ASTM_G_143_-_03_2013.pdf

Designation:G14303(Reapproved 2013)Standard Test Method forMeasurement of Web/Roller Friction Characteristics1This standard is issued under the fixed designation G143;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 covers the simulation of a roller/webtransport tribosystem and the measurement of the static andkinetic coefficient of friction of the web/roller couple whensliding occurs between the two.The objective of this testmethod is to provide users with web/roller friction informationthat can be used for process control,design calculations,andfor any other function where web/roller friction needs to beknown.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1894 Test Method for Static and Kinetic Coefficients ofFriction of Plastic Film and SheetingD3108 Test Method for Coefficient of Friction,Yarn to SolidMaterialE8 Test Methods for Tension Testing of Metallic MaterialsE122 Practice for Calculating Sample Size to Estimate,WithSpecified Precision,the Average for a Characteristic of aLot or ProcessE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodG40 Terminology Relating to Wear and ErosionG115 Guide for Measuring and Reporting Friction Coeffi-cientsG117 Guide for Calculating and Reporting Measures ofPrecision Using Data from Interlaboratory Wear or Ero-sion TestsG163 Guide for Digital Data Acquisition in Wear andFriction Measurements3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 blocking,nunintentional adhesion between plasticfilms or between a film and another surface.D8833.1.2 coeffcient of friction,nin tribologythe dimen-sionless ratio of the friction force(F)between two bodies to thenormal force(N)pressing these bodies together.G403.1.3 friction force,nthe resisting force tangential to theinterface between two bodies when,under the action ofexternal force,one body moves or tends to move relative to theother.G403.1.4 kinetic coeffcient of friction,nthe coefficient offriction under conditions of macroscopic relative motion be-tween two bodies.G403.1.5 stick-slip,na cyclic fluctuation in the magnitudes offriction force and relative velocity between two elements insliding contact,usually associated with a relaxation oscillationdependent on elasticity in the tribosystem and on a decrease ofthe coefficient of friction with onset of sliding or with increaseof sliding velocity.G403.1.5.1 DiscussionClassical or true stick-slip,in whicheach cycle consists of a stage of actual stick followed by astage of overshoot slip,requires that the kinetic coefficient islower than the static coefficient.A modified form of relaxationoscillation,with near-harmonic fluctuation in motion,canoccur when the kinetic coefficient of friction decreases gradu-ally with increasing velocity within a certain velocity range.Athird type of stick-slip can be due to spatial periodicity of thefriction coefficient along the path of contact.Random varia-tions in friction force measurement do not constitute stick-slip.3.1.6 triboelement,none of two or more solid bodieswhich comprise a sliding,rolling,or abrasive contact,or abody subjected to impingement or cavitation.G403.1.6.1 DiscussionContacting triboelements may be in1This test method is under the jurisdiction of ASTM Committee G02 on Wearand Erosion and is the direct responsibility of Subcommittee G02.50 on Friction.Current edition approved Nov.15,2013.Published November 2013.Originallyapproved in 1996.Last previous edition approved in 2009 as G14303(2009).DOI:10.1520/G0143-03R13.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 direct contact,or may be separated by an intervening lubricant,oxide,or other film that affects tribological interactions be-tween them.3.1.7 tribosystem,nany system that contains one or moretriboelements,including all mechanical,chemical,and envi-ronmental factors relevant to tribological behavior.G404.Summary of Test Method4.1 This test method