1、Designation: D1440 07 (Reapproved 2012)Standard Test Method forLength and Length Distribution of Cotton Fibers (ArrayMethod)1This standard is issued under the fixed designation D1440; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、 the 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 determination of the fiberlength and length distribution in loose cotton fibe
3、rs.NOTE 1For another method for measuring fiber length, see TestMethod D1447.1.2 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 determ
4、ine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1441 Practice for Sampling Cotton Fibers for TestingD1447 Test Method for Length and Length Uniformity ofCotton Fibers by Photoelectric MeasurementD1776 Prac
5、tice for Conditioning and Testing TextilesD7139 Terminology for Cotton Fibers3. Terminology3.1 For all terminology related to D13.11, Cotton Fibers, seeTerminology D7139.3.1.1 The following terms are relevant to this standard:coefficient of variation, length group, length interval, meanlength, pull,
6、 upper quartile length.3.2 For all other terminology related to textiles see Termi-nology D123.4. Summary of Test Method4.1 A sorting apparatus consisting of two banks of parallelcombs is used to straighten and align the fibers in a 75-mg testspecimen. The fibers are pulled from one bank of combs an
7、dtransferred to the other in such a manner that one end of eachfiber is aligned with the base comb. The transfer is repeated tostraighten the other ends of the fibers. As the fibers arewithdrawn from the combs for the third time, they are placedin order of length on velvet covered boards. The pulls
8、aremeasured, and those that fall within each length interval arecollected and weighed. From these weight-length data, theupper quartile length, mean length, and coefficient of lengthvariation are calculated.5. Significance and Use5.1 The array method provides objective measurements fordetermining th
9、e fiber length and length distribution in a sampleof cotton. The results can be plotted to show the length-weightdistribution of all the fibers in the sample. Data obtained fromarray tests are useful in fiber length research studies, forinvestigation of changes in fiber length distribution in ginnin
10、gand mill processing, and for other research purposes.5.2 Upper quartile length is correlated with, but usuallylonger than, Fibrograph and 2.5 % span length as defined inTest Method D1447. Judgment must be used in makingcomparisons between length measures from arrays and mea-sures obtained by other
11、methods, which may be basicallydifferent.5.3 The coefficient of length variation is a measure of lengthdistribution, or nonuniformity of length. Because the fiberweight-length distribution is usually highly skewed, statisticaljudgments based on the assumption of normality are notjustified.1This test
12、 method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.11 on Cotton Fibers.Current edition approved July 1, 2012. Published August 2012. Originallyapproved in 1955. Last previous edition approved in 2007 as D1440 07. DOI:10.1520/D1440-
13、07R12.2For 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.1Copyright ASTM International, 100 Barr Harbor Drive, P
14、O Box C700, West Conshohocken, PA 19428-2959, United States.5.4 The array method makes a physical separation of fibersof different lengths. It therefore serves as a standard, orbenchmark, with which other methods may be compared andby which their precision and accuracy may be judged.5.5 Test Method
15、D1440 for testing length and length distri-bution of cotton fibers (array method) is not commonly usedfor acceptance testing of commercial shipments.6. Apparatus and Materials6.1 Double Bank Sorter, and equipment as illustrated in Fig.1. The method outlined here is especially adapted to theSuter-Web
16、b Duplex Cotton Fiber Sorter,3but the proceduremay be carried out with other similar apparatus with more orless obvious alterations.6.2 Balance, with a capacity of at least 25 mg and asensitivity of 60.05 mg.6.3 Balance, with a capacity of at least 100 mg and asensitivity of 60.1 mg.6.4 Standard Cal
17、ibration Cotton Samples, for the calibra-tion of array length measurements.NOTE 2Standard calibration cotton samples are available from theCotton Division, Agricultural Marketing Service, U.S. Department ofAgriculture, 3275 Appling Rd., Memphis, TN 38133.6.5 Secondary Standard CottonLots of cotton t
18、he lengthof which has been established by extensive comparisons withUSDA standards.7. Sampling7.1 Prepare the laboratory sample as directed in PracticeD1441. Take either two or three subsamples depending on theprecision desired. Take subsamples that weigh approximately80 mg each for use in preparing
