ASTM_D_3028_-_95.pdf

Designation:D 3028 95An American National StandardStandard Test Method forKinetic Coefficient of Friction of Plastic Solids1This standard is issued under the fixed designation D 3028;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 covers the determination of sliding(kinetic)friction of plastic solids or sheeting(as movingspecimens)when sliding against similar or dissimilar sub-stances(Note 1)(as fixed specimens)through the speed rangeof approximately 0.10 to 3.00 m/s.The instrument used is avariable speed,variable normal-force frictionometer.2,3NOTE1The physical form for these fixed specimens should be that ofrigid or self-supporting solids.Attempts to mount thin sheeting,film,foil,etc.,are not recommended due to the difficulty encountered whenattempting to meet the weight and concentricity requirements(see 4.1.1).1.2 Rigid or self-supporting specimens must be machined tospecified dimensions.Normally,sheeting exceeding 1.00 mm(0.040 in.)in thickness should not be tested on a mountingwheel of standard diameter.NOTE2An error accumulation of 1%per 0.50 mm(0.020 in.)ofsheeting thickness results as the standard diameter of the test surface isincreased.If the resulting error is not tolerable,undersize mountingwheels can be employed.1.3 Two testing procedures are included.Selection of aprocedure is determined by the specific interests of the inves-tigator.The procedures are:1.3.1 Procedure ADetermination of variable-velocity ki-netic coefficients,and1.3.2 Procedure BDetermination of constant-velocity ki-netic coefficients over an extended period of time.1.4 Test data obtained by this test method is relevant andappropriate for use in engineering design.1.5 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.6This 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 618 Practice for Conditioning Plastics and ElectricalInsulating Materials for Testing4D 4000 Classification System for Specifying Plastic Mate-rials53.Significance and Use3.1 Kinetic coefficients of friction serve as indexes forcharacterizing materials that are subjected to conditions of slip.Many variables affect the frictional behavior of materials andby offering more than a single method of test the influence ofthese variables can be more readily observed.3.2 The specific procedures offer investigators an opportu-nity to select a method of testing that is best suited to theirparticular interests.Diversified applications of frictional infor-mation can thus be served and a closer correlation between testresults and actual performance might be expected.3.3 Procedure A provides data with respect to many differ-ent velocities within a specified range.Effects of wear andtemperature are kept to a minimum.Although these effects areminimized,their influence is often recognized when the valuesobtained while descending the velocity scale(see 8.1)consis-tently differ with those obtained while ascending the velocityscale.3.4 Procedure B provides data with respect to wear andtemperature.Effects of changing velocities are eliminated sincethe testing velocity is held constant.3.5 Since frictional properties often depend on surfaceconditions,it should not necessarily be expected that identicalresults between like specimens will always occur.Surfaceproperties of materials under study can vary greatly when theyare produced by different processes or by like processes ondifferent equipment.In the case of film testing,the time-dependent blooming of lubricants or other processing additivescan produce varying surface conditions.3.6 For many materials,there may be a specification thatrequires the use of this test method,but with some procedural1This test method is under the jurisdiction ofASTM Committee D-20 on Plasticsand is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.Current edition approved Oct.10,1995.Published December 1995.Originallypublished as D 3028 72.Last previous edition D 3028 93.2Available from Custom Scientific Instruments Inc.,Whippany,NJ.3Westover,R.F.,and Vroom,W.I.,“A Variable Speed Frictionometer forPlastics,Rubbers,Metals,and other Materials,”S.P.E.Journal,Vol 19,No.10,October 1963.4Annual Book of ASTM Standards,Vol 08.01.5Annual Book of ASTM Standards,Vol 08.02.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.NOTICE:This standard has either been superseded and replaced by a new version or discon