ASTM D8054 D8054M-2016 6316 Standard Test Methods for Tensile Testing of Para-Aramid Flat Yarns《对位芳纶扁丝拉伸试验的标准试验方法》.pdf

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1、Designation: D8054/D8054M 16Standard Test Methods forTensile Testing of Para-Aramid Flat Yarns1This standard is issued under the fixed designation D8054/D8054M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year of last revis

2、ion. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the tensile testing of para-aramid flat yarns.1.1.1 This standard includes procedures used to measurefo

3、rce at specified elongation (FASE) of para-aramid flat yarns.1.1.2 This standard includes procedures used to measurelinear density of para-aramid flat yarns.1.1.3 This standard includes procedures to determine modu-lus of para-aramid flat yarns.1.2 The values stated in either SI units or inch-pound

4、unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.3 This standard does not purport to addr

5、ess 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 Standards:2D76 Specificat

6、ion for Tensile Testing Machines for TextilesD123 Terminology Relating to TextilesD1776/D1776M Practice for Conditioning and Testing Tex-tilesD1907/D1907M Test Method for Linear Density of Yarn(Yarn Number) by the Skein MethodD2258 Practice for Sampling Yarn for TestingD3800 Test Method for Density

7、of High-Modulus FibersD4848 Terminology Related to Force, Deformation andRelated Properties of TextilesD6477 Terminology Relating to Tire Cord, Bead Wire, HoseReinforcing Wire, and FabricsD6587 Test Method for Yarn Number Using AutomaticTesterD7269 Test Methods for Tensile Testing of Aramid YarnsE69

8、1 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE177 Practice for Use of the Terms Precision and Bias inASTM Test Methods3. Terminology3.1 Definitions:3.1.1 flat yarn, ncontinuous filament yarns which, whenremoved from processing package are fully drawn,

9、withouttwist and untextured.3.1.1.1 DiscussionFlat yarn is either extruded in this formor it could be made as a slit cut structure with no additionalprocessing modifying the extension direction of the individualelements (for example, filaments) in the yarn.3.2 The following terms are relevant to thi

10、s standard:modulus, elongation, force at specified elongation (FASE),force-elongation curve.3.3 For definitions of terms related to industrial fibers andmetallic reinforcements, see Terminology D6477.3.4 For definitions of terms related to force and deformationin textiles, refer to Terminology D4848

11、.3.5 For definitions of other terms related to textiles, refer toTerminology D123.4. Summary of Test Methods4.1 Using various test methods and protocols identified inthe procedures, this standard determines the tensile strength,force at specified elonation (FASE), linear density and modulusof para-a

12、ramid flat yarns.5. Significance and Use5.1 For application areas such as optical fiber and cablereinforcements, aramid is usually used in a linear not twisted form. For designing constructions like this, it is essential touse data based on a specimen without twist applied.5.1.1 The modulus and FASE

13、 of twisted yarns demonstratereduced values when compared to p-aramid flat yarns.5.1.2 Use Test Method D7269 for testing of twistedp-aramid yarns.1These test methods are under the jurisdiction of ASTM Committee D13 onTextiles and are the direct responsibility of Subcommittee D13.19 on IndustrialFibe

14、rs and Metallic Reinforcements.Current edition approved July 1, 2016. Published November 2016. DOI:10.1520/D8054_D8054M-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, re

15、fer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.2 The levels of tensile properties obtained when testingaramid yarns are dependent on the age and history of thespecimen a

16、nd on the specific conditions used during the test.Among these conditions are rate of stretching, type of clamps,gauge length of specimen, temperature and humidity of theatmosphere, rate of airflow across the specimen, and tempera-ture and moisture content of the specimen. Testing conditionsaccordin

17、gly are specified precisely to obtain reproducible testresults on a specific sample.5.3 The FASE is used to describe the absolute resistance ofthe p-aramid flat yarn to an imposed deformation.5.4 The initial modulus of the yarn is the value mostcommonly used when a specified force is applied to the

18、yarn.5.5 Shape, size, and internal construction of the end-productcan have appreciable effect on product performance. It is notpossible, therefore, to evaluate the performance of end productin terms of the reinforcing material alone.5.6 If there are differences of practical significance betweenrepor

19、ted test results for two laboratories (or more), compara-tive tests should be performed to determine if there is astatistical bias between them, using competent statistical assis-tance. As a minimum, test samples should be used that are ashomogeneous as possible, that are drawn from the materialfrom

