1、Designation: D 5587 08Standard Test Method forTearing Strength of Fabrics by Trapezoid Procedure1This standard is issued under the fixed designation D 5587; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 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 covers the measurement of the tearingstrength of textile fabrics by the trapezoid procedure using arecording consta
3、nt-rate-of-extension-type (CRE) tensile testingmachine.1.1.1 The CRE-type tensile testing machine has become thepreferred test apparatus for determining trapezoid tearingstrength. It is recognized that some constant-rate-of-traverse-type (CRT) tensile testing machines continue to be used.Consequentl
4、y, these test instruments may be used when agreedupon between the purchaser and the supplier. The conditionsfor use of the CRT-type tensile tester are included in AppendixX1.1.2 This test method applies to most fabrics includingwoven fabrics, air bag fabrics, blankets, napped fabrics, knittedfabrics
5、, layered fabrics, and pile fabrics. The fabrics may beuntreated, heavily sized, coated, resin-treated, or otherwisetreated. Instructions are provided for testing specimens with orwithout wetting.1.3 Tearing strength, as measured in this test method,requires that the tear be initiated before testing
6、. The reportedvalue obtained is not directly related to the force required toinitiate or start a tear.1.4 Two calculations for trapezoid tearing strength areprovided: the single-peak force and the average of five highestpeak forces.1.5 The values stated in SI units are to be regarded as thestandard.
7、 The values stated in inch-pound units may beapproximate.1.6 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-bili
8、ty of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D76 Specification for Tensile Testing Machines for TextilesD 123 Terminology Relating to TextilesD 629 Test Methods for Quantitative Analysis of Textiles3D 1776 Practice for Conditioning and Testing TextilesD 2904 P
9、ractice for Interlaboratory Testing of a Textile TestMethod that Produces Normally Distributed DataD 2906 Practice for Statements on Precision and Bias forTextiles3D 4850 Terminology Relating to Fabrics and Fabric TestMethods3. Terminology3.1 For all terminology relating to D13.59, Fabric Testmethod
10、s, General, refer to Terminology D 4850.3.1.1 The following terms are relevant to this standard:fab-ric, in textiles; peak force, in tear testing of fabrics; tearingforce, in fabric; tearing strength, in fabrics.3.2 For all other terms related to textiles, refer to Terminol-ogy D 123.4. Summary of T
11、est Method4.1 An outline of an isosceles trapezoid is marked on arectangular specimen (see Fig. 1). The specimen is slit at thecenter of the smallest base of the trapezoid to start the tear. Thenonparallel sides of the marked trapezoid are clamped inparallel jaws of a tensile testing machine. The se
12、paration of thejaws is increased continuously to apply a force to propagate thetear across the specimen.At the same time, the force developedis recorded. The force to continue the tear is calculated fromautographic chart recorders or microprocessor data collectionsystems.1This test method is under t
13、he jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.60 on Fabric Test Methods,Specific.Current edition approved Aug. 1, 2008. Published October 2008. Originallyapproved in 1996. Last previous edition approved in 2007 as D 5587 07a1.2For referenced AS
14、TM 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. The last approved version of this historical standard is referenced
15、on www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Significance and Use5.1 This test method is considered satisfactory for accep-tance testing of commercial shipments because current esti-mates of between-laboratory p
16、recision are acceptable, and thistest method is used extensively in the trade for acceptancetesting.5.2 If there are differences of practical significance betweentest results for two laboratories (or more), comparative testshould be performed to determine if there is a statistical biasbetween them,
17、using competent statistical assistance. As aminimum, use the samples for such a comparative test that areas homogeneous as possible, drawn from the same lot ofmaterial as the samples that resulted in disparate results duringinitial testing. Randomly assign the samples in equal numbersto each laborat
18、ory. The test results from the laboratoriesinvolved should be compared using a statistical test forunpaired data, at a probability level chosen prior to the testingseries. If bias is found, either its cause must be found andcorrected, or future test results for that material must beadjusted in consi
19、deration of the known bias.5.3 The trapezoid tear produces tension along a reasonablydefined course such that the tear propagates across the width ofthe specimen. It is useful for estimating the relative tearresistance of different fabrics or different directions in the samefabric.5.4 Depending on t
