1、Designation: D5587 14D5587 15Standard Test Method forTearing Strength of Fabrics by Trapezoid Procedure1This standard is issued under the fixed designation D5587; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev
2、ision. 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 tearing strength of textile fabrics by the trapezoid procedure using arecording
3、 constant-rate-of-extension-type (CRE) tensile testing machine.1.1.1 The CRE-type tensile testing machine has become the preferred test apparatus for determining trapezoid tearing strength.It is recognized that some constant-rate-of-traverse-type (CRT) tensile testing machines continue to be used. C
4、onsequently, thesetest instruments may be used when agreed upon between the purchaser and the supplier. The conditions for use of the CRT-typetensile tester are included in Appendix X1.1.2 This test method applies to most fabrics including woven fabrics, air bag fabrics, blankets, napped fabrics, kn
5、itted fabrics,layered fabrics, pile, and nonwoven fabrics. The fabrics may be untreated, heavily sized, coated, resin-treated, or otherwise treated.Instructions are provided for testing specimens with or without wetting.1.3 Tearing strength, as measured in this test method, requires that the tear be
6、 initiated before testing. The reported valueobtained is not directly related to the force required to initiate or start a tear.1.4 Two calculations for trapezoid tearing strength are provided: the single-peak force and the average of five highest peakforces.1.5 The values stated in SI units are to
7、be regarded as the standard. The values stated in inch-pound units may be approximate.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices a
8、nd determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D76 Specification for Tensile Testing Machines for TextilesD123 Terminology Relating to TextilesD629 Test Methods for Quantitative Analysis of TextilesD1776 Practice for Conditioning and T
9、esting TextilesD2904 Practice for InterlaboratoryTesting of aTextileTest Method that Produces Normally Distributed Data (Withdrawn 2008)3D2906 Practice for Statements on Precision and Bias for Textiles (Withdrawn 2008)3D4850 Terminology Relating to Fabrics and Fabric Test Methods3. Terminology3.1 Fo
10、r all terminology relating to D13.59, Fabric Test methods, General, refer to Terminology D4850.3.1.1 The following terms are relevant to this standard: fabric, in textiles; peak force, in tear testing of fabrics; tearing force,in fabric; tearing strength, in fabrics; yarn distortion (see Fig. 1).3.2
11、 For all other terms related to textiles, refer to Terminology D123.1 This test method is under the jurisdiction ofASTM Committee D13 on Textiles and is the direct responsibility of Subcommittee D13.60 on Fabric Test Methods, Specific.Current edition approved Feb. 15, 2014July 1, 2015. Published Mar
12、ch 2014September 2015. Originally approved in 1996. Last previous edition approved in 20082014as D5587 08.D5587 14. DOI: 10.1520/D5587-14.10.1520/D5587-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM
13、Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what
14、 changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the
15、official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Summary of Test Method4.1 An outline of an isosceles trapezoid is marked on a rectangular specimen (see Fig. 2). The specimen is slit at the center ofthe smallest ba
16、se of the trapezoid to start the tear. The nonparallel sides of the marked trapezoid are clamped in parallel clampsof a tensile testing machine. The separation of the clamps is increased continuously to apply a force to propagate the tear acrossthe specimen.At the same time, the force developed is r
17、ecorded. The force to continue the tear is calculated from autographic chartrecorders or microprocessor data collection systems.5. Significance and Use5.1 This test method is considered satisfactory for acceptance testing of commercial shipments because current estimates ofbetween-laboratory precisi
18、on are acceptable, and this test method is used extensively in the trade for acceptance testing.5.2 If there are differences of practical significance between test results for two laboratories (or more), comparative test shouldbe performed to determine if there is a statistical bias between them, us
19、ing competent statistical assistance. As a minimum, usethe samples for such a comparative test that are as homogeneous as possible, drawn from the same lot of material as the samplesthat resulted in disparate results during initial testing. Randomly assign the samples in equal numbers to each labora
