1、Designation: D2402 07 (Reapproved 2012)Standard Test Method forWater Retention of Textile Fibers (Centrifuge Procedure)1This standard is issued under the fixed designation D2402; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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 covers the measurement of waterretention of man-made and natural fibers as staple, tow, orfil
3、ament and spun yarns. It is intended to give a measure of theamount of water which cannot be removed from thoroughlywetted fiber solely by mechanical means as applied by cen-trifugal force (see 3.2).1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its
4、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. For specificprecautionary statements, see Section 9.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Rel
5、ating to TextilesD629 Test Methods for Quantitative Analysis of TextilesD2258 Practice for Sampling Yarn for TestingD3333 Practice for Sampling Manufactured Staple Fibers,Sliver, or Tow for TestingD4849 Terminology Related to Yarns and Fibers3. Terminology3.1 For all terminology relating to D13.58,
6、Yarns andFibers, refer to Terminology D4849.3.1.1 The following terms are relevant to this standard:moisture pick-up, water retention.3.2 For all other terminology related to textiles, refer toTerminology D123.4. Summary of Test Method4.1 A specimen is thoroughly wetted-out by immersion,centrifuged
7、for 5 min at an acceleration of 9800 m/s2andweighed wet. Then, the wet specimen is dried and reweighed.Water retention is calculated and reported as a percentage ofthe dry mass.5. Significance and Use5.1 This test method for testing for water retention of fibersafter centrifuging is not recommended
8、for acceptance testing ofcommercial shipments because the test is more appropriate fordevelopment and research. However, if the test is to be used foracceptance testing, comparative tests as described in 5.1.1 areadvised.5.1.1 In the case of a dispute arising from differences inreported test results
9、 using Test Method D2402 for acceptancetesting of commercial shipments, the purchaser and the sup-plier should conduct comparative tests to determine if statisti-cal biases exist between their laboratories. As a minimum, thetwo parties should take a group of test specimens that are ashomogeneous as
10、possible and that are from a lot of material ofthe type in question. The test specimens should then berandomly assigned in equal numbers to each laboratory fortesting. The average results from the two laboratories should becompared using the Students t-test for unpaired data with anacceptable probab
11、ility level chosen by the two parties whiledesigning the test program. If the analysis shows a bias, itscause must be found and corrected, or the purchaser andsupplier must agree to interpret future test data with consider-ation for the known bias.5.2 The amount of water retained by a fiber mass inc
12、reaseswith an increase in the hydrophilic tendency of the fiber. Thusthe data obtained can be used to indicate the following:5.2.1 Differences in water retention between the variousman-made and natural fibers,1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the dir
13、ect responsibility of Subcommittee D13.58 on Yarns and Fibers.Current edition approved July 1, 2012. Published August 2012. Originallyapproved in 1965T Last previous edition approved in 2007 as D2402 07. DOI:10.1520/D2402-07R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or
14、contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards 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.5.2.2 Degree of cr
15、oss-linking in cellulosic fibers,5.2.3 Damage incurred by wool and silk fibers due toalkaline processing, and5.2.4 Persistence of water-repellent treatments.6. Apparatus6.1 Stationary Coarse Comb3, approximately 63 mm longand having needles approximately 12.5 mm long and spaced 19needles to the 10 m
16、m, or6.2 Hand Cards.6.3 Centrifuge,4with trunnions capable of holding at least 2tube assemblies. The centrifuge must be capable of operatingto develop an angular speed that will produce a radial accel-eration of 9800 m/s2(1000 g) on the specimen within 5 min.6.4 Tube Assemblies, each consisting of a
17、 15-mL, polypro-pylene, centrifuge tube with draining holes, shell and supportwire (see Fig. 1).6.5 Timer, suitable for controlling immersion time andcentrifuge time to 61s.6.6 Balance, with sensitivity of 0.5 mg and a capacity of2000 g.6.7 Weighing Containers, air-tight, large enough to hold aspeci
