1、Designation: D 7192 05Standard Test Method forHigh Speed Puncture Properties of Plastic Films Using Loadand Displacement Sensors1This standard is issued under the fixed designation D 7192; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of punctureproperties of plastic films, over a range of t
3、est velocities.1.2 Test data obtained by this test method is relevant andappropriate for use in engineering design.1.3 The values stated in SI units are to be regarded asstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is therespon
4、sibility 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 1This test method does not closely conform to ISO 7765-2.The only similarity between the two tests is that they are both instru-men
5、ted impact tests. The differences in striker, fixture, specimen geom-etries and in test velocity can produce significantly different test results.2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 883 Terminology Relating to PlasticsD 1600 Terminology fo
6、r Abbreviated Terms Relating toPlasticsD 4000 Classification System for Specifying Plastic Mate-rialsD 6988 Guide for Determination of Thickness of PlasticFilm Test Specimens3. Terminology3.1 DefinitionsFor definitions see Terminology D 883 andfor abbreviations, see Terminology D 1600.4. Significanc
7、e and Use4.1 This test method is designed to provide load versusdeformation response of plastic films under essentially multi-axial deformation conditions at impact velocities. This testmethod further provides a measure of the rate sensitivity of theplastic films to impact.4.2 Multi-axial impact res
8、ponse, while partly dependent onthickness, does not necessarily have a linear correlation withspecimen thickness. Therefore, results should be comparedonly for specimens of essentially the same thickness, unlessspecific responses versus thickness formulae have been estab-lished for the plastic films
9、 being tested.4.3 For many plastic films, there may be a specification thatrequires the use of this test method, but with some proceduralmodifications that take precedence when adhering to thespecification. Therefore, it is advisable to refer to that materialspecification before using this test meth
10、od. Table 1 of Classi-fication System D 4000 lists theASTM materials standards thatcurrently exist.4.4 The values obtained by this test method are highlydependent on the method and conditions of film fabrication aswell as the type and grade of resin. Results can vary signifi-cantly, depending upon s
11、ample quality, uniformity of filmgage, die marks, contaminants, and so forth.5. Apparatus5.1 The testing machine shall consist of two assemblies, onefixed and the other driven by a suitable method to achieve therequired impact velocity (that is, hydraulic, pneumatic, me-chanical, or gravity):5.1.1 S
12、pecimen Clamp AssemblyThis device shall bepermitted to be variable with respect to the holding of thespecimen material, depending upon specimen characteristics. Itshall be required of any specimen clamp assembly to have anunsupported region that is 76.0 6 3.0 mm diameter. The edgesof the unsupported
13、 region shall be rounded to a radius of 0.8 60.4 mm. The holding technique employed on the specimenmust not interfere with the radius edge of the clamp assembly.Specimens should be held taut but not stretched so as to causedamage to the specimen prior to test.NOTE 2The following techniques have been
14、 successfully employedfor different types of plastic films: Parallel rigid plates clamped together with sufficient force (mechani-cally, pneumatically or hydraulically) to prevent slippage of the specimenin the clamp during impact.1This test method is under the jurisdiction of ASTM Committee D20 on
15、Plasticsand is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.Current edition approved July 1, 2005. Published August 2005.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStand
16、ards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States. Rubber-like gaskets or o-rings affixed to the rigid plates to providecushioning or gripping of
17、the specimen when clamping force is applied. Removable assemblies, consisting of two concentric rings (one slightlylarger than the other, similar to an embroidery hoop) that, when assembledand clamped between two rigid plates, succeed in pulling the specimentaut over the specified unsupported region
18、 prior to testing.All of the abovetechniques must employ the specified unsupported region and edge radiusas shown in 5.1.1.5.1.2 Plunger Assembly, consisting of a 12.70 6 0.13-mmdiameter rod with a hemispherical end of the same diameterpositioned perpendicular to, and centered on, the clamp hole.Plu