20、he nature of the specimen, the datarecording devices will show the tearing force in the form of apeak or peaks. The highest peaks appear to reflect the strengthof the yarn components, individually or in combination, neededto stop a tear in fabrics of the same construction. The valleysrecorded betwee
21、n the peaks have no specific significance. Theminimum tearing force, however, is indicated to be above thelowest valleys.5.5 Most textile fabrics can be tested by this test method.Some modification of clamping techniques may be necessaryfor a given fabric, depending upon its structure. Strong fabric
22、sor fabrics made from glass fibers require special adaptation toprevent them from slipping in the clamps or being damaged asa result of being gripped in the clamps.5.6 The CRE-type is the preferred tensile testing machine.This test method allows the use of the CRT-type tensilemachine when agreed upo
23、n between the purchaser and thesupplier. There may be no overall correlation, however, be-tween the results obtained with the CRT-type machine and theCRE-type machine. Consequently, these two tensile testerscannot be used interchangeably unless the degree of quantita-tive correlation has been establ
24、ished between the purchaser andthe supplier. In any event, the CRE-type machine shall prevail.6. Apparatus6.1 Tensile Testing Machine4, of the CRE-type conformingto the requirements of Specification D76 with autographicrecorder, or automatic microprocessor data gathering system.6.2 Clamps, having al
25、l gripping surfaces parallel, flat, andcapable of preventing slipping of the specimen during a test,and measuring at least 50 by 75 mm (at least 2 by 3 in.), withthe longer dimension perpendicular to the direction of appli-cation of the force.6.2.1 The use of hydraulic pneumatic clamping systemswith
26、 a minimum of 50 by 75-mm (at least 2 by 3-in.) serrated,waved profile, or padded/coated jaw faces having a clampingforce at the grip faces of 13 to 14 kN (2900 to 3111 lbf.) isrecommended. Manual clamping is permitted providing noslippage of the specimen in the clamp is observed. When usingmanual c
27、lamping, use of torque wrench or other tool isrecommended to consistently achieve 2900-3111lbf.6.2.2 For some fabrics, to prevent slippage in the clampwhen using jaw faces other than serrated, such as rubber facedjaws, the jaw faces may be covered with a No. 80 to 120medium grit emery cloth. Secure
28、the emery cloth to the jawfaces with pressure-sensitive tape.6.3 Cutting Die or Template, having essentially the shapeand dimensions shown in Fig. 1a.6.4 Trapezoid-Shaped Template, having dimensions asshown in Fig. 1b.7. Sampling and Test Specimens7.1 Lot SampleAs a lot sample for acceptance testing
29、,randomly 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 rol
30、lsspecified in Table 1.4Apparatus and accessories are commercially available.(a)(b)FIG. 1 Templates for Cutting and Marking Trapezoid TestSpecimensD5587082NOTE 1An adequate specification or other agreement between thepurchaser and the supplier requires taking into account the variabilitybetween roll
31、s or pieces of fabric and between specimens from a swatchfrom a roll or piece of fabric to provide a sampling plan with a meaningfulproducers risk, consumers risk, acceptable quality level, and limitingquality level.7.2 Laboratory SampleFor acceptance testing, take aswatch extending the width of the
32、 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 willexclude 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
33、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 applicable to a materialspecification or contract order.7.3.1 Direction of TestConsider the long direction as thedirection of test.7.3.2 Cutting
34、 Test SpecimensTake the specimens to beused for the measurement of machine direction with the longerdimension parallel to the machine direction. Take the speci-mens to be used for the measurement of the cross-machinedirection with the longer dimension parallel to the cross-machine direction. When sp
35、ecimens are to be tested wet, takethe specimens from areas adjacent to the dry test specimens.Label to maintain 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 subsequ
36、ent tear will takeplace between these yarns and not across them. This precautionis most important when testing bowed fabrics.7.3.2.2 Cut specimens representing a broad distributionacross the width and length, preferably along the diagonal ofthe laboratory sample, and no nearer the edge than one tent
37、h itswidth. Ensure specimens are free of folds, creases, or wrinkles.Avoid getting oil, water, grease, and so forth, on the specimenswhen handling.7.3.2.3 Use the cutting die or template described in 6.3 andshown in Fig. 1(a). Mark each specimen with an isoscelestrapezoid template (see Fig. 1, Fig.
