1、Designation: D 1004 07Standard Test Method forTear Resistance (Graves Tear) of Plastic Film and Sheeting1This standard is issued under the fixed designation D 1004; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This test method2covers the determination
3、 of the tearresistance of flexible plastic film and sheeting at very low ratesof loading, 51 mm 2 in./min. and is designed to measure theforce to initiate tearing. The specimen geometry of this testmethod produces a stress concentration in a small area of thespecimen. The maximum stress, usually fou
4、nd near the onset oftearing, is recorded as the tear resistance in newtons orpounds-force. The method is not applicable for film orsheeting material where brittle failures occur during testing orwhere maximum extension is greater than 101.6 mm 4 in.NOTE 1Film has been arbitrarily defined as sheeting
5、 having nominalthickness not greater than 0.25 mm 0.010 in.1.2 Constant-Rate-of-Grip Separation TestThis 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 u
6、nits are to be regarded as thestandard. The values given in brackets 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 he
7、alth practices and determine the applica-bility of regulatory limitations prior to use.NOTE 2There is no similar or equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:3D 618 Practice for Conditioning Plastics for TestingD 882 Test Method for Tensile Properties of Thin PlasticSheetingD
8、 883 Terminology Relating to PlasticsD 4000 Classification System for Specifying Plastic Mate-rialsD 5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensE4 Practices for Force Verification of Testing MachinesE 691 Practice for Conducting an Interlaboratory Study toDetermine the Preci
9、sion of a Test Method2.2 ASTM Adjuncts:Die Drawings43. Terminology3.1 Definitions:Definitions of terms applying to this test method appear inTerminology D 883.4. Summary of Test Method4.1 The force to initiate tearing across a specific geometryof a film or sheeting specimen is measured using a const
10、ant-rate-of-grip separation machine. The force necessary to initiatethe tear is calculated from the load-time or load-displacementdata.5. Significance and Use5.1 Tear resistance of plastic film or sheeting is a complexfunction of its ultimate resistance to rupture. The specimengeometry and speed of
11、testing in this test method are controlledto produce tearing in a small area of stress concentration atrates far below those usually encountered in service. Experi-ence has shown the test to have its best reliability for materialswhich do not have brittle failure or do not elongate greater thantwo h
12、undred percent during testing.5.2 The data from this test method furnish comparativeinformation for ranking the tearing resistance of plastic speci-mens of similar composition. Actual use performance intearing of some plastics may not necessarily correlate with datafrom this test method.1This test m
13、ethod is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.19 on Film and Sheeting.Current edition approved April 1, 2007. Published April 2007. Originallyapproved in 1949. Last previous edition approved in 2003 as D 1004 03.2The following r
14、eference may be of interest in connection with this test method:Graves, F. L., “The Evaluation of Tear Resistance in Elastomers,” India RubberWorld, Vol 111, No. 3, December 1944, pp. 305308.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serv
15、iceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from ASTM International Headquarters. Order Adjunct No.ADJD1004.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International
16、, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.3 The resistance to tear of plastic film and sheeting, whilepartly dependent upon thickness, has no simple correlationwith specimen thickness. Hence, tearing forces measured innewtons or pounds-force cannot be no
17、rmalized over a widerange of specimen thickness without producing misleadingdata as to the actual tearing resistance of the material. Datafrom this test method are comparable only from specimens,which vary by no more than 610 % from the nominal oraverage thickness of all specimens tested. Therefore,
18、 thetearing resistance is expressed in maximum newtons orpounds-force of force to tear the specimen.5.4 The tear resistance of plastic film may be a specificationthat requires the use of this test method, but with someprocedural modifications that take precedence when adheringto the specification. T
19、herefore, it is advisable to refer to thatmaterial specification before using this test method. Table 1 ofClassification System D 4000 lists the ASTM materials stan-dards that currently exist.6. Apparatus6.1 Testing MachineA testing machine of the constantrate-of crosshead-movement type and comprisi
