ASTM D6695-16

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Designation: D6695 − 08 D6695 − 16
Standard Practice for
Xenon-Arc Exposures of Paint and Related Coatings
This standard is issued under the fixed designation D6695; 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
1.1 This practice covers the selection of test conditions for accelerated exposure testing of coatings and related products in
xenon arc devices conducted according to Practices G151 and G155. This practice also covers the preparation of test specimens,
the test conditions suited for coatings, and the evaluation of test results.Table 1 describes commonly used test conditions.
NOTE 1—ISO 11341 also describes xenon-arc exposures of paints and coatings. However, the exposure conditions described in ISO 11341 are different
than those listed This practice and ISO 16474-2 address the same subject matter but differ in Table 1.technical content.
1.2 The values SI units are to be regarded as standard. The values given in parentheses are for information only.
1.3 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.
2. Referenced Documents
2.1 ASTM Standards:
D358 Specification for Wood to Be Used as Panels in Weathering Tests of Coatings (Withdrawn 2014)
D523 Test Method for Specular Gloss
D609 Practice for Preparation of Cold-Rolled Steel Panels for Testing Paint, Varnish, Conversion Coatings, and Related Coating
Products
D610 Practice for Evaluating Degree of Rusting on Painted Steel Surfaces
D659 Method for Evaluating Degree of Chalking of Exterior Paints (Withdrawn 1990)
D660 Test Method for Evaluating Degree of Checking of Exterior Paints
D662 Test Method for Evaluating Degree of Erosion of Exterior Paints
D714 Test Method for Evaluating Degree of Blistering of Paints
D772 Test Method for Evaluating Degree of Flaking (Scaling) of Exterior Paints
D823 Practices for Producing Films of Uniform Thickness of Paint, Varnish, and Related Products on Test Panels
D1005 Test Method for Measurement of Dry-Film Thickness of Organic Coatings Using Micrometers
D1186 Test Methods for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to a Ferrous
Base (Withdrawn 2006)
D1400 Test Method for Nondestructive Measurement of Dry Film Thickness of Nonconductive Coatings Applied to a
Nonferrous Metal Base (Withdrawn 2006)
D1729 Practice for Visual Appraisal of Colors and Color Differences of Diffusely-Illuminated Opaque Materials
D1730 Practices for Preparation of Aluminum and Aluminum-Alloy Surfaces for Painting
D2244 Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
D2616 Test Method for Evaluation of Visual Color Difference With a Gray Scale
D3359 Test Methods for Measuring Adhesion by Tape Test
D3980 Practice for Interlaboratory Testing of Paint and Related Materials (Withdrawn 1998)
D4214 Test Methods for Evaluating the Degree of Chalking of Exterior Paint Films
D5870 Practice for Calculating Property Retention Index of Plastics
This practice is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.27 on Accelerated Testing.
Current edition approved June 1, 2008May 1, 2016. Published July 2008May 2016. Originally approved in 2001. Last previous edition approved in 20032008 as
D6695 – 03a.D6695 – 08. DOI: 10.1520/D6695-08.10.1520/D6695-16.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6695 − 16
A
TABLE 1 Test Cycles Commonly Used for Xenon-Arc Exposure Testing of Paints and Related Coatings
Uninsulated Black
B D E
Cycle Number Cycle Description Typical Irradiance Typical Uses
C
Panel, Temperature
1 Continuous light 63 ± 2°C 0.35 ± 0.02 W/(m ·nm) at 340 nm General coatings and
2 G
102 min light only at 50 % ± 5 % RH 145 ± 4°F 41.5 ± 2.5 W/m from 300-400 nm historical convention
F
18 min light and water spray
Repeat continuously
1 Continuous light 63 ± 2°C 0.35 ± 0.02 W/(m ·nm) at 340 nm General coatings and
2 G
102 min light only at 50 % ± 5 % RH 145 ± 4°F 41.5 ± 2.5 W/m from 300-400 nm historical convention
F
18 min light and water spray/
Repeat continuously
2 18 h continuous light using: 63 ± 2°C 0.35 ± 0.02 W/(m ·nm) at 340 nm General coatings
102 min light only at 50 % ± 5 % RH 145 ± 4°F 41.5 ± 2.5 W/m from 300-400 nm
18 min light and water spray 24 ± 1.5°C
6 h dark using:
43 ± 3°F
95 % relative humidity (no water spray)
Repeat continuously
3 4 h light at 50 % ± % RH 63 ± 2°C 0.35 ± 0.02 W/(m ·nm) at 340 nm Exterior pigmented stains
4 h dark with water spray 145 ± 4°F 41.5 ± 2.5 W/m from 300-400 nm
Repeat continuously
3 4 h light at 50 % ± 5 % RH 63 ± 2°C 0.35 ± 0.02 W/(m ·nm) at 340 nm Exterior pigmented stains
4 h dark with water spray 145 ± 4°F 41.5 ± 2.5 W/m from 300-400 nm
Repeat continuously
4 12 h light at 50 % ± 5 % RH 63 ± 2°C 0.35 ± 0.02 W/(m ·nm) at 340 nm Exterior wood stains