19、 the test specimen in one of thefollowing manners:7.1.1 From a hand sliver, carefully separate a 2-in. (50-mm)length of the sliver for each subsample.7.1.2 From a mechanically blended 3-g sliver, separate 2-in.(50-mm) subsamples.7.1.3 From a mechanically blended 10-g sliver, pull out ofthe middle of
20、 the sample a subsample about 2 in. (50 mm) long,extending through its whole thickness, and wide enough toweigh approximately 80 mg. Take subsamples from near thebeginning, midway, and near the end of the sliver.3The sole source of supply of the apparatus known to the committee at this timeis the Al
21、fred Suter Co., New York, NY. If you are aware of alternative suppliers,please provide this information toASTM Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.a and cBanks of combs.bForceps, tips padded with hard
22、leather, for transferring fibers from one set of combs to the other.dDepressor for placing fibers in combs.fDissecting needle.gFork for scooping up fiber groups off velvet surface.hAluminum plate covered with velvet cloth.iSpecial rule for measuring length of fiber groups.kSmooth plate for placing f
23、ibers onto velvet surfaces.lWire rack for holding fiber groups wrapped in papers.mSmooth pointed tweezers.nLift for raising combs in place.oRack for holding velvet-covered boards.pVelvet-covered boards on which several pulls have been arrayed.NOTE 1Other accessories required for length arraying, not
24、 shown above, consist of the following: small whisk broom for cleaning velvet surfaces,one pair of tweezers with smooth round tips, forceps similar to b but having tips padded with rubber for laying groups on velvet surfaces, small papersfor wrapping groups of fibers (papers 212 by 3 in. (62 by 75 m
25、m) with small envelopes for them (212 by 414 in. (62 by 110 mm), and balances havingranges from 0 to 25 mg and 0 to 100 mg.FIG. 1 Combs and Accessories for Arraying Fibers According to LengthD1440 07 (2012)27.2 If the laboratory samples have not been in the standardatmosphere for at least 2 h before
26、 the preparation of sub-samples, bring the subsamples to approximate equilibrium withthe standard atmosphere for testing before preparing speci-mens. Exposure to moving air in the laboratory for2hissufficient.8. Preparation of Test Specimen8.1 Prepare one specimen from each of the three sub-samples.
27、 Gently parallelize the fibers by hand. Remove allforeign matter, but do not discard any fibers.8.2 Separate from each subsample, by longitudinal division,a portion weighing approximately 76 mg. If the specimenweighs more than 77 mg, reduce its weight by removing asmall group of fibers from the side
28、 of the specimen. If thespecimen weighs less than 75 mg, add a small group of fiberstaken from the side of the subsample. Never remove fibersfrom either the specimen or subsample by pulling from theends, as this tends to remove the longest fibers. After adjustingthe specimen weight to approximately
29、76 mg, condition thespecimen and the remaining portion of the subsample inaccordance with Section 9.9. Conditioning9.1 Practice D1776 covers the conditioning of textiles fortesting. If the laboratory samples have a moisture content of10 % or higher, Practice D1776 should be used to condition thesamp
30、les for testing. For samples below 10 % moisture content,the conditioning procedure outlined in 9.2 and 9.3 is consid-ered adequate for length testing by this test method.9.2 If the laboratory samples have not been in the standardatmosphere for at least 2 h before the preparation of thesubsample, br
31、ing the subsamples to approximate equilibriumwith the standard atmosphere for testing before preparingspecimens. Exposure to moving air in the laboratory for4hissufficient.9.3 After the specimens have been prepared, condition themin the standard atmosphere for testing. Exposure to moving airin the s
32、tandard atmosphere for a minimum period of2hisadequate for this test method.10. Procedure10.1 Weigh the conditioned specimen to the nearest 0.1 mg.Do not touch the specimen with the fingers after conditioning.If the specimen weighs more than 75.4 mg, use the tweezers(Fig. 1, m) to remove a small gro
33、up of fibers from the side ofthe specimen. If the weight is less than 74.6 mg, add a smallgroup of fibers taken with tweezers from the side of thesubsample. Do all sorting, measuring, and weighing in thestandard atmosphere for testing.10.2 Before testing other samples, each technician shallhave made
34、 an array on a check test cotton (Note 2), if this hasnot been done during the previous month. Results of regularlyscheduled check tests may be used for this purpose. If theresults do not agree with the standard value for the check testcotton within 60.02 in. (0.51 mm) in both upper quartile andmean
