1、Designation: D 1578 93 (Reapproved 2006)e1Standard Test Method forBreaking Strength of Yarn in Skein Form1This standard is issued under the fixed designation D 1578; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.e1NOTEThe Terminology Section was editorially updated
3、 in July 2006.1. Scope1.1 This test method covers the determination of the break-ing strength of yarn in skein form. The observed breakingstrength is expressed in units of force, and equations areprovided to convert breaking strength to skein breaking tenac-ity and to skein break factor.NOTE 1For th
4、e determination of the breaking strength and elongationof yarn by the single strand method, refer to Test Method D 2256.1.2 This test method is applicable to spun yarns, eithersingle or plied, composed of any fiber or blend of fibers, but isnot suitable for yarns which stretch more than 5 % when the
5、tension is increased from 2.5 to 7.5 mN/tex or 0.03 to 0.08gf/denier.1.3 This test method provides three options based on theperimeter of the reel, the number of wraps in the skein, and themachine speed or time-to-break.1.3.1 Option 1Eighty, forty, or twenty turns on a 1.50-mor 1.5-yd reel, broken a
6、t 300 mm/min or 12 in./min.1.3.2 Option 2Fifty turns on a 1.00-m or 1-yd reel, brokenat 300 mm/min or 12 in./min.1.3.3 Option 3Fifty turns on a 1-m reel, broken in 20 s.NOTE 2Option 1 is in general use in the United States, Option 2 isused for woolen yarns, and Option 3 has been proposed in the Inte
7、rna-tional Standards Organization (ISO) for international use.NOTE 3Metric reels are available with 1 and 1.125-m circumferences.Data from the two reels will be about 1 % different (see 5.6). ISO uses a1-m circumference reel.1.4 This test method is frequently combined with thedetermination of linear
8、 density carried out on the same skeins.Special precautions for reeling such skeins are noted.1.5 Where appropriate, this test method states all require-ments in SI units. The traditional units are inch-pound and areexact values.1.6 This standard does not purport to address all of thesafety problems
9、, 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 Specification for Tensile Testing Machi
10、nes for TextilesD 123 Terminology Relating to TextilesD 1776 Practice for Conditioning and Testing TextilesD 1907 Test Method for Linear Density of Yarn (YarnNumber) by the Skein MethodD 2256 Test Method for Tensile Properties of Yarns by theSingle-Strand MethodD 2258 Practice for Sampling Yarn for
11、TestingD 2904 Practice for Interlaboratory Testing of a Textile TestMethod that Produces Normally Distributed DataD 4849 Terminology Relating to Yarns and Fibers3. Terminology3.1 Definitions:3.1.1 For defintion of textile terms used in this test method:breaking force, force, skein break factor, skei
12、n, skein breakingtenacity, skein strength, strength, refer to Terminology D 4849.3.1.2 For definitions of other textile terms used in this testmethod, refer to Terminology D 123.4. Summary of Test Method4.1 A skein of yarn, prepared by winding the prescribednumber of turns on a reel, is broken on a
13、tensile testingmachine.NOTE 4If the yarn number is also required for the determination ofskein breaking tenacity or break factor, the broken skein may be weighedand the yarn number calculated as directed in Test Method D 1907.5. Significance and Use5.1 Test Method D 1578 for testing any spun yarn fo
14、rbreaking strength is considered satisfactory for acceptance1This 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 edition approved June 1, 2006. Published July 2006. Originally approvedin 1958.
