ASTM D882-2012 Standard Test Method for Tensile Properties of Thin Plastic Sheeting《薄塑料板的抗拉特性的标准试验方法》.pdf

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1、Designation: D882 12Standard Test Method forTensile Properties of Thin Plastic Sheeting1This standard is issued under the fixed designation D882; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number i

2、n parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.These test methods have been approved for use by agencies of the Department of Defense to replace Method 1013 of Federal TestMethod Standard 406.1. Scope*1

3、.1 This test method covers the determination of tensileproperties of plastics in the form of thin sheeting and films (lessthan 1.0 mm (0.04 in.) in thickness).NOTE 1Film is defined in Terminology D883 as an optional term forsheeting having a nominal thickness no greater than 0.25 mm (0.010 in.).NOTE

4、 2Tensile properties of plastics 1.0 mm (0.04 in.) or greater inthickness shall be determined according to Test Method D638.1.2 This test method can be used to test all plastics withinthe thickness range described and the capacity of the machineemployed.1.3 Specimen extension can be measured by grip

5、 separation,extension indicators, or displacement of gage marks.1.4 The procedure for determining the tensile modulus ofelasticity is included at one strain rate.NOTE 3The modulus determination is generally based on the use ofgrip separation as a measure of extension; however, the desirability ofusi

6、ng extensometers, as described in 5.2, is recognized and provision forthe use of such instrumentation is incorporated in the procedure.1.5 Test data obtained by this test method is relevant andappropriate for use in engineering design.1.6 The values stated in SI units are to be regarded as thestanda

7、rd. The values in parentheses are provided for informa-tion only.1.7 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 appl

8、ica-bility of regulatory limitations prior to use.NOTE 4This test method is similar to ISO 527-3, but is not consideredtechnically equivalent. ISO 527-3 allows for additional specimenconfigurations, specifies different test speeds, and requires an extensom-eter or gage marks on the specimen.2. Refer

9、enced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD638 Test Method for Tensile Properties of PlasticsD883 Terminology Relating to PlasticsD4000 Classification System for Specifying Plastic Materi-alsD5947 Test Methods for Physical Dimensions of SolidPlastics Speci

10、mensD6287 Practice for Cutting Film and Sheeting Test Speci-mensD6988 Guide for Determination of Thickness of Plastic FilmTest SpecimensE4 Practices for Force Verification of Testing MachinesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ISO Stand

11、ard:ISO 527-3 PlasticsDetermination of Tensile PropertiesPart 3: Test Conditions for Films and Sheets33. Terminology3.1 Definitions:3.1.1 Definitions of terms and symbols relating to tensiontesting of plastics appear in the Annex to Test Method D638.3.1.2 line gripsgrips having faces designed to con

12、centratethe entire gripping force along a single line perpendicular to thedirection of testing stress. This is usually done by combiningone standard flat face and an opposing face from whichprotrudes a half-round.3.1.3 flat gripsgrips having flat faces and lined with thinrubber, crocus-cloth, emery

13、cloth, or pressure-sensitive tape.3.1.4 tear failurea tensile failure characterized by fractureinitiating at one edge of the specimen and progressing acrossthe specimen at a rate slow enough to produce an anomalousload-deformation curve.1These test methods are under the jurisdiction of ASTM Committe

14、e D20 onPlastics and are the direct responsibility of Subcommittee D20.19 on Film, Sheeting,and Molded Products.Current edition approved Aug. 1, 2012. Published September 2012. Originallyapproved in 1946. Last previous edition approved in 2010 as D882 - 10. DOI:10.1520/D0882-12.2For referenced ASTM

15、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 F

16、loor, 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 States14. Significance and Use4.1 Tensile properties determined by this test method

17、 are ofvalue for the identification and characterization of materials forcontrol and specification purposes. Tensile properties can varywith specimen thickness, method of preparation, speed oftesting, type of grips used, and manner of measuring extension.Consequently, where precise comparative resul

18、ts are desired,these factors must be carefully controlled. This test methodshall be used for referee purposes, unless otherwise indicatedin particular material specifications. For many materials, therecan be a specification that requires the use of this test method,but with some procedural modificat

