1、Designation: D 4329 05Standard Practice forFluorescent UV Exposure of Plastics1This standard is issued under the fixed designation D 4329; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in paren
2、theses indicates the year of last reapproval. Asuperscript epsilon (e) 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 fluorescent UV exposure of plasticsconducted in accordance wit
3、h Practices G 151 and G 154. Thispractice also covers the preparation of test specimens, the testconditions best suited for plastics, and the evaluation of testresults.1.2 The values stated in SI units are be regarded as standard.The values given in brackets are for information only.1.3 This standar
4、d 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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1This practice is technica
5、lly similar to ISO 4892-3.2. Referenced Documents2.1 ASTM Standards:2D 3980 Practice for Interlaboratory Testing of Paint andRelated MaterialsD 5870 Practice for Calculating Property Retention Indexof PlasticsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test
6、MethodG113 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 TestsG 151 P
7、ractice for Exposing Nonmetallic Materials in Ac-celerated Test Devices That Use Laboratory Light SourcesG 154 Practice for Operating Fluorescent Light Apparatusfor UV Exposure of Nonmetallic MaterialsG 169 Guide for Applications of Basic Statistical Methodsto Weathering TestsG 177 Tables for Refere
8、nce Solar Ultraviolet Spectral Dis-tributions: Hemispherical on 37 Degree Tilted Surface2.2 ISO Standard:3ISO 4892-3 PlasticsMethods of Exposure to LaboratoryLight SourcesPart 3, Fluorescent UV Lamps2.3 SAE Standard:4SAE J2020 Accelerated Exposure of Automotive ExteriorMaterials Using a Fluorescent
9、UV and CondensationApparatus3. 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
10、 very significant formany applications. This practice is intended to induce propertychanges associated with end-use conditions, including theeffects of sunlight, moisture, and heat. The exposure used inthis practice is not intended to simulate the deterioration causedby localized weather phenomena,
11、such as, atmospheric pollu-tion, biological attack, and saltwater exposure. (WarningVariation in results may be expected when operating conditionsare varied within the accepted limits of this practice. Therefore,no reference to the use of this practice should be made unlessaccompanied by a report pr
12、epared in accordance with Section8 that describes the specific operating conditions used. Refer toPractice G 151 for detailed information on the caveats appli-cable to use of results obtained in accordance with thispractice.)NOTE 2Additional information on sources of variability and onstrategies for
13、 addressing variability in the design, execution, and dataanalysis of laboratory-accelerated exposure tests is found in Guide G 141.4.2 Reproducibility of test results between laboratories hasbeen shown to be good when the stability of materials isevaluated in terms of performance ranking compared t
14、o other1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.50 on Permanence Properties.Current edition approved July 15, 2005. Published August 2005. Originallyapproved in 1984. Last previous edition approved in 1999 as D 4329
15、 - 99.2For 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 Institute (
16、ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.4Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoho
17、cken, PA 19428-2959, United States.materials or to a control.5,6Therefore, exposure 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
18、 evaluation of results.4.3 Test results will depend upon the care that is taken tooperate the equipment in accordance with Practice G 154.Significant factors include regulation of line voltage, tempera-ture of the room in which the device operates, temperaturecontrol, and condition and age of the la
19、mp.5. Apparatus5.1 Use of fluorescent UV apparatus that conforms to therequirements defined in Practices G 151 and G 154 is requiredto conform to this practice.5.2 Unless otherwise specified, the spectral power distribu-tion of the fluorescent UV lamp shall conform to the require-ments in Practice G
20、 154 for a UVA 340 lamp. Fig. 1 is aspectral irradiance plot for a typical UVA-340 lamp andbenchmark solar radiation.NOTE 3The source of the sunlight data in Fig. 1 is from StandardG 177 standard solar spectrum.5.3 Test Chamber Location:5.3.1 Locate the apparatus in an area maintained between 18and
21、27C 65 and 80F. Measure ambient temperature at amaximum distance of 150 mm 6 in. from the plane door ofthe apparatus. Control of ambient temperature is particularlycritical when one apparatus is stacked above another, becausethe heat generated from the lower unit can interfere with theoperation of t
22、he units above.5.3.2 Place the apparatus at least 300 mm from walls orother apparatus. Do not place the apparatus near a heat sourcesuch as an oven.5.3.3 Ventilate the room in which the apparatus is located toremove heat and moisture.6. Test Specimen6.1 The size and shape of specimens to be exposed
23、will bedetermined by the specifications of the particular 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 th
24、e exposureapparatus. Unless supplied with a specific 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 For specimens of insul
25、ating materials, such as foams,maximum specimen thickness is 20 mm in order to allow foradequate heat transfer for condensation.6.3 To provide rigidity, attach flexible specimens to abacking panel made of aluminum, 0.635 mm 0.025 in. thick.Suggested aluminum alloys are 5052, 6061, or 3003.5Fischer,