35、 length and 62.0 % for the coefficient of length variation,the technician must make some appropriate change in tech-nique and repeat the check test until acceptable results areobtained.10.3 If two or three technicians are available, have eachtechnician sort one of the three specimens.10.4 First Tran
36、sfer:10.4.1 Place the test specimen in the left bank of combsperpendicular to and approximately in the center of the combs.Using the depressor (Fig. 1, d), depress the test specimen atleast116 in. (2 mm) below the tips of the comb teeth, but nolower than half the length of the teeth. The comb fork c
37、an beused to raise any fibers that are depressed below this level.10.4.2 Drop front combs of the left bank until a smallernumber of fibers protrude beyond the comb nearest theoperator.10.4.3 Grip the ends of a few of these fibers with the forceps(Fig. 1, b) and withdraw them from the combs with a sm
38、oothhorizontal motion.10.4.4 Continue holding the fiber ends with the forceps.Place the forceps at the farther edge of the right bank of combsand draw the fibers carefully through the combs until the edgeof the forceps is just touching the near edge of the first comb.Release the fibers from the forc
39、eps. With the depressor, pushthe fibers down for a short distance into the teeth of the combs.Repeat this procedure until the transfer of all protruding fibersis complete. The fibers should not protrude more than116 in. (2mm) beyond the nearer comb of the right bank.10.4.5 Drop an additional comb of
40、 the left bank andcontinue transferring the fibers. Do not withdraw in one pull allof the fibers protruding from a comb, but take four or moreseparate pulls, withdrawing in each pull those fibers whichprotrude farthest. The width of the specimen placed in the rightcomb bank should be no greater than
41、 the width of the forcepsbeing used.10.4.6 Continue the transferring procedure, dropping combsas necessary, until all the fibers have been transferred from theleft to the right set of combs.10.4.7 Using the dissecting needle (Fig. 1, f ), gently un-tangle the fiber ends extending beyond the front co
42、mb. Withthe forceps, pull out any fibers that extend more than approxi-mately116 in. (2 mm) beyond the front comb and replace themin the same bank of combs in the manner described in 10.4.4.Continue until the front ends of the fibers are straight and even.10.4.8 Drop the back combs of the bank conta
43、ining thespecimen until fibers are encountered. Pull these protrudingfibers from the back of the combs and place them on the testspecimen in the same manner as was done in the transfer of thespecimen. Continue this straightening process until fiberspulled from the back combs extend through the front
44、 comb andthe ends of the specimen are straight and even. This completesthe first transfer.10.5 Second Transfer:10.5.1 Raise the empty bank of combs to the workingposition and rotate the sorting apparatus 180 so that thespecimen is on the left.10.5.2 Repeat the procedure used in the first transfer, s
45、teps10.4.2-10.4.8, transferring the specimen back to the first set ofcombs.D1440 07 (2012)310.6 Array:10.6.1 Insert top combs.10.6.2 Revolve the sorting apparatus 180 and drop frontcombs until the longest fibers are reached.10.6.3 Using the rubber-tipped forceps (Fig. 1, b), pull out afew of the lon
46、gest fibers protruding from the front comb. Laythe pull near one end of the velvet covered board and near thelong edge that is farthest from the hand holding the forceps.Continue holding with the forceps and cover the pull with thesmooth plate (Fig. 1, k), press down gently and move forcepsand plate
47、 together toward the nearer edge of the board, thusdragging the fibers across the velvet and straightening them.Press the fibers down firmly against the velvet, release from theforceps, and continue the sliding movement of the plate topress down the front ends of the fibers.10.6.4 Continue the proce
48、ss of withdrawal and placement offibers on the velvet boards, placing each successive pullapproximately316 in. (5 mm) from and parallel to the preced-ing pull. It is convenient, but not essential, to place 10 pulls oneach board. In an acceptable array, the pulls may vary indensity, but will be in or
49、der of length. The total number of pullsin an array should not be less than 65 nor more than 100. Tofacilitate accurate measurement, keep the ends as clearlydefined and as nearly in line as possible. Fiber slippage andgripping of uneven ends during transfer, withdrawal, andlaying down will result in ragged and uneven arrays which aredifficult to measure.10.6.5 Continue the process of withdrawing fibers from thecombs and placing them on the boards, dropping combs asnecessary, until all the fibers have been placed on the boards.10.7 Measuring and Grouping
