ASTM_D_4918_-_97_2002.pdf

Designation:D 4918 97(Reapproved 2002)An American National StandardStandard Test Method forCoefficient of Static Friction of Uncoated Writing andPrinting Paper by Use of the Inclined Plane Method1This standard is issued under the fixed designation D 4918;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 describes a procedure for the determi-nation of the coefficient of static friction of paper measuredwhen sliding against itself.The inclined plane procedure isused.1.2 Although this test method is basic in concept,theprecision statement has been developed on uncoated writingand printing papers.While the use of this test method isrecommended for those grades only,it may be used with othertypes of paper giving specific attention to special papercharacteristics and with the understanding that the precisionmay not be the same.1.3 Static coefficient of friction(COF)relates to the forcerequired to initiate movement between two surfaces whilekinetic COF relates to the force required to cause continuationof the movement at uniform speed.Kinetic COF cannot bemeasured by this test method.Both static and kinetic COF canbe measured by Test Method D 4917.1.4 A horizontal plane method is described in Test MethodD 4917,which gives similar results.The choice of approachdepends upon the equipment available and the means ofmeasurement.1.5 The determination of this characteristic for corrugatedand solid fiberboard is described in Test Methods D 4521 andD 3247.The test methods differ in that,in Test MethodsD 4521 and D 3247,the two specimens are allowed to slipupon one another three times before the angle of inclination isdetermined,while in this test method,the angle is determinedon the first slip.1.6 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 528 Test Method for Machine Direction of Paper andPaperboard2D 585 Practice for Sampling and Accepting a Single Lot ofPaper,Paperboard,Fiberboard or Related Product2D 685 Practice for Conditioning Paper and Paper Productsfor Testing2D 1968 Terminology Relating to Paper and Paper Products2D 3247 Method of Test for Coefficient of Static Friction ofCorrugated and Solid Fiberboard(Horizontal PlaneMethod)3D 3460 Specification for White Watermarked and Unwater-marked Bond,Mimeo,Spirit Duplicator,Reprographic andLaser Printer Cut-Sized Office Papers2D 4521 Test Method for Coefficient of Static Friction ofCorrugated and Solid Fiberboard2D 4917 Test Method for Coefficient of Static and KineticFriction of Uncoated Writing and Printing Paper by Use ofthe Horizontal Plane Method23.Terminology3.1 DefinitionsDefinitions shall be in accordance withTerminology D 1968 and the Dictionary of Paper.44.Summary of Test Method4.1 One specimen of the paper sample is clamped to aninclined plane,the other to a rubber-faced sled.The sled isplaced on the inclined plane and the plane raised until the sledbegins sliding.The coefficient of static friction is equal to thetangent of the angle at which sliding begins.5.Significance and Use5.1 The coefficient of friction of printing and writing papersindicates the ease with which the top or bottom sheet of a stackof paper will slide across the succeeding sheet,such as occurson the infeed of a sheet-fed printing press or the sheet transportinto a copier machine.A minimum coefficient of friction isrequired to prevent the double-feeding of any sheets.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 November 1998.Originallyapproved in 1989.Last previous edition approved in 1995 as D 4918 95.2Annual Book of ASTM Standards,Vol 15.09.3Withdrawn 1988,replaced by Test Method D 4521.4Available from the Technical Association of the Pulp and Paper Industry,P.O.Box 105113,Atlanta,GA 303481Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.5.2 Since each sheet is removed from the stack only once,asingle slide of each pair of specimens is performed and thevalue recorded.6.Apparatus(Fig.1)6.1 Inclined PlaneA plane surface,hinged so that it canbe tilted,with a smooth,incompressible top surface which maybe made of metal,wood,plate glass,or plastic having a widthat least 25 mm(1 in.)wider than the sled and a length sufficientto permit the sled to move at least 15 mm(58in.).The plane isprovided with a clamp at the upper end to fix the t