1、Designation:D 6125 97(Reapproved 2002)An American National StandardStandard Test Method forBending Resistance of Paper and Paperboard(Gurley TypeTester)1This standard is issued under the fixed designation D 6125;the number immediately following the designation indicates the year oforiginal adoption
2、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 determines the bending resistance ofpaper,paperboard,and other fle
3、xible 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
4、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
5、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 prio
6、r 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:D 585 Practice for Sampling and Accepting a Single Lot ofPaper,Paperboard,Fiberboard,and Related Product2D 685 Practice for Co
7、nditioning Paper and Paper Productsfor Testing22.2TAPPI 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 magn
8、itude 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
9、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 resi
10、stance 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 i
11、dentical 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.Sig
12、nificance 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 charac
13、teristic.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 forattaching weights at a distance of 25.4 mm(1 in.),50.8 mm(2in.),and 101.6 mm(4 in.)b
14、elow the center pivot.In non-digitalinstruments,the lower end of the pendulum is pointed andmoves parallel to a scale mounted on the base of the instru-ment.The scale is graduated,in both left and right directions,1This test method is under the jurisdiction of ASTM Committee D06 on Paperand Paper Pr
15、oducts and is the direct responsibility of Subcommittee D06.92 on TestMethods.Current edition approved May 10,1997.Published February 1998.2Annual Book of ASTM Standards,Vol 15.09.3Available from the Technical Association of the Pulp and Paper Industry,Technology Park,P.O.Box 105113,Atlanta,GA 30348
16、.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.from zero to 8 units(corresponding to 10 times the sine of theangle produced by the pendulum)and is subdivided into fivedivisions,permitting readings to 0.1 unit.Newer versionsemploy optical encoders and microprocessors to measure thependulum angle and compute the bending resistance automati-cally.5.1.2 The upper end of the pendulum terminates in atriangular vane,50.8 mm(2 in.)wide at t