19、ions that take precedencewhen adhering to the specification. Therefore, it is advisable torefer to that material specification before using this testmethod. Table 1 in Classification D4000 lists the ASTMmaterials standards that currently exist.4.2 Tensile properties can be utilized to provide data f

20、orresearch and development and engineering design as well asquality control and specification. However, data from suchtests cannot be considered significant for applications differingwidely from the load-time scale of the test employed.4.3 The tensile modulus of elasticity is an index of thestiffnes

21、s of thin plastic sheeting. The reproducibility of testresults is good when precise control is maintained over all testconditions. When different materials are being compared forstiffness, specimens of identical dimensions must be employed.4.4 The tensile energy to break (TEB) is the total energyabs

22、orbed per unit volume of the specimen up to the point ofrupture. In some texts this property has been referred to astoughness. It is used to evaluate materials that are subjected toheavy abuse or that can stall web transport equipment in theevent of a machine malfunction in end-use applications.Howe

23、ver, the rate of strain, specimen parameters, and espe-cially flaws can cause large variations in the results. In thatsense, caution is advised in utilizing TEB test results forend-use design applications.4.5 Materials that fail by tearing give anomalous data whichcannot be compared with those from

24、normal failure.5. Apparatus5.1 Testing MachineA testing machine of the constantrate-of-crosshead-movement type and comprising essentiallythe following:5.1.1 Fixed MemberA fixed or essentially stationarymember carrying one grip.5.1.2 Movable MemberA movable member carrying asecond grip.5.1.3 GripsA s

25、et of grips for holding the test specimenbetween the fixed member and the movable member of thetesting machine; grips can be either the fixed or self-aligningtype. In either case, the gripping system must minimize bothslippage and uneven stress distribution.5.1.3.1 Fixed grips are rigidly attached t

26、o the fixed andmovable members of the testing machine. When this type ofgrip is used, care must be taken to ensure that the test specimenis inserted and clamped so that the long axis of the testspecimen coincides with the direction of pull through thecenter line of the grip assembly.5.1.3.2 Self-ali

27、gning grips are attached to the fixed andmovable members of the testing machine in such a manner thatthey will move freely into alignment as soon as a load isapplied so that the long axis of the test specimen will coincidewith the direction of the applied pull through the center line ofthe grip asse

28、mbly. The specimens must be aligned as perfectlyas possible with the direction of pull so that no rotary motionwill cause slippage to occur in the grips; there is a limit to theamount of misalignment self-aligning grips will accommodate.5.1.3.3 The test specimen shall be held in such a way thatslipp

29、age relative to the grips is prevented insofar as possible.Grips lined with thin rubber, crocus-cloth, emery cloth, orpressure-sensitive tape as well as file-faced or serrated gripshave been successfully used for many materials. The choice ofgrip surface will depend on the material tested, thickness

30、, etc.Line grips padded on the round face with 0.75-1.00 mm(0.030-0.040 in.) blotting paper or filter paper have been foundsuperior. Air-actuated grips have been found advantageous,particularly in the case of materials that tend to “neck” into thegrips, since pressure is maintained at all times (see

31、 Notes 5-7).In cases where samples frequently fail at the edge of the grips,it could be advantageous to slightly increase the radius ofcurvature of the edges where the grips come in contact with thetest area of the specimen.NOTE 5Caution needs to be taken when choosing the type of grips andthe type

32、of grip surfaces to use for testing specimens films composed ofhigh strength LLDPE and VLDPE resins. Test results tend to differ morewhen comparing these types of specimens films tested with the grips linedwith different materials.NOTE 6The gage of pressure sensitive tape, thin rubber, crocus-cloth,

33、and emery cloth needs to be adequate enough to prevent slipping andpremature failures of the test specimens (for example, pressure sensitivetape is used on the surface of the grips: the test specimen can may beginto tear at the edge of the grips during the test if the tape is too thin.).NOTE 7The gr

34、it size of crocus-cloth and emery cloth is suggested tobe at least 800. The use of these materials helps to prevent test specimensfrom slipping in the grips. One must be cautious when using thesematerials so that premature failures of the test specimens do not occur.5.1.4 Drive MechanismA drive mech

35、anism for impartingto the movable member a uniform, controlled velocity withrespect to the stationary member. The velocity shall be regu-lated as specified in Section 9.5.1.5 Load IndicatorA suitable load-indicating mecha-nism capable of showing the total tensile load carried by thetest specimen hel