19、nger assembly shall be of sufficient length so as to allow forcomplete puncture of the test specimen. Plunger assemblymaterial shall be stainless steel, steel or aluminum. Surfacefinish of the plunger assembly shall be 16 in. 0.4 m.5.1.3 Other GeometriesThe dimensions given in 5.1.1and 5.1.2 shall b
20、e the standard geometry. If other plunger orhole sizes are used they shall be highlighted in the report.Correlations between various geometries have not been estab-lished.5.1.4 Load Sensing SystemA load cell of sufficiently highnatural resonance frequency, as described in A1.1, used to-gether with a
21、 calibrating network for adjusting load sensitivity.5.1.5 Plunger Displacement Measurement SystemAmeans of monitoring the displacement of the moving assemblyduring the loading and complete penetration of the specimen.This can be accomplished through the use of a suitabletransducer or potentiometer a
22、ttached directly to the system.Photographic or optical systems can also be utilized formeasuring displacement.5.1.5.1 Alternatively, displacement shall be permitted to becalculated as a function of velocity and total available energyat initial impact, along with increments of load versus time,using
23、a microprocessor.5.1.5.2 Some machines use an accelerometer, whose outputis used to calculate both load and displacement.5.1.6 Display and Recording InstrumentationUse anysuitable means to display and record the data developed fromthe load and displacement-sensing systems, provided its re-sponse cha
24、racteristics are capable of presenting the datasensed, with minimal distortion. The recording apparatus shallrecord load and displacement simultaneously. For furtherinformation, see A1.2.5.1.6.1 The most rudimentary apparatus is a cathode-rayoscilloscope with a camera. This approach also requires ap
25、lanimeter or other suitable device, capable of measuring thearea under the recorded load-versus-displacement trace of theevent with an accuracy of 65%.5.1.6.2 More sophisticated systems are commercially avail-able. Most of them include computerized data reduction andautomatic printouts of results.5.
26、2 Micrometer, accurate to 0.0025 mm in the film thicknessrange from 0.0025 mm to 1 mm (see Guide D 6988).6. Test Specimen6.1 Specimens must be large enough to be adequatelygripped in the clamp. In general, the minimum lateral dimen-sion should be at least 13 mm greater than the diameter of thehole i
27、n the clamp or any clamping gaskets or o-rings incorpo-rated into the clamping mechanism (see 5.1.1 and 9.9).6.2 Specimens shall be cut from plastic films produced byany suitable process.6.3 The specimens shall be free of pinholes, wrinkles, foldsor other obvious imperfection, unless such imperfecti
28、onsconstitute variables under study.7. Conditioning7.1 ConditioningCondition the test specimens in a roomor enclosed space maintained 23 6 2C, and 50 % relativehumidity, in accordance with Procedure A in Practice D 618,unless otherwise specified.7.2 Test ConditionsConduct tests in the standard labor
29、a-tory atmosphere of 23 6 2C, and 50 6 5 % relative humidity,unless otherwise specified. In cases of disagreement, thetolerances shall be 61C, and 62 % relative humidity.7.2.1 By changing the conditioning and test temperature ina controlled manner for a given test velocity, the temperature atwhich t
30、ransition from ductile to brittle failure occurs can bedetermined for most plastic films.8. Speed of Testing8.1 For recommended testing speeds, see 9.4.9. Procedure9.1 Test a minimum of five specimens at each specifiedspeed.9.2 Measure and record the thickness of each specimen tothe nearest 0.0025 m
31、m at the center of the specimen.9.3 Clamp the specimen between the plates of the specimenholder, taking care to center the specimen for uniform gripping.9.4 Set the test speed to the desired value. The testing speed(movable-member velocity at the instant before contact withthe specimen) shall be as
32、follows:9.4.1 For single-speed tests, use a velocity of 200 m/min.9.4.1.1 Other speeds shall be permitted to be used, providedthey are clearly stated in the report.9.4.2 To measure the dependence of puncture properties onimpact velocity, use a broad range of test speeds. Somesuggested speeds are 2.5
33、, 25, 125, 200, and 250 m/min.9.5 Set the available energy so that the velocity slowdown isno more than 20 % from the beginning of the test to the pointof peak load. If the velocity should decrease by more than20 %, discard the results and make additional tests on newspecimens with more available en
34、ergy.NOTE 3It is observed that when the available energy is at least threetimes the absorbed energy at the peak load velocity slow-down is less than20 %.9.6 Make the necessary adjustments to data collectionapparatus as required by the manufacturers instructions orconsult literature such as STP 9363f
