1、Designation: D6486 01 (Reapproved 2017)Standard Practice forShort Term Vehicle Service Exposure of AutomotiveCoatings1This standard is issued under the fixed designation D6486; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar 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. Scope1.1 This practice covers the protocol for vehicle serviceexposure testing of automotive coatings. Such exposure test
3、ingis valuable for the verification of the performance of automo-tive coatings and correlation with laboratory test data. Vehicleservice exposure is intended to provide short term (2 to 20weeks) exposure to the stress factors associated with vehicleoperation. Factors included are scratch, mar, impac
4、t, stonechipping, insect impact, bird dropping, tree sap and staining,environmental fallout, etc.NOTE 1Vehicle service exposure is not intended to provide theconditions that are needed for characterizing the long term effects ofweathering or corrosion exposure.1.2 The exposure conditions are produce
5、d by the placementof multiple test panels of automotive finishes on automotivetest fleets that traverse a defined road course. Exposure to theoperating environment can be 20 h/day, 7 days/week allowingfor accumulation of over 100 000 miles in 10 weeks ofexposure.1.3 The values stated in SI units are
6、 to be regarded as thestandard. The 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
7、 and determine the applica-bility of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Rec
8、om-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D523 Test Method for Specular GlossD609 Practice for Preparation of Cold-Rolled Steel Panelsfor Testing Paint, Varnish, Conversion Coatings, andRelated Coating P
9、roductsD714 Test Method for Evaluating Degree of Blistering ofPaintsD823 Practices for Producing Films of Uniform Thicknessof Paint, Varnish, and Related Products on Test PanelsD1005 Test Method for Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD1186 Test Methods for Nondes
10、tructive Measurement ofDry Film Thickness of Nonmagnetic Coatings Applied toa Ferrous Base (Withdrawn 2006)3D1400 Test Method for Nondestructive Measurement of DryFilm Thickness of Nonconductive Coatings Applied to aNonferrous Metal Base (Withdrawn 2006)3D3170 Test Method for Chipping Resistance of
11、CoatingsD3359 Test Methods for Rating Adhesion by Tape TestD5767 Test Methods for Instrumental Measurement ofDistinctness-of-Image Gloss of Coating Surfaces2.2 U.S. Federal Standard:DOT NHTSA Reg. #49 CFR Part 57543. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 blistering, nfo
12、rmation in the film of dome-shaped,liquid- or gas-filled projections resulting from local loss ofadhesion and lifting of the film from the previously appliedcoating or the substrate.3.1.2 chipping, nremoval of a coating, usually in smallpieces, resulting from impact by hard objects or from weardurin
13、g service.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.55 on Factory Applied Coatings on Preformed Products.Current edition approved June 1, 2017. Published June 2017. Orig
14、inallyapproved in 1999. Last previous edition approved in 2011 as D6486 01 (2011).DOI: 10.1520/D6486-01R17.2For 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 stand
15、ards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.Copyrig
16、ht ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of Internationa
17、l Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.1.3 cracking, nformation of breaks in a film that extendthrough to the underlying surface.3.1.4 distinctness-of-image-gloss, naspect of gloss char-acterized by the sharpness
18、of images of objects produced byreflection at a surface.3.1.5 gloss, nangular selectivity of reflectance, involvingsurface-reflected light, responsible for the degree to whichreflected highlights or images of objects may be seen assuperimposed on a surface.3.1.6 staining, ndiscoloration, arising fro
19、m foreignmaterials, that penetrates into the coating.4. Significance and Use4.1 Since the exposure of automotive coatings to the variousmechanical and chemical stresses encountered in actualoperations, is very opportunistic, obtaining statistically signifi-cant data from which valid conclusions can
20、be drawn, requiresrigorous attention to the experimental designs and conditionsof exposure.5. Limitations5.1 Vehicle service exposure is not intended to provide theconditions that are needed for characterizing the long termeffects of weathering or corrosion exposure.5.2 Vehicle service exposure is n
21、ot intended to provideabsolute values. The performance of the test coatings is relativeto that of a control coating.6. Vehicle Test Fleets6.1 Various commercial organizations operate multi-vehiclefleets that can conform to the required test conditions. Amongother objectives, they are operated to com
22、ply with federal tirewear rating requirements. The U. S. Federal requirements arepublished in DOT NHTSA Reg. #49 CFR Part 575, andspecifies specific route and operating conditions. The additionof properly designed specimen racks to these vehicles can beaccommodated.7. General Requirements7.1 Test pa
23、nels are mounted on the major surfaces (front,sides, and roof) of the vehicle. Since the exposure of automo-tive coatings to the various mechanical and chemical stressesencountered in actual operation is very opportunistic, obtainingstatistically significant data from which valid conclusions canbe d
24、rawn requires rigorous attention to the experimental designand conditions of the exposure.7.1.1 Control and test coatings must be exposed simultane-ously.7.1.2 All coatings must be exposed on the major (front,sides and roof) vehicle surfaces.7.1.3 Exposure specimen positions in the specimen mount-in
