ASTM_D_6736_-_08_2013.pdf

Designation:D673608(Reapproved 2013)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.Scope*1.1 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D523 Test Method for Specular GlossD2486 Test Methods for Scrub Resistance of Wall PaintsD3924 Specification for Environment for Conditioning andTesting Paint,Varnish,Lacquer,and Related Materials3.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 2C(73.5 63.5F);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.7.2 Cheesecloth,4-ply,medium weave.38.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.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 Feb.1,2013.Published February 2013.Originallyapproved in 2001.Last previous edition approved in 2008 as D6736 08.DOI:10.1520/D6736-08R13.2For 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.3Bleached cheesecloth,grade 20B,24/20(medium)weave was used in devel-oping this method.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 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 of the panel,making sure theareas of the readings are within the travel path of the scrubmachine attachment.The resulting average of the three read-ings is used as the initial value prior to rubbing the panel.It issuggested that the gloss readings should be as follows:Semi-Gloss Paints60Sheen Paints60 and 85Flat Paints85In general,if the 60 reading drops below 20 units the 85reading should be recorded.8.1.4 Secure one layer of 4-ply cheesecloth lengthwise inthe sandpaper attachment of the scrub machine.8.1.5 Secure the panel on the scrub machine over the glassplate using the gasket and clamps.Attach the sa