ASTM_D_3121_-_17.pdf

Designation:D312117Standard Test Method forTack of Pressure-Sensitive Adhesives by Rolling Ball1This standard is issued under the fixed designation D3121;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 measurement of the compara-tive tack of pressure-sensitive adhesives by a rolling ball and ismost appropriate for low-tack adhesives.This test method isonly one of several available for the measurement of tack.1.1.1 This test method is not recommended for the specifi-cation of end use products.1.2 Values stated in either SI or inch-pound units are to beregarded separately as standard.The values stated in eachsystem may not be exact equivalents,therefore,each systemmust be used independently without combining values in anyway.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.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:2D907 Terminology of AdhesivesE171 Practice for Conditioning and Testing Flexible BarrierPackagingD5750/D5750M Guide for Width and Length of Pressure-Sensitive Tape3.Terminology3.1 DefinitionsMany of the terms found in this testmethod are defined in Terminology D907.4.Summary of Test Method4.1 In the determination of tack by the rolling-ball method,a steel ball is released at the top of an incline,allowed toaccelerate down the incline and roll on to a horizontal surfacecovered with a pressure-sensitive adhesive.Tack is determinedby measuring the distance that the ball travels across theadhesive before stopping.There are two major retarding forcesapplied by the adhesive to the ball:(1)the adhesion betweenthe ball and the adhesive,often called“grab,”and(2)the“plowing effect”or energy required to push the adhesive out ofthe balls path.4.2 Test results are influenced by(1)adhesive filmthickness,(2)bond of adhesive to backing,and(3)backingrigidity,so these factors must be carefully controlled forsatisfactory comparisons.5.Significance and Use5.1 The rolling-ball tack test is fast,easy to run,and requireslittle investment in equipment and little operator training.Thistest is intended primarily for quality control use since itdemonstrates good reproducibility within a single laboratoryand ability to detect batch-to-batch variations accurately ifadhesive film thickness is held constant.Rolling ball tack is notintended as an investigative tool since for most pressuresensitive adhesive applications rolling ball tack results do notcorrelate well with application tack requirements.6.Apparatus(Fig.1 and Fig.2)6.1 Inclined Trough equipped with a release lever at the topthrough which the ball gains downhill momentum.The ball isa 11 mm(716in.)diameter steel ball unless otherwise specified.7.Reagents7.1 Purity of ReagentsReagent grade chemicals should beused in all tests.Other grades may be used,provided it is firstascertained that the reagent is of sufficiently high purity topermit its use without lessening accuracy of the determination.7.2 Solvents:1This test method is under the jurisdiction of ASTM Committee D10 onPackaging and is the direct responsibility of Subcommittee D10.14 on Tape andLabels.Current edition approved May 1,2017.Published July 2017.Originally approvedin 1973.Last previous edition approved in 2006 as D3121 06 which waswithdrawn January 2015 and reinstated in May 2017.DOI:10.1520/D3121-17.2For 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 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 7.2.1 Any of the following solvents may be used forcleaning:7.2.1.1 Diactone alcohol non-residual,technical grade orbetter,7.2.1.2 Methanol(95%),7.2.1.3 Methyl ethyl ketone(MEK),7.2.1.4 n-Heptane,or7.2.1.5 Acetone.7.2.2 Before selecting or using thes