1、Designation: D 2582 08Standard Test Method forPuncture-Propagation Tear Resistance of Plastic Film andThin Sheeting1This standard is issued under the fixed designation D 2582; 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 () 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 method covers the det
3、ermination of the dy-namic tear resistance of plastic film and thin sheeting subjectedto end-use snagging-type hazards.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of the
4、safety 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.NOTE 1There is no equivalent ISO test method.2. Referenced Documents2.1
5、 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 883 Terminology Relating to PlasticsD 4000 Classification System for Specifying Plastic Mate-rialsD 5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensE 691 Practice for Conducting an Interlaboratory Study toDete
6、rmine the Precision of a Test Method3. Terminology3.1 Descriptions of Terms Specific to This Standard:3.1.1 slit teara single tear parallel to the direction of thefalling carriage.3.1.2 “V” tear a tear that has two individual tear legs (notnecessarily of equal length) radiating approximately 645from
7、 the point the tear was initiated.4. Significance and Use4.1 The puncture-propagation of tear test measures theresistance of a material to snagging, or more precisely, todynamic puncture and propagation of that puncture resulting ina tear. Failures due to snagging occur in a variety of end uses,incl
8、uding industrial bags, liners, and tarpaulins. The unitsreported in this test method are Newtons (tear resistance).4.2 Experience has shown that for many materials puncturedoes not contribute significantly to the force value determined,due to the sharpness of the propagating probe used. However,comp
9、aring the results of prepunctured test specimens withnormal nonpunctured specimens will give an indication of theextent of any puncture resistance in the reported result.4.3 For many materials, there may be a specification thatrequires the use of this test method, but with some proceduralmodificatio
10、ns that take precedence when adhering to thespecification. Therefore, it is advisable to refer to that materialspecification before using this test method. Table 1 of Classi-fication System D 4000 lists the current ASTM materialsstandards.5. Apparatus35.1 As shown in Fig. 1, the instrument consists
11、of:5.1.1 Carriages of different weight, each with a pointedprobe. Each carriage weight shall have a tolerance of 61%ofthe weight desired.5.1.2 A test stand including:5.1.2.1 Carriage release mechanism,5.1.2.2 Scale marked in millimetres,5.1.2.3 Curved specimen holder with a tear slot and fiveclamps,
12、5.1.2.4 Drop base with a guide channel to accommodate thecarriage wheels, and5.1.2.5 Bubble level to level the base.1This test method 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 Nov.
13、1, 2008. Published November 2008. Originallyapproved in 1967. Last previous edition approved in 2007 as D 2582 07.2For 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 th
14、e standards Document Summary page onthe ASTM website.3The sole source of supply of the apparatus known to the committee at this timeis Testing Machines, Inc., 2910 Expressway Drive, South, Islandia, NY 11749. Ifyou are aware of alternative suppliers, please provide this information to ASTMInternatio
15、nal Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee1, which you may attend.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1942
16、8-2959, United States.5.2 The standard drop height is 508 mm (20.0 in.); however,it can be varied to suit the desired end-use-rate condition. See10.3 for an alternative method for calculating tear resistancefor heights other than 508 mm.5.3 The probe is a 3.18-mm (0.125-in.) diameter drill rodhaving
17、 one end a truncated cone, the short base 0.40 mm(0.016 in.) in diameter, with a 30 included angle so that mostof the tear is propagated against the body of the rod. See Fig.2.5.4 Thickness Gauge a dead-weight micrometer as de-scribed in Test Method C of Test Method D 5947,oranequivalent measuring d
18、evice, reading to 0.0025 mm (0.0001in.) or less.6. Test Specimen6.1 Specimens can be cut in any rectangular shape so longas they are approximately 200 mm (8.0 in.) long in thedirection of tear and can be held by all five clamps. Multipletears can be made on a single sheet provided a minimumseparatio
19、n of 25 mm (1 in.) is maintained between tears.6.2 Two sets of specimens shall be cut from each samplesuch that the direction of tear, during the test, will be parallelto (1) MD, the machine direction and (2) TD, the transversedirection, respectively, of the material being tested. Enoughspecimens sh
