ASTM D4120-2007(2012) Standard Test Method for Fiber Cohesion in Roving Sliver and Top in Dynamic Tests《动态试验下粗纱、纱条和毛条的纤维粘附力的标准试验方法》.pdf

《ASTM D4120-2007(2012) Standard Test Method for Fiber Cohesion in Roving Sliver and Top in Dynamic Tests《动态试验下粗纱、纱条和毛条的纤维粘附力的标准试验方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM D4120-2007(2012) Standard Test Method for Fiber Cohesion in Roving Sliver and Top in Dynamic Tests《动态试验下粗纱、纱条和毛条的纤维粘附力的标准试验方法》.pdf（3页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: D4120 07 (Reapproved 2012)Standard Test Method forFiber Cohesion in Roving, Sliver, and Top in Dynamic Tests1This standard is issued under the fixed designation D4120; 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method describes the measurement of fibercohesion as the dynamic cohesive force required to mainta

3、indrafting in rovings, slivers or tops when they are subjected tostress induced by passing between pairs of drafting rolls ofdifferent surface speeds. The cohesive force is converted tocohesive tenacity based on the linear density of the material.NOTE 1For static tests refer to Test Method D2612.1.2

4、 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 prior to use.2. Referenced Docu

5、ments2.1 ASTM Standards:2D123 Terminology Relating to TextilesD519 Test Method for Length of Fiber in Wool TopD1440 Test Method for Length and Length Distribution ofCotton Fibers (Array Method)D1447 Test Method for Length and Length Uniformity ofCotton Fibers by Photoelectric MeasurementD1575 Test M

6、ethod for Fiber Length of Wool in ScouredWool and in Card SliverD1776 Practice for Conditioning and Testing TextilesD2258 Practice for Sampling Yarn for TestingD2612 Test Method for Fiber Cohesion in Sliver and Top(Static Tests)D3333 Practice for Sampling Manufactured Staple Fibers,Sliver, or Tow fo

7、r TestingD4849 Terminology Related to Yarns and Fibers3. Terminology3.1 For all terminology relating to D13.58, Yarns andFibers, refer to Terminology D4849.3.1.1 The following terms are relevant to this standard:cohesive force, fiber cohesion, roving, sliver, tenacity, top.3.2 For all other terms ar

8、e related to textiles, refer toTerminology D123.4. Summary of Test Method4.1 This test method provides an indication of the ability offibers to hold together by measuring the force required to slidefibers in a direction parallel to their length. Specific lengths ofroving, sliver, or top are drafted

9、between two pairs of rollers,with each pair moving at a different peripheral speed. The draftforces are recorded. Test specimens are then weighed and thelinear density calculated. Drafting tenacity, calculated as thedraft resisting force per unit linear density, is considered to bea measure of the d

10、ynamic fiber cohesion.5. Significance and Use5.1 This test method for the determination of cohesion insliver, roving, or top in dynamic tests may be used for theacceptance testing of commercial shipments but caution isadvised since information on between-laboratory precision islacking. Comparative t

11、ests as directed in 5.1.1 may be advis-able.5.1.1 If there are differences or practical significance be-tween reported test results for two laboratories (or more),comparative test should be performed to determine if there is astatistical bias between them, using competent statistical assis-tance. As

12、 a minimum, test samples that are as homogeneous aspossible, drawn from the material from which the disparate testresults were obtained, and randomly assigned in equal numbersto each laboratory for testing. The test results from the twolaboratories should be compare using a statistical test forunpai

13、red data, at a probability level chosen prior to the testingseries. If a 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 cohesive forces overcome in continuous drafting ofslivers, rovings,

14、or tops are affected by surface lubricants andsuch fiber properties as linear density, surface configuration,fiber length, fiber crimp, and fiber-frictional characteristics.5.2.1 The concept of drafting is one of the most importantprinciples in the production of yarn from fibrous raw stock.5.2.2 The

