1、Designation: D 1424 07aStandard Test Method forTearing Strength of Fabrics by Falling-Pendulum Type(Elmendorf) Apparatus1This standard is issued under the fixed designation D 1424; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers th
3、e determination of the forcerequired to propagate a single-rip tear starting from a cut in afabric and using a falling-pendulum type (Elmendorf) appara-tus.1.2 This test method applies to most fabrics includingwoven, layered blankets, napped pile, blanket, and air bagfabrics, provided the fabric doe
4、s not tear in the directioncrosswise to the direction of the force application during thetest. The fabrics may be untreated, heavily sized, coated,resin-treated, or otherwise treated. Instructions are provided fortesting specimens with, or without, wetting.1.3 This method is suitable only for the wa
5、rp direction testsof warp-knit fabrics. It is not suited for the course direction ofwarp knit fabrics or either direction of most other knittedfabrics.1.4 The values stated in either SI units or U.S. customaryunits are to be regarded as standard, but must be usedindependently of each other. The U.S.
6、 customary units may beapproximate.1.5 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 health practices and determine the applica-bility of regulatory limit
7、ations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 123 Terminology Relating to TextilesD 629 Test Methods for Quantitative Analysis of TextilesD 1776 Practice for Conditioning and Testing TextilesD 2261 Test Method for Tearing Strength of Fabrics by theTongue (Single Rip) Procedure (Co
8、nstant-Rate-of-Extension Tensile Testing Machine)D 2904 Practice for Interlaboratory Testing of a Textile TestMethod that Produces Normally Distributed DataD 2906 Practice for Statements on Precision and Bias forTextilesD 4848 Terminology of Force, Deformation and RelatedProperties of TextilesD 4850
9、 Terminology Relating to FabricD 5587 Test Method for Tearing Strength of Fabrics byTrapezoid Procedure3. Terminology3.1 For all terminology relating to D13.59, Fabric TestMethods, General, refer to Terminology D 4850.3.2 For all terminology relating to Force, Deformation andRelated Properties in Te
10、xtiles, refer to Terminology D 4848.3.2.1 The following terms are relevant to this standard:cross-machine direction, CD, length of tear, machine direction,MD, tearing energy, tearing force, tear resistance, tearingstrength, fabric.3.3 For all other terminology related to textiles, refer toTerminolog
11、y D 123.4. Summary of Test Method4.1 A slit is centrally precut in a test specimen held betweentwo clamps and the specimen is torn through a fixed distance.The resistance to tearing is in part factored into the scalereading of the instrument and is computed from this readingand the pendulum capacity
12、.5. Significance and Use5.1 This test method for the determination of tearingstrength by the falling pendulum type apparatus is used in thetrade for the acceptance testing of commercial shipments offabrics, but caution is advised since technicians may fail to getgood agreement between results on cer
13、tain fabrics. Compara-tive tests as directed in 5.1.1 may be needed.1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.60 on Fabric Test Methods,Specific.Current edition approved Dec. 1, 2007. Published January 2008. Orig
14、inallyapproved in 1956. Discontinued January 1995 and reinstated as D 1424 96. Lastprevious edition approved in 2007 as D 142407.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informati
15、on, 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.Copyright by ASTM Intl (all rights reserved); Wed Aug 6 03:35:32 EDT 2008Downloaded/printed byGuo Dehua (CNIS) pursua
16、nt to License Agreement. No further reproductions authorized.5.1.1 In case of a dispute arising from differences inreported test results when using this test method for acceptancetesting of commercial shipments, the purchaser and the sup-plier should conduct comparative tests to determine if there i
17、sa statistical bias between their laboratories. Statistical assis-tance is recommended for the investigation of bias. As aminimum, the two parties should take a group of test speci-mens that are as homogeneous as possible and that are from alot of fabric of the type in question. The test specimens s
18、houldthen be randomly assigned in equal numbers to each laboratoryfor testing. The average results from the two laboratoriesshould be compared using appropriate statistical analysis andan acceptable probability level chosen by the two parties beforethe testing began. If a bias is found, either its c
