ASTM_D_1448_-_11.pdf

Designation:D144811Standard Test Method forMicronaire Reading of Cotton Fibers1This standard is issued under the fixed designation D1448;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.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1This test method covers the determination of themicronaire reading of loose cotton fibers by measuring theresistance of a specific mass(plug)of cotton fibers to air flowunder prescribed conditions.NOTE1For other methods for determining the fineness of fibers basedon the air-flow principle,refer to Test Method D1449,Test Method forSpecific Area and Immaturity Ratio of Cotton Fibers(ArealometerMethod),2and to Test Method D1282,Test Method for Resistance to AirFlow as an Indication of Average Fiber Diameter of Wool Top,CardSliver,and Scoured Wool.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 TextilesD1282 Test Method for Resistance to Airflow as an Indica-tion of Average Fiber Diameter of Wool Top,Card Sliver,and Scoured WoolD1441 Practice for Sampling Cotton Fibers for TestingD1449 Method of Test for Specific Area and ImmaturityRatio of Cotton Fibers(Arealometer Method)(Withdrawn1977)3D1776 Practice for Conditioning and Testing TextilesD5867 Test Methods for Measurement of Physical Proper-ties of Raw Cotton by Cotton Classification InstrumentsD7139 Terminology for Cotton Fibers3.Terminology3.1 For all terminology related to D13.11,refer to Termi-nology D7139.3.1.1 The following terms are relevant to this standard:calibration cotton standards,fineness,micronaire reading.3.2 For all other terminology related to textiles,refer toTerminology D123.4.Summary of Test Method4.1 The resistance a specific mass(plug)of cotton fibersoffers to the flow of air is measured as an approximateindication of the fineness of fiber.A predetermined mass ofloose cotton fibers is placed in the specimen holder andcompressed to a fixed volume.The resistance to air flow ismeasured and expressed as a micronaire reading.5.Significance and Use5.1 This test method is considered satisfactory for accep-tance testing when the levels of the laboratories are controlledby the use of the same reference standard cotton samplesbecause the current estimates of between-laboratory precisionare acceptable under these conditions.If there are differencesof practical significance between reported test results for twolaboratories(or more),comparative tests should be performedto determine if there is a statistical bias between them,usingcompetent statistical assistance.As a minimum,ensure the testsamples to be used are as homogeneous as possible,are drawnfrom the material from which the disparate test results wereobtained,and are randomly assigned in equal numbers to eachlaboratory for testing.The test from the two laboratories shouldbe compared using a statistical test for unpaired data,at aprobability level chosen prior to the testing series.If a bias isfound,either its cause must be found and corrected,or futuretest results for that material must be adjusted in considerationof the known bias.5.2 The micronaire reading of cotton fibers is a function ofboth fineness and maturity and is related to mill processingperformance and to the quality of the end products.Factorscorrelated with micronaire reading include cleaning efficiency,neppiness,and the strength and uniformity of the yarn.NOTE2A modification of this test method is used in commercialtrading to select bales which will conform to contract guarantees for1This 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 Jan.1,2011.Published January 2011.Originallyapproved in 1954 to replace portions of D414.Last previous edition approved in2005 as D144805.DOI:10.1520/D1448-11.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 specified micronaire readings(refer to D5867).For this purpose,it is usualpractice to test only one specimen per sample.6.Apparatus and Materials6.1 Air-Flow Instrument,calibrated in micronair