1、Designation: D 6486 01 (Reapproved 2005)Standard Practice forShort Term Vehicle Service Exposure of AutomotiveCoatings1This standard is issued under the fixed designation D 6486; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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 the protocol for vehicle serviceexposure testing of automotive coatings. Such exposure t
3、estingis 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, im
4、pact, 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 prod
5、uced 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
6、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 thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practi
7、ces and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 523 Test Method for Specular GlossD 609 Practice for Preparation of Cold-Rolled Steel Panelsfor Testing Paint, Varnish, Conversion Coatings, andRelated Coating ProductsD 714 Test
8、Method for Evaluating Degree of Blistering ofPaintD 823 Practices for Producing Films of Uniform Thicknessof Paint, Varnish, and Related Products on Test PanelsD 1005 Test Methods for Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD 1186 Test Methods for Nondestructive Measu
9、rement ofDry Film Thickness of Nonmagnetic Coatings Applied toa Ferrous BaseD 1400 Test Method for Nondestructive Measurement ofDry Film Thickness of Nonconductive CoatingsApplied toa Nonferrous Metal BaseD 3170 Test Method for Chipping Resistance of CoatingsD 3359 Test Methods for Measuring Adhesio
10、n by Tape TestD 5767 Test Methods for Instrumental Measurement ofDistinctness-of-Image Gloss of Coating Surfaces2.2 U.S. Federal Standard:DOT NHTSA Reg. #49 CFR, Part 57533. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 blistering, n formation in the film of dome-shaped,liquid-
11、 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 wearduring service.3.1.3 cracking, nformation of br
12、eaks in a film that extendthrough to the underlying surface.3.1.4 distinctness-of-image-gloss, naspect of gloss char-acterized by the sharpness of images of objects produced byreflection at a surface.3.1.5 gloss, nangular selectivity of reflectance, involvingsurface-reflected light, responsible for
13、the degree to whichreflected highlights or images of objects may be seen assuperimposed on a surface.3.1.6 staining, n discoloration, arising from foreign ma-terials, that penetrates into the coating.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materia
14、ls, and Applications and is the direct responsibility ofSubcommittee D01.55 on Factory Applied Coatings on Preformed Products.Current edition approved May 15, 2005. Published July 2005. Originallyapproved in 1999. Last previous edition approved in 2001 as D 6486 01.2For referenced ASTM standards, vi
15、sit 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 U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St.,
16、 NW, Mail Stop: SDE, Washington, DC 20401.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Significance and Use4.1 Since the exposure of automotive coatings to the variousmechanical and chemical stresses encountered in actual opera
17、-tions, is very opportunistic, obtaining statistically significantdata from which valid conclusions can 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 c
18、haracterizing the long termeffects of weathering or corrosion exposure.5.2 Vehicle service exposure is not 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-vehicle
19、fleets that can conform to the required test conditions. Amongother objectives, they are operated to comply with federal tirewear rating requirements. The U. S. Federal requirements arepublished in DOT NHTSA Reg. #49CFR Part 575, andspecifies specific route and operating conditions. The additionof p
20、roperly designed specimen racks to these vehicles can beaccommodated.7. General Requirements7.1 Test panels 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 operat
21、ion is very opportunistic, obtainingstatistically significant data from which valid conclusions canbe drawn requires rigorous attention to the experimental designand conditions of the exposure.7.1.1 Control and test coatings must be exposed simulta-neously.7.1.2 All coatings must be exposed on the m
22、ajor (front,sides and roof) vehicle surfaces.7.1.3 Exposure specimen positions in the specimen mount-ing 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 control
23、s this require-ment.7.1.5 A sufficient number of vehicles, operating underidentical controlled conditions 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 ex
24、posure to thestress of interest.7.2 The fleet operating environment should be defined tooptimize the stress 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 seas
25、on to evaluate insect impact, etc.8. Procedure8.1 Prepare a minimum of two test panels per specimenrack, in accordance with the coatings manufacturers specifica-tions, for the coatings to be evaluated. Prepare the test panelsas described in Practices D 609 or D 823. The coating filmthickness should
26、be controlled in accordance with the manu-facturers specifications and measured in accordance with TestMethods D 1186, D 1005 or D 1400.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 statistic
27、ally meaningful. Specimen size of 203 by 305 mm (8by 12 in.) has been found to be adequate.8.2 Measure the gloss and distinctness of image (DOI) ofthe test and control coating panels in accordance with TestMethods D 523 and D 5767.8.3 Place the test and control coating panels on the speci-men racks.
28、8.4 Mount the specimen racks on the carrier vehicles.NOTE 3Specimen racks are to be mounted on the center front bumper(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 spec
29、imens acquire the stressesthat are specific to their convoy position.8.5 Begin the operation of the test run.NOTE 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 op
30、erate at specificspeeds over a prescribed route. Such accumulations allow for theaccumulation of 10 000 miles/week 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
31、 test purposes.NOTE 7Periodic exposure to mechanical car washing should beintegrated into the test schedule. This 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
32、 the completion of the test run remove the specimenracks from the test vehicles.8.7 Remove the control and test panels from the specimenracks.8.8 Examine the control and test panels for the following;8.8.1 Gloss in accordance with Test Method D 523.8.8.2 DOI in accordance with Test Methods D 5767.8.
33、8.3 Scratch.8.8.4 Mar.8.8.5 Staining.8.8.6 Etching.8.8.7 Chipping in accordance with Test Method D 3170.8.8.8 Cracking.8.8.9 Adhesion loss in accordance with Test MethodD 3359.8.8.10 Blistering in accordance with Test Method D 714.NOTE 9There are no ASTM methods for quantitatively measuringscratch,
34、mar, staining, chipping or cracking of an automotive coating.Therefore, these observations are subjective and should be made versusthe control coating.D 6486 01 (2005)29. Report9.1 Report the following information:9.1.1 Type of coating tested.9.1.2 Identification of coating tested (control or test c
35、oat-ing).9.1.3 Initial coating film properties to serve as base point(gloss, DOI).9.1.4 Test specimen locations.9.1.5 Test 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 e
36、xposure test.9.1.10 Convoy organization.9.1.11 Road course description.9.1.12 Distance traveled for duration of exposure 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, scra
37、tch,mar, stain, etch), and9.1.16 Final coating film integrity (chips, cracks, adhesionloss, blistering).10. Precision and 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 performanc
38、erankings for test panels. Because of this, no statements onRepeatability and Reproducibility are being made.10.2 BiasSince 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;
39、road hazards; shortterm exposureASTM 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 determination of the validity of any such patent rights, and the riskof
40、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 withdrawn. Your comments are invited either for revision of this st
41、andard 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 comments have not received a fair hearing you shouldmake your
42、 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).D 6486 01 (2005)3
