1、Designation: D 5722 03Standard Practice forPerforming Accelerated Outdoor Weathering of Factory-Coated Embossed Hardboard Using Concentrated NaturalSunlight and a Soak-Freeze-Thaw Procedure1This standard is issued under the fixed designation D 5722; the number immediately following the designation i
2、ndicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers techniques to acc
3、elerate weatheringeffects of factory-coated embossed hardboard using apparatusdescribed in Practice G90.1.2 This practice is based upon Cycle 1 of Practice G90(concentrated natural sunlight with periodic surface waterspray) plus a soak-freeze-thaw cycle (see Section 5 of thispractice).1.3 Testing by
4、 use of the methods described in this practicemay be employed in the qualitative assessment of weatheringeffects. The relative durability of coated hardboards may bebest determined by comparison of their test results with thoseof pass-fail control specimens derived from real time exposuretest experi
5、ence (see 8.2 for specific guidelines).1.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the
6、 user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 660 Test Method for Evaluating Degree of Checking ofExterior PaintsD 661 Test Method for Evaluating Degree
7、 of Cracking ofExterior PaintsD 662 Test Method for Evaluating Degree of Erosion ofExterior PaintsD 772 Test Method for Evaluating Degree of Flaking (Scal-ing) of Exterior PaintsD 4214 Test Methods for Evaluating the Degree of Chalk-ing of Exterior Paint Films3G90 Practice for Performing Accelerated
8、 Outdoor Weath-ering of Nonmetallic Materials Using Concentrated Natu-ral SunlightG113 Terminology Relating to Natural and ArtificialWeathering Tests of Nonmetallic Materials3. Terminology3.1 The terminology used in this practice is defined inTerminology G113.3.2 Definitions:3.2.1 hardboardgeneric t
9、erm for a panel manufacturedprimarily from inter-felted lignocellulosic fibers (usuallywood), consolidated under heat and pressure in a hot press toa density of 0.50 g/cm3(31 lb/ft3) or greater and to which othermaterials may have been added during manufacture to improvecertain properties.3.2.2 embo
10、ssed hardboardhardboard that is manufacturedwith a textured surface.3.2.2.1 DiscussionWood-like and stucco patterns are ex-amples of typical embossed hardboard surfaces.4. Summary of Practice4.1 This practice is used to accelerate long-term weatheringeffects by subjecting the samples to a concentrat
11、ed naturalsunlight (with periodic daytime surface water spray) plus asoak-freeze-thaw cycle.4.2 This practice has been useful in accelerating finishfailure involving loss of film integrity, such as cracking,peeling, and flaking of factory-coated embossed hardboard.5. Significance and Use5.1 The abil
12、ity to quickly and accurately evaluate andpredict long-term weathering performance of factory-appliedcoatings is of paramount importance in making sound businessand technical decisions.5.2 It is important to include control specimens of knownfield performance to determine the efficacy of this practi
13、ce for1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.27 on Accelerated Testing.Current edition approved Oct. 1, 2003. Published October 2003. Originallyapproved in 1995. Last
14、 previous edition approved in 1995 as D 5722 95.2For 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.3Withdrawn.1C
15、opyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.specific substrate(s) and coating system(s). These referencespecimens may include materials known to possess acceptableand unacceptable field performance for the defect(s) underconsiderat
16、ion.5.3 Results derived from this practice are best used tocompare the relative performance of materials tested at thesame time in the same device.5.4 The inclusion of control specimens and their resultingdata will assist in dealing with test variability caused byseasonal or annual variations in imp
17、ortant climatic factors.However, quantitative service life approximations “accelera-tion factors” based on the above data are not recommendedunless a sufficient number of field/accelerated test comparisonshave been analyzed to compute the statistical significance ofthe “time to failure” estimate for
