ASTM_D_4272_-_14.pdf

Designation:D427214Standard Test Method forTotal Energy Impact of Plastic Films By Dart Drop1This standard is issued under the fixed designation D4272;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.Scope*1.1 This test method describes the determination of the totalenergy impact of plastic films by measuring the kinetic energylost by a free-falling dart that passes through the film.1.2 The values stated in SI units are to be regarded asstandard.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.NOTE1Film has been arbitrarily defined as sheeting having nominalthickness not greater than 0.25 m(0.010 in.).NOTE2This test method and ISO 77652 address the same subjectmatter,but differ in technical content(and results cannot be directlycompared between the two test methods).The ISO test method calls for adirect readout of energy by using a load cell as part of the impactor head,while Test Method D4272 calls for a constant weight impactor,thenmeasuring the time of travel through a given distance to get energy values.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1709 Test Methods for Impact Resistance of Plastic Filmby the Free-Falling Dart MethodD3420 Test Method for Pendulum Impact Resistance ofPlastic FilmD5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensD6988 Guide for Determination of Thickness of Plastic FilmTest SpecimensE171 Practice for Conditioning and Testing Flexible BarrierPackagingE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ISO Standard:3ISO 77652 Plastics Film and SheetingDetermination ofImpact Resistance by the Free Falling Dart MethodPart2:Instrumented Puncture Test3.Terminology3.1 TerminologyFor definitions,see Terminology D883.3.2 Definitions of Terms Specific to This Standard:3.2.1 free-fall timethe measured time required for the dartto travel through the sensing area with no film specimen in theclamp.3.2.2 missile mass(SI units)the total mass of the dart(kg)including any attached incremental weights and the lockingcollar.3.2.3 missile weight(in.-lb units)the total weight of thedart(lb)including any attached incremental weights and thelocking collar.3.2.3.1 DiscussionIn the energy calculation,the weight isdivided by the gravitational constant,“g”to obtain the mass.3.2.4 test-fall timethe measured time for the dart to travelthrough the sensing area with a film specimen in the clamp.4.Summary of Test Method4.1 The velocity of a freely falling dart of specified shapethat has passed through a sheet of plastic film is determined bymeans of a photoelectric speed trap.The kinetic energycorresponding to this velocity is calculated and compared withthe kinetic energy of the same dart measured without a plasticfilm in place.The loss in kinetic energy of the dart due torupturing of the film is used as an index of impact resistance.5.Significance and Use5.1 Evaluation of the impact toughness of film is importantin predicting the performance of a material in applications suchas packaging,construction,and other uses.The test simulatesthe action encountered in applications where moderate-velocityblunt impacts occur in relatively small areas of film.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.19 on Film,Sheeting,andMolded Products.Current edition approved April 1,2014.Published April 2014.Originallyapproved in 1983.Last previous edition approved in 2009 as D4272-09.DOI:10.1520/D4272-14.2For 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.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.2 The values obtained by this test method are highlydependent on the method and conditions of film fabrication aswell as the type and grade of resin.5.3 Test methods employing different missile velocities,impinging surface diameters,or effective specimen diameterswill most likely produce different results.Data obtained by thistest method cannot