18、men basket.6.8 Oven, convection type, maintained at 105 to 110C.6.9 Desiccator, with an efficient desiccant such as anhy-drous silica gel, anhydrous calcium sulfate, or phosphorouspentoxide.6.10 Bell Jar, optional, see 10.5.1.7. Hazard7.1 Sodium hydroxide (see Note 4) is a strong base andmust be han
19、dled with appropriate safety precautions. Refer tothe manufacturers material safety data sheet information.8. Sampling8.1 Lot SampleAs a lot sample for acceptance testing,take at random the number of shipping containers directed inthe applicable material specification or other agreement be-tween the
20、 purchaser and supplier, such as an agreement to usePractice D3333 for staple fiber, sliver, top or tow, or to usePractice D2258 for yarn. Consider the shipping containers tobe the primary sampling units.NOTE 1An adequate specification or other agreement between thepurchaser and supplier requires ta
21、king into account the variability betweenshipping containers, between laboratory samples within the shippingcontainer, and between test specimens within a laboratory sample, toprovide a sampling plan with a meaningful producers risk, consumersrisk, acceptable quality level, and limiting quality leve
22、l.8.2 Laboratory SampleAs a laboratory sample for accep-tance testing, proceed as follows:8.2.1 For Staple FiberSystematically take five laboratorysample subunits from each bale in the lot sample as directed inPractice D3333.8.2.2 For Tow and Sliver (or Top)From each shippingcontainer in the lot sam
23、ple, take at least a metre, or yard, ofmaterial from the leading end of the textile strand that has aclean uniform appearance. If the shipping container has mul-tiple packages, take one package drawn at random from thecontainer for that laboratory sample.8.2.3 For Yarn in CasesTake ten yarn packages
24、 as di-rected in Practice D2258. Remove enough traverses of yarn toobtain a surface free of visible damage or soil, and then removeat least a gram of yarn for the laboratory sample from eachlaboratory sampling unit.8.2.4 For Yarn on BeamsSample as agreed upon betweenthe purchaser and supplier.8.3 Te
25、st SpecimensTest two 0.5 g specimens from eachlaboratory sampling unit, preferably from different sections ofthe laboratory sample units.9. Conditioning9.1 Specimens may be tested without any conditioning.10. Specimen Preparation10.1 Foreign Matter and Extractable MatterIf the labo-ratory sample uni
26、ts contain foreign matter, remove the latter bymechanical means (such as hand carding). For samples con-taining nonfibrous natural constituents of the fiber (such as oils3Combs meeting these requirements may be obtained from Alfred Suter Co.,Inc., Prel Plaza, Orangeburg, NY 10962.4A clinical safety-
27、head centrifuge is satisfactory for this procedure.FIG. 1 Cross-section View of Centrifuge Tube AssemblyD2402 07 (2012)2and waxes) or substances added by the manufacturer (such asfinish, starch, soaps, waxes, etc.), extract portions by one ormore of the treatments prescribed in Section 8 on Nonfibro
28、usMaterials of Test Methods D629. Use air-drying instead ofoven-drying.NOTE 2In general, avoid use of temperatures above 50C since suchtemperatures often affect fiber structure and, thus, water retention.10.2 Staple:10.2.1 Prepare composites of each the laboratory sampleunits by taking about 0.1 g p
29、ortions from different areas of eachof the five laboratory subunits for 0.5 g specimens.10.2.2 Using a stationary comb or hand cards, carefullyparallelize the fibers.10.2.3 Prepare 0.5 6 0.05 g specimens of the carded fiberand tie the bundles in their midsections, using some of thesame fiber or a sm
30、all wire (for example 30-gage Nichrome).(See 11.3.) Form a loop with the tying fibers, or hook or loopwith the wire, for suspending the bundle from the support wireof the centrifuge tube. Remove any loose fibers from thebundle before weighing.NOTE 3If wire is used, it must be weighed as part of the
31、weighingcontainer tare mass (11.3) before use in fastening the specimen bundle.10.3 Tow or Sliver (Top):10.3.1 For tow, cut sections, 500 to 1000 mm in length,from different areas of a laboratory tow sample and split off 0.56 0.05 g specimens from the side. Fasten the specimen asdirected in 10.2.3.1
32、0.3.2 For sliver (top), draft short segments from differentsections of a laboratory sample and split off 0.5 6 0.05 gspecimens from the side. Fasten the specimen as directed in10.2.3.10.4 Yarn:10.4.1 Prepare two 0.5 g skeins by winding an appropriatenumber of turns on a tapered mandrel (Note 4) from