15、 Last previous edition approved in 2000 as D 1578 93(2000).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, refer to the standards Document Summary page onthe ASTM website.1C
16、opyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.testing of commercial shipments since the method has beenused extensively in the trade.5.1.1 In case of a dispute arising from differences inreported test results when using Test Method D
17、 1578 foracceptance testing of commercial shipments, the purchaser andthe supplier should conduct comparative tests to determine ifthere is a statistical bias between their laboratories. Competentstatistical assistance is recommended for the investigation ofbias. As a minimum, the two parties should
18、 take a group of testspecimens which are as homogeneous as possible and whichare from a lot of material of the type in question. The testspecimens should then be randomly assigned in equal numbersto each laboratory for testing. The average results from the twolaboratories should be compared using St
19、udents t-test forunpaired data and an acceptable probability level chosen by thetwo parties before testing is begun. If a bias is found, either itscause must be found and corrected or the purchaser and thesupplier must agree to interpret future test results in the light ofthe known bias.5.2 This tes
20、t method is not suitable for yarns that stretchmore than 5 % when the force is increased from 2.5 to 7.5mN/tex or 0.03 to 0.08 gf/denier, because (a) they requirespecial precautions as to tension in reeling, and (b) users ofsuch yarns are more interested in their elastic behavior at lowforces than i
21、n their ultimate breaking strength.5.3 For Option 1, it is advisable to use a tensile testingmachine of the proper capacity to break skeins with 80 turns.If it is necessary to break skeins having only 40 or 20 turns,convert the observed results to an 80-turn basis by multiplyingby factors of 2 or 4,
22、 respectively. (The available literature doesnot show that any significant error is introduced by the use ofthese factors.)5.4 The circumference of the skeins used to determine thebreaking load is not critical, and as a consequence, closecontrol of the tension at which the skeins are wound is notnec
23、essary. If, however, the same skeins are to be used todetermine yarn number for any purpose, the skeins must bereeled under controlled tension on a reel meeting the require-ments given in Test Method D 1907.5.5 For some purposes it may be advisable to convert theskein breaking strength observed for
24、yarn of one number to theestimated skein breaking strength of a different yarn number.Factors for making such a conversion for cotton yarns aregiven in 11.2. No corresponding factors have been developedfor yarns spun from other fibers.5.6 The results obtained from different options are not fullycomp
25、arable because the breaking force per wrap increasesslightly as the perimeter of the skein is reduced. The skeinbreaking tenacity observed for 1-m skeins may be as much as4 % higher, and from 1-yd skeins 5 % higher, than thatobserved for 1.5-yd skeins. These relationships may vary withthe type of ya
26、rn or with yarn unevenness and should not beused as conversion factors. With a reasonable number ofspecimens, this method provides a useful index that combinesthe effects of unevenness and single strand strength.5.7 This method is rarely, if ever, used for filament yarnsbecause their uniformity make
27、s it possible to obtain reliableresults economically by the single-strand method.6. Apparatus6.1 ReelA hand or motor-driven reel having a perimeterof 1.50 m or 1.5 yd for Option 1, 1.0 m or 1 yd for Option 2(see Note 3), or 1 m for Option 3. The reel shall be fitted witha traversing mechanism that w
28、ill minimize bunching the yarnon the reel and with an indicator of the length wound. Awarning bell or an automatic cutoff that will operate at aspecified number of turns is advisable. It is also recommendedthat the reel have a collapsible arm for relaxing the tension onthe skeins to facilitate their
29、 removal from the reel. If yarnnumber is to be determined from the same skeins, refer to TestMethod D 1907 for additional reel specifications.6.2 Package HoldersVertical spindles for bobbins orcones if not provided as an integral part of the reel, shafts onwhich tubes or flanged spools can turn free
30、ly.6.3 Tensile Testing MachineA constant-rate-of-traverse(CRT type) or constant-rate-of-extension (CRE type) tensiletesting machine of suitable capacity as prescribed in Specifi-cation D76, capable of operating the moving clamp (spool) ata uniform speed of 300 6 10 mm/min or 12 6 0.5 in./min (forOpt
31、ions 1 and 2) or capable of operating at a rate that willbreak the skein broken in an average time of 20 6 3 s from thestart of application of tension to the skein (for Option 3). Themachine shall be equipped with spools not less than 25 mm or1 in. nor more than 30 mm or 1.25 in. in both diameter an
32、dlength, and supported with at least one spool free to turn on itsaxis. The distance between the spools shall be sufficient topermit placing the skeins on the spools in a wide, flat band.6.4 Skein Holder or Rack, having parallel pegs or barsplaced a sufficient distance apart to hold the skeins exten