20、all be cut in each direction to provide for aminimum of five tears.7. Preparation and Calibration of Apparatus7.1 Level the base of the tester by centering the spirit levelbubble by adjustment of the leveling legs.7.2 Check “sharpness” of probes by visual observationunder a magnifying glass. If the
21、short base end is not 0.40 mm(0.016 in.) in diameter or any burrs, nicks, or distortions arenoted, or both, replace the probe.7.3 Check the length of the probes by inserting eachcarriage in turn in the guide channel and lowering to thealignment mark on the curved specimen holder. The point ofthe pro
22、be should be aligned with this mark.7.4 Measure the vertical drop height from the specimenholder mark, located near the tear slot, to the horizontal markon the carriage release mechanism. Adjust the selected heightto the nearest 2 mm (0.078 in.). The standard drop height is 5086 2 mm.7.5 Check the a
23、lignment of the specimen holder receivingslot by lowering a carriage with its probe extending into theslot, up and down the slot length. The probe should becentered, that is, not touching either edge of the slot.8. Conditioning8.1 ConditioningCondition the test specimens at 23 62C (73.4 6 3.6F) and
24、50 6 10 % relative humidity for notless than 40 h prior to test in accordance with Procedure A ofPractice D 618 unless otherwise specified by agreement or therelevant ASTM material specification. In cases of disagree-ment, the tolerances shall be 61C (61.8F) and 65%relative humidity.8.2 Test Conditi
25、onsConduct the tests at 23 6 2C (73.4 63.6F) and 50 6 10 % relative humidity unless otherwisespecified by agreement or the relevant ASTM material speci-fication. In cases of disagreement, the tolerances shall be 61C(61.8F) and 65 % relative humidity.9. Procedure9.1 Measure and record the thickness o
26、f each specimentested. Read the thickness to 0.0025 mm (0.0001 in.) or better,except for sheeting greater than 0.25 mm (0.010 in.), whichshall be measured to a precision of 0.025 mm (0.001 in.) orbetter.9.2 Secure the specimen in the holder by placing it under theclamps and setting the clamp lever t
27、o the down position. Thespecimen should drape against the holder contour. Stiffermaterials should be loosely held adjacent to the holder. Eachclamp should apply sufficient pressure to prevent any specimenslippage.Hdrop height, mmLtear length, mmFforce required to produce L, kgfWweight of carriage, k
28、gFIG. 1 Puncture-Propagation of Tear TesterFIG. 2 Short Base ProbeD25820829.3 By trial and error, select the carriage that produces aminimum tear length of 40 mm and does not bottom-outagainst the drop base. Lower selected carriage until the probepoint touches but does not indent the specimen. Adjus
29、t the tearlength indicating rod to “0” on the scale located on the guidechannel.9.4 Place the selected carriage in the release mechanism.9.5 Cock the release mechanism on the left side and releasethe carriage by pushing the button on the front of the releasemechanism.9.6 Read the tear length to the
30、nearest 0.5 mm.9.7 Raise the carriage by pulling the handle on the left sideof the guide channel.9.8 After the carriage has stopped its upward movement,relocate it in the release mechanism by pushing the carriage upin the guide channel by hand. (When the handle is released, thecarriage-raising mecha
31、nism should return to the bottom of theguide channel. However, check before releasing the carriagefor the next test.)9.9 Re-cock the release mechanism.9.10 Release the clamps and relocate the specimen for thenext tear test cycle. Take care not to relocate the specimen sothat the tears are too close
32、to one another, thereby influencingthe tear results.9.11 Make a minimum of five determinations in eachdirection for each sample.10. Calculation10.1 To determine the tear resistance employing a standarddrop height of 508 6 2 mm, use Table 1. (See X1.1.5 for anexplanation of normalization.)10.2 To det
33、ermine the tear resistance employing a nonstand-ard drop height or carriage weight, other than those listedabove, calculate the tear resistance, F, in Newtons, as follows:F 5 W 3 H!/L 1 W! 9.8065! (1)where:W = weight of carriage, kg,H = height of carriage before release, mm,L = length of tear, mm, a
34、nd9.8065 = conversion factor for Newtons.10.3 For inter- and intralaboratory data comparisons, thesame drop height and weight carriage must be used.10.4 Calculate the average tear length, L, in both directions(MD and TD) to the nearest 0.1 mm.10.5 Calculate the tear resistance, F, in each direction