15、 values of force to maintain drafting determined bythis method are induced by mechanical means similar to thoseused in textile processing.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.Current e

16、dition approved July 1, 2012. Published August 2012. Originallyapproved in 1982. Last previous edition approved in 2007 as D4120 07. DOI:10.1520/D4120-07R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of AS

17、TMStandards 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.5.2.3 The attenuation of textile fiber strands while in motionclosely approximates actual

18、 textile processing conditions, andthe relative values of force may be used to predict processingbehaviors.5.3 Fiber cohesion is affected by the alignment of fiber inthe textile strand and strand compaction in addition to thefactors listed in 5.2. Although fibers are more nearly aligned indraw slive

19、r than in card sliver, the draw sliver is more compact.Thus, for a given production run, the drafting forces are higherfor draw sliver than for card sliver.5.4 In addition to the aforementioned effects on draftingforces, the direction of specimen movement through draftingrollers may give different d

20、rafting force. Fibers in slivers mayhave hooks of varying severity at one or both ends. Passagethrough drafting rollers results in higher drafting forces whenthe predominance of fiber hooks are oriented in the trailingmode of the strand.6. Apparatus and Materials6.1 Cohesion Meter,3with rollers and

21、controls for varyingdrafts and rates of drafting.6.2 Tensiometer,3with accessory equipment includingmeasuring heads, integrator, (or computer or programmablecalculator), and recorder for sensing, accumulating, and re-cording drafting forces.6.3 Calibration Mass, 1 kg, NBS Class T.6.4 Tachometer, cap

22、able of measuring roll surface speed towithin 0.1 m/min.6.5 Balance, with sufficient capacity and sensitivity toweigh specimens to within 0.1 % of specimen mass.7. Sampling7.1 Lot SamplingAs a lot sample for acceptance testing,take at random the number of shipping containers directed inthe applicabl

23、e material specification or other agreement be-tween the purchaser and supplier, such as an agreement to usePractice D3333 or Practice D2258. Consider shipping contain-ers to be the primary sampling units.NOTE 2An adequate specification or other agreement between thepurchaser or supplier requires ta

24、king into account the variability betweenshipping units, between packages, ends or other laboratory sampling unitwithin a shipping unit if applicable, and within specimens from a singlepackage, end or other laboratory sampling unit to provide a sampling planwith a meaningful producers risk, consumer

25、s risk, acceptable qualitylevel, and limiting quantity level.7.2 Laboratory SampleAs a laboratory sample for ac-ceptance testing, take at random from each shipping containerin the lot sample the number of laboratory sampling units asdirected in an applicable material specification or other agree-men

26、t between purchaser and supplier such as an agreement touse Practice D3333 or Practice D2258. Preferably, the samenumber of laboratory sampling units are taken from eachshipping container in the lot sample. If differing numbers oflaboratory sampling units are to be taken from shippingcontainers in t

27、he lot sample, determine at random whichshipping containers are to have each number of laboratory unitsdrawn.7.2.1 Each laboratory sampling unit should be at least 100 mlong.7.3 Test SpecimensFrom each laboratory sampling unit,take one specimen. If the standard deviation determined for thelaboratory

28、 sample is more than a value agreed upon betweenthe purchaser and supplier, continue testing one specimen fromeach unit in the laboratory sample until the standard deviationfor all specimens tested is not more than the agreed to value or,by agreement, stop testing after a specified number.8. Prepara

29、tion and Calibration of Equipment8.1 Install the tensiometer measuring head in the cohesionmeter. Selection of the proper capacity head may be deter-mined by trial tests on the materials to be tested, or previousexperience with a given product.8.2 Calibrate the apparatus as directed in the manufactu

30、rersinstructions.8.3 Verify the input and output speeds using a tachometer.8.4 Unless otherwise directed, set the draft ratio for 1.25, thematerial input speed to 5 m/min, the timer to give an input testlength of 10 m and the integration period for 1 min.8.5 Set the gage spacing of the drafting roll