33、ded tonearly their full length without either stretching, kinking, orentangling the yarn.7. Sampling7.1 Lot SampleTake a lot sample as directed in anapplicable specification, or as agreed upon between the pur-chaser and the supplier. In the absence of an applicablespecification or agreement, take a
34、lot sample as directed inPractice D 2258.NOTE 5An adequate specification or other agreement between thepurchaser and the supplier requires taking into account variability betweenshipping units, between packages or ends within a shipping unit, andbetween specimens from a single package so as to provi
35、de a sampling planwith a meaningful producers risk, consumers risk, acceptable qualitylevel, and limited quality level.7.2 Laboratory SampleAs a laboratory sample for accep-tance testing, take a total of ten packages for yarn spun on thecotton or worsted systems and a total of 20 packages for yarnss
36、pun on the woolen system. Select the packages randomly fromall the packages in the lot sampling units.7.3 Number of SpecimensTest one skein from each pack-age in the laboratory sample.8. Conditioning8.1 PreconditioningYarns for testing should be woundinto skeins for preconditioning and conditioning
37、(see Section9). Reel one or more extra skeins for use in determining whenmoisture equilibrium has been reached (see 8.2.1).D 1578 93 (2006)e128.1.1 Precondition the skeins at a temperature no higherthan 50C or 120F in an atmosphere having a relativehumidity between 5 and 25 %. Skeins will usually re
38、achapproximate moisture equilibrium in 4 h especially in movingair. Crowding skeins too close together on the rack, or anythingthat obstructs the circulation of air, may lengthen the timeappreciably.8.2 ConditioningCondition the skeins in the standardatmosphere for testing textiles, which is 21 6 1C
39、 or 70 6 2Fand 65 6 2% relative humidity, until moisture equilibrium hasbeen reached.8.2.1 For cotton yarns, a minimum conditioning time of 4 his specified. Yarns made from other fibers or blends mayrequire other lengths of time. When testing additional samplesof the same type of yarn, it may be ass
40、umed that moistureequilibrium has been reached after exposure for a time 25 %longer than that found by test to be sufficient.8.2.1.1 If necessary use the extra skein(s) to determine thatmoisture equilibrium has been reached when successive weigh-ings at intervals of not less than 15 min do not diffe
41、r by morethan 0.1 %. Do not use the skeins that are to be tested forstrength for determining moisture equilibrium.9. Preparation of Specimens9.1 Mounting of Packages:9.1.1 For yarns on bobbins, cops, cones, or similar pack-ages, draw the yarn off over the end of the package at a speedbetween 100 and
42、 300 rpm of the reel.9.1.2 For yarns on flanged spools or other packages nor-mally unwound from the side, mount the packages to turnfreely and draw the yarn from the side of the package at a speedof 20 to 30 rpm of the reel.9.1.3 When several ends are wound parallel on a singlepackage, draw each end
43、 through a separate guide and reel askein from each end, unwinding from the side of the package.9.1.4 If the yarn is received in skein form, mount it on anumbrella reel or swift and reel at a speed of 20 to 30 rpm.9.2 ReelingDraw each end of yarn through a separateguide and attach the yarn to the re
44、el. Turn the reel at a uniformspeed and maintain sufficient tension to lay the yarn smoothlyon the reel. When the required number of turns have beenreeled, tie the ends of the yarn together loosely but securelywith a nonslipping knot. For easier separation of skeins on therack, a loose loop may be m
45、ade about the skein cross section,and the yarns once again knotted. If skein breaking tenacity orskein break factor is to be calculated, the method of reelingmust comply with the additional requirements in Test MethodD 1907.9.2.1 For Option 1, reel 80 turns on a 1.50-m (1.5-yd) reel.If the breaking
46、strength of such a skein is greater than thecapacity of the available testing machine, try 40 or 20 turns.9.2.2 For Option 2, reel 50 turns on a 1-m or a 1-yd reel.9.2.3 For Option 3, reel 50 turns on a 1-m (1.09yd) reel.Include extra skeins for adjustment of the tester for time tobreak.9.3 Conditio
47、ningTransfer the skeins to the rack carefullywith as little disturbance of the yarn as possible. Keep the yarnsparallel and the skein flat, with no bunching or twisting. Do notstretch or jerk the yarn and do not allow it to kink. If more thanone skein is to be stored on each pair of pegs, the skeins
48、 maybe transferred one at a time to the rack, with rings or washersplaced between them for easier separation. Precondition (if notdone before reeling) and condition as prescribed in Section 8.Do not remove the skeins from the rack until time of test.10. Procedure10.1 Perform all tests in the standar
49、d atmosphere for testingtextiles, which is 21 6 1C or 70 6 2F and 65 6 2 % relativehumidity.10.2 Select the appropriate capacity range of the testingmachine as follows:10.2.1 For Options 1 and 2, a range within which (1) thecalibration of the tensile testing machine is accurate within61.0 % and (2) the breaking force can be read with a precisionof 62.0 %.10.2.2 For Option 3, select the capacity and speed of thetesting machine to reach the breaking force in an average timeof 20 6 3 s or a testing speed agreed upon by purchaser andsupplier. Break one or more
