ASTM_F_392_-_F_392M_-_11_2015.pdf

Designation:F392/F392M11(Reapproved 2015)Standard Practice forConditioning Flexible Barrier Materials for Flex Durability1This standard is issued under the fixed designation F392/F392M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers conditioning of flexible barriermaterials for the determination of flex resistance.Subsequenttesting can be performed to determine the effects of flexing onmaterial properties.These tests are beyond the scope of thispractice.1.2 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.1.3 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:2E171 Practice for Conditioning and Testing Flexible BarrierPackagingF2097 Guide for Design and Evaluation of Primary FlexiblePackaging for Medical Products3.Terminology3.1 pinhole,na small opening of non-specific shape ordimension that passes completely through all layers of aflexible material.3.1.1 DiscussionThe use of the term“pin”provides therelative size reference as in a small hole made with or as if witha pin.4.Summary of Practice4.1 Specimens of flexible materials are flexed at standardatmospheric conditions defined in Specification E171,unlessotherwise specified.Flexing conditions and number and sever-ity of flexing strokes vary with the type of structure beingtested.The flexing action consists of a twisting motionfollowed,in most cases,by a horizontal motion,thus,repeat-edly twisting and crushing the film.The frequency is at a rateof 45 cycles per minute(cpm.)4.2 Flex failure is determined by measuring the effect of theflex conditioning on the barrier and/or mechanical performanceof the structure.The property to be evaluated determines theappropriate conditioning level.4.3 The various flex conditioning levels are summarized asfollows:4.3.1 Condition AFull flex for 1 h(that is,2700 cycles).4.3.2 Condition BFull flex for 20 min(that is,900 cycles).4.3.3 Condition CFull flex for 6 min(that is,270 cycles).4.3.4 Condition DFull flex for 20 cycles.4.3.5 Condition EPartial flex only for 20 cycles.5.Significance and Use5.1 This practice is valuable in determining the resistance offlexible-packaging materials to flex-formed pinhole failures.Conditioning levels A,B,or C are typically used for thisevaluation.5.2 This practice is valuable for determining the effect offlexing on barrier properties such as gas and/or moisturetransmission rates.Conditioning levels D or E are typicallyused for this evaluation.5.3 This practice does not measure any abrasion componentrelating to flex failure.5.4 Failures in the integrity of one or more of the plies of amulti-ply structure may require different testing than thedetection of holes completely through the structure.Perme-ation tests using gas or water vapor can be used in conjunctionwith the flex test to measure the loss of ply integrity.However,any permeation test requiring a pressure differential will notmeasure the permeation coefficient in the presence of pinholes.For a list of test methods refer to Guide F2097.5.4.1 The various conditions described in this procedure areto prevent testing a structure under conditions that either give1This practice is under the jurisdiction of ASTM Committee F02 on FlexibleBarrier Packaging and is the direct responsibility of Subcommittee F02.50 onPackage Design and Development.Current edition approved Oct.1,2015.Published October 2015.Originallyapproved in 1974.Last previous edition approved in 2011 as F392/F392M-11.DOI:10.1520F0392_F0392M-11R15.2For 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 too many holes to effectively count(normally greater than 50),or too few to be significant(normally less than five persample).Material structure,purpose for testing and a mutualagreement between parties involved are important points toconsider in the selection of conditioning level for testing.6.Apparatus6.1 Flex Tester,3designed so that it can be set up inaccordance with the specifications listed in Section 9.Th