ASTM D5722-2008 809 Standard Practice for Performing Accelerated Outdoor Weathering of Factory- Coated Embossed Hardboard Using Concentrated Natural Sunlight and a Soak-Freeze-Thaw.pdf

1、Designation: D 5722 08Standard 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 () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers techniques to acc

3、elerate weatheringeffects of factory-coated embossed hardboard using Cycle 1 ofPractice G90 (concentrated natural sunlight with periodicsurface water spray) plus a soak-freeze thaw cycle (see Section5 of this practice).1.2 Testing by use of the methods described in this practicemay be employed in th

4、e qualitative assessment of weatheringeffects. The relative durability of coated hardboards may bebest determined by comparison of their test results with thoseof control specimens derived from real time exposure testexperience.1.3 The values stated in SI units are to be regarded as thestandard. The

5、 values given in parentheses are for informationonly.1.4 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 establish appro-priate safety and health practices and determine the applica-bility o

6、f 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 of Cracking ofExterior PaintsD 662 Test Method for Evaluating Degree of Erosion ofExterior PaintsD 772 Test Me

7、thod for Evaluating Degree of Flaking (Scal-ing) of Exterior PaintsD 4214 Test Methods for Evaluating the Degree of Chalk-ing of Exterior Paint FilmsG90 Practice for Performing Accelerated Outdoor Weath-ering of Nonmetallic Materials Using Concentrated Natu-ral SunlightG113 Terminology Relating to N

8、atural and ArtificialWeathering Tests of Nonmetallic MaterialsG 169 Guide forApplication of Basic Statistical Methods toWeathering Tests3. Terminology3.1 The terminology used in this practice is defined inTerminology G113.3.2 Definitions:3.2.1 hardboard, ngeneric term for a panel manufacturedprimari

9、ly 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 embossed hardboard, nhardboard that is

10、manufac-tured with 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 concentrated naturalsunlight (with periodi

11、c 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 ability to quickly and accurately ev

12、aluate andpredict long-term weathering performance of factory-appliedcoatings is of paramount importance in making sound businessand technical decisions.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsi

13、bility ofSubcommittee D01.27 on Accelerated Testing.Current edition approved July 1, 2008. Published July 2008. Originally approvedin 1995. Last previous edition approved in 2003 as D 5722 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at ser

14、viceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.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, Un

15、ited States.5.2 It is important to include control specimens of knownfield performance to determine the efficacy of this practice forspecific substrate(s) and coating system(s). These controlspecimens may include materials known to possess acceptableand unacceptable field performance for the defect(

16、s) underconsideration.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

17、 variations in important climatic factors.5.5 Extensive research was performed during the develop-ment of this standard practice. This research showed that thispractice is not useful for determination of quantitative accel-eration factors. However, this test is very useful as a compara-tive test.5.6

18、 Aminimum of two replicates for both control specimensand test specimens is recommended to allow statistical evalu-ation of results. Refer to Practice G 169 for additional guidanceon establishing the number of replicates.6. Apparatus and Materials6.1 Test Machines, as illustrated in a figure titled

19、Sche-matic of a Fresnel Reflecting Concentrator Accelerated Weath-ering Machine” of Practice G90and described in ApparatusSection of Practice G90.6.2 Freezer, capable of maintaining a temperature of 20 65C (4 6 9F). The freezer shall be equipped with athermocouple to monitor air temperature.6.3 Mou

20、nting Board, paper-faced marine grade wood struc-tural panel, surface 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 Attach the specimen to the mounting board. One methodto accom

21、plish this is to apply exterior grade silicone adhesiveto the center of each specimen. Use cotton gloves to press thespecimen into the mounting plate. Other mounting techniques,agreed upon between the testing laboratory and the client arepossible.7.3 Useful results have been achieved when specimen e

22、dgesand backs remain unsealed.8. Procedures8.1 One procedure recommended is in Practice G90.8.2 Soak-Freeze-Thaw Procedure: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 andimme

