1、Designation:D279399(Reapproved 2011)Standard Test Method forBlock Resistance of Organic Coatings on Wood PanelSubstrates1This standard is issued under the fixed designation D2793;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 test method covers the determination of the blockresistance of organic coatings on wood and wood-based panelsubs
3、trates.Block resistance is the ability of a coating to resiststicking to another surface and to resist any change inappearance when it is pressed against that surface for aprolonged period of time.1.2 General methods for determining block resistance areoutlined in Sections 6 and 7.Variations inheren
4、t in usermaterials and procedures,however,may dictate adjustments tothe general method to improve accuracy.Paragraphs 7.3 and7.4 provide guidelines for tailoring the general procedure to ausers specific application.Paragraph 7.5 offers a rating meth-odology.1.3 Test Method D2091 should be used for t
5、he determina-tion of print resistance or pressure mottling of organic coatings,particularly lacquers,applied to wood-based case goods suchas furniture.1.4 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.5 This standard does no
6、t 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:2D
7、2091 Test Method for Print Resistance of Lacquers3.Summary of Test Method3.1 The coatings are prepared for testing in a mannerduplicating production application and curing conditions asnearly as possible on the specified wood substrate.Then a stackof these painted substrates is formed and subjected
8、to aspecified pressure and temperature for a sufficient time todevelop any sticking tendencies that exist.The pressure isreleased and the painted surfaces are examined for any signs ofsticking or pressure mottling.If blocking(forming a block bypanels sticking together)occurs,the material is unsatisf
9、actory.If no sticking or damage to the film surface occurs,the materialis satisfactory.3.2 When the conditions of production finishing are estab-lished and known,the method of application,the substrate,filmthickness,and cure of the film should duplicate these condi-tions as closely as possible.Howev
10、er,some acceleration of thetest may be possible with more severe conditions.4.Significance and Use4.1 Coated wood panel products must be stacked face toface or face to back during warehousing,packaging,andtransportation without the coated finish sticking(blocking)andbecoming damaged.This test method
11、 describes a laboratorymeans of evaluating conditions of blocking using factors ofpressure,heat,time and moisture.4.2 Degrees of hardness or degrees of cure of organiccoatings,or both,can be evaluated using a blocking test.4.3 The rate of volatile loss(drying speed)of organiccoatings can be evaluate
12、d using a blocking test.4.4 The effectiveness of protective packaging materials(slipsheets)for organic coatings on wood substrates can be evalu-ated using a blocking test.5.Apparatus5.1 Hydraulic Press(preferably constant pressure),capableof maintaining the agreed upon stacking pressure.5.2 Rigid Pl
13、atens,at least 4 in.(100 mm)square,capable ofbeing maintained at the desired test temperature.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.52 on Factory Coated Wood Produc
14、ts.Current edition approved June 1,2011.Published June 2011.Originallyapproved in 1969.Last previous edition approved in 2005 as D2793 99(2005).DOI:10.1520/D2793-99R11.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Boo
15、k of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Test Specimens6.1 For those cases where the intended use conditions arenot established
16、 or known,the following specifications or someset of specifications agreed upon between the purchaser andseller apply:6.1.1 The test coating shall be applied by spray to a panel.6.1.2 The panel shall be a piece of 6.4 mm(14in.)smoothtwo side(S2S)standard hardboard or other thickness and typeof wood substrate.6.1.3 The dry film thickness of pigmented coatings shall be1.5 6 0.2 mils(38 6 5 m),and of clear coatings,shall be 306 5 m(1.2 6 0.2 mils)or other agreed upon film thickness.Cure of the coat
