ASTM D6578-2008 516 Standard Practice for Determination of Graffiti Resistance《耐涂写性测定的标准实施规程》.pdf

1、Designation: D 6578 08Standard Practice forDetermination of Graffiti Resistance1This standard is issued under the fixed designation D 6578; 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 pare

2、ntheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers a basic method for evaluatinggraffiti resistance of coatings, and use of this practice toevaluate graffiti resistance of coating

3、s after outdoor or labora-tory accelerated exposure (either prior to or after graffiti isapplied). Graffiti resistance is based on how a defined set ofmarkings is removed by a defined set of cleaning agents.1.2 This practice also defines procedures (optional) toevaluate graffiti removal after re-mar

4、king with subsequentre-cleaning. It does not address recoatability after a coating isno longer graffiti resistant.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafet

5、y 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.2. Referenced Documents2.1 ASTM Standards:2D 523 Test Method for Specular Gl

6、ossD 4587 Practice for Fluorescent UV-Condensation Expo-sures of Paint and Related CoatingsE 1347 Test Method for Color and Color-Difference Mea-surement by Tristimulus ColorimetryE 1349 Test Method for Reflectance Factor and Color bySpectrophotometry Using Bidirectional (45:0 or 0:45)GeometryG7 Pra

7、ctice for Atmospheric Environmental ExposureTesting of Nonmetallic MaterialsG113 Terminology Relating to Natural and ArtificialWeathering Tests of Nonmetallic Materials3. Terminology3.1 The definitions given in Terminology G113are appli-cable to this practice.3.2 Definitions of Terms Specific to Thi

8、s Practice:3.2.1 cleaning agent, na material used to remove amarking material from the coating surface.3.2.2 graffti resistance, nthe property of coatings to beresistant to the application of graffiti or exhibiting removal ofgraffiti without surface damage.3.2.3 marking material, na material that ca

9、n be used toproduce graffiti.3.2.4 recleanability, nthe ability of a coating to withstandmultiple cycles of marking with subsequent cleaning whilemaintaining its original characteristics.3.2.5 repellent, nthe property of coatings that preventsmaterials commonly used as graffiti markings, from formin

10、g acontinuous film upon application.4. Summary of Practice4.1 A series of materials typically used as graffiti markingsis applied to test panels of the surface being evaluated. Testspecimens may be exposed to outdoor or accelerated exposures(either before or after markings have been applied). The gr

11、affitimarkings are removed using a series of procedures that beginwith wiping with a dry cloth and end with cleaning the surfacewith an aggressive cleaner. After the best attempt has beenmade to remove markings, specimens are evaluated visually, oralternatively, by gloss and color change measurement

12、s todetermine cleanliness. The graffiti resistance is reported as acleanability level based on the mildest cleaning agent thatcompletely removes the graffiti marking without damaging thecoating.5. Significance and Use5.1 Graffiti on building and structures is an ongoing andincreasing problem. A numb

13、er of coatings have been producedthat are intended to be resistant to the application of a graffitimarking, or to provide a surface from which such markings canbe easily removed. The procedures described in this practice1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelat

14、ed Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.46 on Industrial Protective Coatings.Current edition approved Oct. 15, 2008. Published December 2008. Originallyapproved in 2000. Last previous edition approved in 2000 as D 6578 - 00.2For referenced ASTM st

15、andards, 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken

16、, PA 19428-2959, United States.provide a standard set of conditions that can be used to evaluatethe graffiti resistance of a surface.5.2 Graffiti resistance determined according to this practiceis applicable to smooth surfaces. Graffiti resistance of the samecoatings applied to a rough or textured s

17、urface may be lower.5.3 Graffiti resistance of coatings determined after natural orlaboratory accelerated weathering, either before or after mark-ing, conducted according to this practice, is considered ashaving more weight than graffiti resistance of the same coatingdetermined without weathering. G

18、raffiti resistance of coatingsdetermined after natural weathering should be considered ashaving more weight than graffiti resistance determined afterlaboratory accelerated weathering.6. Apparatus6.1 15 by 30 cm (6 by 12 in.) panels representing theintended substrate.6.2 Lint-Free Cotton Cloth.6.3 Gr

19、affti Marking Material:6.3.1 Solvent-Based Permanent Ink Marker, blue,6.3.2 Solvent-Based Acrylic Spray Paint, red,6.3.3 Solvent-Based Alkyd Spray Paint, red,6.3.4 Wax Crayon, blue or black,6.3.5 Ballpoint Ink,6.3.6 Water-based Ink Marker, black,6.3.7 Other marking materials based on mutual agreemen

