ASTM D5870-95(2003)

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 in accordance with 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

• Status: Historical
• Publication Date: 09-May-2003
• ICS: 83.080.20 - Thermoplastic materials
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.50 - Durability of Plastics

Relations

• Replaces: ASTM D5870-95 - Standard Practice for Calculating Property Retention Index of Plastics
• Effective Date: 10-May-2003
• Replaced By: ASTM D5870-11 - Standard Practice for Calculating Property Retention Index of Plastics
• Effective Date: 01-Feb-2011
• Referred By: ASTM D4674-19 - Standard Practice for Accelerated Testing for Color Stability of Plastics Exposed to Indoor Office Environments
• Effective Date: 10-May-2003
• Referred By: ASTM G201-16 - Standard Practice for Conducting Exposures in Outdoor Glass-Covered Exposure Apparatus with Air Circulation
• Effective Date: 10-May-2003
• Referred By: ASTM D822/D822M-13(2018) - Standard Practice for Filtered Open-Flame Carbon-Arc Exposures of Paint and Related Coatings
• Effective Date: 10-May-2003
• Referred By: ASTM D3361/D3361M-22 - Standard Practice for Unfiltered Open-Flame Carbon-Arc Exposures of Paint and Related Coatings
• Effective Date: 10-May-2003
• Referred By: ASTM D5031/D5031M-13(2018) - Standard Practice for Enclosed Carbon-Arc Exposure Tests of Paint and Related Coatings
• Effective Date: 10-May-2003
• Referred By: ASTM D5071-06(2021) - Standard Practice for Exposure of Photodegradable Plastics in a Xenon Arc Apparatus
• Effective Date: 10-May-2003
• Referred By: ASTM G152-13(2021) - Standard Practice for Operating Open Flame Carbon Arc Light Apparatus for Exposure of Nonmetallic Materials
• Effective Date: 10-May-2003
• Referred By: ASTM D5208-14(2022) - Standard Practice for Fluorescent Ultraviolet (UV) Exposure of Photodegradable Plastics
• Effective Date: 10-May-2003
• Referred By: ASTM D6695-16 - Standard Practice for Xenon-Arc Exposures of Paint and Related Coatings
• Effective Date: 10-May-2003
• Referred By: ASTM G151-19 - Standard Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources
• Effective Date: 10-May-2003
• Referred By: ASTM G154-23 - Standard Practice for Operating Fluorescent Ultraviolet (UV) Lamp Apparatus for Exposure of Materials
• Effective Date: 10-May-2003
• Referred By: ASTM D4329-21 - Standard Practice for Fluorescent Ultraviolet (UV) Lamp Apparatus Exposure of Plastics
• Effective Date: 10-May-2003
• Referred By: ASTM D6360-15(2021) - Standard Practice for Enclosed Carbon-Arc Exposures of Plastics
• Effective Date: 10-May-2003