25、g racks must be randomized.7.1.4 All coatings must be exposed to the maximum prob-ability of stresses in the shortest possible time. The selection ofthe specific road course to be traversed controls this require-ment.7.1.5 A sufficient number of vehicles, operating underidentical controlled conditio
26、ns must be available, to allow formaximum exposure and minimum vehicle operational prob-lems.7.1.6 The selection of the operational environment must bechosen to ensure the highest probability of exposure to thestress of interest.7.2 The fleet operating environment should be defined tooptimize the st
27、ress factors of interest. Examples are; gravel/unpaved road segments to evaluate stone chipping, mechanicalcar washing after dust road travel to evaluate mar resistance,operation during insect season to evaluate insect impact, etc.8. Procedure8.1 Prepare a minimum of two test panels per specimenrack
28、, in accordance with the coatings manufacturersspecifications, for the coatings to be evaluated. Prepare the testpanels as described in Practices D609 or D823. The coatingfilm thickness should be controlled in accordance with themanufacturers specifications and measured in accordance withTest Method
29、s D1186, D1005 or D1400.NOTE 2Control and test coating specimens (panels) must have a largeenough surface area to be able to accumulate sufficient occasions of stress,and thus be statistically meaningful. Specimen size of 203 by 305 mm (8by 12 in.) has been found to be adequate.8.2 Measure the gloss
30、 and distinctness of image (DOI) ofthe test and control coating panels in accordance with TestMethods D523 and D5767.8.3 Place the test and control coating panels on the speci-men racks.8.4 Mount the specimen racks on the carrier vehicles.NOTE 3Specimen racks are to be mounted on the center front bu
31、mper(front), right and left front doors (side) and roof of the vehicle.NOTE 4Aminimum of three test vehicles, operating in convoy, so thatby rotating position periodically, all test specimens acquire the stressesthat are specific to their convoy position.8.5 Begin the operation of the test run.NOTE
32、5It is highly desirable that the vehicles providing the testplatform operate 24 h/day over a broad range of road surfaces, forexample, dirt, gravel, concrete, etc. The vehicles should operate at specificspeeds over a prescribed route. Such accumulations allow for theaccumulation of 10 000 miles/week
33、 and therefore a high increase of stresswith minimal weathering exposure.NOTE 6From a cost consideration the test should be conducted bypiggybacking on vehicle fleets operating for other test purposes.NOTE 7Periodic exposure to mechanical car washing should beintegrated into the test schedule. This
34、will provide exposure to mar andscratching.NOTE 8Periodic parking under trees should be integrated into the testschedule. This will provide exposure to tree sap and bird droppings.8.6 At the completion of the test run remove the specimenracks from the test vehicles.8.7 Remove the control and test pa
35、nels from the specimenracks.8.8 Examine the control and test panels for the following;8.8.1 Gloss in accordance with Test Method D523.8.8.2 DOI in accordance with Test Methods D5767.8.8.3 Scratch.D6486 01 (2017)28.8.4 Mar.8.8.5 Staining.8.8.6 Etching.8.8.7 Chipping in accordance with Test Method D31
36、70.8.8.8 Cracking.8.8.9 Adhesion loss in accordance with Test Method D3359.8.8.10 Blistering in accordance with Test Method D714.NOTE 9There are no ASTM methods for quantitatively measuringscratch, mar, staining, chipping or cracking of an automotive coating.Therefore, these observations are subject
37、ive and should be made versusthe control coating.9. Report9.1 Report the following information:9.1.1 Type of coating tested.9.1.2 Identification of coating tested (control or test coat-ing).9.1.3 Initial coating film properties to serve as base point(gloss, DOI).9.1.4 Test specimen locations.9.1.5 T
38、est specimen rotation sequence.9.1.6 Any special stress conditions.9.1.7 Name of fleet operator and location.9.1.8 Time frame of exposure test.9.1.9 Number of vehicles involved in exposure test.9.1.10 Convoy organization.9.1.11 Road course description.9.1.12 Distance traveled for duration of exposur
39、e test.9.1.13 Stress conditions encountered, for example, bugs,stone chips, etc.9.1.14 Weather conditions during exposure test.9.1.15 Final coating film properties (gloss, DOI, scratch,mar, stain, etch), and9.1.16 Final coating film integrity (chips, cracks, adhesionloss, blistering).10. Precision a
40、nd Bias10.1 PrecisionIt is not practical to specify precisionbecause the values obtained by this practice have no absolutevalue and should only be used to derive relative performancerankings for test panels. Because of this, no statements onRepeatability and Reproducibility are being made.10.2 BiasS
41、ince there is no accepted reference proceduresuitable for determining the bias for this practice, no statementon bias is being made.11. Keywords11.1 coatings; coatings performance; road hazards; shortterm exposureASTM International takes no position respecting the validity of any patent rights asser
42、ted in connection with any item mentionedin this 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
43、the responsible technical committee and must be 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 receiv
44、e careful consideration at a meeting of theresponsible 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 Intern
45、ational, 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 01 (2017)3
