ASTM D4724-2011 Standard Test Method for Entanglements in Untwisted Filament Yarns by Needle Insertion《针入法测定反捻长丝纱的缠结度的标准试验方法》.pdf

《ASTM D4724-2011 Standard Test Method for Entanglements in Untwisted Filament Yarns by Needle Insertion《针入法测定反捻长丝纱的缠结度的标准试验方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM D4724-2011 Standard Test Method for Entanglements in Untwisted Filament Yarns by Needle Insertion《针入法测定反捻长丝纱的缠结度的标准试验方法》.pdf（6页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: D4724 11Standard Test Method forEntanglements in Untwisted Filament Yarns by NeedleInsertion1This standard is issued under the fixed designation D4724; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r

2、evision. 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 two options for the measure-ment of entanglements in untwisted filament yarns usingneedle insertion

3、options for instrument (A) and manual (B)techniques.1.2 The values stated in either SI or inch-pound units (inparentheses) are to be regarded separately as standard. Thevalues stated in each system may not be exact equivalents;therefore, each system must be used independently of the otherwithout com

4、bining values in any way.1.3 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-bility of regulatory limitations pri

5、or to use.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1776 Practice for Conditioning and Testing TextilesD2258 Practice for Sampling Yarn for TestingD4849 Terminology Related to Yarns and Fibers3. Terminology3.1 Definitions:3.1.1 For definitions of terms relating

6、 to yarns and fibers,refer to Terminology D4849.3.1.1.1 The following terms are relevant to this standard:entanglement, filament yarn.3.2 For definitions of other textile terms used in this testmethod, refer to Terminology D123.4. Summary of Test Method4.1 A summary of each option is in the section

7、for thatoption.5. Significance and Use5.1 Option 1 of this test method for the determination of thedegree of untwisted filament yarn entanglement, as measuredinstrumentally, is used for acceptance testing of commercialshipments; however, caution is advised because information onbetween-laboratory pr

8、ecision is lacking. Comparative tests, asdirected in 5.1.1, may be advisable.5.1.1 If there are differences of practical significance be-tween the reported test results for two or more laboratories,comparative tests should be performed by those laboratories todetermine if there is a statistical bias

9、 between them, usingcompetent statistical assistance. As a minimum, samples usedfor each comparative test should be as homogeneous aspossible, drawn from the same lot of material as the samplesthat results in disparate results during initial testing, andrandomly assigned in equal numbers to each lab

10、oratory. Otherfabrics with established test values may be used for thispurpose. The test results from the laboratories involved shouldbe compared appropriate statistical analysis and a probabilitylevel chosen by the two parties before testing begins, at aprobability level chosen prior to the testing

11、 series. If a bias isfound, either its cause must be found and corrected or futuretest results must be adjusted in consideration of the knownbias.5.2 Option 2 for this test method is intended for use whenthe supply of yarn is limited.5.3 The instrumental option of this test method is based onthe tot

12、al randomization of the entanglements in the yarn;therefore, the distance measured between the point of insertionof a pin in the middle of the yarn and the point at which anentanglement is encountered, by movement of the yarn or thepin until it is stopped at a preset level of force, is representativ

13、eof the distance between two entanglements at some location inthe yarn.5.4 Entanglements are used frequently instead of twist toensure the integrity of filament yarns. Such entanglementsgenerally give somewhat less protection during weaving orknitting than twist, but with proper care, will perform q

14、uitesatisfactorily.6. Sampling and Test Specimens6.1 Primary Sampling UnitConsider shipping containersof yarn to be the primary sampling unit.1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.Curre

15、nt edition approved Jan. 1, 2011. Published January 2011. Originallyapproved in 1999. Last previous edition approved in 2010 as D472410. DOI:10.1520/D4724-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of A

16、STMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.NOTE 1A realistic specification or other agreement between thepurchaser and the supplier

17、 requires taking into account the variabilitybetween shipping containers, packages within a shipping container, andsuccessive lengths from a package to provide a plan that, at the specifiedlevel for the property of interest, has a meaningful producers risk,consumers risk, acceptable quality level, a

18、nd limiting quality level.6.2 Laboratory Sample UnitFor each primary samplingunit, take laboratory sampling units as directed in PracticeD2258. Do not rewind or transfer material from packages takenfrom shipping containers to another packages.6.3 Test SpecimenFor acceptance testing, use laboratoryun

19、its as a source of specimens. Make 20 observations on eachlaboratory sampling unit.7. Conditioning7.1 Preparation of Test PackageBefore preconditioningor conditioning the test package, remove at least 100 m or 110yds of yarn from the test package to avoid testing nonrepre-sentative yarn.7.2 Precondi

