ASTM D6611-2000 Standard Test Method for Wet and Dry Yarn-on-Yarn Abrasion Resistance《干湿纱耐磨性的标准试验方法》.pdf

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1、Designation: D 6611 00Standard Test Method forWet and Dry Yarn-on-Yarn Abrasion Resistance1This standard is issued under the fixed designation D 6611; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num

2、ber 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 describes the measurement of abrasionresistance properties for manufactured fiber yarns in dry andwet conditions.1.2 Thi

3、s test method applies to manufactured yarns used inrope making.1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are provided forinformation only.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. I

4、t 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:D 123 Terminology Relating to Textiles2D 1776 Practice for Conditioning Textiles

5、 for Testing2D 2904 Practice for Interlaboratory Testing of a Textile TestMethod that Produces Normally Distributed Data23. Terminology3.1 Definitions:3.1.1 abrasion, nthe wearing away of any part of amaterial by rubbing against another surface.3.1.2 apex angle, nthe angle formed between the incom-i

6、ng and outgoing yarn at the top (and bottom) of the inter-wrapped yarn area in the static condition (see Annex A1).3.1.2.1 DiscussionIn yarn abrasion testing, the state of ayarn, which has been soaked for a prescribed period of time inwater before testing and then immersed in water during theabrasio

7、n test.3.1.3 applied tension, nin yarn abrasion testing, the statictension exerted on the weighted end of the yarn by the appliedweight.3.1.3.1 DiscussionTension in the yarn varies along itslength during each cycle because of friction and dynamiceffects. The tension at any point in the interwrapped

8、yarnregion and at any time may differ substantially from the appliedtension but is a function of that applied tension.3.1.4 cycles to failure, CTF, nin yarn abrasion testing, thenumber of cycles applied to the yarn before it fails due toabrasion.3.1.4.1 DiscussionFailure is considered to occur when

9、theyarn is completely separated.3.1.5 dry, adjthe state of a yarn which has not beenexposed to excessive moisture.3.1.6 rope, na compact and flexible, generally torsionallybalanced continuous structure, greater than 4-mm (332-in.)diameter, capable of applying or transmitting tension betweentwo point

10、s.3.1.7 wet, adjthe state of a yarn which has been exposedto excessive moisture.3.2 For definitions of other textile terms used in this testmethod, refer to Terminology D 123.4. Summary of Test Method4.1 A length of yarn is interwrapped in contact with itselfbetween three pulleys that are positioned

11、 in a defined geometryto produce a specific intersection angle. A weight is attached toone end of the yarn to apply a prescribed tension. The other endis drawn back and forth through a defined stroke at a definedspeed until the yarn fails due to abrasion upon itself within theinterwrapped region. Th

12、e yarn abrasion test can be conductedin either the dry state or the wet state.5. Significance and Use5.1 This test method is intended for testing dry and wetabrasion resistance of manufactured fiber yarns. This testmethod is especially useful for ropes intended for use in themarine environment. The

13、test method has been used with yarnshaving linear densities ranging from 70 to 300 tex, but may beused with yarns outside these ranges.5.2 Limited interlaboratory correlation testing has beenconducted to date. Single-laboratory testing, in accordancewith ASTM practices, has now been conducted. Addit

14、ionalinterlaboratory testing, in accordance with ASTM practices,will be conducted after approval of a definitive test method.Test results should be used with caution pending completion ofinterlaboratory testing.1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the d

15、irect responsibility of Subcommittee D13.16 on Rope and Cordage.Current edition approved Nov. 10, 2000. Published February 2001.2Annual Book of ASTM Standards, Vol 07.01.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.3 This test m

16、ethod is not recommended for acceptancetesting of commercial shipments in the absence of reliableinformation on between-laboratory precision.5.4 If there are differences of practical significance betweenreported test results for two or more laboratories, comparativetests should be performed to deter

17、mine if there is a statisticalbias between them, using competent statistical assistance. As aminimum the test samples used should be as homogeneous aspossible, be drawn from the material from which the disparatetest results were obtained, and be randomly assigned in equalnumbers to each laboratory f

18、or testing. Other materials withestablished test values may be used for this purpose. The testresults from the two or more laboratories should be comparedusing a statistical test for unpaired data, at a probability levelchosen prior to testing. If a bias is found, either its cause mustbe found and c

19、orrected, or future test results must be adjustedin consideration of the known bias.5.5 This test method is conducted at one or several appliedtensions that may depend upon the yarn material and size. Thenumber and magnitudes of applied tensions and the number ofeight specimen sets generally are agr