35、to thenearest 0.1 Newton.10.6 Calculate the standard deviation (estimated) for eachdirection tested as follows:s 5 =(X22 nX2!/n 2 1! (2)where:s = estimated standard deviation,X = value of single observation,n = number of observations, andX= arithmetic mean of the set of observations.11. Report11.1 R
36、eport the following information:11.1.1 Complete identification of the sample tested,11.1.2 Average tear resistance for the direction tested,11.1.3 Drop height selected, if nonstandard,11.1.4 Carriage used,11.1.5 Number of specimens tested, if greater or less thanfive,11.1.6 Average thickness, in mil
37、s,11.1.7 Type of tears produced, for example, “V” or slit, and11.1.8 Standard deviation for each direction tested, reportedto two significant digits.12. Precision and Bias412.1 Table 2 is based on a round robin conducted in 1990 inaccordance with Practice E 691 involving eight materialstested in bot
38、h MD and TD directions by six laboratories.All thesamples were prepared at one source. Each test result was theaverage of five individual determinations. Each laboratoryobtained two test results for each material. WarningThefollowing explanations of r and R (12.2-12.2.3 are onlyintended to present a
39、 meaningful way of considering theapproximate precision of this test method. The data in Table 2should not be rigorously applied to acceptance or rejection ofmaterial, as those data are specific to the round robin and maynot be representative of other lots, conditions, materials, or4Supporting data
40、are available from ASTM Headquarters. Request RR: D20-1168.TABLE 1 Normalized Equations for Each Carriage Weight Usingthe Standard Drop HeightCarriage WeightCarriage No. kg 6 1% lb 6 1% EquationsNo. 1 0.1134 0.250 F = (564.93/L) + 11.670No. 2 0.2268 0.500 F = (1129.85/L) + 9.179No. 3 0.3402 0.750 F
41、= (1694.78/L) + 6.953No. 4 0.4536 1.00 F = (2259.70/L) + 4.452No. 5 0.6804 1.50 F = (3389.55/L) 0.284No. 6 0.9072 2.00 F = (4519.40/L) 4.727No. 7 1.1340 2.50 F = (5649.24/L) 9.541No. 8 1.3608 3.00 F = (6779.10/L) 14.234TABLE 2 Precision and BiasAMaterialThicknessAVG SrSRBrBRCmm milsPE/EVAPE/EVAMDTD0
42、.050.052221.640.50.61.10.74.01.63.01.911.1PPPPMDTD0.10.14449.959.51.11.32.64.53.03.77.212.6PEPEMDTD0.080.083361.567.41.11.23.25.33.23.39.114.7PETGPETGMDTD0.230.239967.476.23.54.96.29.29.813.817.425.8PEPEMDTD0.20.28874.981.22.02.09.18.15.65.525.622.7LLPELLPEMDTD0.130.135579.485.91.51.54.67.64.34.112.
43、921.4PEPEMDTD0.150.156693.597.12.82.49.98.87.96.627.724.7LLPELLPEMDTD0.250.251010136.5134.21.62.29.314.04.66.026.239.1AValues expressed in NewtonsBr = 2.83 3 SrCR = 2.83 3 SRD2582083between specific laboratories. Users of this test method shouldapply the principles outlined in Practice E 691 to gene
44、rate dataspecific to their laboratory and materials, or between specificlaboratories. The principles of 12.2-12.2.3 would then be validfor such data.12.2 Concept of r and RIf Srand SRhave been calculatedfrom a large enough body of data, and from test results thatwere an average from testing five spe
45、cimens:12.2.1 Repeatability Limit, r (Comparing two test results forthe same material, obtained by the same operator using thesame equipment on the same day): The two test results shouldbe judged not equivalent if they differ by more than the “r”value for that material.r 5 2.83 Sr12.2.2 Reproducibil
46、ity Limit, R (Comparing two test resultsfor the same material, obtained by different operators usingdifferent equipment in different laboratories): The two testresults should be judged not equivalent if they differ by morethan the “R” value for that material.R 5 2.83 SR12.2.3 Any judgment in accorda
47、nce with 12.2.1 and 12.2.2would have an approximate 95 % (.95) probability of beingcorrect.12.3 BiasThere are no recognized standards by which toestimate bias of this test method.13. Keywords13.1 plastic film; plastic sheeting; puncture propagation;slit tear; snagging; tear resistance; “V” tearAPPEN
48、DIX(Nonmandatory Information)X1. DERIVATION OF EQUATION FOR TEAR RESISTANCEX1.1 The equation for determining average tear resistance(effective force to tear) has been derived for a drop height of508 mm (20.0 in.) as follows:X1.1.1 Potential energy of carriage beforerelease = W(H+L) = work done on sa
49、mple in bringing car-riage to a stop, where: W = weight of the carriage, H = heightof carriage before release, and L = length of tear.X1.1.2 Work done on sample = effective force exerted byprobe in propagating tear ( = tear resistance) 3 length oftear = F 3 L, where: F = effective force exerted by probe andL = length of tear.X1.1.3 Equating the two, W (H+L)= F 3 L, so that: tearresistance (in Newtons), F = (W 3 H)/L+W9.8065.NOTE X1.1The preceding equation is to be used for nonstandard dropheight tests.X1.1.4 The following approximations w