18、 each exposure.5.5 Aminimum of two replicates for both control specimensand test specimens is recommended to allow statistical evalu-ation of results.6. Apparatus and Materials6.1 Test Machines, as illustrated in a figure titled “Sche-matic of a Fresnel Reflecting Concentrator Accelerated Weath-erin
19、g Machine” of Practice G90and described in ApparatusSection of Practice G90.6.2 Freezer, capable of maintaining a temperature of 18C6 3C (0F 6 5F). The freezer shall be equipped with athermocouple to monitor air temperature.6.3 Mounting Board, paper-faced marine grade wood struc-tural panel, surface
20、 routed to accept the test specimens duringexposure (see Fig. 1).7. Test Specimens7.1 Recommended specimen size is 5 by 13 by maximum1.3 cm (2 by 5 by maximum12 in.).7.2 Apply exterior grade silicone adhesive to the fourcorners and center of each specimen. Use cotton gloves topress the specimen into
21、 the mounting plate. Other mountingtechniques, agreed upon between the testing laboratory and theclient are possible.7.3 Useful results have been achieved when specimen edgesand backs remain unsealed.8. Procedures8.1 One procedure recommended is Procedure B in PracticeG90.8.2 Soak-Freeze-Thaw Proced
22、ure:8.2.1 Following daily exposure in the Fresnel reflectingconcentrator accelerated weathering machine in Practice G90,Cycle 1, the mounting plate with specimens is removed andimmersed in a deionized water soak tank maintained at 21C 63C (70F 6 5F) for 1 h.Aminimum exposure of 1 MJ/m2ofultraviolet
23、radiation as measured per Practice G90constitutesa daily cycle. If a minimum of 1 MJ/m2of ultraviolet radiationis not accumulated in one day of exposure, the specimens areto be left on the apparatus and are not to be immersed or frozenthat day. This exposure day does not constitute one test cycle.Co
24、ntinue with the exposure the following morning.8.2.2 After soak, the plate with specimens is placed for 12 hin a freezer maintained at 18C 6 3C (0F 6 5F). Thefollowing morning, allow the samples to thaw for a minimumof 1 h under laboratory ambient conditions.8.2.3 The plate with specimens is remount
25、ed on the expo-sure device as prescribed in Practice G90.8.2.4 The completion of 8.2.1, 8.2.2, and 8.2.3 constitutesone test cycle. Report test results after 30 cycles or otheragreed upon time period.9. Test Evaluation9.1 Applicable criteria for weathering evaluation may in-clude, but are not limite
26、d to, the following test methods:chalking (Test Methods D 4214), checking (Test MethodD 660), cracking (Test Method D 661), discoloration, erosion(Test Method D 662), face fiber swelling, flaking (Test MethodD 772), and intercoat adhesion.9.2 Testing laboratory and client shall agree upon evaluation
27、criteria, using applicable standards, and evaluation frequency.9.3 The use of pass-fail reference specimens for specificweathering criteria is strongly suggested.9.4 Initial pre-exposure inspection of all samples must beconducted to document any pre-existing surface imperfection.FIG. 1 Routed Specim
28、en Mounting Board Showing Placement ofSpecimensD572203210. Report10.1 Report the following information:10.1.1 A record of the type and identification of the producttested,10.1.2 Method used,10.1.3 Rating,10.1.4 Other pertinent information must be shown on theinspection report for each evaluation,10.
29、1.5 Date of inspection,10.1.6 Date of exposure start,10.1.7 Method of exposure (Practice D 5722),10.1.8 Total solar radiant exposure, MJ/m2,10.1.9 Ultra violet radiant exposure (UV) (300 to 385 nm),MJ/m2,10.1.10 Number of cycles,10.1.11 Remarks about unusual weather, and10.1.12 Any comments felt to
30、be relevant to the exposure orthe test results.11. Precision and Bias11.1 PrecisionVarying weather conditions from year toyear and at different exposure sites preclude a precisionstatement.11.2 BiasAs no accepted reference material exists, a biasstatement is not possible.12. Keywords12.1 accelerated
31、 weathering; factory coatings (hardboard);film integrity; hardboard (composition board siding)ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determinat
32、ion of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withd
33、rawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your
34、 comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D5722033
