ASTM_D_1440_-_07_2012.pdf

Designation:D144007(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,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 fibers.NOTE1For 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 determine 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 Practice 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,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 andtransferred 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 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 the 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 ginningand 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 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.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 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 the1This test method is under the jurisdiction ofASTM 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/D1440-07R12.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Suter-Webb 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 Calibration Cotton Samples,for the calibra-tion of array length measurements.NOTE2Standard 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 CottonL