20、tory. The testresults from the laboratories involved should be compared using a statistical test for unpaired data, at a probability level chosenprior to the testing series. If bias is found, either its cause must be found and corrected, or future test results for that material mustbe adjusted in co
21、nsideration of the known bias.5.3 The trapezoid tear produces tension along a reasonably defined course such that the tear propagates across the width of thespecimen. It is useful for estimating the relative tear resistance of different fabrics or different directions in the same fabric.5.4 Dependin
22、g on the nature of the specimen, the data recording devices will show the tearing force in the form of a peak orpeaks. The highest peaks appear to reflect the strength of the yarn components, individually or in combination, needed to stop atear in fabrics of the same construction. The valleys record
23、ed between the peaks have no specific significance. The minimumtearing force, however, is indicated to be above the lowest valleys.5.5 Most textile fabrics can be tested by this test method. Some modification of clamping techniques may be necessary for agiven fabric, depending upon its structure. St
24、rong fabrics or fabrics made from glass fibers require special adaptation to preventthem from slipping in the clamps or being damaged as a result of being gripped in the clamps. In some cases, due to fabricconstructions, individual yarns may not rupture but show a high peak and yarn distortion withi
25、n the test specimen. Whereverpossible, this shall be prevented. If you have tried all of these steps and yarn distortion still occurs, this must be included in thereport.5.6 The CRE-type is the preferred tensile testing machine. This test method allows the use of the CRT-type tensile machinewhen agr
26、eed upon between the purchaser and the supplier. There may be no overall correlation, however, between the resultsobtained with the CRT-type machine and the CRE-type machine. Consequently, these two tensile testers cannot be usedinterchangeably unless the degree of quantitative correlation has been
27、established between the purchaser and the supplier. In anyevent, the CRE-type machine shall prevail.FIG. 1 Photograph Showing Yarn Distortion in a Modern Technical Type FabricD5587 1526. Apparatus6.1 Tensile Testing Machine4, of the CRE-type conforming to the requirements of Specification D76 with a
28、utographic recorder,or automatic microprocessor data gathering system.6.2 Clamps, having all clamping surfaces parallel, and capable of preventing slipping of the fabric specimen during a test, andmeasuring at least 50 by 75 mm (at least 2 by 3 in.), with the longer dimension perpendicular to the di
29、rection of application ofthe force.6.2.1 The use of hydraulic Hydraulic or pneumatic clamping systems with a minimum of 50 by 75-mm (at least 2 by 3-in.)rubber, metal, or padded/coated clamps faces shall be used. The faces shall have an appropriate clamping force at the clamp facesdepending on the t
30、ype of fabric under test. The pressure should be sufficient to prevent slippage of the fabric specimen from theclamps during the test, while ensuring the specimen is not damaged at the clamps edge. For certain industrial type fabrics agripping force at the clamps of 13 to 14 kN (2900 to 3111 lbf) is
31、 recommended. Manual clamping is permitted providing no fabricspecimen slippage in the clamp is observed. When using manual clamping, use of torque wrench or other tool is recommendedto consistently achieve 2900-3111 lbf.6.2.2 For some fabrics, to prevent fabric slippage or yarn distortion from the
32、clamp when using clamp faces other than serrated,such as rubber faced clamps, the clamps faces may be covered with a No. 80 to 120 medium grit emery cloth. Secure the emerycloth to the clamps faces with pressure-sensitive tape. Other techniques may also be used such as resins if necessary. If fabric
33、slippage or yarn distortion continues to occur, then serrated or interlocking clamps faces should be used.6.3 Cutting Die or Template, having essentially the shape and dimensions shown in Fig. 2.7. Sampling and Test Specimens7.1 Lot SampleAs a lot sample for acceptance testing, randomly select the n
34、umber of rolls or pieces of fabric directed in anapplicable material specification or other agreement between the purchaser and the supplier. Consider the rolls or pieces of fabricto be the primary sampling units. In the absence of such an agreement, take the number of fabric rolls specified in Tabl
