ASTM_D_7879_-_13_2018.pdf

Designation:D787913(Reapproved 2018)Standard Test Method forDetermining Flax Fiber Widths Using Image Analysis1This standard is issued under the fixed designation D7879;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 involves the measurement and analysisof two-dimensional projections of flax fibers using imageanalysis software in the longitudinal plane to determine theaverage and distribution of fiber widths.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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 Practice for Conditioning and Testing TextilesD6798 Terminology Relating to Flax and Linen3.Terminology3.1 Definitions:3.1.1 For all terminology related to Flax and Linen seeTerminology D123.3.1.1.1 The following terms are relevant to this standard:average fiber width(m).3.1.1.2 For definitions of all other textile terms see Termi-nology D6798.4.Summary of Test Method4.1 This test method involves the preparation of flax fibersfor digital capture,the scanning of the fibers for analysis,andthe calibration and standardization of the image processing.From the image analysis,the arithmetic mean and its standarddeviation,median,and numerical distribution of the fiberwidths are calculated.5.Significance and Use5.1 Longitudinal preparation is much quicker and lessdamaging than cross-sectional analysis and allows the fibers tobe evaluated in their natural state.5.2 This test method provides measurement of a flax fiberspecimen that uses less specimen preparation,produces con-sistent results,and minimal specimen modification.It has beenshown that the median values of width correlate very well withthe Optical Fiber Diameter Analyzer(OFDA),an apparatusdeveloped for measuring the value and distribution of woolfiber diameters.6.Interferences6.1 Out of focus objects.6.2 Real resolution of image capturing device impactsmeasurements.6.3 Fingerprints,cracks,scratches,tape,dust and otherimpurities(non-fibrous objects)on the glass slides can biasmeasurement results.6.4 Results will be incorrect or misleading if the operator ofthe software has not properly set up the image captureparameters.6.5 Image processing techniques employed to completemissing or incompletely developed fiber boundaries must beused with caution as false boundaries may be created.6.6 Vibrations or movement of the sample during imagecapture can blur the image and must be minimized or elimi-nated when using automatic image analysis.6.7 Non-uniform illumination can influence feature detec-tion and threshold using automatic image analyzers.6.8 Operation of the equipment in a non-environmentallycontrolled room may result in fiber shape deviations afterinitial fiber conditioning has occurred.1This 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 July 1,2018.Published August 2018.Originallyapproved in 2013.Last previous edition approved in 2013 as D787913.DOI:10.1520/D7879-182For 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.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.17.Apparatus7.1 Fiber Preparation Apparatus:7.1.1 Acoarse comb or other device used to distribute fibersto create a single focal plane and better enable fiber edgedetection.NOTE1Excessive overlap of fibers reduces the possibility of observ-ing all of the fibers in a single focal plane.7.1.2 Two flat surfaces capable of compressing the samplewhere at leas