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:D5870–95 (Reapproved 2003)
Standard Practice for
Calculating Property Retention Index of Plastics
This standard is issued under the fixed designation D5870; 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 practice covers procedures for the calculation of a 2.1 ASTM Standards:
property retention index (PRI) of thermoplastic and thermoset D543 Practices for Evaluating the Resistance of Plastics to
plastics after exposure to thermal aging, natural or artificial Chemical Reagents
accelerated weathering, or chemical exposures. D618 Practice for Conditioning Plastics for Testing
1.2 This practice is not intended to establish a fixed proce- D883 Terminology Relating to Plastics
dure for conducting the exposure test, but it is intended to D1435 Practice for Outdoor Weathering of Plastics
provide a set of specific procedures used to calculate the F1499 Specification for Coextruded Composite Drain,
retention index of a characteristic property of the material after Waste, and Vent Pipe (DWV)
it has been exposed. Selection of the specific exposure test D1898 Practice for Sampling of Plastics
conditions depends on the material being tested and the D2565 Practice for Xenon-Arc Exposure of Plastics In-
property being measured. It is up to the user to determine tended for Outdoor Applications
whichexposuretestconditionsaremostrelevanttothespecific D3045 Practice for Heat Aging of Plastics Without Load
material and the service condition being used. The exposure D4329 Practice for Fluorescent UV Exposure of Plastics
test used must be conducted in accordance with conditions D4364 PracticeforPerformingOutdoorAcceleratedWeath-
described in specific exposure standards. ering Tests of Plastics Using Concentrated Sunlight
1.3 This practice does not describe procedures for sampling D4459 Practice for Xenon-Arc Exposure of Plastics In-
thematerialstobetested.Theseproceduresaredescribedinthe tended for Indoor Applications
standards and specifications applicable to the material being D4674 Practice for Accelerated Testing for Color Stability
evaluated. of Plastics Exposed to Indoor Office Environments
1.4 The procedure used to calculate the PRI depends on D6360 Practice for Enclosed Carbon-Arc Exposures of
whether the test used to characterize the materials being Plastics
exposedisdestructiveornondestructive.ThePRIcanbeuseful G113 TerminologyRelatingtoNaturalandArtificialWeath-
in describing short-term mechanical, electrical, and other ering Tests 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, toWeathering 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
Light Sources Part 1: General Guidance, Part 2: Xenon
NOTE 1—There is no similar or equivalent ISO standard. ISO DIS
Arc Exposures, Part 3: Fluorescent UV Exposures, and
11248 is significantly different since it pertains only to thermosetting
Part 4: Filtered Open Flame Carbon Arc Exposures
resins.
ISO DIS 11248 Plastics—Thermosetting Molding Materi-
als, Evaluation of Short-Term Performance at Elevated
Temperatures
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
ThispracticeisunderthejurisdictionofASTMCommitteeD20onPlasticsand Standards volume information, refer to the standard’s Document Summary page on
is the direct responsibility of Subcommittee D20.50 on Durability of Plastics. the ASTM website.
Current edition approved May 10, 2003. Published June 2003. Originally Withdrawn.
approved in 1995. Last previous edition approved in 1995 as D5870 - 95. DOI: Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
10.1520/D5870-95R03. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5870–95 (2003)
3. Terminology which the physical properties were determined (for example,
temperatureandrelativehumidity);(5)completedescriptionof
3.1 Definitions: The terminology given in Terminologies
the procedure used to determine the physical properties tested,
D883 and G113 is applicable to this practice.
including the rate at which specimens were tested, if appli-
cable; (6) if applicable, void content of the specimens tested
4. Significance and Use
and the method used to measure void content.
4.1 The property retention index (PRI) determined by this
practice is intended primarily to provide relative durability
NOTE 2—It is not the intent of this practice to require users to divulge
proprietary information regarding composition. To avoid divulging pro-
performance information on materials for design engineers. It
prietary information, generic descriptions may be used to provide infor-
isuptotheusertoensurethatappropriatesamplingprocedures
mation on material composition.
are used for the selection of specimens to be exposed so that
the PRI data obtained is actually representative of the material
4.6 When destructive tests are used to determine a physical
being evaluated.
or chemical change, or both, which occurs as a result of
4.2 The PRI obtained depends on the material being tested,
exposure, the amount of change is expressed as a function of
property being evaluated, and exposure condition used. A PRI
the value obtained for the material tested at a specified test
obtained for one property will probably not be the same as the
environment (for example, temperature and humidity). The
PRI for a different property of the same material, even if the
exposed and reference specimens are measured at the same
same exposure test is used.
time in the specified test environment.
4.3 Plastics exposed to a combination of environmental and
4.7 When nondestructive tests are used to determine a
thermal treatments may undergo a change in functional perfor-
physical or chemical change, or both, which occurs as a result
mance.Any laboratory-accelerated aging procedure, especially
ofexposure,theamountofchangeisexpressedasafunctionof
thosethatuseonlyasinglestress,maynotrealisticallyindicate
the value obtained on the specimens prior to exposure. Prop-
the changes a plastic may undergo in actual use conditions.
erty measurement tests on the specimens before and after
This practice provides a means for expressing the changes in
exposure shall be conducted at the same conditions (for
properties as a function of time exposed in a wide variety of
example, temperature and humidity).
tests. The PRI data obtained is best used for comparing the
4.8 The property or properties to be measured may be
performance of materials subjected to the same exposure test
specified in an ASTM, ISO, or other appropriate standard for
simultaneously.
the material being tested, or by any prior agreement between
4.3.1 Both laboratory-accelerated and outdoor exposure
interested parties. If the method used to measure the property