35、e 1.NOTE 1An adequate specification or other agreement between the purchaser and the supplier requires taking into account the variability between rollsor pieces of fabric and between specimens from a swatch from a roll or piece of fabric to provide a sampling plan with a meaningful producers risk,c
36、onsumers risk, acceptable quality level, and limiting quality level.7.2 Laboratory SampleFor acceptance testing, take a swatch extending the width of the fabric and approximately 1 m (1 yd)along the machine direction from each roll or piece in the lot sample. For rolls of fabric, take a sample that
37、will exclude fabricfrom the outer wrap of the roll or the inner wrap around the core of the roll of fabric.4 Apparatus and accessories are commercially available.FIG. 2 Templates for Cutting and Marking Trapezoid Test Specimens (mm)D5587 1537.2.1 Stretch FabricsFor fabrics with stretch yarns, labora
38、tory samples shall be allowed to relax lying flat for 24 h in theconditioned atmosphere outlined in Section 9. Once relaxed, samples are to be marked and cut as described above.7.3 Test SpecimensFrom each laboratory sampling unit, take five specimens from the machine direction and five specimensfrom
39、 the cross-machine direction, for each test condition described in 9.1 and 9.2, as applicable to a material specification orcontract order.7.3.1 Direction of TestConsider the long direction as the direction of test.7.3.2 Cutting Test SpecimensTake the specimens to be used for the measurement of mach
40、ine direction with the longerdimension parallel to the machine direction. Take the specimens to be used for the measurement of the cross-machine directionwith the longer dimension parallel to the cross-machine direction. When specimens are to be tested wet, take the specimens fromareas adjacent to t
41、he dry test specimens. Label to maintain specimen identity.7.3.2.1 In cutting the woven fabric specimens, take care to align the yarns running in the short direction parallel with the diesuch that when the slit is cut, the subsequent tear will take place between these yarns and not across them. This
42、 precaution is mostimportant when testing bowed fabrics.7.3.2.2 Cut specimens representing a broad distribution across the width and length, preferably along the diagonal of thelaboratory sample, and no nearer the edge than one tenth its width. Ensure specimens are free of folds, creases, or wrinkle
43、s.Avoidgetting oil, water, grease, and so forth, on the specimens when handling.7.3.2.3 Use the cutting die or template described in 6.3 and shown in Fig. 2. Mark each specimen with an isosceles trapezoidtemplate (see Fig. 2). Make a preliminary cut 15 mm (0.625 in.) long at the center of the 25-mm
44、(1-in.) edge, as shown in Fig.2.NOTE 2Tests were carried out in 2007 to evaluate whether the specimen size and clamps separation could be increased to facilitate easier loadingof the specimen. It was found that this caused a difference in the final results depending on the fabric type. Therefore, it
45、 is not possible to increase thespecimen size.8. Preparation of Test Apparatus and Calibration8.1 Set the distance between the clamps at the start of the test at 25 6 1 mm (1 6 0.05 in.).8.2 Select the full-scale force range of the testing machine such that the maximum force occurs between 15 and 85
46、 % offull-scale force.8.3 Set the testing speed to 300 6 10 mm (12 6 0.5 in./min).8.4 Verify calibration of the tensile testing machine as specified in the manufacturers instructions and Specification D76.8.5 When using microprocessor automatic data gathering systems, set the appropriate parameters
47、as specified in themanufacturers instructions.9. Conditioning9.1 Condition 1, for Standard Testing:9.1.1 Precondition the specimens by bringing them to approximate moisture equilibrium in the standard atmosphere forpreconditioning textiles as specified in Practice D1776, unless otherwise specified i
48、n a material specification or contract order. Inaddition to conditioning, fabric with stretch characteristics must be allowed to relax for a period of 24 h prior to sample preparation.9.1.2 After preconditioning, bring the test specimens to moisture equilibrium for testing in the standard atmosphere
49、 for testingtextiles as specified in Practice D1776 or, if applicable, in the specified atmosphere in which the testing is to be performed, unlessotherwise directed in a material specification or contract order.9.2 Condition 2, for Wet Specimen Testing:9.2.1 Submerge the specimen in a container of distilled or deionized water at ambient temperature until thoroughly soaked.9.2.1.1 The time of immersion must be sufficient to wet out the specimens, as indicated by no significant change in tearing forcefollowed by longer periods of immersion. For most fabrics, this tim
