ASTM D4364-94
(Practice)Standard Practice for Performing Outdoor Accelerated Weathering Tests of Plastics Using Concentrated Sunlight
Standard Practice for Performing Outdoor Accelerated Weathering Tests of Plastics Using Concentrated Sunlight
SCOPE
1.1 This practice covers the use of Fresnel-reflecting concentrators that use the sun as a source of ultraviolet (UV) and longer-wavelength radiation. Such devices are used in the outdoor-accelerated-exposure testing of plastics.
1.2 This practice provides a procedure for performing outdoor-accelerated-exposure testing of plastics using a Fresnel-reflector outdoor-accelerated weathering test machine. The apparatus is described herein and in Practice G90 more completely.
1.3 This practice is applicable to a range of plastic materials including, but not limited to, plastic films, sheets, laminates, and extruded and molded products in a variety of shapes and sizes, as specified in 8.2 and 8.3.
1.4 This practice describes test conditions that attempt to simulate plastics exposures in desert and subtropical climates. Specimen preparation, property testing procedures, and the evaluation of results are covered in existing test methods or specifications for specific materials.
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. Specific precautionary statements are given in Section 7. Note 1-This standard and ISO 877.2-1991, Method C, are technically equivalent.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.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 4364 – 94
Standard Practice for
Performing Outdoor Accelerated Weathering Tests of
Plastics Using Concentrated Sunlight
This standard is issued under the fixed designation D 4364; 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 4141 Practice for Conducting Accelerated Outdoor Expo-
sure Tests of Coatings
1.1 This practice covers the use of Fresnel-reflecting con-
D 4517 Test Method for Low-Level Total Silica in High-
centrators that use the sun as a source of ultraviolet (UV) and
Purity Water by Flameless Atomic Absorption Spectros-
longer-wavelength radiation. Such devices are used in the
copy
outdoor-accelerated-exposure testing of plastics.
E 772 Terminology Relating to Solar Energy Conversion
1.2 This practice provides a procedure for performing
E 824 Method for Transfer of Calibration from Reference to
outdoor-accelerated-exposure testing of plastics using a
Field Pyranometers
Fresnel-reflector outdoor-accelerated weathering test machine.
G 7 Practice for Atmospheric Environmental Exposure
The apparatus is described herein and in Practice G 90 more
Testing of Nonmetallic Materials
completely.
G 24 Practice for Conducting Natural Light Exposures Un-
1.3 This practice is applicable to a range of plastic materials
der Glass
including, but not limited to, plastic films, sheets, laminates,
G 90 Practice for Performing Accelerated Outdoor Weath-
and extruded and molded products in a variety of shapes and
ering of Nonmetallic Materials Using Concentrated Natu-
sizes, as specified in 8.2 and 8.3.
ral Sunlight
1.4 This practice describes test conditions that attempt to
G 113 Terminology Relating to Natural and Artificial
simulate plastics exposures in desert and subtropical climates.
Weathering Tests of Nonmetallic Materials
Specimen preparation, property testing procedures, and the
2.2 ISO Standard:
evaluation of results are covered in existing test methods or
ISO 877.2-1991, Method C, Methods of Exposure to Direct
specifications for specific materials.
Weathering, to Weathering Using Glass-Filtered Daylight,
1.5 This standard does not purport to address all of the
and to Intensified Weathering Using Fresnel Mirrors
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3. Terminology
priate safety and health practices and determine the applica-
3.1 Definitions—For definitions of technical terms pertain-
bility of regulatory limitations prior to use. Specific precau-
ing to plastics used in this practice, see Terminologies D 883,
tionary statements are given in Section 7.
D 1600, G 113, and E 772.
NOTE 1—This standard and ISO 877.2-1991, Method C, are technically
equivalent.
4. Significance and Use
4.1 This practice involves the concentration of sunlight by a
2. Referenced Documents
system of plane mirrors, arranged to simulate a parabolic
2.1 ASTM Standards:
trough focused on an air-cooled target board on which the test
D 859 Test Method for Silica in Water
specimens are mounted. Two exposure methods are used, as
D 883 Terminology Relating to Plastics
described in Procedures A and B.
D 1293 Test Methods for pH of Water
4.1.1 Procedure A—Procedure A outdoor exposure tests are
D 1435 Practice for Outdoor Weathering of Plastics
performed in an absence of a programmed moisture cycle and
D 1600 Terminology for Abbreviated Terms Relating to
are intended to simulate conventional exposure testing on
Plastics
south-facing racks in desert and arid regions.
