1、Designation:D 3459 98Standard Test Method forHumid-Dry Cycling for Coatings on Wood and WoodProducts1This standard is issued under the fixed designation D 3459;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision
2、.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 test method covers the evaluation of coatingsdesigned for use on interior wood and wood products sub-strates by exposure alternate
3、ly to low and high humidity at anelevated temperature.1.2 This test method is applicable to any coated material orproduct that is affected either entirely or partly by changes inatmospheric relative humidity.1.3 This test method applies only to those coatings appliedin sufficient quantity to form a
4、continuous film.1.4 The values stated in the inch/pound units are to beregarded as the standard.The values given in parenthese are forinformation only.1.5 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 st
5、andard 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:D 714 Test Method for Evaluating Degree of Blistering ofPaints2D 1005 Test Methods for Measurement of Dry-Film Thick-ness of O
6、rganic Coatings Using Micrometers2D 2691 Test Methods for Microscopical Measurement ofDry Film Thickness of Coatings on Wood Products3E 145 Specification for Gravity-Convection and Forced-Ventilation Ovens43.Significance and Use3.1 Wood substrates and the coatings applied to themexpand and contract
7、to different degrees as the humiditychanges,causing stresses that may produce checks,cracks,splits,blisters,swelling,loss of adhesion,and various changesin surface appearance.This test method is intended for usewhere the coating is applied in sufficient quantity to form acontinuous film on the wood
8、or wood product substrate.It isnot possible to make any direct correlation between the resultsobtained from humid/dry cycling and the results expected in aspecific period of time in service because of variations result-ing from geographic locations,location within the building,care of the panel(such
9、 as waxing),and variations withinmaterials involved.4.Test Panels and Panel Preparation4.1 Test panels shall be regular production finished panels ifavailable.4.2 If regular production finished panels are not availablethe purchaser and the seller shall agree upon the followingvariables:type of wood
10、or wood substrate,sanding method(s)and paper(s),sealer(s)or toner(s),filler(s),stain,primer orbasecoat,print(s),and topcoat(s),methods of application,andthe number of surfaces to be coated.If rotary-cut veneeredpanels are used,it should also be agreed whether the veneer isto be open or close faced.5
11、.Apparatus5.1 Ovena gravity-convection or forced-ventilation elec-trically heated oven meeting the requirements of SpecificationE 145 and providing a continuous temperature of 122 6 3.5F(50 6 2C).5.2 Constant Elevated-Temperature and Constant-HumidityChamber,maintained at a relative humidity of 97 6
12、 2%anda temperature of 122 6 3.5F(50 6 2C).5.3 Constant-Temperature and Constant-Humidity Cham-ber,maintained at a relative humidity of 50 6 5%and atemperature of 73.5 6 3.5F(23 6 2C).6.Test Specimens6.1 Test specimens shall be large enough to be representa-tive of the material or product and to per
13、mit easy observationof possible defects.This usually means a minimum area ofapproximately 12 by 12 in.(300 by 300 mm).6.2 Unexposed control specimens of each coating or coatingsystem or product tested shall be held in reserve in a constant-temperature and constant-humidity area(5.3)to prevent anycha
14、nges.6.3 Whenever possible,comparative control specimens of asimilar material or product with known service characteristics1This test method is under the jurisdiction of ASTM Committee D-1 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D 01.52
15、 on Factory-Coated Wood Products.Current edition approved May 10,1998.Published September 1998.Originallypublished as D 3459 75 Last previous edition D 3459 97.2Annual Book of ASTM Standards,Vol 06.01.3Discontinued;see 1992 Annual Book of ASTM Standards,Vol 06.01.4Annual Book of ASTM Standards,Vol 1
16、4.02.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTMshould also be exposed.6.4 Three specimens are usually adequate unless a lack ofuniformity is suspected in the substrate,coating,or coatingsystem.7.Conditioning7.1 Place the specimens in a conditioned room or chamber(5.3)so that air is free to circulate on all sides of each specimenso as to avoid localized overheating.Allow them to remainthe
