ASTM_D_6961_-_D_6961M_-_09_2021.pdf

Designation:D6961/D6961M09(Reapproved 2021)Standard Test Method forColor Measurement of Flax Fiber1This standard is issued under the fixed designation D6961/D6961M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the instrumental color measure-ment of flax fiber.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system are not necessarily exact equivalents;therefore,toensure conformance with the standard,each system shall beused independently of the other,and values from the twosystems shall not be combined.1.3 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.1.4 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 TextilesD1776/D1776M Practice for Conditioning and Testing Tex-tilesD6798 Terminology Relating to Flax and LinenE284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects by Usingthe CIE SystemE1164 Practice for Obtaining Spectrometric Data for Object-Color Evaluation2.2 Other Standard:AATCC Evaluation Procedure 6 Instrumental Color Mea-surement33.Terminology3.1 For all terminology related to Flax see TerminologyD6798.3.1.1 The following terms are relevant to this standard:dew-retting,enzyme-retting,and water-retting.3.2 For other textile terminology,see Terminology D123.4.Summary of Test Method4.1 Samples of flax fiber are presented to a color spectro-photometer.Color measurements are taken through a largeaperture port 25.4 mm 1 in.diameter,in order to average overthe natural color variation that occurs in flax fiber.Theinstrument aperture is fitted with a quartz window.The windowserves two functions,namely,to provide a base for compactingthe sample during measurement,and to protect the instrumentfrom accumulation of stray fiber particles.CIELAB L*,a*,andb*measurements are taken and are instrumentally calculatedfrom tristimulus X,Y,and Z data,observer function,andilluminant data.5.Significance and Use5.1 Few standards exist to objectively judge flax quality.Color is an important factor in the quality of flax fiber.Naturalvariations in raw flax fiber,various processing steps,fiberblending,and a wide range of end uses contribute to the needfor a standard method of objectively measuring the color offlax fiber.Spectrophotometic data provide an accurate,precisedetermination of the color of flax fiber.Colorimetric data areobtained through specimen measurement by combining speci-men spectral data with data representing a CIE standardobserver and a CIE standard illuminant,as described inPractice E308.5.2 If there are differences of practical significance betweenreported test results for two(or more)laboratories,compara-tive tests should be performed to determine if there is a1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.17 on Bast Fibers and Plants.Current edition approved July 1,2021.Published July 2021.Originally approvedin 2003.Last previous edition approved in 2015 as D6961/D6961M09(2015)1.DOI:10.1520/D6961_D6961M-09R21.2For 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.3Available from American Association of Textile Chemists and Colorists(AATCC),P.O.Box 12215,Research Triangle Park,NC 27709-2215,http:/www.aatcc.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.1statistical bias between them,using competent statistical assis-tance.As a minimum,use the samples for such a comparativetest that are as homogeneous as possible,drawn from the samelot of material as the samples that resulted in disparate resultsduring initial testing and rando