26、R., “Results of Round Robin Studies of Light- and Water-ExposureStandard Practices,” Accelerated and Outdoor Durability Testing of OrganicMaterials, ASTM STP 1202, Warren D. Ketola and Douglas Grossman, eds.,American Society for Testing and Materials, Philadelphia, 1993.6Ketola, W., and Fischer, R.,
27、 “Characterization and Use of Reference Materialsin Accelerated Durability Tests,” VAMAS Technical Report No. 30, available fromNIST, Gaithersburg, MD.FIG. 1 Representative Spectral Power Distribution of UVA-340 Fluorescent LampsD43290526.4 Seal any holes in specimens larger than 2 mm and anyopening
28、s larger than 1 mm around irregularly shaped speci-mens to prevent loss of water vapor. Attach porous specimensto a solid backing such as aluminum that can act as a vaporbarrier.6.5 Unless otherwise specified, expose at least three repli-cate specimens of each test and control material.6.6 Follow th
29、e procedures described in Practice G 147 foridentification, conditioning, and handling of specimens of test,control, and reference materials prior to, during, and afterexposure.6.7 Do not mask the face of a specimen for the purpose ofshowing on one panel the effects of various exposure times.Mislead
30、ing 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.6.8 Since the thickness of a specimen may markedly affectthe results, thickness of test and control specimens shall bewithin 6
31、10 % of the nominal dimensions.NOTE 4This is especially important when mechanical properties arebeing investigated.6.9 Retain a supply of unexposed file specimens of allmaterials evaluated.6.9.1 When destructive tests are run, ensure that sufficientfile specimens are retained so that the property of
32、 interest canbe determined on unexposed file specimens each time exposedmaterials are evaluated.6.10 Specimens should not be removed from the exposureapparatus for more than 24 h and then returned for additionaltests, since this does not produce the same results on allmaterials as tests run without
33、this type of interruption. Whenspecimens are removed from the exposure apparatus for 24 h ormore and then returned for additional exposure, report theelapsed time as noted in accordance with Section 9.NOTE 5Since the stability of the file specimen may also be time-dependent, users are cautioned that
34、 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. Procedure7.1 When the test and control specimens do not
35、 completelyfill the specimen racks, fill all empty spaces with blank panelsto maintain the test conditions within the chamber.7.2 Unless otherwise specified, program the device to one ofthe following test cycles. Operate the device continuously.7.2.1 Cycle A:8 h UV with uninsulated black panel tempe
36、rature controlled at 60 63C4 h condensation with uninsulated black panel temperature con-trolled at 50 6 3C(Used for most general applications)7.2.2 Cycle B:8 h UV with uninsulated black panel temperature controlled at 70 63C4 h condensation with uninsulated black panel temperature con-trolled at 50
37、 6 3C(Typically used for automotive applications) Note: Cycle B is equiva-lent to the exposure test cycle specified in SAE J2020.7.2.3 Cycle C:8 h UV with uninsulated black panel temperature controlled at 50 63C4 h condensation with uninsulated black panel temperature con-trolled at 50 6 3C(Typicall
38、y used for some plastic building products)7.3 Practice G 154 lists several other exposure cycles thatare used for fluorescent UV exposures of nonmetallic materi-als. Obtain mutual agreement between all concerned parties forthe specific exposure cycle used.7.4 In order to minimize any effects from te
39、mperature orUV light variation, reposition the specimens as follows. Fig. 2shows a diagram of the specimen repositioning.7.4.1 Reposition the specimens horizontally to ensure thateach specimen spends the same amount of exposure time ineach horizontal position within the specimen holder by (1)moving
40、the two extreme right-hand holders to the far left of theexposure area, and (2) sliding the remaining holders to theright.7.4.2 Reposition the specimens vertically so that each speci-men spends the same amount of exposure time in each verticalposition within the specimen holder. For instance, if two
41、specimens are stacked vertically in each holder, then the topand bottom specimens should switch places halfway throughthe test. If four specimens are stacked vertically, then thespecimens should be repositioned vertically three times duringthe test.7.5 Water PurityThe purity of water used for specim
42、enspray is very important. Follow the purity requirements inPractice G 151 for water sprayed on specimen surfaces. It isrecommended that deionized water be used for water used toproduce condensation.7.6 It is recommended that a control material be exposed atthe same time as the test specimens for co
43、mparison purposes,if performance 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 m
44、ost cases, periodic evaluation 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
45、to evaluateor rank the stability 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
46、 required for conformanceto 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 sh
47、all be that nec-essary to produce a substantial change in the property ofD4329053interest 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
48、time to failure in an exposureconducted 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 outd
49、oor environment because they cangive 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.NOTE 6An example of a statistical analysis using multiple-laboratoryand exterior exposures to calculate an acceleration factor is described bySimms.7See Practice G 151 for more information and additional cautionsabout the use of accel