D 1898 Practice for Sampling of Plastics
1 4
This practice is under the jurisdiction of ASTM Committee D-20 on Plastics Annual Book of ASTM Standards, Vol 06.01.
and is the direct responsibility of Subcommittee D20.50 on Permanence Properties. Annual Book of ASTM Standards, Vol 11.02.
Current edition approved March 15, 1994. Published May 1994. Originally Annual Book of ASTM Standards, Vol 12.02.
published as D 4364 – 84. Last previous edition D 4364 – 84. Annual Book of ASTM Standards, Vol 14.02.
2 8
Annual Book of ASTM Standards, Vol 11.01. 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.
D 4364
4.1.2 Procedure B—Procedure B accelerated-outdoor- mation on the relationship between accelerated and real-time
exposure tests are essentially identical to Procedure A, but they tests, the acceleration factor found for the reference material
shall possess the feature of spraying high-purity water on the cannot be used to extrapolate results of the accelerated test to
specimens in a regular, periodic fashion that is intended to predict lifetimes under natural exposure except for the specific
simulate the results of conventional exposure testing on fixed material for which the relationship has been established.
south-facing racks in subtropical, semi-humid, and temperate
5. Apparatus
regions. Water-spray cycles that are recommended by this
practice are given in Table 1.
5.1 The testing apparatus shall be a Fresnel-reflecting de-
4.2 The effectiveness of the Fresnel-reflector accelerated-
vice possessing ten flat mirrors that focus direct sunlight onto
outdoor-weathering test machines depends primarily on the
an air-cooled specimen area. A more complete description of
amount and character of the UV in the direct-beam component
the apparatus may be found in Practice G 90. See Fig. 1.
of sunlight.
NOTE 4—The apparatus should be operated in dry, sunny climates
receiving 3500 to 4000 h or more of sunshine per year and an average
NOTE 2—Use of the apparatus in regions of moderate- to high-diffuse
annual relative humidity of approximately 30 % or less.
irradiance will reduce the test machine’s effectiveness substantially for
providing concentrated UV in the target (specimen) area.
5.2 Water Quality:
4.3 Testing to specific levels (quantities) of solar-ultraviolet- 5.2.1 Water used for the specimen tray shall have a pH of
radiant exposure is recommended. Elapsed-time-exposure-
6.0 to 8.0. Measure the pH in accordance with Test Method
level determinations shall not be used for testing with this D 1293.
practice. Testing to specific levels of UV irradiation, whether to
5.2.2 The purity of water used for specimen spray is very
total UV or within selected wavebands, is an effective method
important. Without proper treatment to remove cations, anions,
for improving agreement between wintertime and summertime
organics, and particularly silica, exposed panels will develop
testing on the Fresnel-reflector weathering-test machines.
spots or stains that do not occur in exterior exposures.
Other seasonal factors such as temperature and time of wetness
5.2.3 Water used for specimen spray shall leave no objec-
can affect the weathering of test specimens significantly.
tional deposits or stains on the exposed specimens. It is
4.4 The weathering machines described provide for speci-
strongly recommended that the water contain below 1 ppm
men cooling that reduces thermal problems in most materials.
solids and below 0.2 ppm silica. Silica levels should be
It is recommended that monthly temperature measurements be
determined in accordance with the procedures in Test Methods
performed on heat-sensitive plastics to record the typical
D 859 or D 4517. Prepackaged analysis kits are commercially
monthly test specimen test temperatures.
available that are capable of detecting silica levels of below
200 ppb. A combination of deionization and reverse-osmosis
NOTE 3—It is possible for heat-sensitive plastic materials and thick
treatment can produce water with the desired purity effectively.
specimens that are self-insulating to exhibit thermal-induced degradation
The solids and silica levels must be reported if the spray water
that is unrealistic compared to natural weathering. Clear, thin-film
photodegradeable plastics are not recommended for testing with this used is above 1 ppm solids.
practice for this reason.
6. Reagents and Materials
4.5 Since the natural environment varies with respect to
6.1 Water shall conform to the specifications presented in
time, geography, and topography, it may be expected that the
5.2.1-5.2.3.
effects of natural exposure will vary accordingly. Furthermore,
6.2 The mirrors used on Fresnel-reflector test machines
all materials are not affected equally by increased irradiance
shall be flat and have a specular UV reflectance of 65 % or
and te
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.