12 h dark with water spray 145 ± 4°F 41.5 ± 2.5 W/m from 300-400 nm and clears
Repeat continuously
5 8 h light at 50 % ± 5 % RH 63 ± 2°C 0.35 ± 0.02 W/(m ·nm) at 340 nm Marine enamels
10 h light and water spray 145 ± 4°F 41.5 ± 2.5 W/m from 300-400 nm
6 h dark with water spray
Repeat continuously
2 H
6 40 min light at 50 % ± 5 % RH 70 ± 2 °C (158 ± 4 °F) 0.55 ± 0.02 W/(m ·nm) at 340 nm Automotive exterior
20 min light and water spray 70 ± 2 °C (158 ± 4 °F) 65.5 ± 2.5 W/m from 300-400 nm
60 min light at 50 % ± 5 % RH 38 ± 2 °C (100 ± 4 °F)
60 min dark at 95 % ± 5 % RH
(water spray on front and back of specimens)
Repeat continuously
2 I
7 3.8 h light at 50 % ± 5 % RH 89 ± 3 °C (192 ± 5 °F) 0.55 ± 0.02 W/(m ·nm) at 340 nm Automotive interior
1.0 h dark at 95 %± 5 % RH 38 ± 2 °C (100 ± 4 °F) 65.5 ± 2.5 W/m from 300-400 nm
Repeat continuously
2 I
7 3.8 h light at 50 % ± 5 % RH 89 ± 3 °C (192 ± 5 °F) 0.55 ± 0.02 W/(m ·nm) at 340 nm Automotive interior
1.0 h dark at 95 % ± 5 % RH 38 ± 2 °C (100 ± 4 °F) 65.5 ± 2.5 W/m from 300-400 nm
Repeat continuously
A
The cycles described are not listed in any order indicating importance, and are not necessarily recommended for the applications shown.
B
As stated in 5.2, the spectral power distribution (SPD) of the xenon lamp shall conform to the requirements of Practice G155 for a xenon lamp with daylight filters.
C
Unless otherwise indicated, black panel temperatures apply during light-only portion of the cycle. The equilibrium black panel temperature is obtained without a spray
period. For light intervals shorter than 30 min, the black panel temperature might not reach equilibrium. Unless otherwise specified, add 6°C (11°F) to the temperature given
for the uninsulated black panel when an insulated black panel is used. Practice G151 provides more information on the temperatures indicated by insulated and uninsulated
black panels, which can depend on irradiance level, and the type of xenon-arc filter used.
D
The irradiance values given are those that have historically been used. In devices capable of producing higher irradiance, the actual irradiance used may be higher than
the stated values. For example, Japanese auto industry specifications allow use of exposures according to Cycle 1 with 300 to 400 nm irradiance of up to 180 W/m .
E
Typical uses does not imply that results from exposures of these materials according to the cycle described will correlate to those from actual use conditions.
F
Unless otherwise specified, water spray refers to water sprayed on the exposed surface of the test specimens.
G
This cycle has been used for coatings by historical convention and may not adequately simulate the effects of outdoor exposure.
H
This cycle is based on the conditions of SAE J2527, but there may be additional requirements in the SAE standard not shown here.
I
This cycle is based on the conditions of SAE J2412, but there may be additional requirements in the SAE standard not shown here.
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E1347 Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry
G113 Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials
G141 Guide for Addressing Variability in Exposure Testing of Nonmetallic Materials
G147 Practice for Conditioning and Handling of Nonmetallic Materials for Natural and Artificial Weathering Tests
G151 Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources
G155 Practice for Operating Xenon Arc Light Apparatus for Exposure of Non-Metallic Materials
G169 Guide for Application of Basic Statistical Methods to Weathering Tests
D6695 − 16
2.2 ISO Standards:
ISO 11341ISO 16474-2 Paints and Varnishes—Artificial Weathering and Exposure to Artificial Radiation—Exposure to Filtered
Xenon-Arc RadiationVarnishes—Methods of exposure to laboratory light sources—Part 2: Xenon-arc lamps
2.3 Society of Automotive Engineers Standards:
SAE J2412 Accelerated Exposure of Automotive Interior Trim Components using a Controlled Irradiance Xenon-Arc
Apparatus
SAE J2527 Performance Based Standard for Accelerated Exposure of Automotive Exterior Materials using a Controlled
Irradiance Xenon-Arc Apparatus
3. Terminology
3.1 The definitions given in Terminology G113 are applicable to this practice.
4. Significance and Use
4.1 The ability of a paint or coating to resist deterioration of its physical and optical properties caused by exposure to light, heat,
and water can be very significant for many applications. This practice is intended to induce property changes associated with end
use conditions, including the effects of sunlight,daylight, moisture, and heat. The exposure used in this practice is not intended to
simulate the deterioration caused by localized weather phenomena such as atmospheric pollution, biological attack, and salt water
exposure.
