ASTM_D_6125_-_97_2007.pdf

Designation:D6125 97(Reapproved 2007)An American National StandardStandard Test Method forBending Resistance of Paper and Paperboard(Gurley TypeTester)1This standard is issued under the fixed designation D6125;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 determines the bending resistance ofpaper,paperboard,and other flexible flat-sheet materials bymeasuring the force required to bend a specimen undercontrolled conditions.The instrument described allows for awide variation in specimen length,width and applied force.1.2 This test method is not recommended for soft,limp orcreped materials.Materials such as tissue or toweling wouldnot normally be tested by this procedure and materials with apronounced degree of curl would give erroneous results.Products with a bending resistance below 1.39 Gurley Units(orproducts not able to give a deflection between 1 and 7 on thescale when using the lightest weight)should not be tested bythis procedure.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.1.4 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.2.Referenced Documents2.1 ASTM Standards:2D585 Practice for Sampling and Accepting a Single Lot ofPaper,Paperboard,Fiberboard,and Related ProductD685 Practice for Conditioning Paper and Paper Productsfor Testing2.2TAPPI Standards:3T 543 Bending Resistance of PaperT 1200 Interlaboratory Evaluation of Test Methods to De-termine TAPPI Repeatability and Reproducibility3.Terminology3.1 Definitions:3.1.1 bending resistance,na material attribute quantifiedby the magnitude of an applied force which produced deflec-tion of a specimen having specified dimensions.3.1.2 stiffness,of paper and paperboard,na synonym forbending resistance.3.1.3 machine direction bending resistance,nthe bendingresistance of a test specimen,clamped with the machinedirection of the paper perpendicular to the specimen clamp.3.1.4 cross direction bending resistance,nthe bendingresistance of a test specimen,clamped with the cross directionof the paper perpendicular to the specimen clamp.3.2 Definitions of Terms Specific to This Standard:3.2.1 Gurley stiffness,nstiffness or bending resistance ofpaper and paperboard determined using measurements madewith a specific instrument patented by W&L.E.Gurley Co.3.2.2 Gurley units,nthe units assigned to represent theforce required to bend the specimen.Traditionally the resultshave been reported in terms of milligrams of force(mgf)whichare identical to the now preferred term of Gurley units.In termsof force units(milliNewtons)the following applies:Force,mN 5 9.807 3 103Gurley units!(1)3.2.3 Taber stiffness,nstiffness of paper and paperboarddetermined using measurements made with a specific instru-ment patented by Taber Industries.4.Significance and Use4.1 The bending resistance of paper affects many convertingoperations and most end-users.The bending resistance ofpaperboard is basic to many of the uses into which this materialis placed.It is necessary to have a convenient,reproducible testmethod to measure this fundamental characteristic.5.Apparatus5.1 Bending Resistance Tester:5.1.1 The instrument,shown in Fig.1,consists of a bal-anced pendulum or pointer,pivoted at its center of gravity,mounted in jewel bearings,and provided with holes for1This test method is under the jurisdiction of ASTM Committee D06 on Paperand Paper Products and is the direct responsibility of Subcommittee D06.92 onStandard Documents Relating to Paper and Paper Products.Current edition approved Dec.1,2007.Published December 2007.Originallyapproved in 1997.Last previous edition approved in 2002 as D6125 97(2002).DOI:10.1520/D6125-97R07.2For 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 Technical Association of the Pulp and Paper Industry(TAPPI),15 Technology Parkway South,Norcross,GA 30092,http:/www.tappi.org.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.NOTICE:This standard has either been superseded and replaced by a new version or withdrawn.Contact ASTM International(www.astm.org)for the latest information.attaching weights at a distance of 25.4 mm(1 in.),50.8 mm(2in.),and 101.6 mm(4 in.)below the center pivot.In non-digitalinstruments,the lower end of the pendulum is pointe