1、Designation: D 2565 99Standard Practice forXenon-Arc Exposure of Plastics Intended for OutdoorApplications1This standard is issued under the fixed designation D 2565; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This practice covers specific procedure
3、s and test condi-tions that are applicable for xenon-arc exposure of plasticsconducted in accordance with Practices G 151 and G 155. Thispractice also covers the preparation of test specimens, the testconditions best suited for plastics, and the evaluation of testresults.NOTE 1Previous versions of t
4、his practice referenced xenon-arc de-vices described in Practice G26, which described very specific equipmentdesigns. Practice G26 is being replaced by Practice G 151, whichdescribes performance criteria for all exposure devices that use laboratorylight sources and by Practice G 155, which gives req
5、uirements forexposing nonmetallic materials in xenon-arc devices. Practice G26willbe balloted for withdrawal before December 2000.1.2 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 standard to establis
6、h appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 2This practice is technically equivalent to ISO 4892-2.2. Referenced Documents2.1 ASTM Standards:2D 1293 Test Methods for pH of WaterD 3980 Practice for Interlaboratory Testing of
7、Paint andRelated MaterialsD 5870 Practice for Calculating Property Retention Indexof PlasticsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodG26 Practice for Operating Light-Exposure Apparatus(Xenon-Arc Type) With and Without Water for Exposureof Nonm
8、etallic MaterialsG113 Terminology Relating to Natural and ArtificialWeathering Tests of Nonmetallic MaterialsG 141 Guide forAddressing Variability in Exposure Testingon Nonmetallic MaterialsG 147 Practice for Conditioning and Handling of Nonme-tallic Materials for Natural and Artificial Weathering T
9、estsG 151 Practice for Exposing Nonmetallic Materials in Ac-celerated Test Devices That Use Laboratory Light SourcesG 155 Practice for Operating Xenon-Arc Light Apparatusfor Exposure of Nonmetallic Materials2.2 ISO Standard:3ISO 4892-2 PlasticsMethods of Exposure to LaboratoryLight Sources Part 2, X
10、enon Arc Lamp3. Terminology3.1 The definitions in Terminology G113are applicable tothis practice.4. Significance and Use4.1 The ability of a plastic material to resist deterioration ofits electrical, mechanical, and optical properties caused byexposure to light, heat, and water can be very significa
11、nt formany applications. This practice is intended to induce propertychanges associated with end-use conditions, including theeffects of daylight, moisture, and heat. The exposure used inthis practice is not intended to simulate the deterioration causedby localized weather phenomena, such as, atmosp
12、heric pollu-tion, biological attack, and saltwater exposure.4.2 CautionVariations in results may be expected whenoperating conditions are varied within the accepted limits ofthis practice. Therefore, all references to the use of this practicemust be accompanied by a report prepared in accordance wit
13、hSection 9 that describes the specific operating conditions used.Refer to Practice G 151 for detailed information on the caveatsapplicable to use of results obtained in accordance with thispractice.NOTE 3Additional information on sources of variability and onstrategies for addressing variability in
14、the design, execution, and data1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.50 on Durability of Plastics.Current edition approved Jan. 10, 1999. Published April 1999. Originallypublished as D 2565 66T. Last previous edi
15、tion D 2565 92a.2For referenced 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.3Available from American National Standards I
16、nstitute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.analysis of laboratory-accelerated exposure tests is foun
17、d in Guide G 141.4.3 Reproducibility of test results between laboratories hasbeen shown to be good when the stability of materials isevaluated in terms of performance ranking compared to othermaterials or to a control.4,5Therefore, exposure of a similarmaterial of known performance (a control) at th
18、e 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.4.4 Test results will depend upon the care that is taken tooperate the equipment in accordance with Practice G 155.Signi
19、ficant factors include regulation of line voltage, freedomfrom salts or other deposits from water, temperature andhumidity control, and condition and age of the burner andfilters.5. Apparatus5.1 Use xenon-arc apparatus that conform to the require-ments defined in Practices G 151 and G 155.5.2 Unless
20、 otherwise specified, the spectral power distribu-tion (SPD) of the xenon lamp shall conform to the require-ments of Table 1 in Practice G 155 for a xenon lamp withdaylight filters.6. Test Specimen6.1 The size and shape of specimens to be exposed will bedetermined by the specifications of the partic
21、ular test methodused to evaluate the effects of the exposure on the specimens;the test method 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
22、backing as anintegral part of the test, specimens shall be mounted so thatonly the minimum 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 e
23、ach test material and of the control material,if used.6.3 Follow the procedures described in Practice G 147 foridentification and conditioning and handling of test specimens,control, and reference materials prior to, during, and afterexposure.6.4 Do not mask the face of a specimen for the purpose of
24、showing on one panel the effects of various exposure times.Misleading results may be obtained 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 markedly affectthe
25、 results, thickness of test and control specimens shall bewithin 610 % of the nominal dimensions.NOTE 4This is especially important when mechanical properties arebeing investigated.6.6 Incident energy at the extremes of the specimen expo-sure area in older equipment may be only 70 % of that at thece
