1、Designation: D5748 95 (Reapproved 2012)Standard Test Method forProtrusion Puncture Resistance of Stretch Wrap Film1This standard is issued under the fixed designation D5748; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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 ra
3、te,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 standa
4、rd 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 AST
5、M Standards:2D618 Practice for Conditioning Plastics for TestingD996 Terminology of Packaging and Distribution Environ-mentsD1898 Practice for Sampling of Plastics3D2103 Specification for Polyethylene Film and SheetingE122 Practice for Calculating Sample Size to Estimate,With Specified Precision, th
6、e Average for a Characteristicof a Lot or ProcessE691 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 D996.3.2 Definitions of Terms Speci
7、fic 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.3.2.5 protrusion punc
8、ture 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-mance of stretch wrap
9、 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 punctureresistance performance u
10、nder 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, weight, andconfigura
11、tion 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 load cell.5.4 ProbeA
12、 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 D2103.5.7 Template, 6 by 6 in. (150 by 150 mm
13、).5.8 Specimen Cutter.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, 2012. Published May 2012. Originallyapproved in 1995. Last previous editi
14、on approved in 2007 as D5748 95 (2007).DOI: 10.1520/D5748-95R12.2For 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 websi
15、te.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4The probe 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 194
16、28-2959, United States.6. Sampling6.1 Acceptance SamplingSampling shall be in accordancewith Practice D1898.6.2 Sampling for Other PurposesThe sampling and thenumber of test specimens depend on the purpose of the testing.Practice E122 is recommended. Test specimens are taken fromseveral rolls of fil
17、m, and where possible, from several produc-tion runs of film. Strong conclusions about 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 sett
18、ing up and operating theapparatus, consult the operations manual.8.2 Install probe apparatus (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 h
19、prior to testing in accordance with Procedure A of PracticeD618.9.2 Conduct tests in the 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 testequipmen
20、t following the manufacturers instructions.10.2 Select an equipment load range so that 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 thecen
21、ter of each specimen and record the average.10.5 Set universal tester crosshead speed 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 pr
22、obe asclose as possible to the specimen without actually touching.10.7 Set the appropriate 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. Wherehole
23、s occur other than at the probe point, the specimen testresults should be discarded. See Fig. 3.10.9 Record specimen identification, peak force at break,maximum force, energy (work) to break, and probe penetrationdistance at break, from mechanical testing software output. IfNOTE 1Measurements are in
24、 inches (millimetres).FIG. 1 ProbeNOTE 1Measurements are in inches (millimetres).FIG. 2 ClampD5748 95 (2012)2using 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 graphicaloutp
25、ut of test performed.10.10 Repeat test sequence (10.1 through 10.9) for theremaining 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 th
26、e same value (Fig. 4).11.1.1 Software computed values are acceptable.11.2 Use the following 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 for
27、ce to break, lb (N),R = chart reading, 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 finish, andW = full scale width of chart, in. (mm).11.2.2 Calculate the maximum forcehighest force achievedduring a test, lb
28、(N):M 5 R 3 L orDW3 L (2)where:M = maximum force achieved, lb (N),R = chart reading, 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 Calculat
29、e the probe penetration distancedepth probetraveled in penetrating specimen in. (mm), 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 fin
30、ish,S = crosshead speed, in./min (mm/min), andC = chart speed, in./min (mm/min).11.2.4 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),FIG. 3 Universal TesterFIG. 4 Graphical Output of Protrusion Puncture Resistance TestStress/Strai
31、n Curve ExamplesD5748 95 (2012)3S = crosshead speed, in./min (mm/min),I = integrator 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
32、 break, lb (N),12.1.2.2 Maximum force achieved, lb (N),12.1.2.3 Energy to break, in./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 test
33、ed by six laboratories, based on a round robinconducted in 1993, in accordance with Practice E691. 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 pea
34、k forceto break was 0.66 lb with a standard deviation of 4.0 percent-age points within 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 percentag
35、e pointsand the estimated reproducibility limits are 42.5 percentagepoints.13.1.2 Maximum 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 m
36、ayhave higher or lower variability. Based on this, the estimated95 % repeatability 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
37、 3.5 percentage points within each laboratory and astandard deviation of 9.8 percentage 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
38、percentage points.13.1.4 Energy to Break DataThe average energy to breakwas 3.55 inlb 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, t
39、he estimated95 % repeatability limits are 15.1 percentage points and theestimated reproducibility 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 defin
40、ed inthe terms of this test method.14. Keywords14.1 plastic films; protrusion puncture; 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 th
41、at determination of the validity of any such patent rights, and the riskof infringement 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 reappr
42、oved or withdrawn. Your comments are invited either for revision of this standard or 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 f
43、eel that your comments have not received a fair hearing you shouldmake your views known 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 re
44、prints (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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D5748 95 (2012)4