19、ause must befound and corrected or the purchaser and the supplier mustagree to interpret future test results with consideration to theknown bias.5.2 Microprocessor systems for automatic collection of datacan provide economical and reliable results when properlycalibrated. See Test Methods D 2261 and
20、 D 5587.6. Apparatus6.1 Falling-Pendulum (Elmendorf) Type Tester3The testerincludes: a stationary clamp, a clamp carried on a pendulumthat is free to swing on a bearing, means for leveling asapplicable, means for holding the pendulum in a raisedposition, means for instantly releasing the pendulum, a
21、ndmeans for measuring the force to tear the test specimen.6.1.1 A knife can be mounted on a stationary post for initialslitting of the specimens centered between the clamps andadjusted in height to give a tearing distance of 43.0 6 0.15 mm(1.69 6 0.005 in.); that is, the distance between the end of
22、theslit made by the knife and the upper edge of the specimen is43.0 6 0.15 mm (1.69 6 0.005 in.) when the lower edge of the63.0-mm (2.5 6 0.005 in.) wide specimen rests against thebottom of the clamp.6.1.2 With the pendulum in its initial position ready for atest, the two clamps are separated by a d
23、istance of 2.5 6 0.25mm (0.1 6 0.01 in.) and are aligned such that the clampedspecimen lies in a plane parallel to the axis of the pendulum,the plane making an angle of 0.480 rad (27.5 6 0.5) with theperpendicular line joining the axis and the horizontal lineformed by the top edges of the clamping j
24、aws. The distancebetween the axis and the top edges of the clamping jaws is1036 0.1 mm (4.055 6 0.004 in.). The clamping surface ineach jaw is at least 25 mm (1.0 in.) wide and 15.9 6 0.1 mm(0.625 6 0.004 in.) deep.6.1.3 The tester may have a pointer mounted on the sameaxis as the pendulum to regist
25、er the tearing force, or it may besubstituted by means of calculating and displaying the requiredresults without the use of a pointer, such as digital display andcomputer driven systems. Preferably the clamps may be airactuated, but manual clamping is permitted.6.1.4 The test instrument should be eq
26、uipped to provideinterchangeable full scale force ranges. Typical full scaleranges are shown in Table A3.1.6.2 Calibration Weight(s) for graduation of 50 % of the fullscale force range, or other means as described by the manu-facturer of the test apparatus.6.3 Cutting Die having essentially the shap
27、e and dimen-sions shown in Fig. 1(a) or (b). Either die provides the basicrectangular test specimen 100 6 2mm(46 0.05 in.) long by63 6 0.15 mm (2.5 6 0.005 in.) wide, along with additionalfabric at the top edge of the specimen to help ensure the bottomportion of specimen will be torn during the test
28、. The criticaldimension of the test specimen is the distance 43.0 6 0.15 mm(1.696 0.005 in.) which is to be torn during the test.NOTE 1The improved die model shown in Fig. 1(a) has two newfeatures not found in the original model, Fig. 1(b), namely a cutout for thebottom of the specimen to aid in cen
29、tering it in the clamps, and (optional)provision for cutting the 20.0 mm (0.75 in.) slit prior to inserting thespecimen in the tester. These dies can be made to order by most diemanufacturers.6.4 Air Pressure Regulator, capable of controlling gage airpressure between 410 kPa and 620 kPa (60 psi and
30、90 psi),when applicable, for air clamps.6.5 Setting Gage for Cutting Blade that will provide a cutslit that leaves a 43 6 0.15 mm (1.69 6 0.005 in.) specimentearing distance for a 63 6 0.15 mm (2.5 6 0.005 in.) widespecimen, or equivalent.6.6 Jaw Spacing Gage 2.5 6 0.25 mm (0.1 6 0.01 in.)width, or
31、equivalent.6.7 Oil, light weight, non-gumming clock type.6.8 Silicone Grease, when applicable, for air clamp lubri-cation.6.9 Vacuum Cleaner, when applicable, for cleaning dust andfiber from sensor, or equivalent.7. Sampling and Test Specimens7.1 Lot SampleAs a lot sample for acceptance testing,rand
32、omly select the number of rolls or pieces of fabric directedin an applicable material specification or other agreementbetween the purchaser and the supplier. Consider the rolls orpieces of fabric to be the primary sampling units. In theabsence of such an agreement, take the number of fabric rollsor
33、pieces specified in Table 1.NOTE 2An adequate specification or other agreement between thepurchaser and supplier requires taking into account the variability betweenrolls or pieces of fabric and between specimens from a swatch from a rollor piece of fabric to provide a sampling plan with a meaningfu
34、l producersrisk, consumers risk, acceptable quality level, and limiting quality level.3Apparatus is commercially available. FIG. 1 Die Diagram for Cutting Notched SpecimensD 1424 07a2Copyright by ASTM Intl (all rights reserved); Wed Aug 6 03:35:32 EDT 2008Downloaded/printed byGuo Dehua (CNIS) pursua