33、 differentsections of each of the laboratory sample units.NOTE 4A No. 4 rubber stopper, which has been boiled in sodiumhydroxide solution to remove sulfur, has been found to be a convenientsize (see 7.1).10.4.2 Tie each of the skeins in two places about half thecircumfence apart using yarn of the sa
34、me supply.11. Procedure11.1 Make all weighings in the standard atmosphere fortesting textiles, which is 21 6 1C (70 6 2F) and 65 6 2%relative humidity.11.2 Calculate the angular speed required to produce aradial acceleration of 9800 m/s2(1000 g), using Eq 1:n 5 8.943 3 1063 1/r!1/2(1)where:n = revol
35、utions per minute, andr = radial distance of the fiber mass from the center ofrotation, mm.11.3 Weigh dry, identified weighing containers and coversto the nearest 0.001 g. If wire is needed to tie specimen bundles(10.2.3), include the wire in the individual container taremasses. Record each tare mas
36、s, T.11.4 Immerse each prepared specimen in an identifiedbeaker of distilled water at room temperature for 5 min, orlonger if needed to completely wet out the specimen. Recordthe immersion time.11.4.1 If air is entrapped in the specimen, remove the airbubbles either by (1) mechanical agitation, or (
37、2) covering thebeaker and specimen with a bell jar and lowering the airpressure until the water boils.11.5 At the end of the immersion period, remove thespecimen from the distilled water. Attach the specimen to thetube assembly support wire through the yarn skein, or fiber orwire loop or wire hook o
38、f the fiber bundle.11.6 Suspend the specimen in an identified centrifuge tubeby the support wire.NOTE 5Dissection needles may be useful in inserting the specimen inthe tube.11.7 Transfer the tubes to the centrifuge. Distribute thetubes evenly spaced about the centrifuge, filling in with emptytubes a
39、s needed to balance the load.11.8 Start the centrifuge and spin for 5 min 6 5 s, includingacceleration time.11.9 At the end of the spin, stop the centrifuge quickly andimmediately transfer the specimens back to their individualweighing containers and put the covers on.11.10 Weigh the containers with
40、 the specimens, and wires ifused, to the nearest 0.001 g. Record each wet mass, M.11.11 Place the wet specimens, weighing containers, covers,and wires, if any, in the oven and dry them at 105 to 110C forabout 1.5 h.11.12 Transfer the dry specimens with their weighing con-tainers, covers, and wires,
41、if any, to the desiccator and cool.11.13 Weigh the dried specimens with their weighing con-tainers, covers, and wires, if any, to the nearest 0.001 g. Recordthese masses as dry mass, D.12. Calculation12.1 Calculate the water retention, to the nearest 0.1 %,using Eq 2:R 5 100 M 2 D!/D 2 T! (2)where:R
42、 = water retention, %,M = mass of moist specimen with its tare mass (11.10), g,D = mass of dried specimen with its tare mass (11.13), g,andT = mass of the tare (see 11.3).12.2 Calculate the average percent water retention for thetwo specimens for each laboratory sampling unit, and theaverage for the
43、 lot.12.3 If requested, calculate the standard deviation, or coef-ficient of variation, or both, for each laboratory sampling unitand for the lot.13. Report13.1 State that the samples were tested as described in TestMethod D2402. Describe the material(s) and product(s)sampled, and the method of samp
44、ling used.13.2 Report the following information:D2402 07 (2012)313.2.1 The individual and average percent water retentionfor each laboratory sampling unit,13.2.2 The average percent water retention for the lot,13.2.3 The standard deviation, or the coefficient of varia-tion, or both, if calculated, a
45、nd13.2.4 The range for the immersion times for the specimens.14. Precision and Bias14.1 PrecisionBecause of the limited use of Test MethodD2402 for water retention of textile fibers, data has beenobtained for a within laboratory comparison instead of theusual interlaboratory comparison test. Two ope
46、rators in onelaboratory tested twelve specimens from each of two materials,cotton and polyester, representing two levels of water reten-tion. Data, tabulated below shows more variance at the lowerlevels of water retention. See Table 1.14.2 BiasThe procedure in Test Method D2402 for mea-suring the wa
47、ter retention of fibers has no bias because thevalue for this property can be measured only in terms of a testmethod.15. Keywords15.1 textile fibers; water retentionASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this
48、 standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be
49、reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International,