20、eed upon in a materialspecification or contract order. Guidance on determining theappropriate number and magnitudes of applied tensions isgiven in Annex A2.6. Apparatus6.1 The Yarn-on-Yarn Abrasion Test Apparatus is shownschematically in Fig. 1 and consists of the following:6.2 Yarn Guide PulleysThr

21、ee pulleys are arranged on avertical frame with the centerline spacing indicated. All of thepulleys have the same diameter. The pulleys have low-frictionbearings.6.3 Arrangement of Guide PulleysThe upper pulley cen-terlines are separated by 140 6 2 mm. The lower pulleycenterline is 254 6 2 mm below

22、a line connecting the upperpulley centerlines. This arrangement produces an apex angle of10.8 radians (34). Other spacings may be used which producethe same apex angle, when analyzed by the procedure given inAnnex A1.6.4 Wet Testing ArrangementFor wet testing, the lowerpulley is placed on a bar exte

23、nding down from a support frame,such that a beaker of water can be placed around it to immersethe interwrapped portion of the yarn. The lower pulley has abushing-type bearing suitable for prolonged service immersedin water.6.5 Drive MotorAn eccentric crank driven by a gearmotor is arranged in alignm

24、ent with one of the upper pulleys.The crank is offset by 25 6 2 mm from the drive motor shaftto create a yarn stroke of 50 6 4 mm. The gear motor drivesthe crank at between 60 and 70 revolutions/min. Other drivearrangements, which accomplish the specified stroke and drivespeed may alternatively be u

25、sed.6.6 Multi-Station TesterSeveral test stations may be ar-ranged on a support frame and driven by the same motor.6.7 Cycle Counter ArrangementA means of counting thenumber of yarn abrasion strokes to failure is provided. Thismay be a counter directly connected to the drive motor or acounter, which

26、 is indexed by each revolution of the crank ordirectly by each stroke of the yarn. This counter is arranged tostop counting when the yarn breaks and to retain a count of thenumber of strokes until it is reset. For multistation testers, sucha counter is provided for each yarn station.6.8 Yarn Twist C

27、ontrolIf the yarn has pronounced twist,or if the yarn tends to twist or untwist during testing, a meansshould be provided to control yarn twist, such as an extensionarm on the applied weight which follows a guide.7. Sampling and Test Specimens7.1 Primary Sampling UnitConsider spools or beams tobe th

28、e primary sampling unit.7.2 Laboratory Sampling UnitAs a laboratory samplingunit take from the primary sampling unit a total length of yarnFIG. 1 General Arrangement of the Yarn-on-Yarn Abrasion Test ApparatusD6611002that will provide eight test specimens for each of the appliedtensions as determine

29、d in Annex A2.7.2.1 Determine the specimen length sufficient to accommo-date the distance needed to secure the yarn to the test apparatusmotor crank, through the pulley arrangement and to the appliedweight, allowing for movement of the crank and weight duringthe test. Add to this a suitable allowanc

30、e for the length neededto attach the yarn to the crank and to the weight.7.2.2 Determine the number and magnitudes of appliedtensions as directed in Annex A2.7.2.3 Remove sufficient yarn from the primary sample priorto taking the laboratory sample to assure the test yarn has notbeen exposed to light

31、, handling abuse, or other outside influ-ences.7.2.4 Handle the test specimens carefully to avoid alteringits natural state, including twist level.7.2.5 If testing is not conducted immediately, wind a suffi-cient length of yarn on a small spool or bobbin and place in amoisture proof container or pac

32、kage, and store in a dark areanot exposed to direct sunlight or other strong light sources.7.3 Test SpecimensFrom each laboratory sampling unit,cut individual specimens to a length as determined in 7.2.7.3.1 Securely tie knots at each end of the specimen toprevent untwisting. For convenience, a smal

33、l hook, suitable forengaging the drive attachment and the applied tension, can beattached to each end of the specimen by means of a knot.8. Conditioning8.1 Preconditioning for Dry TestingIn preparation for drytesting, precondition each specimen in an atmosphere with arelative humidity between 55 and

34、 75 % and a temperaturebetween 16 and 25C (61 and 77F) for at least 1 h and forsufficient time to bring to equilibrium, as specified in PracticeD 1776.8.2 Preconditioning for Wet TestingIn preparation for wettesting, precondition each specimen in a fresh tap water bath ata temperature between 16 and

35、 25C (61 and 77F) for 1 h 6 6min. This may be done either by soaking the yarn in a separatebath prior to mounting it on the test machine or by soaking theyarn mounted on the test machine prior to beginning testing. Ifa separate bath is used, care must be taken to avoid damagingthe yarn while mountin

