the exposure loca-
appropriate standard, a description of the test method shall be
tion and the time of year when the exposure is conducted.
included in the report of test results.
Variability in laboratory-accelerated exposure tests can result
4.9 It is realized that a material cannot be tested without
in large differences in PRI data from two laboratories running
specifying the method of preparation. To have any meaning in
supposedly identical tests. PRI data obtained from exposure to
comparative testing, specimens of each material being evalu-
laboratory-accelerated tests cannot be used to predict the PRI
ated by these test procedures should be prepared or molded
for exposure to natural weathering or actual use conditions
from the same lot under identical processing conditions and
unless there is a sufficient amount of data from both types of
randomized prior to testing at the conditions desired. It must be
exposure to allow valid statistical comparisons.
realized that lot-to-lot variation in the material may cause
4.4 A number of different exposure techniques can be used
additional variability in results.
to provide information on the effects of environmental stresses
such as light, heat, and water on plastics (see Practices D 1435,
NOTE 3—For those plastics with a Tg greater than ambient, the slow
D 1499, D 2565, D 4329, D 4364, and D 4459; Test Method
collapse of free volume, with attendant significant changes in mechanical
D 4674; and ISO 4892 and 877). When it is desirable to
properties such as fatigue resistance, impact resistance, yield stress, and
evaluate the effects of heat alone, exposures should be con- vapor transmission, etc. will be accelerated at elevated temperatures below
the Tg but will be reversed at temperatures above the Tg. Therefore,
ducted in accordance with Practice D 3045. When it is desir-
incubation at elevated temperatures in the Tg range may be erratically
able to evaluate the effects of chemical exposures, the expo-
susceptible to oven fluctuation effects.
sures should be conducted in accordance with Test Method
D 543. 4.10 The results depend on which side of the test specimen
4.5 There are a number of factors influencing the physical is exposed with some tests. In bending tests, for example,
properties and the retention of these properties after exposure. different results are obtained according to whether the exposed
In addition to a complete description of the exposure test surface or the unexposed surface of the test specimen is placed
conditions used, the following information shall be included in under tension. Care must be taken to ensure that all specimens
any report referencing this practice: (1) complete description of being exposed have the same orientation in the test fixture used
the material tested, including the type, source, manufacturer’s to hold the specimens during exposure. In addition, the results
code number, form, and previous history; (2) methods of also depend on the orientation of test specimens during the
preparation for the material and individual test specimens; (3) procedure used to measure the property being monitored. This
procedure used for specimen conditioning prior to and after is especially true with impact tests. During the procedure used
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.
D5870–95
to measure the characteristic property, care must be taken to 8.1.2 Expose all replicate test specimens to the environment
ensure that all specimens are oriented the same way in the test desired, conducting exposures according to the applicable
fixture. ASTM standards.
4.11 Before proceeding with this practice, reference should
8.1.2.1 When determining the PRI for materials exposed to
be made to the specification of the material being tested. Any
natural weathering, conduct exposures according to Practice
test specimen preparation, conditioning, or dimensions, or
D 1435.
some combination thereof, and testing parameters covered in
8.1.2.2 When the PRI for exposure to concentrated natural
the material’s specification shall take precedence over those
sunlight is to be determined, conduct exposures according to
mentioned in this practice. The default conditions described in
Practice D 4364.
this practice apply if there are no material specifications.
8.1.2.3 When the PRI for exposure to laboratory light
sources is to be determined, conduct exposures according to
5. Apparatus
one of the following ASTM standards:
5.1 The apparatus used for exposure and measurement of
(1) Practice D 1499 for exposures to carbon-arc light
the property desired will depend on the particular exposure
sources;
used and property being measured. Refer to the appropriate
(2) Practice D 2565 for exposures to xenon-arc light
ASTM or ISO standards for requirements on the apparatus
sources;
needed.
(3) Practice D 4329 for exposure to fluorescent ultraviolet
(UV) light sources; and
6. Sampling
(4) Procedures for exposure to these and other types of
6.1 Sampling of materials for testing is covered under
light sources are also described in ASTM or ISO standards
applicable standards or specifications for the material being
applicable to specific types of materials; these can also be used
tested.
when mutually agreed upon by all interested parties.
6.2 It is important to select samples for testing that are
8.1.2.4 When the PRI for exposure to heat onermined,
representative of the material being evaluated. Procedures for
conduct exposures according to Practice D 3045. Exposures
sampling plastics are described in Practice D 1898.
used to determine the PRI will typically be conducted at one or
two temperatures. The procedures covered in Practice D 3045,
7. Test Specimens
which describe the calculation of a time to fail, would not be
7.1 The test specimens shall be in accordance with the used for tests to determine the PRI.
appropriate test method used for the properties being mea-
8.1.2.5 When the PRI for chemical exposure is to be
sured.
determined, conduct exposures according to Test Method
7.2 All test specimens shall be prepared in accordance with
D 543.
the pertinent material standards and other relevant ASTM
8.1.3 Measure the desired property after exposure, P ,
i,x
standards.
using the same test method used to determine the level of t
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.