ASTM_D_3111_-_19.pdf

Designation:D311119Standard Practice forFlexibility Determination of Hot-Melt Adhesives by MandrelBend Test1This standard is issued under the fixed designation D3111;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 practice covers the determination of the flexibilityof a hot-melt adhesive in sheet form under specific testconditions.This is a working practice.Its results are useful forcomparing adhesives,not for absolute characterization ofadhesives.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,health,and environmental practices and deter-mine the applicability 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/E171M Practice for Conditioning and Testing FlexibleBarrier Packaging3.Terminology3.1 DefinitionsMany of the terms found in this practiceare defined in Terminology D907.3.2 Definitions of Terms Specific to This Standard:3.2.1 flexibility,nthat property of a material by virtue ofwhich it may be flexed or bowed repeatedly without undergo-ing rupture.4.Summary of Practice4.1 Test strips of a hot-melt adhesive,properly sized andconditioned,are bent 180 over a mandrel(rod).Using a freshspecimen for each test,the test is repeated with smallerdiameter mandrels until the adhesive fails on bending.Theflexibility of the adhesive is the smallest diameter mandrel overwhich four out of five test specimens do not break.5.Significance and Use5.1 The“Mandrel Bend”test is simple and fast.It requireslittle investment in equipment and little operator training.Theprime purpose is to determine whether a hot-melt adhesivemeets flexibility requirements.This test is also useful forcomparing flexibility of several adhesives.It can be used todesign adhesives by comparing the flexibility of variousformulations to meet specific end use parameters.The adhesiveflexibility can be determined at temperatures other than ambi-ent by conditioning the test apparatus and test specimens at thedesired temperature and performing the test under thesetemperature conditions.6.Apparatus6.1 The test apparatus consists of a series of differentdiameter cylindrical rods or mandrels supported at each end.There shall be enough space to permit placement of the flat sideof a test specimen tangentially at right angles to the longitu-dinal axis of the test mandrel.Individual requirements deter-mine the diameter and lengths of the rods needed.For mosttests,3.2 mm(;18in.),6.4 mm(;14in.),and 12.8 mm(;12in.)diameter by 75 to 150-mm(;3 to 6-in.)long rods made ofbrass or stainless steel are satisfactory.Fig.1 describes twosimple test frames,one with fixed mandrels and the otherdesigned to take any diameter mandrel.7.Test Specimen7.1 The test specimen dimensions can be varied dependingon the end use requirements of the hot-melt adhesive.Fig.2describes a recommended specimen size.It is 10 mm(;0.41This practice is under the jurisdiction of ASTM Committee D10 on Packagingand is the direct responsibility of Subcommittee D10.14 on Tape and Labels.Current edition approved April 1,2019.Published June 2019.Originallyapproved in 1972.Last previous edition approved in 2018 as D311110(2018).DOI:10.1520/D3111-19.2For 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 in.)wide,75 mm(;3 in.)long and 1.25 6 0.01 mm(;0.05in.)thick.The thickness dimension is critical and must beaccurately measured.The test specimens shall be cut frommolded or extruded sheets or film.Plying of several thinnersamples shall not be permitted.No flaws visible anywhere inthe sample to the naked eye shall be permitted.