testing can be highly variable, and the PRI data will be
being evaluated is not described in an ASTM, ISO, or other
influenced by this variability. For example, PRI data from
appropriate standard, a description of the test method shall be
outdoor exposures can vary depending on the exposure loca-
included in the report of test results.
tion and the time of year when the exposure is conducted.
4.9 It is realized that a material cannot be tested without
Variability in laboratory-accelerated exposure tests can result
specifying the method of preparation. To have any meaning in
in large differences in PRI data from two laboratories running
comparative testing, specimens of each material being evalu-
supposedly identical tests. PRI data obtained from exposure to
ated by these test procedures should be prepared or molded
laboratory-accelerated tests cannot be used to predict the PRI
from the same lot under identical processing conditions and
for exposure to natural weathering or actual use conditions
randomizedpriortotestingattheconditionsdesired.Itmustbe
unless there is a sufficient amount of data from both types of
realized that lot-to-lot variation in the material may cause
exposure to allow valid statistical comparisons.
additional variability in results.
4.4 A number of different exposure techniques can be used
to provide information on the effects of environmental stresses
NOTE 3—For those plastics with a Tg greater than ambient, the slow
such as light, heat, and water on plastics (see Practices D1435,
collapse of free volume, with attendant significant changes in mechanical
F1499, D2565, D4329, D4364, and D4459; Test Method
properties such as fatigue resistance, impact resistance, yield stress, and
vaportransmission,etc.willbeacceleratedatelevatedtemperaturesbelow
D4674; and ISO 4892 and ). When it is desirable to evaluate
the Tg but will be reversed at temperatures above the Tg. Therefore,
the effects of heat alone, exposures should be conducted in
incubation at elevated temperatures in the Tg range may be erratically
accordance with Practice D3045. When it is desirable to
susceptible to oven fluctuation effects.
evaluate the effects of chemical exposures, the exposures
should be conducted in accordance with Test Method D543. 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 in accordance with whether the
In addition to a complete description of the exposure test exposed surface or the unexposed surface of the test specimen
conditions used, the following information shall be included in is placed under tension. Care must be taken to ensure that all
anyreportreferencingthispractice:(1)completedescriptionof specimens being exposed have the same orientation in the test
the material tested, including the type, source, manufacturer’s fixtureusedtoholdthespecimensduringexposure.Inaddition,
code number, form, and previous history; (2) methods of the results also depend on the orientation of test specimens
preparation for the material and individual test specimens; (3) during the procedure used to measure the property being
procedure used for specimen conditioning prior to and after monitored.This is especially true with impact tests. During the
exposure; (4) complete description of the environment in procedure used to measure the characteristic property, care
D5870–95 (2003)
must be taken to ensure that all specimens are oriented the 8.1.3 When the PRI for exposure to laboratory light sources
same way in the test fixture. is to be determined, conduct exposures in accordance with one
of the following ASTM standards:
4.11 Before proceeding with this practice, reference should
be made to the specification of the material being tested. Any (1) Practice F1499 for exposures to filtered open-flame
carbon-arc light sources;
test specimen preparation, conditioning, or dimensions, or
some combination thereof, and testing parameters covered in (2) Practice D2565 for exposures to xenon-arc light
sources;
the material’s specification shall take precedence over those
mentioned in this practice. The default conditions described in (3) Practice D4329 for exposure to fluorescent ultraviolet
(UV) light sources; and
this practice apply if there are no material specifications.
(4) Practice D6360, D4329 for exposures to enclosed
carbon-arc light sources;
5. Apparatus
(5) Procedures for exposure to these and other types of
5.1 The apparatus used for exposure and measurement of
light sources are also described in ASTM or ISO standards
the property desired will depend on the particular exposure
applicable to specific types of materials; these can also be used
used and property being measured. Refer to the appropriate
when mutually agreed upon by all interested parties.
ASTM or ISO standards for requirements on the apparatus
8.1.4 When the PRI for exposure to heat onermined, con-
needed.
duct exposures in accordance with Practice D3045. Exposures
used to determine the PRI will typically be conducted at one or
6. Sampling
two temperatures. The procedures covered in Practice D3045,
6.1 Sampling of materials for testing is covered under
which describe the calculation of a time to fail, would not be
applicable standards or specifications for the material being
used for tests to determine the PRI.
tested.
8.1.5 When the PRI for chemical exposure is to be deter-
6.2 It is important to select samples for testing that are
mined, conduct exposures in accordance with Test Method
representative of the material being evaluated. Procedures for
D543.
sampling plastics are described in Practice D1898.
8.2 Material Properties Measured with Nondestructive
Tests—When material properties are measured using non-
7. Test Specimens
destructive methods (for example, gloss, haze, and transpar-
ency), determine the PRI as follows:
7.1 The test specimens shall be in accordance with the
8.2.1 Determine the initial level of the measured property,
appropriate test method used for the properties being mea-
P , for each replicate specimen of the materials being tested.
sured.
i,o
8.2.2 Expose all replicate test specimens to the environment
7.2 All test specimens shall be prepared in accordance with
desired, conducting exposures in accordance with the appli-
the pertinent material standards and other relevant ASTM
cable ASTM standards.
standards.
8.2.3 Measure the desired property after exposure, P ,
7.3 Annealing of thermoplastic materials and post-curing of i,x
using the same test method used to determine the level of the
thermosetting materials has a significant effect on many
initial property.
properties. To minimize errors caused by these effects, anneal-
8.2.4 Determine the PRI for each replicate specimen, z ,as
ing and post-curing shall be conducted accurate
...