ASTM_D_3818_-_92_scan.pdf

A S T I DI818 92 0759510 0523580 729(b Designation:D 3818-92 AMERICAN SOCIETY FOR TESTING AND MATERIALS 191 6 Race S t Philadelphia,Pa 191 03 Reprinted from he Annual Book of ASTM Standards.Copyright ASTM li noi listed in the current combined index,will appear in the ne*edition.Standard Test Method for Linear Density and Maturity Index of Cotton Fibers(IC-Shirley Fineness/Maturity Tester)This standard is issued under the fixed designation D 38 18;the number immediately following the designation indicates the year of original adoption or.in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.INTRODUCTION The porous plug airflow method provides an indirect measure of fiber specific surface,that is,surface area per unit volume,which depends upon the average fiber perimeter and the average fiber maturity.If the perimeter is known,then the airflow measurement or micronaire reading may be related directly to fiber linear density or mass per unit length,which,for a certain perimeter depends upon the maturity.Conversely,if the maturity is known,then the airflow reading may be related to the perimeter.In American Upland cottons(Gossypium hirsutum L.)the average fiber perimeter varies only within a narrow range and so the airflow measurement or micronaire reading can be taken as an indication of wall thickness and hence maturity for all practical purposes.Cottons of other types will not necessarily behave in the same manner.For example,American Pima cottons(Gossypium barbadense L.)have a substantially smaller perimeter than the Upland types and therefore would give a lower micronaire reading for the same maturity.Asiatic or cross-bred types would show yet other relationships.In a dual compression airflow instrument a sample can be measured at two different conditions of density.Linear density and maturity index can be derived from the measurements of airflow at the two densities(1,2,3,4).2 1.Scope 1.1 This test method covers the determination of linear density and maturity index of loose randomized cotton fibers by measuring the resistance to air flow of a plug of cotton fibers under two prescribed conditions.NOTE I-For other methods for determining linear density and maturity properties of cotton fibers,see Test Methods D 1442,D 1448,D 1769,D2480,D3817,British Standards BS 2016,BS 3085,and IS0 2403.1.2 This standard does not purport to address all o f the safety problems,if any,associated with its use.It is the responsibility o f the user o f this standard to establish appro-priate safety and health practices and determine the applica-bility o f regulatory limitations prior to use.2.Referenced Documents 2.I ASTM Standards:D 123 Terminology Relating to Textiles3 D 144 1 Practice for Sampling Cotton Fibers for Testing3 D 1442 Test Method for Maturity of Cotton Fibers(So-dium Hydroxide Swelling and Polarized Light Proce-dure)I This test method is under the jurisdiction of ASTM Committee D-13 on Textiles and is the direct responsibility of Subcommittee D13.1 1 on Cotton Fibers.Current edition approved Oct.IS,1992.Published January 1993.Originally published as D 3818-79.Last previous edition D 3818-79(1984).2The boldface numbers in parentheses refer to the list of references at the end of this test method.3 Annual Book ofASTM Standards,Vol 07.01.D 1448 Test Method for Micronaire Reading of Cotton Fibers3 D 1769 Test Method for Linear Density of Cotton Fibers(Array Sample)4 D 1776 Practice for Conditioning Textiles for Testing3 D2480 Test Method for Maturity Index and Linear Density of Cotton Fibers by the Causticaire Method3 D3025 Practice for Standardizing Cotton Fiber Test Results by Use of Calibration Cotton Standard3 D 38 17 Test Method for Maturity Index of Cotton Fibers By the Fibrograph Method5 2.2 British Standards6 BS 2016 Determination of Weight per Unit Length of Textile Fibers BS 3085 Cotton Fiber Maturity(Estimation by Classifica-tion of Fibers Swollen in Sodium Hydroxide Solution)2.3 IS0 Standards?IS0 1973 Textile Fibers-Determination of Linear Density IS0 2403 Textiles-Cotton Fibers(Determination of Micro-(Gravimetric Method)naire Value)3.Definitions 3.1 calibration cotton standards,n-cotton samples taken Discontinued-See 1988 Annual Book of ASTM Standards,Vol 07.02.5 Annual Book ofASTM Standards,Vol 07.02.6Available from British Standards Institute,2 Park Street,London,WiA 2BS Available from ISO,I Rue de Varembe,Geneva CH-12 I 1 20 SWITZER-UNITED KINGWM.LAND.I NOTICE:This standard has either been superseded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.ASTM D3818 92 0759530 0521581 665)D3818 from blended bulk source on which fiber properties have been determined under the International Calibration Cotton Standards Program.3.2 mafurity,cotton,n-the degree of fiber wall develop ment.3.3 maturity