23、rsed in a deionized water soak tank maintained at 25 65C (77 6 9F) for at least 1 h but not more than1h15min.If the board containing specimens floats in the immersion tank,the board may have to be inserted upside down for thespecimens to be completely immersed in water. A minimumexposure of 1 MJ/m2o

24、f ultraviolet radiation as measured perPractice G90 constitutes a daily cycle. If a minimum of 1MJ/m2of ultraviolet radiation (295 to 385 nm) is not accumu-lated in one day of exposure, the specimens are to be left on theapparatus and are not to be immersed or frozen that day. Thisexposure day does

25、not constitute one test cycle. Continue withthe exposure the following morning.8.2.2 After soak, the plate with specimens is placed for aminimum of 12 h and a maximum of 15 h in a freezermaintained at 20 6 5C (4 6 9F). The following morning,allow the samples to thaw for a minimum of 1 h underlaborat

26、ory ambient conditions.NOTE 1Because the start of the accelerated weathering after thawingcan be delayed due to weather, the precise time of the thaw portion of thecycle cannot be specified.8.2.3 The plate with specimens is remounted on the expo-sure device as prescribed in Practice G90.8.2.4 The co

27、mpletion 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.8.2.5 At least every week, replace the water used forsoaking test panels with new deionized water.FIG. 1 Routed Specimen Mounting Board Showing Placement ofSpecimensD572

28、20829. Test Evaluation9.1 Applicable criteria for weathering evaluation may in-clude, but are not limited 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

29、Test MethodD 772), and intercoat adhesion.9.2 Testing laboratory and client shall agree upon evaluationcriteria, using applicable standards, and evaluation frequency.9.3 The use of control specimens for specific weatheringcriteria is strongly suggested.9.4 Initial pre-exposure inspection of all sam

30、ples must beconducted to document any pre-existing surface imperfection.10. 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, if applicable,10.1.4 Other pertinent information must be shown on theinspectio

31、n report for each evaluation,10.1.5 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) (295 to 385 nm),MJ/m2,10.1.10 Number of cycles, and10.1.11 Any comments felt to be rel

32、evant to the exposure orthe test results.11. Keywords11.1 accelerated weathering; factory coatings (hardboard);film integrity; hardboard (composition board siding)SUMMARY OF CHANGESCommittee D01 has identified the location of selected changes to this standard since the last issue(D 5722 - 03) that m

33、ay impact the use of this standard. (Approved July 1, 2008.)(1) Section 1slight changes were made to the wording in theScope.(2) Section 5changes were made in Significance and Useregarding changing the term “reference specimens” to “controlspecimens.” A sentence regarding quantitative service lifeap

34、proximations was deleted from 5.4. A subsection was added(5.5) to indicate that even though this was not to be used forquantitative service life predictions, it was useful as a com-parative test.(3) Section 6the freezer requirement was changed from 186 3C to 20 6 5C.(4) Section 7slight changes were

35、made in the recommendedmounting procedure.(5) Subsection 8.2changes were made in the soak portion ofthe test cycle, changing the soak duration from a precise timeof one hour to a range which extends from one hour to one hourand fifteen minutes. Also in Subsection 8.2, the freezingduration was change

36、d from a precise time of 12 hours to arange which extends from 12 hours to 15 hours. The soaktemperature was changed from 21 6 3C to 25 6 5C. Thefreezing temperature was changed from 18 6 3C to 20 65C.Arequirement was added to change the soak water at leastevery week.(6) Section 9the phrase “pass-fa

37、il reference” was changed to“control.”(7) Section 10minor changes were made to the reportrequirements.(8) Section 11 Precision and Bias was deleted from thisstandard.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin thi

38、s standard. Users of this standard are expressly advised that determination 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

39、 reviewed every five years andif not revised, either reapproved or withdrawn. 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 theresp

40、onsible technical committee, which you may attend. If you feel that your 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).D5722083