20、 which the disparate test results were obtained, and thatare randomly assigned in equal numbers to each laboratory fortesting. Other materials with established test values may beused for this purpose. The test results from the two laboratoriesshould be compared using a statistical test for unpaired

21、data, ata probability level chosen prior to the testing series. If a bias isfound, either its cause must be found and corrected, or futuretest results must be adjusted in consideration of the knownbias.6. Apparatus6.1 Tensile Testing MachineA single-strand tensile testingmachine of the constant rate

22、 of extension (CRE) type. Thespecifications and methods of calibration and verification ofthese machines shall conform to Specification D76. The testingmachine shall be equipped with an autographic recorder(rectilinear coordinates preferred). It is permissible to usetensile testing machines that hav

23、e a means for calculating anddisplaying the required results without the use of an auto-graphic recorder.6.2 Clamps shall grip the test specimen without spuriousslippage or damage to the test specimen which can result in jawbreaks. The clamps shall maintain constant gripping conditionsduring the tes

24、t by means of pneumatic or hydraulic clamps. Thesurface of the jaws in contact with the specimen shall be of amaterial and configuration that minimizes slippage or specimenfailure, or both, in the clamping zone. (see Appendix X1;Figure X1.1). It is recommended to use pneumatic clampswhich can be ope

25、rated using a foot pedal.6.3 The compliance of the total testing system (tensiletester, load cell, and clamping system) shall be less than 0.2 m106in. per newton.6.4 Gauge LengthThe gauge length is the total lengthbetween the jaw faces (see Fig. X1.1).NOTE 1The selected testing equipment (tester, cl

26、amp, gauge length) isknown to have an influence on the properties measured. A method foreliminating the influences introduced by the selected testing equipment isgiven in Test Methods D7269, Appendix X1.7. Sampling7.1 YarnFor acceptance testing, sample each lot as di-rected in Practice D2258. Take t

27、he number of specimens fortesting specified for the specific property measurement to bemade.7.1.1 Number of Samples and SpecimensThe recom-mended number of specimens is included in the appropriatesections of specific test methods covered in this standard.Where such is not specified, the number of sp

28、ecimens is asagreed upon between buyer and supplier. Take samples atrandom from each of a number of cones, tubes, bobbins, orspools within a lot to be as representative as possible withinpractical limitations. Make only one observation on an indi-vidual package for each physical property determinati

29、on. Takethe number of samples, therefore, that will be sufficient tocover the total number of specimens required for the determi-nation of all physical properties of the yarn.7.1.2 Preparation of SamplesRemove and discard a mini-mum of 25 m 75 yd from the outside of the package beforetaking the samp

30、le or any specimens. Use care in handling thesample. Special care should be used to prevent over handlingand disruption of the filament alignment in the yarn bundle.Discard any sample subjected to any change of twist, kinking,or making any bend with a diameter less than 10 times the yarnthickness (o

31、r diameter).8. Conditioning8.1 Without pre-drying, bring the bobbin with yarn toequilibrium in the atmosphere for testing as directed in PracticeD1776/D1776M for aramid.9. Linear Density9.1 This test method is used to determine the linear densityof flat yarn for use in the calculation of tensile pro

32、perties suchas modulus.9.1.1 Determine linear density as directed in Option 1 ofTest Method D1907/D1907M or use an Automated Tester asdirected in Test Method D6587. For both test methods,condition the yarn as specified in Section 8.9.1.2 If scoured oven-dried linear density is needed, use TestMethod

33、 D1907/D1907M, Option 5.9.2 Report the average linear density of the sample and themethod used.10. Sample Preparation10.1 Sample PreparationTake test specimens directlyfrom the original package. Rewound and skein specimen willlikely result in lower values. Remove the surface layer anddiscard.10.2 Sp

34、ecimen PreparationMount the sample onto aframe using the “Rolling take off” method. Examples ofsuitable frames are shown in Fig. 1. Take off test specimentangentially from the bobbin directly without touching any ofthe measured part of the yarn and without applying any twist.D8054/D8054M 16210.3 Hol

35、ding the yarn firmly at the free end and using the“rolling take off” method, remove about 1 m for the specimen.Do not use yarn within 50 mm of either end of the sample ball.Do not let test specimen sag or loop.10.4 Clamp the specimen in the clamps ensuring that whenclamped the tension does not excee

