1、Designation:D193814Standard Test Method forTear-Propagation Resistance(Trouser Tear)of Plastic Filmand Thin Sheeting by a Single-Tear Method1This standard is issued under the fixed designation D1938;the number immediately following the designation indicates the year oforiginal adoption or,in the cas
2、e 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 covers the determination of the forcenecessary to propagate a tear in plastic f
3、ilm and thin sheeting(thickness of 1 mm(0.04 in.)or less)by a single-tear method.The method is not applicable for film or sheeting materialwhere brittle failures occur during testing.NOTE1Film has been arbitrarily defined as sheeting having nominalthickness not greater than 0.25 mm(0.010 in.).1.2 Co
4、nstant-Rate-of-Grip Separation Test This testmethod employs a constant rate of separation of the gripsholding the test specimen.1.2.1 Specimen extension may be measured in this testmethod by grip separation.1.3 The values stated in SI units are to be regarded asstandard.The values given in parenthes
5、es are provided forinformation only.1.4 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 limitat
6、ions prior to use.NOTE2This standard is similar to ISO 6383-1,but is not consideredtechnically equivalent.The specimen size for ISO 6383-1 is larger,and themethod specifies different test speeds.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD882 Test Me
7、thod for Tensile Properties of Thin PlasticSheetingD883 Terminology Relating to PlasticsD4000 Classification System for Specifying Plastic Materi-alsD5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensD6988 Guide for Determination of Thickness of Plastic FilmTest SpecimensE4 Practic
8、es for Force Verification of Testing MachinesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ISO Standard:ISO 6383-1 Film and SheetingDetermination of Tear Re-sistance Part 1 Trouser Tear Method33.Terminology3.1 Definitions:For definitions of terms
9、 used in this testmethod,refer to Terminology D883.4.Summary of Test Method4.1 The force to propagate a tear across a film or sheetingspecimen is measured using a constant-rate-of-grip separationmachine as described in Test Methods D882 and is calculatedfrom the load-time chart.5.Significance and Us
10、e5.1 This test method is of value in rating the tear-propagation resistance of various plastic films and thin sheetingof comparable thickness.For highly extensible film or sheetingthe deformation energy of the specimen legs is significantlygreater than the tearing energy.The tear-propagation resista
11、ncein slightly extensible or non-extensible film or sheeting isdistinguished from the tear-propagation resistance in highlyextensible film or sheeting by the load-time or load-displacement data,(Fig.1 and Fig.2).The tear-propagationforce for slightly extensible or non-extensible material isdetermine
12、d from the average tear force versus the initial andpeak force for a highly extensible material.5.2 This test method shall be used for specification accep-tance testing only after it has been demonstrated that the datafor the particular material are acceptably reproducible.1This test method is under
13、 the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.19 on Film,Sheeting,andMolded Products.Current edition approved Dec.1,2014.Published December 2014.Originallyapproved in 1962.Last previous edition approved in 2008 as D1938 08.DOI:10.1520/D1938-1
14、4.2For 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
15、.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 5.3 The data obtained by this test method furnish informa-tion for r
16、anking the tear-propagation resistance of plastic filmsand sheeting of similar composition.Actual use performancemay not necessarily correlate with data from this test method.Sets of data from specimens of dissimilar thickness are usuallynot comparable.5.4 Before proceeding with this test method,referenceshould be made to the specification of the material being tested.Any test specimen preparation,conditioning,dimensions,ortesting parameters,or combination thereof,covered in therelevant ASTM mat