20、tioningNormally, preconditioning is not nec-essary unless the test packages are received with higher thanthe normal moisture level. If preconditioning is necessary, treatthe packages as directed in Practice D1776.7.3 ConditioningCondition the test packages as directedin Practice D1776.OPTION 1INSTRU

21、MENTAL MEASUREMENT OFTHE DEGREE OF ENTANGLEMENT OFUNTWISTED FILAMENT YARN8. Summary of Option8.1 A yarn is passed at constant speed and constant preten-sion through the thread path of the instrument. After a requiredyarn length has run through, the yarn is pierced by a needle,and advanced automatica

22、lly until a preset needle tension isattained. Then, the needle is withdrawn, and the yarn lengthfrom insertion to this critical point is measured automatically.This cycle of yarn advance, piercing by the needle, and lengthmeasurement is repeated for a predetermined number of times.The individual mea

23、sured pulled yarn lengths and the total ofthese yarn lengths are automatically recorded.9. Apparatus9.1 Automatic Needle Pull Entanglement Testers, rapidautomatic pin insertion detector (RAPID)3and Rothschildautomatic yarn entanglement testers NPT.39.2 Standard Laboratory Weights, ranging from 1 to

24、100 g.9.3 Stopwatch, with15-s divisions.9.4 Speed Indicator, tachometer, 0 to 1000 rpm range.9.5 Magnetic Whorl Tensioning Device, optional.10. Procedure10.1 Test the yarn in the standard atmosphere for testingtextiles, as directed in Practice D1776.10.2 Calibrate the entanglement tester and tensiom

25、eter asprescribed by the instrument manufacturer.10.3 Mount the test package on a suitable holder.10.4 Yarn PretensionCalculate the pretension by usingone of the equations below:YP g!5D 0.5! 0.75 (1)YP cN!5T 0.5! * 0.70 (2)10.5 Trip Level TensionCalculate the trip level by usingone of the equations

26、below:TLTg!5D 0.35! * 3.5 (3)TLT cN!5T 0.35! * 3.31 (4)where:YP = Yarn pretension,TLT = trip level tension, c/tex (gf/d),T = linear density, tex,D = linear density, denier, andF = filament count.10.6 Set the RAPID instrument as follows:10.6.1 Measuring Speed1020 m/min.10.6.2 Observations/Package20.1

27、0.6.3 No-Show LengthRefer to the manufacturersmanual.10.6.4 Present the loose end of the yarn to the inlet gun (seeFig. 1). The instrument will string up, automatically strip some3Apparatus is commercially available.FIG. 1 Yarn String-Up Diagram for Rapid Automatic Pin Insertion Detector (RAPID)D472

28、4 112yarn, start the measurement cycle, and discard the tested yarnto waste.10.6.4.1 If there is no entanglement in the “No-Show”length, the instrument will do the following:(1) If the “Pin Miss Ignored Limit” has not been exceeded,rotate the pinwheel, reinsert the needle in the yarn, andcontinue te

29、sting. The test is aborted and a “No-Show” re-corded.(2) If the “Pin Miss Ignored Limit” has been exceeded, entera “Freeze” state and request confirmation of pin insertion. Theoperator will restart the test if the pin did not pierce the yarn(increasing the “Pin Miss Count” by 1, or the operator will

30、acknowledge pin piercing by pressing the “Confirm” buttondesignating this a true no entanglement section, which adds thelength to the results.10.7 Set the Rothschild instrument as follows:10.7.1 Measuring Speed1020 m/min.10.7.2 Forwarding Time5 s.10.7.3 Observations/Package (decade counter)20.10.7.4

31、 No-Show Length500 mm or as specified by user.This is an optional setting and the length should be establishedbased on the product or end-use of the product.10.7.5 Feed the yarn from the package through the preten-sion device. The yarn then is threaded across the needlepiercing section and through t

32、he measuring head. Then, yarngoes to a yarn speed roll and is taken up to the “Take-up” wheel(see Fig. 2) or can bypass the “Take-up” wheel and go into theaspirator after the yarn speed roll, to prevent buildup on thetake-up wheel. The software initializes a specified length forstripping and starts

33、the test.10.7.5.1 If there is no entanglement in the “No-Show”length, the instrument will do the following:(1) Stop the yarn and withdraw the needle.(2) Record a “No-Show” in the software (and on theprintout).(3) Reinsert the needle into the yarn and wind until a node(entanglement) is detected.(4) T

34、he first entanglement after a “No-Show” is ignored.(5) The needle is withdrawn, and the yarn is advanced thespecified length of the entanglement and is reinserted into theyarn and the test continues. This is to ensure that an accuratereference between entanglement is established.10.7.6 Remove the ya