20、ng essentiallythe following:6.1.1 Fixed MemberA fixed or essentially stationarymember carrying one grip.6.1.2 Movable MemberA movable member carrying asecond grip.6.1.3 GripsPreferably, a set of self-aligning grips forholding the test specimen between the fixed member and themovable member of the te
21、sting machine. The grips shouldminimize both slippage and uneven stress distribution.6.1.3.1 Fixed grips are rigidly attached to the fixed andmovable members of the testing machine. Fixed grips may beused if extreme care is taken to ensure that the test specimen isinserted and clamped so that the lo
22、ng axis of the test specimencoincides with the direction of pull through the center line ofthe grip assembly.6.1.3.2 Self-aligning grips are attached to the fixed andmovable member of the testing machine in such a manner thatthey will move freely into alignment as soon as any load isapplied so that
23、the long axis of the test specimen will coincidewith the direction of the applied pull through the center line ofthe grip assembly.NOTE 3The specimens should be aligned as perfectly as possible withthe direction of pull so that no rotary motion that may induce slippage willoccur in the grips; there
24、is a limit to the amount of misalignmentself-aligning grips will accommodate.NOTE 4Grips lined with thin rubber have been used successfully.Grips may be of the self-tightening type. In cases where specimensfrequently fail at the edge of the grips, the radius of curvature of the edgesof the grips may
25、 be increased slightly at the point where they come incontact with the specimen.6.1.4 Drive MechanismA drive mechanism capable ofseparating the movable member (grip) from the stationarymember (grip) at a controlled velocity of 51 mm 2 in. 65 %/min.6.1.5 Load IndicatorA suitable load-indicating mecha
26、-nism capable of showing the total tensile load carried by thetest specimen held by the grips. The testing machine shall beessentially free from inertial lag at the specified rate of testingand shall indicate the load with an accuracy of 61 %. Theaccuracy of the testing machine shall be verified in
27、accordancewith Practices E4.6.1.6 Crosshead Extension IndicatorAsuitable extension-indicating mechanism capable of showing the amount ofchange in the separation of the grips (crosshead movement).6.2 ThicknessAmicrometer as prescribed in Test MethodsD 5947, or an equivalent measuring device, reading
28、to 0.025mm 0.0001 in. or less. The pressure exerted by the gage onthe specimen being measured shall not distort or deform thespecimen. For thin films, # 0.025 mm 0.001 in., or filmswhich exhibit visual deformation during measurement, a maxi-mum pressure of 70 kPa 10 psi is recommended. For thickeror
29、 stiffer films, the pressure shall be between 160 and 185 kPa23 and 27 psi.6.3 Die4A die having the dimensions shown in Fig. 1shall be used to cut all specimens. The 90 angle shall be honedsharp with no radius or have a minimum practical radius. Thecutting edge of the die shall have a 5 negative rak
30、e, and shallbe kept sharp and free from nicks to avoid leaving raggededges on the specimen. Wetting the surface of the sample andthe cutting edges of the die with water may facilitate cutting.The sample shall rest on the smooth, slightly yielding surfacethat will not damage the die blade. Lightweigh
31、t cardboard or apiece of leather belting is suitable. Care should be taken thatthe cut edges of the specimen are perpendicular to its othersurfaces and that the edges have a minimum of concavity.7. Test Specimens7.1 The test specimens shall be cut out with a die conform-ing to the dimensions shown i
32、n Fig. 1 and shall not vary bymore than 0.5 % from these dimensions. The cutting edges ofthe die shall be kept sharp and free of all nicks to avoid leavingragged edges on the specimens.NOTE 5Caution should be used to ensure all samples are the samedimension if multiple specimens are cut at one time
33、by stacking (layering)film.Tolerance 6 0.5Table of Metric Equivalentsin. mm4.0 101.600.750 19.051.061 26.951.000 25.401.118 28.402.0 50.800.002 0.0510.500 12.70FIG. 1 Die for Tear Test SpecimenD10040727.2 Machine direction specimens are cut perpendicular tothe machine direction and transverse direct
34、ion specimens arecut perpendicular to the transverse direction.7.3 At least ten specimens shall be tested for each sample, inthe case of isotropic materials.7.4 Test a minimum of ten specimens each in the machinedirection and in the transverse direction for each anisotropictest sample.7.5 Data from