36、g the yarn for testing.NOTE 1The yarn test specification may give a different soak time fortesting, with agreement of the interested parties. The yarn should not besoaked for more than the specified time, as the abrasion resistanceproperties of some yarns is sensitive to the length of soak.9. Proced

37、ure9.1 Handle the test specimen carefully to avoid altering thenatural state of the yarn, including the level of twist.9.2 Mounting Specimen on Test MachineAttach one endof the specimen to the drive motor crank or to an extensiontether attached to the crank. Place the specimen over the firstupper gu

38、ide pulley, around the opposite side of the lower guidepulley, under that lower pulley, and across itself and over thesecond upper guide pulley. This preliminary crossed-yarnposition is shown at the left in Fig. 2.NOTE 2This position in which the yarn touches itself at the cross-overpoint but does n

39、ot yet wrap around itself is referred to as the zero wrapposition.9.3 Mounting of WeightAttach weights of sufficient massto produce the prescribed applied tension to the other end of thespecimen.9.4 Application of Yarn InterwrapsPlace the fingers of ahand or a suitable support object within the bigh

40、t formed by theyarn passing under the lower pulley and temporarily removethe yarn from that pulley. Twist the hand or support object toapply three wraps to the yarn. Replace the yarn around thelower pulley. The resulting yarn interwrap region shouldappear as shown at the right in Fig. 2.NOTE 3The ya

41、rn should have three complete warps producing aninterwrap angle of 1080 (3 3 360). The yarn should pass out of theinterwrapped region continuing in the same direction as it entered into theregion.NOTE 4The yarn test specification may give a different number ofinterwraps for testing a particular yarn

42、 category, with agreement of theinterested parties.FIG. 2 Correct Method of Counting Number of Yarn Interwraps for Yarn-on-Yarn Abrasion Test MethodD66110039.4.1 Relation of Direction of Twist to Direction ofInterwrapIf the yarn has a pronounced twist, the interwrapshould be applied in the same dire

43、ction as the twist, unless theyarn test specification gives different instructions.9.5 Dry TestingFor dry testing, conduct the test in anatmosphere with a relative humidity between 55 and 75 % anda temperature between 16 and 25C (61 and 77F).9.6 Wet TestingFor wet testing, place a beaker of fresh ta

44、pwater at a temperature of between 16 and 25C (61 and 77F)around the yarn such that the interwrapped region of the yarnis completely immersed.9.7 Start of TestReset the counter(s) to zero. Start thedrive motor.9.8 Conduct of TestCarry out the test until the yarn(s) failsdue to interyarn abrasion at

45、the applied tension.9.9 Conclusion of TestAfter the yarn(s) fails, shut off thedrive motor. Record the number(s) of Cycles to Failure (CTF)for each specimen.9.10 Test eight yarn specimens as directed in this section foreach designated applied tension and for each set of testconditions.10. Calculatio

46、n10.1 Mean Cycles to FailureCalculate mean cycles tofailure by the average-of-logarithms method as follows:M 5 Ln215FLn CTF11 Ln CTF21 .1 Ln CTFNNG(1)where:M = Mean cycles to failure,CTFi= Cycles to failure for i th specimen,N = Number of specimens,Ln = Natural (Naperian) logarithm,Ln1= Inverse natu

47、ral logarithm,= eL,= 2.71828Logarithm,10.2 Log Standard Deviation of CTFCalculate the logstandard deviation, Ln s,ofCTF by the following equation.Lns5Ln CTF12 Ln M !21 Ln CTF 2 Ln M!21 . Ln CTFN2 Ln M!2N 2 1(2)where:Ln s = Log standard deviation of cycles to failure.10.3 Ln 2s CTF BandCalculate the

48、log mean CTF 6 2standard deviation band by the following equations.Upper M 6 2s Bound 5 Ln M 1 2Lns (3)Lower M 6 2s Bound 5 Ln M 2 2Lns (4)10.4 Data AdjustmentIf the Ln CTF for any of the teststations deviates by more than 2 Ln s from the Ln M or isotherwise judged to be an outlier, then test an add

49、itional fouryarns and reanalyze the results. Judgement may be used inaccepting or rejecting data CTF data, which deviates more than2 s from the M after conducting the additional four tests.10.5 Present the cycles-to-failure results against appliedtension on a semi-log plot, with cycles-to-failure on the logaxis. Guidance on presenting the results is given in Annex A2.11. Report11.1 Report that the yarn-on-yarn abrasion resistance wasdetermined as directed in Test Method D 6611.11.2 Report the following information for the laboratory