ASTM_D_5803_-_97_2002.pdf

Designation:D 5803 97(Reapproved 2002)An American National StandardStandard Test Method forTensile Strength at Zero-Span(“Wet Zero-Span Tensile”)1This standard is issued under the fixed designation D 5803;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.INTRODUCTIONThe determination of the tensile strength of paper and paperboard when dry or wet is described inTest Methods D 828 and D 829,respectively.In these procedures,the standard effective specimenlength is defined by the tensile tester grip separation at the start of the test.This standard gripseparation,sometimes called gage length or span,is 180 mm(7.1 in.).Other gage lengths arepermitted for specific testing purposes and are described in the respective test methods.At a gage length of 180 mm,the measured tensile strength of a sheet of paper or paperboard isheavily impacted by sheet structural characteristics such as formation,basis weight,fiber orientation,and other structural characteristics,and is essentially unchanged at gage lengths ranging from 50 to200 mm.Sheet structural characteristics,in turn,are dependent upon fundamental properties of theindividual fibers and the way these properties are impacted throughout the entire papermaking process.This is true whether the specimens for testing are taken from an early or intermediate point in thepapermaking process,or are sampled after the finished paper material has been produced.At a gage length of zero,however,tensile strength is highly dependent upon fundamental strengthand other quality properties of individual fibers rather than sheet structural properties.Tensile datameasured at a gage length of zero is typically higher than that measured using Test Method D 828,because the strength of individual fibers,as opposed to the cumulative effect of fiber properties(particularly bonding)on sheet characteristics is being measured.Tensile strength data at a gage length of zero may be used to assess the retention of fiber strengthand fiber quality parameters through the entire fiber processing chain,thereby providing opportunitiesto optimize fiber characteristics and utilization in various paper grades.Tensile strength valuesdetermined at a gage length of zero contribute to our understanding of finished sheet strength and areof increasing importance in measuring the impact of new pulping,bleaching,and papermakingprocesses on fiber quality characteristics.In turn,fiber quality characteristics impact fiber processingand utilization considerations,and of most importance,the overall finished paper or paperboardproperties and quality.For ease in communication,as well as theoretical considerations,very short-span measurement offibers in sheeted form is generally done at“zero-span,”that is,at an effective gage length of 0.00 mm(0.000 in.).When the specimen is tested in the dry state,this measurement is generally referred to as“zero-span tensile strength.”When the specimen is tested after wetting,the measurement is describedas“wet zero-span tensile strength.”1.Scope1.1 This test method provides a quick,reliable means tomeasure the wet zero-span tensile strength of a specimen ofsheeted material.1.2 In cases where fibers are to be tested prior to finishedproduction of paper or paperboard,a random standard aggre-gate of pulp fibers,or handsheet,produced using a standardizedprocedure,such as,TAPPI T 205 is required.1.3 This test method requires specimens such as thosedescribed in 1.2.1.4 While testing is possible on finished paper or paper-board,information on fiber quality from intermediate steps inthe pulping or papermaking process,or both,is frequently1This 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 November 1998.Originallyapproved in 1995.Last previous edition approved in 1995 as D 5803 95.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.more useful for improving finished paper and paperboardquality or improving fiber utilization of recycled fibers,orfibers subjected to new pulping,bleaching,or finishing pro-cesses(1,2,3,4).21.5 The modifications of this test method required fortesting finished paper is straightforward;however,testing shallbe done in the two principle directions of the sheet,as requiredin Test Method D 829.The finished paper or paperboard willgenerally have nonrandom fiber orientation,resulting in differ-ent strength properties in the two principle directions of thefinished sheet.Testing of sheets having a grammage greaterthan 100 g/m2,which includes some paper materials describedas paper and many paperboards,is difficult because of pr