35、specimens which break at some obvious flawor which break in or at the edges of the grips shall be discardedand additional specimens tested, unless such failures constitutea variable whose effect is being studied.7.6 Data from specimens which deviate markedly from themean value of all tests shall be
36、rejected if the deviation of thedoubtful value is more than five times the standard deviationfrom the mean value obtained by excluding the doubtfulresults.NOTE 6For certain materials whose properties vary considerablythroughout the film or sheeting, as many as 50 specimens cut from randomportions of
37、 the sheet must be tested if reliable tear resistance data aredesired.8. Conditioning8.1 ConditioningCondition the test specimens at 23 62C 73.4 6 3.6F and 50 6 5 % relative humidity for not lessthan 40 h prior to test in accordance with Procedure A ofPractice D 618, for those tests where conditioni
38、ng is required.In cases of disagreement, the tolerances shall be 61C61.8F and 62 % relative humidity.8.2 Test ConditionsConduct tests in the standard labora-tory atmosphere of 23 6 2C 73.4 6 3.6F and 50 6 5%relative humidity, unless otherwise specified in the applicableASTM material specification. I
39、n cases of disagreements, thetolerances shall be 61C 61.8F and 62 % relative humid-ity.9. Procedure9.1 An initial jaw separation of 25.4 mm 1 in. shall beused. The rate of travel of the power activated grip shall be51-mm 2-in./min.NOTE 7In this test method, resistance to tear is calculated from them
40、aximum load recorded. In testing most plastics, this maximum load isgenerated at the onset of tearing across the 13-mm 0.5-in. testing widthof the specimen.9.2 Measure the thickness of the specimen at several pointsin the notched area to the accuracy limits of the measuringdevices specified in 6.2.
41、Record the average thickness inmicrons mil.9.3 Place the specimen in the grips of the testing machine sothat the long axis of the enlarged ends of the specimen is in linewith the center line of the grip assembly.9.4 After complete rupture of the specimen, the maximumtearing load in newtons pounds-fo
42、rce, and the maximumextension in mm in. shall be recorded.10. Calculation10.1 Calculate the mean maximum resistance to tearing, andthe maximum extension for all specimens tested in eachprincipal direction of orientation. Record maximum tear resis-tance expressed in newtons pounds-force to three sign
43、ificantfigures and maximum extension expressed in mm in. to twosignificant figures.NOTE 8Resistance to tear may be expressed in newtons per microns,pounds-force per mil of specimen thickness where correlation for theparticular material being tested has been established. However, it shouldbe realized
44、 that comparison between films of dissimilar thickness may notbe valid.10.2 Calculate standard deviation.11. Report11.1 Report the following information:11.1.1 Complete identification of the material tested, includ-ing type, source, manufacturers code number, form, principaldimensions, previous hist
45、ory, and orientation of sample withrespect to anisotropy, if any.11.1.2 Average thickness of each test specimen and averagethickness of all test specimens.11.1.3 Type of testing machine used.11.1.4 Number of specimens tested in each principal direc-tion.11.1.5 Average value of tear resistance calcul
46、ated in new-tons pounds-force and the maximum extension in mm in.11.1.6 Standard deviation from the averaged values ob-tained for specimens tested in each principal direction.12. Precision and Bias512.1 Table 1 and Table 2 are based on a round robinconducted between 1986 and 1990 in accordance with
47、PracticeE 691, involving seven materials tested by seven laboratories.For each material, all the samples were prepared at one source,and randomized sections of film were sent to each of thelaboratories which prepared the test specimens and testedthem. Each “test result” was the average of ten determ
48、inations.Each laboratory obtained two test results for each material.5Supporting data are available from ASTM Headquarters. Request RR:20-1177.TABLE 1 Initial Tear Resistance (Graves Tear) Machine DirectionMaterialValues Expressed in Units of Grams-ForceAverage SrASRBrCRDLDPELD 104 314.6 31.98 55.79
49、 89.53 156.2LLDPE 384.9 7.80 41.73 21.84 116.8Polystyrene 459.8 98.06 261.6 274.6 732.3HDPE No. 2 474.0 19.82 55.42 55.51 155.2Polypropylene 503.9 29.87 77.45 83.64 216.9HDPE No. 1 570.9 36.35 78.20 101.8 219.0Polyester 2494.0 6407.9 599.2 1142.0 1678.0ASr= within-laboratory standard deviation for the material stated. It is obtainedby pooling the standard deviations of the test results from each laboratory:Sr5 (S1!21 S2!2. 1 Sn!2#/n12BSR= between-laboratories standard deviation for the mater