20、tbetween all interested parties.6.4 15 by 30 cm (6 by 12 in.) Template, with 25 by 25 mm(1 by 1 in.) square holes used to define area where graffitimarking material will be applied. The number of holes shouldbe equal to the number of marking materials, should be spreadapart from each other as much a

21、s possible, and should have a13 mm (0.5 in.) margin along the perimeter.6.5 Cleaning Agents:6.5.1 Dry, Lint-Free Cotton Cloth,6.5.2 Mild Detergent, as agreed upon between purchaserand seller (a solution of 5 % sodium phosphate is recom-mended),6.5.3 Isopropyl Alcohol,6.5.4 Mineral Spirits,6.5.5 Xyle

22、ne,6.5.6 Methyl Ethyl Ketone (MEK).6.6 For Outdoor ExposuresOutdoor Exposure Rack,meeting the requirements of Practice G7 for open backedexposures.6.7 For Laboratory Accelerated ExposuresFluorescentUV Exposure Device, equipped with fluorescent UVA lampswith peak emission at 343 nm, and operated in a

23、ccordance withPractice D 4587.6.8 Proper Safety Equipment, as determined from the sol-vent Material Safety Data sheets (MSDS), for example, solventresistant gloves, and respirator.6.9 Glossmeter, 60, (for Evaluation Method B only).6.10 Colormeter, capable of D65, CIE LAB measurementsmeeting Test Met

24、hod E 1347 or Test Method E 1349 (forEvaluation Method B only).7. Test Specimen7.1 Apply the coating to be evaluated for graffiti resistanceto the 15 by 30 cm (6 by 12 in.) test panels according to themanufacturers instructions, following any relevant proceduresfor surface preparation prior to appli

25、cation.7.2 Prepare at least three specimens of each coating beingevaluated.7.3 Prepare also at least one file specimen that can be usedfor comparison to the unmarked or unexposed materials.7.4 Unless otherwise specified, allow the coated test speci-mens to cure for at least 24 h at room temperature

26、beforecontinuing the test.NOTE 1It may be useful to prepare several sets of panels for eachcoating and allow the different sets to cure for different periods. Thepurpose would be to determine the point at which optimum graffitiresistance occurs.7.5 Measure and record initial 60 gloss in accordance w

27、ithTest Method D 523 and color in accordance with Test MethodE 1347 or Test Method E 1349 (using a D65 illuminant, CIELAB calculations) on coated test specimens (for EvaluationMethod B only).7.6 Place the template described in 6.4 over the preparedtest panel and apply the entire complement of markin

28、g mate-rials prescribed in 6.3 so that each panel is marked with a 25 by25 mm (1 by 1 in.) square of all graffiti materials (one markingmaterial for each space in the template).7.6.1 Be careful not to cross-contaminate one markingmaterial with another. Remove template. Store the markedpanels at room

29、 temperature for at least 24 h before beginningto evaluate for removal.7.7 If the graffiti marking material does not uniformly coverthe test area of the panel, or resists adhering to it, the testsurface is considered “repellent.” In this case, beading of themarking material might occur. In this case

30、, the appearance ofthe dried marking may be very irregular.8. Graffiti Removal Procedure8.1 Attempt to remove each marking material from thepanel with a cotton cloth alone, then by using a cotton cloththat has been wetted with the following cleaning agents,working through them in the order listed (i

31、ncreasing strength).(a) mild detergent(b) isopropyl alcohol (IPA)(c) mineral spirits(d) xlyene(e) methyl ethyl ketone (MEK)The area of the cotton cloth that is wetted should be wellsaturated, but not dripping.8.2 Rub each marking vigorously until it is completelycleaned off, or until it is visually

32、evident that no more of themark can be removed.8.3 Reposition and re-wet the cotton cloth between mark-ings as necessary, working through the entire panel with onecleaning agent at a time.8.4 Use a different cotton cloth with each cleaning agent.NOTE 2As cleaning agents of increasing strength are us

33、ed, some ofthe markings will probably be cleanable, whereas others will not. Exercisecare so that areas that have been cleaned are not contaminated withD6578082stronger agents that are being used to clean other marks.9. Evaluation of Cleanability9.1 Method A, Visual:9.1.1 After the best attempt has

34、been made to clean a mark,visually examine it and note any trace of the mark, that is, acolor change (shadow) or a loss of gloss.9.1.2 If the spot has returned to its original condition beforemarking, note which cleaning agent was used to remove themark. The mark will be considered to be cleanable w

