ASTM D882-2009 Standard Test Method for Tensile Properties of Thin Plastic Sheeting.pdf

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1、Designation: D 882 09Standard Test Method forTensile Properties of Thin Plastic Sheeting1This standard is issued under the fixed designation D 882; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number

2、 in 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

3、*1.1 This test method covers the determination of tensileproperties of plastics in the form of thin sheeting, includingfilm (less than 1.0 mm (0.04 in.) in thickness).NOTE 1Film has been arbitrarily defined as sheeting having nominalthickness not greater than 0.25 mm (0.010 in.).NOTE 2Tensile proper

4、ties of plastics 1.0 mm (0.04 in.) or greater inthickness shall be determined according to Test Method D 638.1.2 This test method may be used to test all plastics withinthe thickness range described and the capacity of the machineemployed.1.2.1 Static Weighing, Constant-Rate-of-Grip SeparationTestTh

5、is test method employs a constant rate of separation ofthe grips holding the ends of the test specimen.1.3 Specimen extension may be measured in these testmethods by grip separation, extension indicators, or displace-ment of gage marks.1.4 A procedure for determining the tensile modulus ofelasticity

6、 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 ofusing extensometers, as described in 5.2, is recognized and provision forthe use of such instrumentation is incorporated in the proce

7、dure.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 thestandard. The values in parentheses are provided for informa-tion only.1.7 This standard does not purport to address all of thesafety co

8、ncerns, 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.NOTE 4This test method is similar to ISO 527-3, but is not consideredtechnically

9、 equivalent. ISO 527-3 allows for additional specimen configu-rations, specifies different test speeds, and requires an extensometer orgage marks on the specimen.2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 638 Test Method for Tensile Properties of

10、 PlasticsD 4000 Classification System for Specifying Plastic Mate-rialsD 5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensD 6287 Practice for Cutting Film and Sheeting Test Speci-mensE4 Practices for Force Verification of Testing MachinesE 691 Practice for Conducting an Interlabor

11、atory Study toDetermine the Precision of a Test Method2.2 ISO Standard:ISO 527-3 PlasticsDetermination of Tensile PropertiesPart 3: Test Conditions for Films and Sheets33. Terminology3.1 DefinitionsDefinitions of terms and symbols relatingto tension testing of plastics appear in the Annex to TestMet

12、hod D 638.3.1.1 line gripsgrips having faces designed to concentratethe 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.3.1.2 tear failurea tensile

13、 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 Committee D20 onPlastics and are the direct responsibility of Subcomm

14、ittee D20.19 on Film andSheeting.Current edition approved Jan. 1, 2009. Published January 2009. Originallyapproved in 1946. Last previous edition approved in 2002 as D 882 - 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. F

15、or 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.1*A Summary of Changes section appears at the end of this

16、 standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Significance and Use4.1 Tensile properties determined by this test method are ofvalue for the identification and characterization of materials forcontrol and specification p

17、urposes. Tensile properties may varywith specimen thickness, method of preparation, speed oftesting, type of grips used, and manner of measuring extension.Consequently, where precise comparative results are desired,these factors must be carefully controlled. This test methodshall be used for referee

18、 purposes, unless otherwise indicatedin particular material specifications. For many materials, theremay be a specification that requires the use of this test method,but with some procedural modifications that take precedencewhen adhering to the specification. Therefore, it is advisable torefer to t

19、hat material specification before using this testmethod. Table 1 in Classification D 4000 lists the ASTMmaterials standards that currently exist.4.2 Tensile properties may be utilized to provide data forresearch and development and engineering design as well asquality control and specification. Howe

20、ver, 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 thestiffness of thin plastic sheeting. The reproducibility of testresults is good when precise control is main

21、tained 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 energyabsorbed per unit volume of the specimen up to the point ofrupture. In some texts this property has be

22、en referred to astoughness. It is used to evaluate materials that may besubjected to heavy abuse or that might stall web transportequipment in the event of a machine malfunction in end-useapplications. However, the rate of strain, specimen parameters,and especially flaws may cause large variations i

23、n the results.In that sense, 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 normal failure.5. Apparatus5.1 Testing MachineA testing machine of the constantrate-of-crosshead

24、-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 set of grips for holding the test specimenbetween the fixed member and the movable member of thet

25、esting 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 to the fixed andmovable members of the testing machine. When this type ofgrip is used, care must

26、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-aligning grips are attached to the fixed andmovable members of the testing machine in such a manner

27、 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 assembly. The specimens should be aligned as per-fectly as possible with the direction of pull so th

28、at no rotarymotion that may induce slippage will occur in the grips; thereis a limit to the amount of misalignment self-aligning grips willaccommodate.5.1.3.3 The test specimen shall be held in such a way thatslippage relative to the grips is prevented insofar as possible.Grips lined with thin rubbe

29、r, crocus-cloth, or pressure-sensitivetape as well as file-faced or serrated grips have been success-fully used for many materials. The choice of grip surface willdepend on the material tested, thickness, etc. Line grips paddedon the round face with 1.0 mm (40 mil) blotting paper or filterpaper have