36、d 20 mN/tex.10.5 During testing, monitor the sample for slippage andsplayed yarn due to excessive catenary.10.6 If slippage is monitored, reject by deletion, cleanclamps and repeat.NOTE 2Test specimen should be taken off freely with no great drag onthe specimen which would increase tension, but stil

37、l with enough tensionapplied by hand to remove and keep removed any catenary present. Thisis particularly important when the specimen is made up of more than onethreadline as it requires more tension by hand to ensure that the catenaryis all removed. As long as the mounted specimen does not give a r

38、eadinggreater than 20 mN/tex, the test will be valid.11. Determination of the Modulus of FASE Values ofAramid Flat YarnThis test method describes two options for the determinationof the modulus and FASE values of aramid flat yarn:Option 1: Measurement of the FASE and modulus of flat yarns (see 11.1)

39、.Option 2: Compute the flat yarn FASE and modulus from twisted yarn test-results (see 11.2).11.1 Option 1: Tensile Testing of Flat Yarns:11.1.1 General:11.1.1.1 The velocity of conditioned air flowing across aspecimen while determining tensile properties can have ameasurable effect on the breaking f

40、orce and elongation at breakbecause of the Gough-Joule effect. The magnitude of this effectdepends on the type of fiber, air velocity, and sample history.Interlaboratory testing of nylon, polyester, and rayon cordsindicates that air velocities of less than 250 mm/s 50 ft/minacross the specimen will

41、not significantly bias the comparisonof cord properties between laboratories.311.1.1.2 Tensile TesterSelect a load cell and the settings ofthe tensile tester such that the estimated breaking force of thespecimen will fall in the range from 10 to 90 % of the full-scaleforce effective at the time of t

42、he specimen break. This selectionof the full scale force may be done manually by the operatorbefore the start of the test or by electronic means or computercontrol during the test by automatically adjusting the amplifi-cation of the load cell amplifier.11.1.1.3 Gauge LengthAdjust the distance betwee

43、n theclamps on the testing machine so that the nominal gauge lengthof the specimen, measured between the jaw faces of theclamps, is 500 6 2 mm 20.00 6 0.01 in. Make all tests onthe conditioned yarns in the atmosphere for aramid yarn.Remove the specimen from the sample and handle it to preventany cha

44、nge in configuration prior to closing the jaws of theclamps on the specimen. Avoid any damage to the yarn.11.1.1.4 Test SpeedUse a crosshead travel rate of 250 6 1mm/min 10.00 6 0.05 in./min. This is 50 % of the nominalgauge length of the specimen.11.1.1.5 Slack StartThread one end of the specimenbe

45、tween the jaws of one of the clamps and close it. Place theother end of the specimen through the jaws of the second clampand keep the specimen just slack (zero tension) and close theclamp, taking care that the thread is positioned in the centerlineof the jaws of the clamp. Operate the testing machin

46、e at the rateas specified in 11.1.1.4 and stretch the specimen until itruptures. If the clamps are of the air-actuated type, adjust theair pressure to prevent specimens slipping in the jaws, but keepthe air pressure below the level that will cause specimens tobreak at the edge of the jaws. The gauge

47、 length is defined as thelength at a pretension level of 20 mN/tex. The slack startprocedure has the effect that the nominal gauge length of thespecimen is not exactly 500 mm 20 in. as specified in11.1.1.3, but always will be slightly increased due to slack inthe specimen after closing the clamps.11

48、.1.2 Tenacity:11.1.2.1 This test method is used to determine the tenacityof yarns after conditioning in the atmosphere for testing aramidat any force level. The calculation of tenacity is required todetermine the modulus (11.1.4).11.1.2.2 TenacityTenacity is defined by dividing the load(force) by th

49、e linear density using Eq 1.TF5FLD(1)3Jones, R. E., and Desson, M. J., “Adiabatic Effects on Tensile Testing,” Journalof the I.R.I., June 1967.FIG. 1 Examples of Frames/Holders for “Rolling Take Off” SamplingD8054/D8054M 163where:F = force, N gf,LD = linear density, tex den, andTF= tenacity, N/tex gf/den.11.1.2.3 ReportingThis parameter is used for determiningthe modulus and is not reported.11.1.3 Elongation of Flat Yarns:11.1.3.1 This test method is used to determine the elonga-tion of yarns after conditioning in the atmosphere for testingar