ASTM_D_6961_-_D_6961M_-_09_2015e1.pdf

Designation:D6961/D6961M09(Reapproved 2015)1Standard 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.1NOTEThe Terminology section was updated in accordance with D13 policy in February 2015.1.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 may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1776 Practice for Conditioning and Testing TextilesD6798 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 millimeter 1-in.diameter,in order toaverage over the natural color variation that occurs in flax fiber.The instrument aperture is fitted with a quartz window.Thewindow serves two functions,namely,to provide a base forcompacting the sample during measurement,and to protect theinstrument from accumulation of stray fiber particles.CIELABL*,a*,and b*measurements are taken and are instrumentallycalculated from tristimulus X,Y and Z data,observer function,and illuminant 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 inMethod 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 astatistical 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 randomly assigned in equal numbersto each laboratory.The results from the laboratories involved1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.17 on Flax and Linen.Current edition approved Feb.1,2015.Published April 2015.Originallyapproved in 2003.Last previous edition approved in 2009 as D696109.DOI:10.1520/D6961_C6961M-09(15)E01.2For 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,http:/www.aatcc.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 should be compared using a statistical test for unpaired data,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 fiber sample type must be adjusted inconsideration of the known bias.6.Apparatus6.1 A visible range spectrophotometer(minimum of 20-point)is recommended.Such an instrument provides greateraccuracy than colorimeters,spectro-colorimeters,or 10-pointcolor spectrophotometers.6.1.1 Instrument Configura