1、Designation: D 2653 07Standard Test Method forTensile Properties of Elastomeric Yarns (CRE Type TensileTesting Machines)1This standard is issued under the fixed designation D 2653; 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.1. Scope1.1 This test method covers the determination of the tensileproperties of “as produced” elastomeric yarns made
3、fromnatural rubber, spandex or other elastomers, using a constant-rate-of-extension (CRE) type tensile testing machine. Theproperties included in this test method are: (1) force at firstfilament break, (2) tenacity at first filament break, (3) elonga-tion at first filament break, (4) work to break a
4、t first filamentbreak, and (5) toughness at first filament break.1.2 This test method does not apply to covered, wrapped, orcore-spun yarns or yarns spun from elastomeric staple.1.3 This test method is applicable to elastomeric yarns in therange from 40 to 3200 dtex (36 to 2900 denier).1.4 The value
5、s stated in either SI units or U.S. Customaryunits are to be regarded separately as standard. Within the text,the U.S. Customary units are given in parentheses. The valuesstated in each system are not exact equivalents; therefore, eachsystem shall be used independently of the other.1.5 This standard
6、 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 ASTM
7、Standards:2D76 Specification for Tensile Testing Machines for TextilesD 123 Terminology Relating to TextilesD 1776 Practice for Conditioning and Testing TextilesD 2258 Practice for Sampling Yarn for TestingD 2591 Test Method for Linear Density of ElastomericYarns _Short Length Specimens_D 4848 Termi
8、nology of Force, Deformation and RelatedProperties of TextilesD 4849 Terminology Relating to Yarns and FibersD 6717 Test Method for Linear Density of ElastomericYarns (Skein Specimens)3. Terminology3.1 For all terminology relating to D13.58, Yarns andFibers, refer to Terminology D 4849.3.1.1 The fol
9、lowing terms are relevant to this standard:elastomeric yarn, elongation, force, linear density, tenacity,toughness, work, work to break.3.2 For definitions of other terms related to force anddeformation, refer to Terminology D 4848. For all otherterminology related to textiles, refer to Terminology
10、D 123.4. Summary of Test Method4.1 A specimen is clamped in a CRE-type tensile testingmachine and extended to rupture. Force at first filament breakand elongation at first filament break, work and toughness arecalculated from a force-elongation curve or with an interfacedcomputer. Tenacity at first
11、filament break can be calculatedbased on the determined linear density of the yarn. Otherproperties, such as force at specified elongation (FASE),elongation at specified force (EASF), may also be calculated.5. Significance and Use5.1 This test method is considered satisfactory for accep-tance testin
12、g of commercial shipments since current estimatesof between-laboratory precision are acceptable and the methodis used extensively in the trade for acceptance testing.5.1.1 If there are differences of practical significance be-tween reported test results for two laboratories (or more),comparative tes
13、ts should be performed to determine if there isa statistical bias between them, using competent statisticalassistance. As a minimum, use samples for such comparativetests that are as homogeneous as possible, drawn from the samelot of material as the samples that resulted in disparate resultsduring i
14、nitial testing, and randomly assigned in equal numbersto each laboratory. The test results from the laboratoriesinvolved should be compared using a statistical test forunpaired data, at a probability level chosen prior to the testing1This test method is under the jurisdiction of ASTM Committee D13 o
15、n Textilesand is the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.Current edition approved Jan. 1, 2007. Published January 2007. Originallyapproved in 1967. Discontinued 1979 and reinstated as D 2653 01. Last previousedition approved in 2001 as D 265301.2For referenced ASTM stand
16、ards, 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, P
17、A 19428-2959, United States.series. If bias is found, either its cause must be found andcorrected, or future test results for that material must beadjusted in consideration of the known bias.5.2 The force at first filament break of elastomeric yarnsmay depend on its construction and manufacturing pr
18、ocess andprovides an indication of the breaking strength of fabrics madefrom the yarn.5.3 Elongation is an indication of the ability of a fiber toabsorb energy. The elongation of yarn or fabric must be greatenough to withstand strains experienced in processing and enduse, and to absorb the energies
