ASTM_D_2524_-_13.pdf

Designation:D252413Standard Test Method forBreaking Tenacity of Wool Fibers,Flat Bundle Method18-in.(3.2-mm)Gage Length1This standard is issued under the fixed designation D2524;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 break-ing tenacity of wool fibers as a flat bundle with a18-in.(3.2-mm)clamp separation.1.2 This test method is especially adapted to the fiber bundleclamps and strength testing instruments specified,but may beused on other tensile testing machines when equipped withappropriate adapters to accommodate the prescribed clamps.1.3 This test method is applicable to wool in any formwhich can be hand-combed into small bundles of parallelizedfibers.NOTE1Other test methods for measuring breaking tenacity of fiberbundles include Test Methods D1294,D1445,and D540.1.4 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.5 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ASTM Standards:2D123 Terminology Relating to TextilesD540 Methods of Testing Man-Made Staple Fibers;Re-placed by D 3660(Withdrawn 1973)3D1294 Test Method for Tensile Strength and Breaking Te-nacity of Wool Fiber Bundles 1-in.(25.4-mm)GageLengthD1445 Test Method for Breaking Strength and Elongation ofCotton Fibers(Flat Bundle Method)D1776 Practice for Conditioning and Testing TextilesD4845 Terminology Relating to WoolD2525 Practice for Sampling Wool for Moisture3.Terminology3.1 For all terminology related to D13.13,Wool and Felt,see Terminology D4845.3.1.1 The following terms are relevant to this standard:breaking tenacity,constant-rate-of-extension(CRE)type ten-sile testing machine,constant-rate-of-loading(CRL)type ten-sile testing machine,constant-rate-of-traverse(CRT)type ten-sile testing machine,gage length,tenacity,wool.3.2 For definitions of all other textile terms see TerminologyD123.4.Summary of Test Method4.1 Abundle of fibers is combed until parallel,placed undera uniform tension sufficient to remove as much crimp aspossible without stretching the fibers,and secured in specialclamps.The fibers are then cut to a known length,broken in thetensile testing machine,removed from the clamps,andweighed.Breaking tenacity is calculated from the ratio ofbreaking force to bundle linear density.The length measuredunder the applied tension is the basis for computing lineardensity from bundle mass.5.Significance and Uses5.1 Test Method D2524 for testing wool fibers for tenacityis considered satisfactory for acceptance testing when theparticipating laboratories,using a reference wool,have shownacceptable between-laboratory precision.It is recommendedthat any program of acceptance testing be preceded by aninterlaboratory check in the laboratory of the purchaser and thelaboratory of the seller on replicate specimens of samples ofthe material to be evaluated.In cases of dispute,the statisticalbias,if any,between the laboratory of the purchaser and theseller should be determined with each comparison being basedon testing randomized specimens from one sample of materialof the type being evaluated.1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.13 on Wool and Felt.Current edition approved July 1,2013.Published August 2013.Originallyapproved in 1966.Last previous edition approved in 2008 as D2524 95(2008).DOI:10.1520/D2524-13.2For 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 5.2 Values obtained from flat bundle tenacity show a goodcorrelation with values obtained from single fiber tests andrequire much less time.5.3 The basic differences between the procedures describedin Test Method D2524 and those described in Test MethodD1294 lie in the manner of clamping the bundles and theshorter gage length employed.The special clamps used in thismethod allow quicker and easier bundle preparation;however,for Test Method D1294 no special clamps are required.Closeragreement with single fiber tenacity is