35、nt to License Agreement. No further reproductions authorized.7.2 Laboratory SampleFor acceptance testing, take aswatch extending the width of the fabric and approximately 1m (1 yd) along the machine direction from each roll or piece inthe lot sample. For rolls of fabric, take a sample that willexclu
36、de fabric from the outer wrap of the roll or the inner wraparound the core of the roll of fabric.7.3 Test SpecimensFrom each laboratory sampling unit,take five specimens from the machine direction and fivespecimens from the cross-machine direction, for each testcondition described in 9.1 and 9.2, as
37、 applicable to a materialspecification or contract order.7.3.1 Direction of TestConsider the long direction of thespecimen as the direction of test.7.3.2 Cutting Test SpecimensTake the specimens to beused for the measurement of machine direction with the longerdimension parallel to the machine direc
38、tion. Take the speci-mens to be used for the measurement of the cross-machine withthe longer dimension parallel to the cross-machine direction.Use the cutting die described in 6.3 and shown in Fig. 1(a) or(b), as applicable. When specimens are to be tested wet, cutfrom areas adjacent to the dry test
39、 specimens. Label tomaintain specimen identity.7.3.2.1 In cutting the woven fabric specimens, take care toalign the yarns running in the short direction parallel with thedie such that when the slit is cut, the subsequent tear will takeplace between these yarns and not across them. This precautionis
40、most important when testing bowed fabrics.7.3.2.2 Cut specimens representing a broad distributionacross the width and length, and preferably along the diagonalof the laboratory sample, and no nearer the edge than one-tenthits width. Ensure specimens are free of folds, creases, orwrinkles.Avoid getti
41、ng oil, water, grease, etc. on the specimenswhen handling.NOTE 3The reading obtained is directly proportional to the length ofthe material torn, therefore, it is essential that the specimen be prepared tothe exact size specified.8. Preparation of Apparatus and Calibration8.1 Select test instrument f
42、orce range, such that the tearoccurs between 20 and 80 % or 20 and 60 % of the full-scalerange as applicable. Ensure the clamps are spaced as directedin A1.4.NOTE 4For standard test apparatus, the useable portion of the fullscale force range is 20 to 80 %. For the high capacity test instrument, theu
43、seable portion of the full scale force range is 20 to 60 %.8.2 When equipped with a registering sensor, examine thescale and the complementary sensor, as applicable. Using careand without touching the sensor, vacuum away any loose fibersand dust.8.3 Examine the knife edge for sharpness, wear, and ce
44、ntralalignment as directed in A1.5-A1.7.8.4 For air clamps, set the air gage pressure to the clamps toabout 550 kPa (80 psi).8.4.1 Maximum gage pressure should be no more than 620kPa (90 psi) and minimum gage pressure no less than 410 kPa(60 psi).8.5 When using microprocessor automatic data gatherin
45、gsystems, set the appropriate parameters as defined in themanufacturers instructions.8.6 Verify the calibration of the selected pendulum full scaleforce range using the procedure described in Annex A2, unlessotherwise specified.9. Conditioning9.1 Condition 1, Standard Testing Conditioning:9.1.1 Prec
46、ondition the specimens by bringing them to ap-proximate moisture equilibrium in the standard atmosphere forpreconditioning textiles as directed in Practice D 1776, unlessotherwise directed in a material specification or contract order.9.1.2 After preconditioning, bring the test specimens tomoisture
47、equilibrium for testing in the standard atmosphere fortesting textiles as directed in Practice D 1776 or, if applicable,in the specified atmosphere in which the testing is to beperformed, unless otherwise directed in a material specificationor contract order.9.2 Condition 2, Wet Specimen Testing Con
48、ditioning:9.2.1 When desizing treatments are specified prior to wettesting, use desizing treatments that will not affect the normalphysical property of the fabric as directed in Test MethodD 629.9.2.2 Submerge the specimens in a container of distilled ordeionized water at ambient temperature until t
49、horoughlysoaked (see 8.2.1.1).9.2.2.1 The time of immersion must be sufficient to wet outthe specimens, as indicated by no significant change in tearingforce followed by longer periods of immersion. For mostfabrics this time period will be about 1 h. For fabrics notreadily wet out with water, such as those treated with water-repellent, or water resistant materials, add a 0.1 % solution ofa nonionic wetting agent to the water bath.10. Procedure10.1 Test the conditioned specimens in the standard atmo-sphere for testing textiles, which is 21 6 1C (70 6 2F) and65 6 2 %
