1、Designation: D4459 12Standard Practice forXenon-Arc Exposure of Plastics Intended for IndoorApplications1This standard is issued under the fixed designation D4459; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers specific procedures and test condi-tions that are applicable for exposure of plastics in windowglass-fi
3、ltered xenon-arc devices in accordance with PracticesG151 and G155 for evaluating the stability of plastics intendedfor use in indoor applications.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this sta
4、ndard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1There is no known ISO equivalent to this practice.2. Referenced Documents2.1 ASTM Standards:2D1729 Practice for Visual Appraisal of Colors and ColorDifferences of
5、 Diffusely-Illuminated Opaque MaterialsD2244 Practice for Calculation of Color Tolerances andColor Differences from Instrumentally Measured ColorCoordinatesD3980 Practice for Interlaboratory Testing of Paint andRelated Materials (Withdrawn 1998)3D4674 Practice forAccelerated Testing for Color Stabil
6、ity ofPlastics Exposed to Indoor Office EnvironmentsD5870 Practice for Calculating Property Retention Index ofPlasticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodG113 Terminology Relating to Natural and Artificial Weath-ering Tests of Nonmetallic M
7、aterialsG141 Guide for Addressing Variability in Exposure Testingof Nonmetallic MaterialsG147 Practice for Conditioning and Handling of Nonmetal-lic Materials for Natural and Artificial Weathering TestsG151 Practice for Exposing Nonmetallic Materials in Accel-erated Test Devices that Use Laboratory
8、Light SourcesG155 Practice for Operating Xenon Arc Light Apparatus forExposure of Non-Metallic MaterialsG169 Guide for Application of Basic Statistical Methods toWeathering Tests3. Terminology3.1 The definitions in Terminology G113 are applicable tothis practice.4. Significance and Use4.1 This pract
9、ice is intended to simulate the effects pro-duced by exposure to solar radiation through glass. Thispractice uses exposure in a xenon-arc device equipped withwindow glass filters and operated in accordance with PracticesG151 and G155.NOTE 2Practice D4674 describes exposures in a device that uses aco
10、mbination of fluorescent “cool white” and ultraviolet (UV) lamps tosimulate the effects of exposures to indoor fluorescent light and windowglass filtered daylight.4.2 WarningVariation in results may be expected whenoperating conditions are varied within the accepted limits ofthis practice. Therefore
11、, all references to the use of this practicemust be accompanied by a report prepared in accordance withSection 9 that describes the specific operating conditions used.Refer to Practice G151 for detailed information on the caveatsapplicable to use of results obtained in accordance with thispractice.N
12、OTE 3Additional information on sources of variability and onstrategies for addressing variability in the design, execution and dataanalysis of laboratory accelerated exposure tests is found in Guide G141.4.3 Test results will depend upon the care that is taken tooperate the equipment in accordance w
13、ith Practice G155.Significant factors include regulation of line voltage, tempera-ture and humidity control, and condition and age of the lampsand filters.4.4 Reproducibility of test results between laboratories hasbeen shown to be good when the stability of materials is1This practice is under the j
14、urisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.50 on Durability of Plastics.Current edition approved Nov. 15, 2012. Published November 2012. Originallyapproved in 1985. Last previous edition approved in 2006 as D4459 - 06. DOI:10.1520/D4459-12.2For r
15、eferenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is reference
16、d onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1evaluated in terms of performance ranking compared to othermaterials or to a control.4,5Therefore, expos
17、ure of a similarmaterial of known performance (a control) at the same time asthe test materials is strongly recommended. It is recommendedthat at least three replicates of each material be exposed toallow for statistical evaluation of results.5. Apparatus5.1 Use xenon-arc apparatus that conforms to
18、the require-ments defined in Practices G151 and G155.5.2 The spectral power distribution of the xenon-arc lampshall conform to the requirements described in Practice G155for a xenon-arc lamp with window glass filters.5.3 Unless otherwise specified, use a xenon-arc deviceequipped with a radiometer ca
19、pable of monitoring eithernarrow-band or broad-band irradiance incident on test speci-mens.6. Test Specimen6.1 The size and shape of specimens to be exposed will bedetermined by the specifications of the particular test methodused to evaluate the effects of the exposure on the specimens;the test met