35、ith thisagent.9.2 Method B, Instrumentally:9.2.1 Retention of 60 GlossAfter the graffiti marking hasbeen removed, measure the 60 gloss. Determine the ratio ofthe average gloss measured after the marking has been re-moved to the average gloss measured on the panels prior tomarking. The ratio shall be

36、 at least 0.90.9.2.2 Color ShiftAfter the graffiti marking has been re-moved, measure color in the area where the graffiti wasremoved. Calculate Delta E CIE LAB based on comparison ofthe average color coordinates for the cleaned surface, and theaverage color coordinates for the surface prior to mark

37、ing, orfor an unmarked area of the same specimen. For a graffitimarking to be considered as completely removed, the Delta Eshall be less than 2.9.2.3 Note the cleaning agent. The mark will be consideredto be cleanable with this agent if the criteria in 9.2.1 and 9.2.2are met.10. Confirmation of Clea

38、nability10.1 Repeat procedures in Sections 8 and 9 (using eitherMethod A or B for Section 9) on the other two replicates, onlybegin with the next weakest cleaning agent that removed eachmark from the first replicate of each system rather thanbeginning all removal attempts with a dry cotton cloth. If

39、 itdoes not remove the mark move to the next strongest agent (theone that removed the mark the previous time). Althoughunlikely, it may be that this does not remove the mark. If thisoccurs, work up through the cleaning agents in order ofstrength. If a particular mark was not removed from the firstre

40、plicate with MEK, begin with xylene on subsequent repli-cates.10.2 If it is not possible to completely remove the spotwithout adversely affecting the film, it is considered to be notcleanable.10.3 Based upon the average of the results of the 3 replicatetrials, use the following rating scale for clea

41、nability for eachcoating.Cleanable with a dry rag = 10Cleanable with detergent = 9Cleanable with IPA = 8Cleanable with mineral spirits = 7Cleanable with xylene = 6Cleanable with MEK = 5Not cleanable, gloss loss = 4Not cleanable, slight shadow = 3Not cleanable, heavy shadow = 2Not cleanable, shadow a

42、nd gloss loss = 111. Recleanability Procedure (Optional)11.1 In some cases, it is necessary to evaluate whether agraffiti resistant material will show the same level of cleanabil-ity after it has been cleaned and remarked with graffiti.11.2 Re-mark the areas on the panels in the same locationsthat t

43、hey were marked prior to cleaning with the same markingmaterials and allow the markings to cure for at least 24 hours.11.3 Attempt to remove the mark using procedures inSections 8 and 9.11.4 If the marking is completely removed, repeat steps 11.2and 11.3 until the marking cannot be completely remove

44、dwithout damaging the coating. The recleanability is classifiedas the number of cycles performed until the marking is nolonger cleanable.12. Graffiti Removal From Panels That Have BeenSubjected To Outdoor Exposure12.1 Method ARemoval of freshly applied graffiti mark-ings from coatings that have been

45、 subjected to outdoorexposure:12.1.1 Prepare a set of specimens to be evaluated inaccordance with 7.1-7.4.12.1.2 Engrave or indent each of the panels so that they canbe identified upon return from exposure.12.1.3 Unless otherwise specified, expose this set of panelsin accordance with Practice G7on a

46、n open backed rack thatfaces the Equator and oriented at an angle of 45 to thehorizontal for 24 months. Note general atmospheric conditions,geographical location, and dates of exposure.NOTE 3Conditions will vary among geographic locations, whichcould produce different results. South Florida and Ariz

47、ona desert arecommonly used locations.12.1.4 Remove from exposure and apply graffiti markings inaccordance with 7.5-7.7.NOTE 4The purchaser and seller shall agree upon whether or not thepanels should be washed (or to what extent the panels should be washed)before marking.12.1.5 Determine cleanablili

48、ty of marked panels in accor-dance with Sections 8-10.12.1.6 Determine recleanability in accordance with Section11 (optional).12.2 Method BRemoval of graffiti markings after themarked panel has been subjected to outdoor exposure:12.2.1 Apply the coating and mark with materials in accor-dance with 7.

49、1-7.7.12.2.2 Expose panels per 12.1.3.12.2.3 Determine cleanability of the marked, exposed pan-els in accordance with Sections 8-10.12.2.4 Determine recleanability in accordance with Section11 (optional).13. Graffiti Removal From Panels That Have BeenSubjected to Laboratory-Accelerated WeatheringExposure13.1 Method ARemoval of freshly applied graffiti mark-ings from coatings that have been subjected to laboratory-accelerated weathering:13.1.1 Prepare the panels in accordance with 7.1-7.4.D657808313.1.2 Unless otherwise specified, expose this set of panelsin