19、of applied forces repeatedly.5.4 Fabric manufacturers use force and elongation informa-tion of elastomeric yarns in determining machine set-upconditions.5.5 Other parameters such as elongation at specified force(EASF), force (or tenacity) at specified elongation (FASE,TASE), work and toughness may b
20、e calculated from force-elongation curves. EASF and FASE information is needed fortests involving cycling of yarn in determination of elasticproperties.5.6 This test method was developed using elastomeric yarnsin the “as-produced” condition, but may be used for treatedelastomeric yarns provided the
21、treatment is specified. Themethod does not cover the removal of finish for determinationof tensile properties of “finish-free” elastomeric yarns.6. Apparatus36.1 Specimen Boards, with short pile or plush surfaces orblack or contrasting color, for storing specimens during con-ditioning.6.2 Tensile Te
22、sting Machine, CRE-type, conforming toSpecification D76with respect to force indication, workingrange, capacity and verification of recorded elongation, anddesigned for operation at a pulling speed of 500 mm/min (20in./min) or 1000 % extension per min.6.3 Clamping Assembly, pneumatically operated, w
23、ith jawfaces as described in 6.3.1 or 6.3.2.6.3.1 Option A, PreferredOne jaw with a flat acrylic facenominally 25 mm 3 12.5 mm (1 in. 3 0.5 in.) and theopposing jaw approximately 12.5 mm (0.5 in.) wide with aconvex approximately 7.1 mm (0.28 in.) radius, steel orchrome face.6.3.2 Option BOne jaw wit
24、h a flat, steel or chrome facenominally 25 mm 3 12.5 mm (1 in. 3 0.5 in.) and theopposing jaw approximately 12.5 mm (0.5 in.) wide with aconvex approximately 8.5 mm (0.375 in.) radius acrylic face.6.4 Computer or Microprocessor, interfaced, with auto-matic data gathering system, optional.6.5 Tension
25、ing Weights, with various masses from 10 mg to3 g as required to pretension the specimen to 30 to 50 mN/tex(0.3 to 0.5 mgf/d) before testing.6.6 Air Supply, capable of providing 415 kPa (60 psi) to thepneumatic clamps.7. Sampling, Test Specimens, and Test Units7.1 Lot SampleAs a lot sample for accep
26、tance testing,take a random number of shipping units directed in anapplicable material specification or other agreement betweenthe purchaser and the supplier, such as an agreement to usePractice D 2258. Consider shipping cases or other shippingunits to be the primary sampling units.NOTE 1An adequate
27、 specification or other agreement between thepurchaser and the supplier requires taking into account the variabilitybetween shipping units, between packages or ends within a shipping unit,and between specimens from a single package to provide a sampling witha meaningful producers risk, consumers ris
28、k, acceptable quality leveland limiting quality level.7.2 Laboratory SampleAs a laboratory sample for accep-tance testing, take at random from each shipping unit in the lotsample the number of packages directed in an applicablematerial specification or other agreement between the pur-chaser and the
29、supplier, such as an agreement to use PracticeD 2258. Preferably, take the same number of packages fromeach of the shipping units, determine at random which shippingunits are to have each number of packages for testing.7.3 Test SpecimensFrom each package or end in thelaboratory sample, take specimen
30、s as directed in 7.3.1.7.3.1 Remove the outer layer of yarn from the package.Avoid any damaged areas in selecting segments for testing.Carefully unwind yarn from the package with as low as tensionas possible to avoid stretching. As test specimens, cut approxi-mately 125 mm (5 in.) long segments of y
31、arn from eachpackage, taking them at intervals of at least1m(1yd). Threeof the six specimens are used as spare to allow for unacceptablebreaks, such as caused by slippage or breaking in the clamps.7.4 Determine the tex (denier) of the yarn for each labora-tory sample using Test Method D 2591 or Test
32、 Method D 6717.8. Preparation of Apparatus8.1 Prepare and verify the calibration of the tensile testingmachine as directed in the manufacturers instructions.8.2 Set up and adjust the CRE-type tensile testing machineas follows:8.2.1 Examine the acrylic jaw face of the clamps for wearand replace as ne
33、eded. Position the clamp faces with theircontact line horizontal.8.2.2 Set the distance between clamps, (gage length) to 506 1mm(26 0.05 in.), nip to nip.NOTE 2A convenient technique for checking the gage length is toplace a piece of carbon paper and white paper in the clamps and close theclamps. Th
34、e distance between the marks made on the white paper by thecarbon paper represents the set gage length.8.2.3 Use a force measuring system such that the breakingforce will fall between 30 and 80 percent of its full scalecapacity.8.2.4 Set the crosshead speed to 500 mm/min (20 in./min) or1000 % extens