35、rn from the take-up wheel frequentlyto avoid excessive waste build-up. Use care if a sharp blade isused. To avoid any build-up, the yarn may be placed in theaspirator after the last wrap on the “Yarn speed roll.”11. Calculations11.1 In the following way the tester computer will calculatethe average

36、number of entanglements per metre using:The total count of entanglements measured must equal 100.The Distances between Entanglements (DE) must be re-corded individually.The average Distance between Entanglements (DEavg)iscalculated using Eq 5:DEavg5(i 51100DEi100(5)The standard deviation in this ave

37、rage value is calculatedusing Eq 6:DEstdev5(i 5 1100DEi DEavg!299(6)The average number of entanglements per meter (EPM) iscalculated using Eq 7:EPM 51DEavg(7)FIG. 2 Yarn String-Up Diagram for Rothschild Needle Insertion Entanglement ApparatusD4724 113The standard deviation in the average number of e

38、ntangle-ments is calculated using Eq 8:EPMstdev5DEstdevDEavg!2(8)The half length of the 95% confidence interval (CI95) iscalculated using Eq 9:C195 5 t2=n 0.2 s (9)where:DE = Distance between Entaglements, andEPM = average number of entanglements/m.11.2 Calculate the average entanglements/m for the

39、lot.12. Report12.1 State that the packages were tested as directed inOption 1 of Test Method D4724. Describe the material orproduct sampled and the method of sampling used.12.2 The report shall include the following information:12.2.1 Nominal linear density.12.2.2 Pretension level used.12.2.3 Trip l

40、evel tension used.12.2.4 Measuring speed.12.2.5 Transport time.12.2.6 The distances between entanglements for each speci-men.12.2.7 No show distance and any no shows encountered foreach specimen.12.2.8 The EMC for each package and the average for thelot.12.2.9 The instrument used.12.2.10 Any modific

41、ations to the test.OPTION 2MANUAL MEASUREMENT OF DEGREEOF FILAMENT ENTANGLEMENT13. Summary of Option13.1 A stationary needle is inserted in the yarn. A hook isplaced in the same opening made by the needle. The hook isattached to one end of a flexible cord and a tensioning weightto the other end of t

42、he cord. The weight is allowed to dropvertically and gradually until the hook is stopped by anentanglement in the yarn. The needle is then moved in theopposite direction along the length of the specimen until itencounters another entanglement. The distance between thehook and needle is recorded as t

43、he distance between entangle-ments. See Fig. 3.14. Apparatus14.1 Weight, 2.5 6 0.01 g.14.2 J-Shaped Hook, approximately 25 mm long.14.3 Cord, or thread, flexible, No. 50 cotton.14.4 Illuminated Magnifier3, with a lens capable of 3x to10x magnifications.14.5 Horizontal Test Board, equipped with a sli

44、ding metricscale, movable black plastic perforated card 25 by 75 by 1.6mm (1.0 by 3.0 by116 in.), and yarn clamp.FIG. 3 Entanglement Tester (Manual Method)D4724 11414.6 Air Jet Suction.14.7 Pick Needle.14.8 Tensiometer.15. Procedure15.1 Test the yarn in the standard atmosphere for testingtextiles, a

45、s directed in Practice D1776.15.2 Place the yarn package on a suitable stand under thetable supporting the test apparatus.15.3 Feed the yarn through the test apparatus.15.4 Open the main air valve completely for the air jetsuction device and strip off the outside layer of yarn.15.5 Attach the J-hook

46、 to one end of the cord, or thread, andfeed the other end through the guide at the left side of the testboard. Cut the cord to a length that allows it to hang at least750 mm above the floor. Attach the weight to the free end ofthe cord.15.6 Adjust tension on the yarn to 0.1 cN (0.01 gf/d) usinga val

47、ve at the air jet. Do this while the air jet is pulling againstthe yarn that is held stationary by a clamp on the right side ofthe test board.15.7 Place the magnifier over the control test area.15.8 Slide the plastic card under the yarn.15.9 Push the pick needle through the center of the yarn andmak

48、e an opening wide enough for the J-hook. Extend the pickneedle into a hole in the card.15.10 Insert the hook into the opening next to the pickneedle and let the hook move gently to the left until it catcheson an entanglement (hard node) and its mass holds it in theyarn.15.11 With the pick needle sti

49、ll in the yarn, pull it from thecard and gently move it to the right until resistance due toanother entanglement (hard node) is encountered.15.12 Move the card out of the way, measure the distancebetween the hook, and pick needle (two entanglements) to thenearest mm.15.13 Remove the hook and pick needle, open the clampand allow yarn to pass through the air jet for approximately 10s.15.14 Repeat 15.5-15.13 until 20 observations have beenmade on each test package.16. Calculation16.1 Calculate the average distance between entanglement