ASTM_D_4213_-_08_2012.pdf

Designation:D421308(Reapproved 2012)Standard Test Method forScrub Resistance of Paints by Abrasion Weight Loss1This standard is issued under the fixed designation D4213;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 parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers an accelerated procedure fordetermining the resistance of paints to erosion caused byscrubbing.(Note:The term wet abrasion is sometimes used forscrubbing,and wet abrasion resistance or scrubbability forscrub resistance.)Although scrub resistance tests are intendedprimarily for interior coatings,they are sometimes used withexterior coatings as an additional measure of film performance.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 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 of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D562 Test Method for Consistency of Paints MeasuringKrebs Unit(KU)Viscosity Using a Stormer-Type Viscom-eterD1193 Specification for Reagent WaterD1475 Test Method For Density of Liquid Coatings,Inks,and Related ProductsD2486 Test Methods for Scrub Resistance of Wall PaintsD3450 Test Method for Washability Properties of InteriorArchitectural CoatingsD3980 Practice for Interlaboratory Testing of Paint andRelated Materials(Withdrawn 1998)3D4828 Test Methods for Practical Washability of OrganicCoatingsE70 Test Method for pH of Aqueous Solutions With theGlass ElectrodeE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)3E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Summary of Test Method3.1 The material under test is applied to a black plastic scrubtest panel,and after drying one week,a section of the test panelis placed in a straight-line abrasion tester,adjacent to a similarsection of a standard calibration panel.The two sections arescrubbed simultaneously to produce essentially identical abra-sion experiences and the amount of erosion loss in each sectiondetermined from the panel weights before and after scrubbing.3.2 The scrub resistance on a dry-film basis is calculated asthe percent ratio of the weight loss of the calibration panel tothat of the test panel.From that value,scrub resistance iscalculated on the basis of both dry-and wet-film volume.4.Significance and Use4.1 Interior paint films often become soiled,especially neardoorways,windows,and play areas,and frequently need to becleaned by scrubbing.This test method covers the determina-tion of the relative resistance of paints to erosion whenscrubbed.4.2 The precision of scrub resistance measurements inabsolute physical values,such as Test Methods D2486 cycles-to-failure or this test method,microlitres per 100 cycles,is poordue to the relatively large effect of subtle and difficult-to-control variables in test conditions.The test method describedherein minimizes this problem by using a standard calibrationpanel as an integral part of each scrubbing operation andrelating its weight loss to that of the paint film under test toestablish the latters scrub resistance.NOTE1The numerical scrub resistance values obtained by this testmethod are of significance only in relation to the specific calibration paneltypes with which the value is obtained.Thus,for example,a scrubresistance value of 83 with a Type X calibration panel would be reportedas 83X.4.3 Results obtained by this test method do not necessarilyrepresent the scrub resistance that might be determined if the1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.42 on Architectural Coatings.Current edition approved July 1,2012.Published August 2012.Originallyapproved in 1983.Last previous edition approved in 2008 as D4213 08.DOI:10.1520/D4213-08R12.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 test film is allowed to dry before testing appreciably longerthan the seven-day period specified herein.4.4 Results obtained by this test method do not necessarilyrelate to ease o