35、or further informationregarding setting up data acquisition systems.9.7 Conduct the test, following the manufacturers instruc-tions, for the specific equipment used.3Instrumented Impact Testing of Plastics and Composite Materials, ASTM STP936, ASTM, 1986.D71920529.8 Remove the specimen and inspect t
36、he gripped portionfor striations or other evidence of slippage. If there is evidenceof slippage, modify the clamping conditions or increase thespecimen size and repeat test procedures.9.9 Check plunger assembly for any film debris or residuebefore performing subsequent tests.10. Calculation10.1 Usin
37、g the load-versus-displacement trace and appro-priate scaling factors, calculate the following:10.1.1 Peak load, in Newtons.10.1.2 Deflection, in millimetres, to the point where peakload first occurred.10.1.3 From the area within the trace, calculate:10.1.3.1 Energy, in Joules, to the point where pe
38、ak load firstoccurred.10.1.3.2 Total energy absorbed. The point for determiningthis has not been standardized. Therefore, the point used foreach test must be stated in the report.10.1.4 Load, deflection, energy, or combination thereof, atany other specific point of interest (see Appendix X1).10.2 Fo
39、r each series of tests, calculate the arithmetic meanfor each of the above, to three significant figures.10.3 Calculate the estimated standard deviations as follows:S 5 S(X22 nX2n 2 1D1/2 (1)where:S = estimated standard deviation,X = value of a single determination,n = number of determinations, andX
40、= arithmetic mean of the set of determinations.11. Report11.1 Report the following information:11.1.1 Complete identification of the material tested, includ-ing type, source, manufacturers code number, form andprevious history,11.1.2 Specimen size and thickness,11.1.3 Method of preparing test specim
41、ens (extrusion mold-ing, blow molding, and so forth),11.1.4 Geometry of clamp and plunger, if different from5.1.1 and 5.1.2,11.1.5 Source and types of equipment,11.1.6 Speed of testing (see 9.4),11.1.7 The point on the curve at which total energy wascalculated (see 10.1.3.2),11.1.8 Average value and
42、 standard deviation for each of theproperties listed in 10.1,11.1.9 Whether or not any slippage of the specimens wasdetected (see Note 3),11.1.10 If the effect of testing speeds was studied (see9.4.2),11.1.11 Type of plunger material used for the test, and11.1.12 Test specimen conditioning, if diffe
43、rent from 7.1.NOTE 4When slippage or cutting of the test specimen occurs at ornear the edge of the support clamp, the result shall be considered invaliddue to the error in calculated energy absorption caused by the slipping orcutting of the specimen during the impact test. Alternate clampingtechniqu
44、es, adhering to the requirements of 5.1.1, must be used to preventany slippage or cutting of the test specimen.12. Precision and Bias12.1 Precision and Bias for this test method are currentlyunder investigation.13. Keywords13.1 falling weight; impact testing; plastic thin film; punc-ture propertiesA
45、NNEX(Mandatory Information)A1. MINIMUM INSTRUMENTATION REQUIREMENTSA1.1 Force MeasurementAny transducer that meets theperformance requirements for dynamic force measurementshall be permitted to be used. This includes, but is not limitedto, strain gage force transducers, piezo-electric force transduc
46、-ers and accelerometers.A1.1.1 Performance RequirementsThe natural frequency(fdev) of the transducer plus striker shall be sufficient to avoiddistortion of the force-time or acceleration-time data. The timefailure (tf), in seconds, of a given test specimen regulates theminimum natural frequency for
47、a transducer/striker assemblyby the following relationship:tf5 3/fdev(A1.1)Since time to failure is generally greater than 0.5 ms forplastics, a transducer assembly with a natural frequency greaterthan 6 kHz is recommended (0.0005 $ 3/6000). In addition,the transducer must have the durability to sur
48、vive repeatedimpact tests without change in output from its initially cali-brated state.NOTE A1.1Failure has been shown to be difficult to universallydefine. One application might define failure as the point on a load versustime curve where the load returns to zero. Another might define failure asa
49、sharp drop in load, followed by a change in load slope, indicatingformation of a crack.D7192053A1.1.2 Natural FrequencyThe mass of the striker assem-bly between transducer and specimen is directly related to thenatural frequency (fdev) of that transducer and can influence theforce or acceleration data. Appendix X1,(X1.9.3) describes amethod for approximating fdevfor any given transducer assem-bly.A1.1.3 Transducer LocationThe transducer should belocated as close as possible to the impact point of thetransducer/striker assembly to minimize the mass effect
