ASTM_D_1146_-_00_2013.pdf

Designation:D114600(Reapproved 2013)Standard Test Method forBlocking Point of Potentially Adhesive Layers1This standard is issued under the fixed designation D1146;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.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1 This test method covers the determination of the block-ing point of a thermoplastic or a hygroscopic layer or coatingof potentially adhesive material.Potentially adhesive materialscomprise those materials in a substantially nonadhesive statewhich may be activated to an adhesive state by application ofheat or solvents.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:2D907 Terminology of Adhesives3.Terminology3.1 DefinitionsMany terms in this test method are definedin Terminology D907.3.2 Definitions of Terms Specific to This Standard:3.2.1 adhesive blocking,nthe blocking of a potentiallyadhesive face and a standard test paper.3.2.2 blocking,nthe adhesion between touching layers ofsimilar or dissimilar material,such as occurs under moderatepressures during storage or use.3.2.3 cohesive blocking,nthe blocking of two similar,potentially adhesive faces.3.2.4 critical humidity,nthe lowest humidity at whichblocking of a given degree occurs.3.2.5 critical temperature,nthe lowest temperature atwhich blocking of a given degree occurs.3.2.6 first degree blocking,nan adherence between thesurfaces under test of such degree that when the upperspecimen is lifted the lower specimen will cling thereto,butmay be parted with no evidence of damage to either surface.3.2.7 second degree blocking,nan adherence of suchdegree that when the surfaces under tests are parted one surfaceor the other will be found to be damaged.NOTE1It is permissible to designate such other degrees of blockingas may be agreed upon between the manufacturer and the purchaser of theadhesive.4.Significance and Use4.1 Since some potentially adhesive materials are boththermoplastic and hygroscopic,this test method providesmeans for estimating,on the same material,both thermoplasticand hygroscopic blocking.Because some requirements aremore strict than others,two varying degrees of blocking arerecognized and defined:(1)First degree blocking,and(2)Second degree blocking.Two types of blocking are covered:(1)Cohesive blocking,and(2)Adhesive blocking.5.Apparatus and Materials5.1 Constant-Temperature Oven,capable of maintainingtemperatures up to 85 6 1C(185 6 2F),and of sufficient sizeto hold one or more desiccators of the type described in 5.2.5.2 Desiccators,for use as humidity chambers,with aminimum diameter of 150 mm(6 in.).The desiccators aremade of glass,with ground flanges and fitting covers.Groundedges are clean and well lubricated with stopcock grease.5.3 Weights,of 0.45 kg(1 lb)each,having a flat base 645mm2(1 in.2)in area.5.4 Glass Plates,of plate glass,measuring 38 by 38 mm(112by 112in.).5.5 Standard PaperGeneral usage filter paper cut in by 38by 38-mm(112by 112-in.)squares.1This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is the direct responsibility of Subcommittee D14.10 on WorkingProperties.Current edition approved Oct.1,2013.Published October 2013.Originallyapproved in 1951.Last previous edition approved in 2007 as D1146 00(2007).DOI:10.1520/D1146-00R13.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 NOTE2In cases where standard paper is deemed inadequate,adifferent paper,or material other than paper,may be substituted byagreement between the manufacturer and the purchaser of the adhesive.6.Materials6.1 Various Salts,for maintaining constant humidity condi-tions within the desiccators,as follows:6.1.1 Anhydrous calcium chloride(CaCl2),for lowhumidity,and6.1.2 The following salts,employed in saturated solution:SaltApproximate Relative Humidity overSaturated Solution at 38C(100F),%Sodium dichromate(Na2Cr2O72H2O)50ASodium bromide(NaBr)54ASodium nitrite(NaNO2)62ASodium acetate(NaC2H3O23H2O)68ASodium chloride(NaCl)75APotassium chloride(KCl)83BAmmonium monophosphate(NH4H2PO4)91AA“Equilibrium Relative Humid