ASTM D882-2002 Standard Test Method for Tensile Properties of Thin Plastic Sheeting《塑料薄板材抗拉特性的标准试验方法》.pdf

1、Designation: D 882 02Standard 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 (e) 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. Scop

3、e*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 prope

4、rties 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 SeparationTestT

5、his 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 ofelasticit

6、y 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 proc

7、edure.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 c

8、oncerns, 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 consideredtechnicall

9、y 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 o

10、f 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 Interlabo

11、ratory 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 TestMe

12、thod 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 tensil

13、e 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 Subcom

14、mittee D20.19 on Film andSheeting.Current edition approved April 10, 2002. Published June 2002. Originallypublished as D 882 46 T. Last previous edition D 882 01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book

15、of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute, 25 W. 43rd St., 4thFloor, New York, NY 10036.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 10

16、0 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 purposes. Tensile properties may varywith s

17、pecimen 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 purposes, unless otherwise indicatedin pa

18、rticular 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 that material specification before using th

19、is 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. However, data from suchtests cannot be conside

20、red 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 maintained over all testconditions. When diffe

21、rent 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 been referred to astoughness. It is used to

22、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 in the results.In that sense, caution is ad

23、vised 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-movement type and comprising essentiallyt

24、he 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 thetesting machine; grips can be either the fi

25、xed 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 be taken to ensure that the test specimeni

26、s 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 thatthey will move freely into alignment

27、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 that no rotarymotion that may induce slippag

28、e 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 rubber, crocus-cloth, or pressure-sensitivetape

29、 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 been found superior. Air-actuated grips h

30、ave 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 radius ofcurvature of the edges where the gri

31、ps 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 9.5.1.5 Load IndicatorA suitable load-indicatin

32、g 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), themotion of the weighing system shall not exc

33、eed 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 inaccordance with Practices E4.5.1.6 Crosshead

34、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 5) and shallindicate the crosshead movemen

35、t 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 employed, shall be so designed asto minimi

36、ze 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 the start of the test, or both. If only th

37、e 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).D8820225.2.1 Modulus of Elasticity and Low-ExtensionMeasurementsExtensometers used for modulus of elasticityand low-extension (less than 20 %

38、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 % elonga-tion or greater) measurements shall be a

39、ccurate 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(high or low elongation) and the rate of s

40、training.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 capable of measuring 0.25 mm (0.010in.) o

41、r 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 above10 to 20 %.5.5.2 The use of punch press or

42、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 nominal width of the specimens shall be not le

43、ssthan 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 nicks and tears which are likely to cause pre

44、maturefailures (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 possible, the test specimens shall be selectedso

45、 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 thickness but less than 1.00 mm (0.040 in.) in thi

46、ckness.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 their long axesrespectively parallel with a

47、nd 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 results. When this length is not feasible,test

48、 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 strain rate to be equivalent to that of the sta

49、ndardspecimen.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 62C (73.4 6 3.6F) and 50 6 5 % relativ