ASTM_F_88_-_F_88M_-_09.pdf

Designation:F88/F88M09Standard Test Method forSeal Strength of Flexible Barrier Materials1This standard is issued under the fixed designation F88/F88M;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 the measurement of the strengthof seals in flexible barrier materials.1.2 The test may be conducted on seals between a flexiblematerial and a rigid material.1.3 Seals tested in accordance with this test method may befrom any source,laboratory or commercial.1.4 This test method measures the force required to separatea test strip of material containing the seal.It also identifies themode of specimen failure.1.5 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.6 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:2D882 Test Method for Tensile Properties of Thin PlasticSheetingE171 Practice for Conditioning and Testing Flexible BarrierPackagingE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions:3.1.1 average seal strength,naverage force per unit widthof seal required to separate progressively a flexible materialfrom a rigid material or another flexible material,under theconditions of the test.3.1.1.1 DiscussionThe average force normally is calcu-lated by the testing machine from the digitized plot of forceversus grip travel.The plot starts from zero force after slackhas been removed from the test strip.The initial ramp-up fromzero to the force level required to peel the seal is not indicativeof seal strength,and data from that part of the curve should notbe included in the calculation of average strength,nor shouldthe return to zero following complete failure of the specimen.The amount of data actually discarded on each end of themeasured seal-profile curve must be the same for all testswithin any set of comparisons of average seal strength(see6.1.1 and 9.8.1).3.1.2 flexible,adjindicates a material with flexuralstrength and thickness permitting a turn back at an approximate180 degree angle.3.1.3 maximum seal strength,nmaximum force per unitwidth of seal required to separate progressively a flexiblematerial from a rigid material or another flexible material,under the conditions of the test.4.Significance and Use4.1 Seal strength is a quantitative measure for use in processvalidation,process control,and capability.Seal strength is notonly relevant to opening force and package integrity,but tomeasuring the packaging processes ability to produce consis-tent seals.Seal strength at some minimum level is a necessarypackage requirement,and at times it is desirable to limit thestrength of the seal to facilitate opening.4.1.1 The maximum seal force is important information,butfor some applications,average force to open the seal may beuseful,and in those cases also should be reported.4.2 A portion of the force measured when testing materialsmay be a bending component and not seal strength alone.Anumber of fixtures and techniques have been devised to holdsamples at various angles to the pull direction to control thisbending force.Because the effect of each of these on testresults is varied,consistent use of one technique(TechniqueA,1This test method is under the jurisdiction ofASTM Committee F02 on FlexibleBarrier Packaging and is the direct responsibility of Subcommittee F02.20 onPhysical Properties.Current edition approved June 15,2009.Published July 2009.Originallyapproved in 1968.Last previous edition approved in 2007 as F88 07a.DOI:10.1520/F0088_F0088M-09.2For 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 Technique B,or Technique C)throughout a test series isrecommended.Examples of fixtures and techniques are illus-trated in Fig.1.4.2.1 Technique A:UnsupportedEach tail of the specimenis secured in opposing grips and the seal remains unsupportedwhile the test is being conducted.4.2.2 Technique B:Supported 90(By Hand)Each tail ofthe specimen is secured in opposing grips and th