26、nter. If the irradiance at any position within the exposure areais less than 90 % of the peak irradiance, follow one of theprocedures outlined in Practice G 155 to ensure either equalradiant exposure or compensation for differences in radiantexposure.6.7 Retain a supply of unexposed file specimens o
27、f allmaterials evaluated.6.7.1 When destructive tests are run, ensure that sufficientfile 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 m
28、ore than 24 h and then returned for additionaltests, since this does not produce the same results on allmaterials as tests run without this type of interruption. Whenspecimens are removed from the exposure apparatus for 24 h ormore and then returned for additional exposure, report theelapsed time in
29、 accordance with Section 9.NOTE 5Since the stability of the file specimen may also be 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 b
30、e valid.Instrumental measurements are recommended whenever possible.7. Procedure7.1 Practice G 155 lists several exposure cycles that areused for xenon-arc exposures of nonmetallic materials. Table 1lists several of these cycles. Obtain mutual agreement betweenall concerned parties for the specific
31、exposure cycle used.7.2 If no other cycle is specified, use Cycle No. 1.7.2.1 Unless otherwise specified, control the irradiance toproduce 0.35 6 0.02 W/m2at 340 nm or 41.5 6 2.5 W/m2between 300 and 400 nm. If the exposure device is notequipped with irradiance control, follow the device manufac-ture
32、rs recommendations to produce this irradiance, or otherspecified irradiance level.7.2.2 Unless otherwise specified, in devices which allow forcontrol of relative humidity, maintain relative humidity at 50 65 % equilibrium during the light-only interval.7.2.3 Unless otherwise specified, the equilibri
33、um tempera-ture of an un-insulated black panel thermometer shall be 63 62C.7.3 It is recommended that all unused spaces in the speci-men exposure area be filled with blank metal panels.7.4 Water Purity:7.4.1 The purity of water used for specimen spray is veryimportant. Without proper treatment to re
34、move cations, anions,organics, and particularly silica, exposed panels will developspots or stains that may not occur in exterior exposures.7.4.2 Follow the requirements for water purity described inPractice G 151.7.4.3 If specimens are found to have deposits or stains afterexposure in the apparatus
35、, the water purity must be checked todetermine if it meets the requirements of 7.4.2. On someoccasions, exposed specimens can be contaminated by deposits4Fischer, R., “Results of Round Robin Studies of Light- and Water-ExposureStandard Practices,” Accelerated and Outdoor Durability Testing of Organi
36、cMaterials, 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 fromNIST, Gai
37、thersburg, MD.D2565992from bacteria that can grow in the purified water used forspecimen spray. If bacterial contamination is detected, theentire system used for specimen water spray must be flushedwith chlorine and thoroughly rinsed prior to resuming expo-sures.7.4.4 The temperature of water used f
38、or specimen sprayshould be 16 6 5C (60.8 6 9F).7.4.5 When the preceding water purity requirements are metand there is disagreement between parties on the extent ofproblems caused by stain or deposit, run referee tests in at leastone other laboratory that can meet the water quality require-ments desc
39、ribed in 7.4.7.5 Some tests for lightfastness are run without any speci-men wetting. When this type of test is required, omit the periodwhere water is sprayed on specimens.7.6 It is recommended that a control material be exposed atthe same time as the test specimens for comparison purposes,if perfor
40、mance comparisons are not being made between thetest materials themselves. All concerned parties must agree onthe control material used.7.6.1 Identification of any control specimen used shallaccompany the report.8. Periods of Exposure and Evaluation of Test Results8.1 In most cases, periodic evaluat
41、ion of test and controlmaterials is necessary to determine the variation in magnitudeand direction 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 stab
42、ility of materials. This method is preferred overevaluating materials after an arbitrary exposure 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
43、 a particular specification. When a single exposure period isused, select a time or radiant 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 p
44、roduce a substantial change in the property ofinterest for the least stable material being evaluated. Anexposure time that 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 to failure in an exposurecondu
45、cted in accordance with this practice and service life inan outdoor environment requires determination 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 cangiv
46、e erroneous information. The acceleration factor is material-dependent and is only valid if 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.N
47、OTE 6An example of a statistical analysis using multiple-laboratoryand exterior exposures to calculate an acceleration factor is described bySimms.6See Practice G 151 for more information and additional cautionsabout the use of acceleration factors.8.3 After each exposure increment, evaluate or rate
48、 changesin exposed test specimens in accordance with applicableASTM test methods.6Simms, J.A., Journal of Coatings Technology, Vol 50, 1987, pp. 45-53.TABLE 1 Test Cycles Commonly Used for Xenon-Arc ExposureTesting of PlasticsACycleNumberCycle DescriptionBUn-insulatedBlackPanelTemperature,CCTypicalI
49、rradianceTypicalUsesD1 102 min light only followedby 18 min of light with waterspray (102/18 cycle)E63 6 2 0.35 6 0.02W/m2at 340 nm41.5 6 2.5 W/m2from 300 to 400nmhistoricalconventionF2 18-h, consisting ofalternating intervals of 102min light only followed by 18min of light with water spray63 6 2 0.35 6 0.02W/m2at 340 nm41.5 6 2.5 W/m2from 300 to 400nmgeneralplastics6 h dark, at 95 6 4%RHwith no water spray38 6 2repeat3 1.5 h light at 70 6 5%RH0.5 h light and water spray77 6 3 0.35 6 0.02W/m2at 340 nmfabricsrepeat41.5 6 2.5 W/m2from 300 to 400nm4 40 min light at 5