36、d by the grips. This mechanism shall beessentially free of inertial lag at the specified rate of testing (seeNote 8). Unless a suitable extensometer is used (see 5.2), themotion of the weighing system shall not exceed 2 % of thespecimen extension within the range being measured. The loadindicator sh

37、all determine the tensile load applied to thespecimen with an accuracy of 61 % of the indicated value, orbetter. The accuracy of the testing machine shall be verified inaccordance with Practices E4.5.1.6 Crosshead Extension IndicatorAsuitable extension-indicating mechanism capable of showing the amo

38、unt ofchange in the separation of the grips, that is, crossheadmovement. This mechanism shall be essentially free of inertiallag at the specified rate of testing (see Note 8) and shallD882 122indicate the crosshead movement with an accuracy of 61%ofthe indicated value, or better.5.2 Extensometer (Op

39、tional)A suitable instrument usedfor determining the distance between two designated points onthe test specimen as the specimen is stretched. The use of thistype of instrument is optional and is not required in this testmethod. This apparatus, if employed, shall be so designed as tominimize stress o

40、n the specimen at the contact points of thespecimen and the instrument (see 8.3). It is desirable that thisinstrument automatically record the distance, or any change init, as a function of the load on the test specimen or of theelapsed time from the start of the test, or both. If only the latteris

41、obtained, load-time data must also be taken. This instrumentmust be essentially free of inertial lag at the specified speed oftesting (see Note 8).5.2.1 Modulus of Elasticity and Low-ExtensionMeasurementsExtensometers used for modulus of elasticityand low-extension (less than 20 % elongation) measur

42、ementsshall, at a minimum, be accurate to 61 % and comply with therequirements set forth in Practice E83 for a Class C instrument.5.2.2 High-Extension MeasurementsInstrumentation andmeasuring techniques used for high-extension (20 % elonga-tion or greater) measurements shall be accurate to 610 % oft

43、he indicated value, or better.NOTE 8A sufficiently high response speed in the indicating andrecording system for the load and extension data is essential. The responsespeed required of the system will depend in part on the material tested(high or low elongation) and the rate of straining.5.3 Thickne

44、ss GaugeA dead-weight dial or digital mi-crometer as described in Test Methods D5947 or D6988 asappropriate for the material or specimen geometry being tested.5.4 Width-Measuring DevicesSuitable test scales or otherwidth measuring devices capable of measuring 0.25 mm (0.010in.) or less.5.5 Specimen

45、CutterRefer to Practice D6287 for theapparatus and techniques for cutting film and sheeting used inthis test method.5.5.1 Devices that use razor blades have proven especiallysuitable for materials having an elongation-at-fracture above10 to 20 %.5.5.2 The use of a punch press or a striking die is no

46、trecommended because of their tendency to produce poor andinconsistent specimen edges.5.5.3 The use of a cutting template and a single razor bladeis not recommended as it will affect the parallelism of the testspecimen.6. Test Specimens6.1 The test specimens shall consist of strips of uniformwidth a

47、nd thickness at least 50 mm (2 in.) longer than the gripseparation used.6.2 The nominal width of the specimens shall be not lessthan 5.0 mm (0.20 in.) or greater than 25.4 mm (1.0 in.).6.3 A width-thickness ratio of at least eight shall be used.Narrow specimens magnify effects of edge strains or fla

48、ws, orboth.6.4 The utmost care shall be exercised in cutting specimensto prevent nicks and tears that cause premature failures (seeNote 9). The edges shall be parallel to within 5 % of the widthover the length of the specimen between the grips.NOTE 9Microscopical examination of specimens can be used

49、 to detectflaws due to sample or specimen preparation.6.5 Test specimens shall be selected so that thickness isuniform to within 10 % of the thickness over the length of thespecimen between the grips in the case of specimens 0.25 mm(0.010 in.) or less in thickness and to within 5 % in the case ofspecimens greater than 0.25 mm (0.010 in.) in thickness butless than 1.00 mm (0.040 in.) in thickness.NOTE 10In cases where thickness variations are in excess of thoserecommended in 6.5, results tend not to be characteristic of the materialunder test.6.6 If the mat