20、hod shall be determined by the parties concerned.Where practical, it is recommended that specimens be sized tofit specimen holders and racks supplied with the exposureapparatus. Unless supplied with a specific backing as anintegral part of the test, specimens shall be mounted so thatonly the minimum
21、 specimen area required for support by theholder shall be covered. This unexposed surface must not beused as part of the test area.6.2 Unless otherwise specified, expose at least three repli-cate specimens of each test material and of the control material,if used.6.3 Follow the procedures described
22、in Practice G147 foridentification and conditioning and handling of specimens oftest, control, and reference materials prior to, during, and afterexposure.6.4 Do not mask the face of specimen for the purpose ofshowing on one panel the effects of various exposure times.Misleading results may be obtai
23、ned by this method, since themasked portion of the specimen is still exposed to temperatureand humidity cycles that in many cases will affect results.6.5 Since the thickness of a specimen may affect markedlythe results, thickness of test and control specimens shall bewithin 610 % of the nominal dime
24、nsions.NOTE 4This is especially important if changes in mechanical prop-erties are being investigated.6.6 Incident energy at the extremes of the specimen expo-sure area in older equipment may be only 70 % of that at thecenter. If the irradiance at any position within the exposure areais less than 90
25、 % of the peak irradiance, follow one of theprocedures outlined in Practice G155 to ensure either equalradiant exposure or compensation for differences in radiantexposure.6.7 Retain a supply of unexposed file specimens of allmaterials evaluated.6.7.1 When destructive tests are run, ensure than suffi
26、cientfile specimens are retained so that the property of interest canbe determined on unexposed file specimens each time exposedmaterials are evaluated.6.8 Specimens should not be removed from the exposureapparatus for more than 24 h and then returned for additionaltests, since this does not produce
27、 the same results on allmaterials as tests run without this type of interruption. Whenspecimens are removed from the exposure apparatus for 24 h ormore then returned for additional exposure, report the elapsedtime as noted in accordance with Section 9.NOTE 5Since the stability of the file specimens
28、is also time-dependent, users are cautioned that over prolonged exposure periods, orwhere small differences in the order of acceptable limits are anticipated,comparison of exposed specimens with the file specimen may not be valid.Instrumental measurements are recommended whenever possible.7. Procedu
29、re7.1 Operate the xenon-arc device in continuous light modewithout any water spray.7.2 Unless otherwise specified, control the irradiance at oneof the following levels:7.2.1 0.30 6 0.02 W/(m2 nm) at 340 nm.7.2.2 0.80 6 0.05 W/(m2 nm) at 420 nm.7.2.3 36.5 6 2.5 W/m2between 300 and 400 nm.7.2.4 If the
30、 exposure device is not equipped with irradiancecontrol, follow the manufacturers recommendations to pro-duce the specified irradiance levels.7.3 Unless otherwise specified, control the temperature ofan uninsulated black panel at 55 6 2C (131 6 4F).7.4 Unless otherwise specified, control relative hu
31、midity at50 6 10 %.NOTE 6The 6 are the operational fluctuations and are the allowabledeviations from the specified set points for irradiance, temperature andrelative humidity during equilibrium operation. They do not imply that theuser is allowed to program a set point higher or lower than that spec
32、ified.If the operational fluctuations are greater than the maximum allowableafter the equipment has stabilized, discontinue the test and correct thecause of the problem before continuing.7.5 It is recommended that a control material be exposed atthe same time as the test specimens for comparison pur
33、poses,if performance comparisons are not being made between thetest materials themselves. All concerned parties must agree onthe control material used.7.6 Unless otherwise specified, expose at least three repli-cates of each test and control material evaluated to allow forstatistical evaluation of r
34、esults.7.6.1 It is recommended that all unused spaces in thespecimen exposure area be filled with non-ultraviolet reflectingblanks, for example, grey card stock.4Fischer, R., “Results of Round Robin Studies of Light- and Water-ExposureStandard Practices,” Accelerated and Outdoor Durability Testing o
