1、Designation: D 5748 95 (Reapproved 2007)Standard Test Method forProtrusion Puncture Resistance of Stretch Wrap Film1This standard is issued under the fixed designation D 5748; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r 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 determines the resistance of a stretchwrap film to the penetration of a probe at a standard low
3、 rate,a single test velocity. Performed at standard conditions, the testmethod imparts a biaxial stress that is representative of the typeof stress encountered in many product end-use applications.The maximum force, force at break, penetration distance, andenergy to break are determined.1.2 This sta
4、ndard 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 applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1
5、ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 996 Terminology of Packaging and Distribution Environ-mentsD 1898 Practice for Sampling of Plastics3D 2103 Specification for Polyethylene Film and SheetingE 122 Practice for Calculating Sample Size to Estimate,With a Specified Tol
6、erable Error, the Average for aCharacteristic of a Lot or ProcessE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 DefinitionsGeneral definitions for packaging and dis-tributions environments are found in Terminology D 996.3.2 Definiti
7、ons of Terms Specific to This Standard:3.2.1 break forceforce achieved at break.3.2.2 energywork to break.3.2.3 maximum forcegreatest force achieved.3.2.4 penetration distancedepth probe traveled in pen-etrating film specimen, from initial probe contact with filmspecimen, to penetration at break.3.2
8、.5 protrusion puncture resistancethe ability of a plasticfilm to withstand the force exerted by a protrusion.3.2.6 thickness (caliper, gage)the perpendicular distancebetween the opposite surfaces of a plastic film.4. Significance and Use4.1 Puncture resistance is very important in end-use perfor-man
9、ce of stretch wrap film used in consumer and industrialproduct applications. Puncture resistance is a measure of theenergy-absorbing ability of a stretch wrap film in resisting aprotrusion. The test method is designed to provide the userwith a means of measuring the stretch wrap films punctureresist
10、ance performance under essentially biaxial deformationconditions. A biaxial stress is representative of the type ofstress encountered by stretch wrap products in many end-useapplications.4.2 Although this test method cannot be expected to dupli-cate all field experiences, since the rate of speed, we
11、ight, andconfiguration of such destructive forces vary widely, a gener-ally reliable comparison of samples may be made from the dataobtained.5. Apparatus5.1 Universal Testing Apparatus.5.2 Integrator and Chart Recorder.5.3 Appropriate Load CellThe test may be performedusing compression or tension lo
12、ad cell.5.4 ProbeA 0.75 in. (19 mm) diameter pear-shaped TFE-fluorocarbon coated probe4(Fig. 1), for general application andstandard comparison of plastic films and interlaboratory re-sults.5.5 Specimen Clamping Fixture (Fig. 2).5.6 Micrometre, conforming to Specification D 2103.5.7 Template, 6 by 6
13、 in. (150 by 150 mm).1This test method is under the jurisdiction of ASTM Committee D10 onPackaging and is the direct responsibility of Subcommittee D10.25 on Palletizingand Unitizing of Loads.Current edition approved April 1, 2007. Published May 2007. Originallyapproved in 1995. Last previous editio
14、n approved in 2001 as D 5748 95 (2001).2For referenced ASTM 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.3Withdrawn.4The probe
15、is coated with duPont 954-101 Teflon S a thickness of 0.0015 in.(0.0381 mm). Available from duPont.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.8 Specimen Cutter.6. Sampling6.1 Acceptance SamplingSampling shall be in accordancew
16、ith Practice D 1898.6.2 Sampling for Other PurposesThe sampling and thenumber of test specimens depend on the purpose of the testing.Practice E 122 is recommended. Test specimens are taken fromseveral rolls of film, and where possible, from several produc-tion runs of film. Strong conclusions about
17、a specific propertyof a film cannot be based on a single roll of film.7. Number of Test Specimens7.1 Test a minimum of five specimens for each sample.8. Preparation of Apparatus8.1 For specific instruction in setting up and operating theapparatus, consult the operations manual.8.2 Install probe appa
18、ratus (Fig. 2).8.3 Center the probe (Fig. 1) over the specimen clampingfixture (Fig. 2).9. Conditioning9.1 Condition the test specimens at 73.4 6 3.6F (23 62C) and 50 6 5 % relative humidity for not less than 40 hprior to testing in accordance with Procedure A of PracticeD 618.9.2 Conduct tests in t
19、he standard laboratory atmosphere of23 6 2C (73.4 6 3.6F) and 50 6 5 % relative humidityunless otherwise specified in the test method.10. Procedure10.1 With the probe apparatus installed, calibrate the testequipment following the manufacturers instructions.10.2 Select an equipment load range so that
20、 specimenpuncture occurs within 20 to 80 % of the same.10.3 Using the template and specimen cutter, prepare aminimum of five specimens from each sample.10.4 Measure the caliper (average of three readings) in thecenter of each specimen and record the average.10.5 Set universal tester crosshead speed
21、at 10 in./min (250mm/min) and chart recorder speed at 10 in./min (250 mm/min).If using an integrator instead of a data acquisition system, setthe counters to zero.10.6 Clamp the specimen in the holder. Lower the probe asclose as possible to the specimen without actually touching.10.7 Set the appropr
