ASTM_D_5804_-_97_2002.pdf

Designation:D 5804 97(Reapproved 2002)An American National StandardStandard Test Methods forZero-Span Tensile Strength(“Dry Zero-Span Tensile”)1This standard is issued under the fixed designation D 5804;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method provides a quick reliable means tomeasure the zero-span tensile strength of a randomly orientedspecimen of fibers when dry.1.1.1 Similar procedures for determining the zero-spantensile strength of a randomly oriented specimen of fibers whenwet are found in Test Method D 5803.1.2 In this test method,the fibers are tested as a handsheetproduced using a standardized procedure such as TAPPI T 205.1.3 While testing is possible on finished paper materials,information on fiber quality from intermediate steps in thepulping or paper making process,or both,is frequently moreuseful for improving finished paper quality or improving fiberutilization of,for example,recycled fibers,or fibers subjectedto new pulping,bleaching,or finishing processes.1.4 The modifications of the procedure described in this testmethod required for testing finished paper is straightforward;however,testing must be done in the two principle directions ofthe sheet,as required in Test Method D 828,since the finishedpaper or paperboard will generally have non-random fiberorientation,resulting in different strength properties in the twoprinciple directions of the finished sheet.Testing of sheetshaving a grammage greater than 100 g/m2,which includessome paper materials described as paper and many paper-boards,is difficult because of problems associated with clamp-ing of individual fibers as the number of fibers per unit areaincreases.1.5 Such modifications are not described in this test method,and if they are made,they shall be acknowledged and clearlydescribed in the report as deviations from the standard proce-dure.1.6 In addition to a measure of the dry zero-span tensilestrength of the specimen of fibers,an index of the cohesivenessof fibers in the sheet is also provided by the ratio of the tensilestrength determined using Test Method D 828 and the tensilestrength determined using this test method when all testing isdone on handsheets having random fiber orientation(1).21.7 Two instrumental approaches for accomplishing themeasurement of dry tensile strength at zero-span are described.1.7.1 One approach is the use of specially constructed pairof“zero-span”jaws which are used in conjunction with aconventional tensile testing machine.1.7.1.1 One such design for“zero-span”jaws was proposedby Clark(1).A second design was proposed by Wink and VanEperen(2).1.7.2 A second approach is the use of a special instrumentincorporating both“zero-span”jaws and measurement andreadout devices in a single instrument.31.7.3 When properly adjusted and calibrated,either of theinstrumental approaches may be used to perform this testmethod.1.8 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:D 586 Test Method for Ash in Pulp,Paper,and PaperProducts4D 685 Practice for Conditioning Paper and Paper Productsfor Testing4D 828 Test Method for Tensile Breaking Strength of Paperand Paperboard4D 1193 Specification for Reagent Water5D 1968 Terminology Relating to Paper and Paper Products4D 5803 Test Method for Wet Tensile Strength at Zero-Span(“Wet Zero-Span Tensile”)42.2TAPPI Test Methods:1This test method is under the jurisdiction of ASTM Committee D06 on Paperand Paper Products and is the direct responsibility of Subcommittee D06.92 on TestMethods.Current edition approved Dec.10,1997.Published October 1998.Originallyapproved in 1995.Last previous edition approved in 1995 as D 580495.2The boldface numbers in parentheses refer to the list of references at the end ofthis test method.3One self-contained instrument suitable for making the measurements describedin this test method is available from Pulmac Instruments International,Box 50,HCR34,Montpelier,VT 05602.There may be other sources.4Annual Book of ASTM Standards,Vol 15.09.5Annual Book of ASTM Standards,Vol 11.01.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.T 205 Forming handsheets for physical tests of pulp6T 220 Physical testing of pulp handsheets63.Terminology3.1 Definitions shall be in accordance with Terminology D1968 and the Dictionary of Paper.64.Significance and Use4.1 The zero-span tensile test measures the tensile strengthat the moment of tensile failure of fibers randomly o