35、f OrganicMaterials, ASTM STP 1202, Warren D. Ketola and Douglas Grossman, eds.,American Society for Testing and Materials, Philadelphia, 1993.5Ketola, W., and Fischer, R., “Characterization and Use of Reference Materialsin Accelerated Durability Tests,” VAMAS Technical Report No. 30, available fromN
36、IST, Gaithersburg, MD.D4459 1227.7 Expose the test and control materials (if used) for a timeor radiant exposure agreed upon between all interested parties.7.7.1 Determine the color difference between the exposedand file specimens in accordance with Test Method D2244 orPractice D1729. If materials a
37、re not evaluated within 4 h afterremoval from exposure, store specimens at a temperature of-15 to -20C. Test all specimens within one week after removalfrom exposure.7.7.2 Where desired, measurement of other properties canalso be made on exposed specimens.7.8 When a control material is used, a compl
38、ete descriptionof the control material shall be included when reporting resultsobtained in accordance with this practice.8. Periods of Exposure and Evaluation of Test Results8.1 In most cases, periodic evaluation of test and controlmaterials is necessary to determine the variation in magnitudeand di
39、rection of property change as a function of exposure timeor radiant exposure.8.2 The time or radiant exposure necessary to produce adefined change in a material property can be used to evaluateor rank the stability of materials. This method is preferred overevaluating materials after an arbitrary ex
40、posure time or radiantexposure.8.2.1 Exposure to an arbitrary time or radiant exposure maybe used for the purpose of a specific test if agreed uponbetween the parties concerned or if required for conformanceto a particular specification. When a single exposure period isused, select a time or radiant
41、 exposure that will produce thelargest performance differences between the test materials orbetween the test material and the control material.8.2.2 The minimum exposure time used shall be that nec-essary to produce a substantial change in the property ofinterest for the least stable material being
42、evaluated. Anexposure time than produces a significant change in one type ofmaterial cannot be assumed to be applicable to other types ofmaterials.8.2.3 The relation between time in failure in an exposureconducted in accordance with this practice and service life inan outdoor environment requires de
43、termination of a validacceleration factor. Do not use arbitrary acceleration factorsrelating time in an exposure conducted in accordance with thispractice and time in an outdoor environment because they cangive erroneous information. The acceleration factor is material-dependent and is only valid if
44、 it is based on data from asufficient number of separate exterior and laboratory-accelerated exposures so that results used to relate times tofailure in each exposure can be analyzed using statisticalmethods.NOTE 7An example of a statistical analysis using multiple-laboratoryand exterior exposures t
45、o calculate an acceleration factor is described bySimms.6See Practice G151 for more information and additional cautionsabout the use of acceleration factors.8.3 After each exposure increment, evaluate or rate changesin exposed test specimens in accordance with applicableASTM test methods.NOTE 8For s
46、ome materials, changes may continue after the specimenhas been removed from the exposure apparatus. Measurements (visual orinstrumental) should be made within a standardized time period or asagreed upon between interested parties. The standardized time periodneeds to consider conditioning prior to t
47、esting.8.4 Use of results from exposures conducted in accordancewith this practice in specifications:8.4.1 If a standard or specification for general use requires adefinite property level after a specific time or radiant exposurein an exposure test conducted in accordance with this practice,base the
48、 specified property level on results from round-robinexperiments run to determine the test reproducibility from theexposure and property measurement procedures. Conduct theseround robins in accordance with Practice E691 or PracticeD3980 and include a statistically representative sample of alllaborat
49、ories or organizations who would normally conduct theexposure and property measurement.8.4.2 If a standard or specification for use between two orthree parties requires a definite property level after a specifictime or radiant exposure in an exposure test conducted inaccordance with this practice, base the specified property levelon two independent experiments run in each laboratory todetermine the reproducibility for the exposure and propertymeasurement process. The reproducibility of the exposure/property measurement process is then used to determine theminimum level
