ASTM_D_6736_-_08_2019.pdf

Designation:D673608(Reapproved 2019)Standard Test Method forBurnish Resistance of Latex Paints1This standard is issued under the fixed designation D6736;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 a procedure for measuring theresistance of latex paints to burnishing under dry conditions.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 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 Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D523 Test Method for Specular GlossD2486 Test Methods for Scrub Resistance of Wall PaintsD3924 Specification for Standard Environment for Condi-tioning and Testing Paint,Varnish,Lacquer,and RelatedMaterials(Withdrawn 2016)33.Terminology3.1 Definitions:3.1.1 burnish resistance,nthe ability of a coating to resistan increase in its gloss(sheen)value after polishing or rubbing.4.Summary of Test Method4.1 Test paints are drawn down lengthwise on plastic panelsusing a 0.18-mm(7.0-mil)applicator and allowed to air dry forone week.Gloss readings are taken at three equally spacedpoints,lengthwise along the center of the panel.The panel isthen rubbed for 20 cycles on a scrub machine,after which glossreadings are again taken along the same path abraded by thescrub machine.The initial values are averaged and the finalvalues are averaged.The difference between the initial andfinal gloss readings divided by the initial reading times 100 isa quantitative indication of the paints resistance to burnishing.Higher percentage increases denote poorer resistance andvice-versa.5.Significance and Use5.1 Interior flat paints may become burnished in areas whereclothing or upholstered furniture rub against a wall.Thisrubbing may cause a smoother,glossier surface at the contactedarea,depending on the level or type of pigments in the paintand binder hardness.This method permits a more quantitativeestimate of burnish resistance than those using manual rubbingtechniques.6.Apparatus6.1 Constant temperature/humidity room 23 6 2 C(73.5 63.5 F);50 6 5%relative humidity(standard conditions,Specification D3924).6.2 Washability Machine(Scrub Machine),described in TestMethods D2486.6.2.1 Accessory Apparatus:6.2.1.1 Sandpaper Attachment,total weight 454 g.6.2.1.2 Glass Plate,measured to fit.6.2.1.3 Gasket Frame and Clamps.6.3 Large Vacuum Plate.6.4 Film Caster,having a 0.18-mm(7.0-mil)clearance.6.5 Glossmeter(s),capable of measuring 60 and 85 glossin accordance with Test Method D523.7.Materials7.1 Plastic Scrub Panels,43.5 by 16.5 mm(17 by 6.5 in.),white or black.1This 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 April 1,2019.Published April 2019.Originallyapproved in 2001.Last previous edition approved in 2013 as D6736 08(2013).DOI:10.1520/D6736-08R19.2For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 7.2 Cheesecloth,4-ply,medium weave.48.Procedure8.1 Application and Evaluation of Test Paints:8.1.1 Attach a plastic panel to the vacuum plate and drawdown the test paint uniformly lengthwise,using the 0.18-mm(7.0-mil)side of the applicator.8.1.2 Condition the panels for one week in the constanttemperature/humidity room or under other conditions agreedupon between the buyer and seller.8.1.3 Take three equally spaced gloss readings(Test MethodD523)along the center length