22、iate stops and returns on the universaltester. Reset data collection devices if applicable.10.8 Activate the universal tester. Stop the crosshead whenthe puncture probe passes completely through the film. Whereholes occur other than at the probe point, the specimen testresults should be discarded. S
23、ee Fig. 3.10.9 Record specimen identification, peak force at break,maximum force, energy (work) to break, and probe penetrationNOTE 1Measurements are in inches (millimetres).FIG. 1 ProbeNOTE 1Measurements are in inches (millimetres).FIG. 2 ClampD 5748 95 (2007)2distance at break, from mechanical tes
24、ting software output. Ifusing chart recording instruments, record specimen identifica-tion on chart and integrator reading if used. Return crossheadto start position and remove specimen. See Fig. 4 for graphicaloutput of test performed.10.10 Repeat test sequence (10.1 through 10.9) for theremaining
25、sample specimens.11. Calculations11.1 Compute the values of peak force at break, maximumforce, energy (work) to break and probe penetration distance.In some instances, peak force at break and maximum force willbe the same value (Fig. 4).11.1.1 Software computed values are acceptable.11.2 Use the fol
26、lowing formulas for calculating the requiredvalues for data acquisition with a time based chart recorder.11.2.1 Calculate peak force to breakpeak force to achievebreak, lb (N):N 5 R 3 L orDW3 L (1)where:N = peak force to break, lb (N),R = chart reading, expressed as a decimal, %,L = full scale load
27、(FSL), lb, N,D = recorded actual in. (mm) of chart in vertical axis, fromstart of test to finish, andW = full scale width of chart, in. (mm).11.2.2 Calculate the maximum forcehighest force achievedduring a test, lb (N):M 5 R 3 L orDW3 L (2)where:M = maximum force achieved, lb (N),R = chart reading,
28、expressed as a decimal, %,L = full scale load (FSL), lb, N,D = recorded actual in. (mm) of chart in vertical axis, fromstart of test to maximum force point, andW = full scale width of chart, in. (mm).11.2.3 Calculate the probe penetration distancedepth probetraveled in penetrating specimen in. (mm),
29、 from initial probecontact with specimen, to penetration at break:P 5D 3 SC(3)where:P = probe travel to penetration at break, in. (mm),D = recorded actual in. (mm) of chart in vertical axis, fromstart of test to finish,S = crosshead speed, in./min (mm/min), andC = chart speed, in./min (mm/min).11.2.
30、4 Calculate energy in./lb (J) to break:J 5 I 3 L 3SZ(4)where:J = energy, in./lb (J),L = full scale load (FSL), lb (N),S = crosshead speed, in./min (mm/min),FIG. 3 Universal TesterFIG. 4 Graphical Output of Protrusion Puncture Resistance TestStress/Strain Curve ExamplesD 5748 95 (2007)3I = integrator
31、 reading (counts), andZ = integrator (counts/min).12. Report12.1 Report the following information:12.1.1 Sample identification,12.1.2 Mean and standard deviation of five values for thefollowing:12.1.2.1 Peak force at break, lb (N),12.1.2.2 Maximum force achieved, lb (N),12.1.2.3 Energy to break, in.
32、/lb (J),12.1.2.4 Probe penetration distance, in. (mm), and12.1.2.5 Caliper (average) of film specimens for eachsample, in. (mm).13. Precision and Bias13.1 PrecisionThe following summaries involve four ma-terials tested by six laboratories, based on a round robinconducted in 1993, in accordance with
33、Practice E 691. Samplerolls of each material were provided to each participatinglaboratory, and that laboratory evaluated the material five timesto produce a final result.13.1.1 Peak Force to Break DataThe average peak forceto break was 0.66 lb with a standard deviation of 4.0 percent-age points wit
34、hin each laboratory and a standard deviation of15.2 percentage points between laboratories; other materialsmay have higher or lower variability. Based on this, theestimated 95 % repeatability limits are 11.1 percentage pointsand the estimated reproducibility limits are 42.5 percentagepoints.13.1.2 M
35、aximum Force DataThe average maximum forcewas 0.65 lb, with a standard deviation of 2.9 percentage pointswithin each laboratory and a standard deviation of 13.4percentage points between laboratories; other materials mayhave higher or lower variability. Based on this, the estimated95 % repeatability
36、limits are 8.2 percentage points and theestimated reproducibility limits are 37.5 percentage points.13.1.3 Probe Penetration Distance DataThe averageprobe penetration distance was 0.39 in., with a standarddeviation of 3.5 percentage points within each laboratory and astandard deviation of 9.8 percen
37、tage points between laborato-ries; other materials may have higher or lower variability.Based on this, the estimated 95 % repeatability limits are 9.8percentage points and the estimated reproducibility limits are27.5 percentage points.13.1.4 Energy to Break DataThe average energy to breakwas 3.55 in
38、lb with a standard deviation of 5.4 percentagepoints within each laboratory and a standard deviation of 25.6percentage points between laboratories; other materials mayhave higher or lower variability. Based on this, the estimated95 % repeatability limits are 15.1 percentage points and theestimated r
39、eproducibility limits are 71.5 percentage points.13.2 BiasThe procedure in this test method has no biasbecause the values of peak force to break, maximum force,probe penetration distance, and energy to break are defined inthe terms of this test method.14. Keywords14.1 plastic films; protrusion punct
40、ure; puncture resistanceASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringe
41、ment of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard o
42、r for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views k
43、nown to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 5748 95 (2007)4