31、ers for 1.43 themean staple length of the fiber in the test specimen.8.5.1 Use the staple length determined using Test MethodD1440 or Test Method D1447 for cotton, or the staple lengthassigned by the fiber producer to manufactured fibers devel-oped for processing on the cotton system. For wool orman

32、ufactured fibers with great variability in their lengthdistribution and developed for processing on a long staple fibersystem, use the fiber length which includes 95 % of the fibersin the specimen as determined from a fiber sorting, using TestMethods D519 or D1575.9. Conditioning9.1 Precondition and

33、 condition the laboratory samples asdirected in Practice D1776.10. Procedure10.1 Test the adequately conditioned specimens in thestandard atmosphere for testing textiles that is 21 6 1C (70 62F) and 65 6 2 % relative humidity.10.2 With instrument at slow speed (2 m/min), start test bypressing CONTIN

34、UOUS RUN button on the cohesion meterand threading the specimen strand through input rollers, aroundmeasuring head guide roller and through output (delivery)rollers.10.3 Operate 10 to 15 s, or long enough for slack to beremoved from strand and tension to build up on measuringhead. Turn the tensiomet

35、er range selector switch to the positionwhich most nearly keeps the galvanometer needle at mid-scale.Change speed to 5 m/min, press timer to start the automatic 10m test length and immediately cut the specimen strand evenwith the front edge of the discharge chute.3The sole source of supply of the ap

36、paratus known to the committee at this timeis Rothschild, Zurich, Switzerland, and it may be obtained from Lawson-HemphillSales, Inc., P.O. Drawer 6388, Spartanburg, SC 29304. If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments w

37、ill receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.D4120 07 (2012)210.4 If an on-line computer or programmable calculator isused, run for 1 min taking a minimum of 50 readings, or,10.4.1 If an integrator is used, press the SINGLE pushbutton and

38、 record the integrator value when the cohesion meterautomatically stops at the 10-m length.10.5 Cut the delivered specimen strand even with the frontedge of the discharge chute and weigh to the nearest 0.1 g.10.6 Continue as directed in 10.2-10.5 until the necessarynumber of specimens have been test

39、ed.11. Calculation11.1 Calculate the dynamic cohesion as the cohesive tenac-ity of each specimen to the nearest 0.1 mgf/tex, using Eq 1.Cohesive tenacity, mgf/tex 5 F3 L/M (1)where:F = drafting force, gf,L = specimen length, m, andM = specimen mass, g.NOTE 3Drafting tenacity as micronewtons per tex

40、(N/tex) is numeri-cally equal to drafting tenacity as mgf/tex times 9.81.11.2 Calculate the average drafting tenacity for each labo-ratory sample testing direction and for the lot sample to thenearest 0.1 mgf/tex.11.3 Calculate the standard deviation, the coefficient ofvariation, or both, for the la

41、boratory sample and the lot sample,if requested.12. Report12.1 State that the specimens were tested as directed inASTM Test Method D4120. Describe the materials tested byfiber type, staple length, nominal linear density of the fibers inthe material (if known), crimp of the fibers (if known),processi

42、ng step from which the material was obtained, andmethod of sampling used.12.2 Report the following information:12.2.1 The number of specimens tested in each laboratorysample testing direction,12.2.2 The average cohesive tenacity for each laboratorysample testing direction,12.2.3 The average cohesive

43、 tenacity for the lot sample, and12.2.4 The standard deviation, coefficient of variation, orboth, for each laboratory sample testing direction and the lotsample, if calculated.13. Precision and Bias13.1 PrecisionThe precision for measuring fiber cohesionin dynamic tests as drafting tenacity is being

44、 determined.13.2 BiasThe value for dynamic fiber cohesion as mea-sured by drafting tenacity can only be defined in terms ofspecific methods. Within this limitation, the procedure in thistest method for determining this property has no known bias.14. Keywords14.1 fiber cohesion; textile strandASTM In

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48、tandards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D4120 07 (2012)3