38、2). Make a preliminary cut15 mm (0.625 in.) long at the center of the 25-mm (1-in.) edge,as shown in Figs. 1 and 2.8. Preparation of Test Apparatus and Calibration8.1 Set the distance between the clamps at the start of thetest at 25 6 1mm(16 0.05 in.).8.2 Select the full-scale force range of the tes
39、ting machinesuch that the maximum force occurs between 15 and 85 % offull-scale force.8.3 Set the testing speed to 300 6 10 mm (12 6 0.5in./min).8.4 Verify calibration of the tensile testing machine asspecified in the manufacturers instructions and SpecificationD76.8.5 When using microprocessor auto
40、matic data gatheringsystems, set the appropriate parameters as specified in themanufacturers instructions.9. Conditioning9.1 Condition 1, for Standard Testing:9.1.1 Precondition the specimens by bringing them to ap-proximate moisture equilibrium in the standard atmosphere forpreconditioning textiles
41、 as specified in Practice D 1776, unlessotherwise specified in a material specification or contract order.9.1.2 After preconditioning, bring the test specimens tomoisture equilibrium for testing in the standard atmosphere fortesting textiles as specified in Practice D 1776 or, if applicable,in the s
42、pecified atmosphere in which the testing is to beperformed, unless otherwise directed in a material specificationor contract order.9.2 Condition 2, for Wet Specimen Testing:9.2.1 Submerge the specimen in a container of distilled ordeionized water at ambient temperature until thoroughlysoaked.9.2.1.1
43、 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 approximately 1 hr. For fabricsnot readily wet out with water, such as those treated withwater-r
44、epellent or water-resistant materials, add a 0.1% solu-tion of a nonionic wetting agent to the water bath.9.2.2 When a desizing treatment is to be performed prior towet testing, use one of the treatments specified in Test MethodsD 629. If desized specimens are to be tested wet, follow thesteps in an
45、d 9.2.1.1. If desized specimens are to be tested in theconditioned state, follow the steps in 9.1.1 and 9.1.2.9.2.2.1 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
46、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 of anonionic wetting agent to the water bath.TABLE 1 Number of Rolls or Pieces of Fabric in the Lot SampleNumber of Rolls or Piecesi
47、n Lot, InclusiveNumber of Rolls or Pieces in Lot Sample1to3 all4to24 425 to 50 5over 50 10 % to a maximum of 10 rolls or piecesFIG. 2 Diagram of Marked Trapezoid SpecimenD558708310. Procedure10.1 Test the conditioned specimens in the standard atmo-sphere for testing textiles, which is 21 6 1C (70 6
48、2F) and65 6 2 % relative humidity, unless otherwise specified in amaterial specification or contract order.10.2 Secure the test specimen in the machine, clampingalong the nonparallel sides of the trapezoid such that the endedges of the clamps are in line with the 25-mm (1-in.) long sideof the trapez
49、oid, and the cut is halfway between the clamps.Hold the short edge taut, and let the remaining fabric lie infolds.10.2.1 For wet testing, remove a specimen from the water,and immediately mount it on the testing machine in the normalsetup. Perform the test within 2 min after removal of thespecimen from the water. If more than 2 min elapse betweentaking the wet specimen from the water bath and starting thetension testing machine, discard the specimen and take another.10.3 Start the machine and record the tearing force on therecording device. The tearing force may increase