30、 been found superior. Air-actuated grips have beenfound advantageous, particularly in the case of materials thattend to “neck” into the grips, since pressure is maintained at alltimes. In cases where samples frequently fail at the edge of thegrips, it may be advantageous to increase slightly the rad

31、ius ofcurvature of the edges where the grips come in contact with thetest area of the specimen.5.1.4 Drive MechanismA drive mechanism 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

32、.5 Load IndicatorA suitable load-indicating mecha-nism capable of showing the total tensile load carried by thetest specimen held by the grips. This mechanism shall beessentially free of inertial lag at the specified rate of testing (seeNote 5). Unless a suitable extensometer is used (see 5.2), them

33、otion of the weighing system shall not exceed 2 % of thespecimen extension within the range being measured. The loadindicator shall 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 inacc

34、ordance with Practices E4.5.1.6 Crosshead Extension IndicatorAsuitable extension-indicating mechanism capable of showing the amount 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

35、5) and shallindicate the crosshead movement with an accuracy of 61%ofthe indicated value, or better.5.2 Extensometer (Optional)A suitable instrument may, ifdesired, be used for determining the distance between twodesignated points on the test specimen as the specimen isstretched. This apparatus, if

36、employed, shall be so designed asto minimize stress on 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

37、the start of the test, or both. If only the latteris obtained, load-time data must also be taken. This instrumentmust be essentially free of inertial lag at the specified speed oftesting (see Note 5).D8820925.2.1 Modulus of Elasticity and Low-ExtensionMeasurementsExtensometers used for modulus of el

38、asticityand low-extension (less than 20 % elongation) measurementsshall, at a minimum, be accurate to 61 % and comply with therequirements set forth in Practice E 83 for a Class C instru-ment.5.2.2 High-Extension MeasurementsInstrumentation andmeasuring techniques used for high-extension (20 % elong

39、a-tion or greater) measurements shall be accurate to 610 % ofthe indicated value, or better.NOTE 5A 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

40、(high or low elongation) and the rate of straining.5.3 Thickness GageA dead-weight dial micrometer asprescribed in Method C of Test Methods D 5947,oranequivalent measuring device, reading to 0.0025 mm (0.0001in.) or less.5.4 Width-Measuring DevicesSuitable test scales or otherwidth measuring devices

41、 capable of measuring 0.25 mm (0.010in.) or less.5.5 Specimen CutterFor the apparatus and techniques forcutting film and sheeting used in this test method, refer toPractice D 6287.5.5.1 Devices that use razor blades have proven especiallysuitable for materials having an elongation-at-fracture above1

42、0 to 20 %.5.5.2 The use of punch press or striking dies are notrecommended because poor and inconsistent specimen edgesmay be produced.6. Test Specimens6.1 The test specimens shall consist of strips of uniformwidth and thickness at least 50 mm (2 in.) longer than the gripseparation used.6.2 The nomi

43、nal 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 flaws, orboth.6.4 The utmost care shall be exercised in cutting specimensto prevent nic

44、ks and tears which are likely to cause prematurefailures (Note 6). The edges shall be parallel to within 5 % ofthe width over the length of the specimen between the grips.NOTE 6Microscopical examination of specimens may be used todetect flaws due to sample or specimen preparation.6.5 Wherever possib

45、le, the test specimens shall be selectedso that thickness is uniform to within 10 % of the thicknessover the length of the specimen between the grips in the caseof materials 0.25 mm (0.010 in.) or less in thickness and towithin 5 % in the case of materials greater than 0.25 mm (0.010in.) in thicknes

46、s but less than 1.00 mm (0.040 in.) in thickness.NOTE 7In cases where thickness variations are in excess of thoserecommended in 6.5, results may not be characteristic of the materialunder test.6.6 If the material is suspected of being anisotropic, two setsof test specimens shall be prepared having t

47、heir long axesrespectively parallel with and normal to the suspected directionof anisotropy.6.7 For tensile modulus of elasticity determinations, aspecimen gage length of 250 mm (10 in.) shall be consideredas standard. This length is used in order to minimize the effectsof grip slippage on test resu

48、lts. When this length is not feasible,test sections as short as 100 mm (4 in.) may be used if it hasbeen shown that results are not appreciably affected. However,the 250-mm gage length shall be used for referee purposes. Thespeed of testing of shorter specimens must be adjusted in orderfor the strai

49、n rate to be equivalent to that of the standardspecimen.NOTE 8Two round robin tests4have shown that, for materials of lessthan 0.25-mm (10-mil) thickness, line grips padded on the round side with1.0-mm (40-mil) blotting paper give the same results with a 100-mm testsection as a 250-mm test section produces with flat-face grips.NOTE 9Excessive jaw slippage becomes increasingly difficult toovercome in cases where high modulus materials are tested in thicknessesgreater than 0.25 mm (0.010 in.).7. Conditioning7.1 ConditioningCondition the test specimens at 23