4.2 Caution—Variation in results may be expected when different operating conditions are used. Therefore, no reference to the
use of this practice shall be made unless accompanied by a report prepared according to Section 109 that describes the specific
operating conditions used. Refer to Practice G151 for detailed information on the caveats applicable to use of results obtained
according to this practice.
NOTE 2—Additional information on sources of variability and on strategies for addressing variability in the design, execution and data analysis of
laboratory accelerated exposure tests is found in Guide G141.
4.2.1 The spectral power distribution of light from a xenon-arc is significantly different from that produced in light and water
exposure devices using carbon-arc or other light sources. The type and rate of degradation and the performance rankings produced
by exposures to xenon-arcs can be much different from those produced by exposures to other types of laboratory light sources.
4.2.2 Interlaboratory comparisons are valid only when all laboratories use the same light source, filter type, and exposure
conditions.
4.3 Reproducibility of test results between laboratories has been shown to be good when the stability of materials is evaluated
6,7
in terms of performance ranking compared to other materials or to a control. Therefore, exposure of a similar material of known
performance (a control) at the same time as the test materials is strongly recommended. It is recommended that at least three
replicates of each material be exposed to allow for statistical evaluation of results.
4.4 Test results will depend upon the care that is taken to operate the equipment according to Practice G155. Significant factors
include regulation of line voltage, freedom from salts or other deposits from water, temperature and humidity control, and
condition and age of the burnerlamp and filters.
4.5 All references to exposures in accordance with this practice must include a complete description of the test cycle used.
5. Safety Hazards
5.1 Warning—Never look directly at the xenon-arc because UV radiation can damage the eye. Most xenon-arc machines are
equipped with door safety switches, but users of old equipment must be certain to turn the power to the lamp off before opening
the test-chamber door.
5.2 Xenon-arc lamps should be at or near room temperature before handling.
5. Apparatus
5.1 Use xenon-arc apparatus that conforms to the requirements defined in Practices G151 and G155.
5.2 Unless otherwise specified, the spectral power distribution of the xenon-arc shall conform to the requirements in Practice
G155 for xenon-arc with daylight filters.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Available from Society of Automotive Engineers (SAE), 400 Commonwealth Dr., Warrendale, PA 15096-0001, http://www.sae.org.
Fischer, R., “Results of Round Robin Studies of Light- and Water-Exposure Standard Practices,” Accelerated and Outdoor Durability Testing of Organic Materials, ASTM
STP 1202, Warren D. Ketola and Douglas Grossman, Eds, ASTM, 1993.
Ketola, W., and Fischer, R. “Characterization and Use of Reference Materials in Accelerated Durability Tests,” VAMAS Technical Report No. 30, available from NIST,
June 1997.
D6695 − 16
6. Test Specimens
6.1 Apply the coating to flat (plane) panels with the substrate, method of preparation, method of application, coating system,
film thickness, and method of drying consistent with the anticipated end use, or as mutually agreed upon between the producer
and user.
6.2 Panel specifications and methods of preparation include but are not limited to Practices D609, D1730, or Specification
D358. Select panel sizes suitable for use with the exposure apparatus.
6.3 Coat test panels in accordance with Practices D823 and then measure the film thickness in accordance with an appropriate
procedure selected from Test Methods D1005, D1186, or D1400. Nondestructive methods are preferred because panels so
measured need not be repaired.
6.4 Prior to exposing coated panels in the apparatus, condition them at 23 6 2°C (73 6 3°F) and 50 6 5 %10 % relative
humidity for one of the following periods in accordance with the type of coating:
Baked coatings 24 h
Radiation-cured coatings 24 h
All other coatings 7 days min
6.4.1 Other procedures for preparation of test specimens may be used if agreed upon between all interested parties.
6.5 Mount specimens in holders so that only the minimum specimen area required for support by the holder is covered. Do not
use this covered area of the specimen This unexposed surface must not be used as part of the test area. In cases where it is necessary
to support flexible specimens during exposure, attach the flexible specimens to a thin supporting panel.
NOTE 3—For supporting flexible specimens, aluminum panels that are 0.025 in. (0.64 mm) which have been found to be acceptable for many
applications.
6.6 Unless otherwise specified, expose at least three replicate specimens of each test and control material.
6.6.1 If performance comparisons are not being made between the test materials themselves, it is recommended that a control
material be exposed simultaneously with experimental materials for determination of relative performance. All concerned parties
must agree on the control material, if any is used.
6.7 Follow the procedures described in Practice G147 for identification and conditioning and handling of specimens of test,
control, and reference materials prior to, during, and after exposure.
6.8 Do not mask the face of a specimen for the purpose of showing on one panel the effects of various exposure times.
Mislea
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