ASTM_D_1442_-_06_2019.pdf

Designation:D144206(Reapproved 2019)Standard Test Method forMaturity of Cotton Fibers(Sodium Hydroxide Swelling andPolarized Light Procedures)1This standard is issued under the fixed designation D1442;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 per-centage of mature fibers in a sample of loose,chemicallyuntreated cotton fibers,whether taken before processing orunravelled from a textile product.1.2 This test method gives two optional procedures fordetermining maturity,as follows:1.2.1 Procedure 1Sodium Hydroxide Swelling.1.2.2 Procedure 2Polarized Light.NOTE1For other test methods for the determination of maturity ofcotton fibers refer to Test Methods D1464 and D2480.1.3 The values stated in SI units are to be regarded asstandard.No other units of measure are included in thisstandard.1.4 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1440 Test Method for Length and Length Distribution ofCotton Fibers(Array Method)D1447 Test Method for Length and Length Uniformity ofCotton Fibers by Photoelectric MeasurementD1464 Practice for Differential Dyeing Behavior of CottonD1776 Practice for Conditioning and Testing TextilesD2480 Test Method for Maturity Index and Linear Densityof Cotton Fibers by the Causticaire Method(Withdrawn1992)3D7139 Terminology for Cotton Fibers3.Terminology3.1 For all terminology relating to D13.11,Cotton Fibers,refer to Terminology D7139.3.1.1 The following terms are relevant to this standard:cotton fiber maturity,immature fibers,in testing with sodiumhydroxide solutions(See Fig.1 and Fig.2),immature fibers,observed under polarized light,lumen,mature fibers,in testingwith sodium hydroxide solutions(see Fig.3),mature fibers,observed under polarized light(see Table 1),micronairereading,test specimen,in cotton maturity test.3.2 For all other terminology related to textiles,refer toTerminology D123.4.Summary of Test Method4.1 Fibers are laid parallel on a microscope slide,coveredwith a cover glass,treated with a mounting medium,and themagnified images are then classified as mature or immaturefibers.4.2 The method offers two procedures for classifying thefibers as mature or immature:4.2.1 Procedure 1,Sodium Hydroxide Swelling,which usesan 18%solution of sodium hydroxide as the mountingmedium and a laboratory microscope for viewing the fibers ata magnification of 400.4.2.2 Procedure 2,Polarized Light,which uses clear min-eral oil as the mounting medium and requires a polarizingmicroscope giving a magnification of 100.Fibers are classi-fied according to their second-order interference colors,usinga first-order(or full wave)retardation plate(Table 1).1This 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 1,2019.Published July 2019.Originally approvedin 1952.Last previous edition approved in 2012 as D1442 06(2012).DOI:10.1520/D1442-06R19.2For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 5.Significance and Use5.1 Information regarding the percentage of immature fibersis desirable because immature fibers:(1)break easily duringprocessing;(2)have a tendency to form neps;(3)have atendency to become entangled around particles of trash andleaf,thus making cleaning more difficult and increasing theamount of fiber removed with foreign matter;(4)adverselyaffect yarn and fabri