35、ion per min.8.2.5 Set the extension measuring system as follows:8.2.5.1 When using a chart recorder, set the chart speed to500 mm/min (20 in./min). Not needed with computer inter-faced testing machines.3Apparatus and accessories are commercially available. Clamps may need to bemodified to accept jaw
36、 faces and attachment to some tensile testing machine.D26530728.2.5.2 When using an interfaced computer or microproces-sor, set parameters to obtain selected properties using suppli-ers directions and Specification D76.8.2.6 Set air pressure for pneumatic clamps to 415 kPa (60psi). At this pressure,
37、 the clamping force is approximately 450N (100 lb).9. Conditioning9.1 No preconditioning is required. for currently producedrubber yarns and other elastomeric yarns.9.2 Condition the specimens relaxed on specimen boards inthe standard atmosphere for testing textiles as directed inPractice D 1776 whi
38、ch is 21 6 1C (70 6 2F) and 65 6 2%relative humidity for a minimum of 4 h.10. Procedure10.1 Test the relaxed specimens in the standard atmospherefor testing textiles.NOTE 3The force measuring system should be zeroed prior to runningany specimens and periodically during the course of the test, partic
39、ularlyif drift is observed in the zero value of the force measuring system.10.2 Select the appropriate pretensioning weight based onthe linear density of the yarn that will provide a 30 to 50mN/tex (0.3 to 0.5 mgf/d) tension to the yarn.10.3 Attach the selected tensioning weight (10.2)tothespecimen
40、such that when the specimen is place in the lowerclamp, the tensioning weight will hang freely.10.4 Position a specimen centrally between the top clampfaces and close the clamp. Ensure that the tensioning weight ishanging freely below the botton clamp.10.5 Close the lower clamp and remove the tensio
41、ningweight.10.6 Start the tester and observe the specimen behavior.Record the breaking force when the first filament break isobserved.10.6.1 If the specimen breaks within 3 mm (0.13 in.) ofeither jaw, or the slippage is indicated by a leveling in the forcedirection with abnormally high elongation, d
42、iscard the resultand test another specimen from the same package.10.6.2 If many specimens exhibit what appears to be slip-page, replace the acrylic jaw face and retest.10.7 Remove the specimen and continue testing until a totalof 3 specimens have been tested for each laboratory samplingunit.11. Calc
43、ulation or Interpretation of Results11.1 Force at First Filament BreakCalculate the Force atFirst Filament Break (FFB) as follows:11.1.1 Read the force at FFB value to the nearest 0.1 cN (0.1gf) from the force elongation curve and record the value.NOTE 4In elastomeric yarns, FFB is the first on the
44、force-elongationcurve that is followed by a drop in force of at least 5 % of the force at thatpoint for this specimen or the equivalent in a computer algorithm.11.1.2 Calculate the average force at FFB for each labora-tory sampling unit and for the lot.11.2 Tenacity at First Filament BreakCalculate
45、the Te-nacity at First Filament break as follows:11.2.1 Calculate the tenacity at FFB for each specimen tothe nearest 0.1 cN/tex (0.01 gf/d), using Eq 1.T 5 F/D (1)where:T = tenacity at FFB, cN/tex (gf/d),F = force at FFB, cN (gf), andD = average linear density, tex (denier).11.2.2 Calculate the ave
46、rage breaking tenacity for eachlaboratory sampling unit and for the lot.11.3 Percent Elongation at First Filament BreakCalculate the Percent Elongation at First Filament Break asfollows:11.3.1 Read the elongation at the force at FFB value foreach specimen to the nearest 0.1 % from the force-elongati
47、oncurves.11.3.1.1 If force-extension curves are used, determine theextension corresponding to the force at FFB and calculate thepercent elongation at FFB, using Eq 2.E 5 100 3 L/G (2)where:E = elongation at FFB, %,L = the extension (distance on the extension axis from theorigin to the extension line
48、 corresponding to the forceat FFB), mm (in.), andG = the nominal gage length, mm (in.).11.3.2 Calculate the average percent elongation at FFB foreach laboratory sampling unit and for the lot.11.4 Work to Break at First Filament Break (FFB)Calculate the Work to Break at FFB as follows:11.4.1 Using th
49、e force-extension curve, draw a line from thepoint of first filament break of each specimen perpendicular tothe extension axis. Measure the area bounded by the curve, theperpendicular, and the extension axis. This area may beestimated by counting squares, measured with a planimeter, ordetermined by electronic means.11.4.2 Calculate the work to break at FFB for each speci-men to the nearest. 0.01 mJ ( 0.01 in-lbf.), or the specific workto break at FFB to the nearest 0.01 J/m (0.01 in-lbf./in.) usingEq3orEq4.Wb5 A 3 F 3 E (3)Wsb5 A 3 F 3 E/G (4)where:Wb= work to
