ASTM_D_5605_-_94_2021.pdf

Designation:D560594(Reapproved 2021)Standard Practice forStyrene-Butadiene Rubber(SBR)Establishing RawMooney Viscosity Target Values1This standard is issued under the fixed designation D5605;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 practice covers a means for producers and users ofemulsion styrene-butadiene rubber(SBR)to establish commontarget values for the Mooney viscosity of these rubbers.1.2 Mooney viscosity is a widely used measurement forrubber as defined in Test Methods D1646 where the procedurefor its measurement is specified.1.3 The Mooney viscosity target value is defined as themidpoint of a Mooney viscosity specification range establishedby a producer or user of rubber.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1646 TestMethodsforRubberViscosity,StressRelaxation,andPre-VulcanizationCharacteristics(Mooney Viscometer)3.Significance and Use3.1 Mooney viscosity is used extensively in the rubberindustry as a measurement of the general quality of raw orcompounded uncured rubber.This special viscosity has beenrelated to average molecular weight and to handling andprocessing characteristics in various rubber operations such asmixing,extruding,molding,and so forth.3.2 This practice addresses the raw Mooney viscosity ofSBR in its finished state at the SBR manufacturers plant andin the ready-to-use state at the rubber product manufacturersplant.3.3 Different processes and different processing equipmentoften require rubber of the same composition at different rawMooney viscosity levels.The use of this practice enablesproducers of SBR to offer each rubber with a number ofstandard target Mooney viscosity values and informs userswhich Mooney viscosity rubbers are available.NOTE1Use of this practice will eliminate the need for producers tomanufacture rubbers of the same composition with target Mooney valuesunrealistically close together.This will allow the manufacturers to produceto each target,and eliminate the need to sort product for many differentspecification ranges.The result will be improved process performanceindexes and more consistent rubber for all users.NOTE2Using this practice will benefit users by providing a publishedlist of the producers Mooney viscosity target values and improvedconsistency of the rubber they receive.The better consistency will resultfrom producing rubber to a target rather than sorting it after it is tested.Interchangeability of rubbers from different producers should be simpli-fied.4.Establishing Target Values4.1 Target values for raw Mooney viscosity of SBR shall bechosen from values ending in a 0 or a 5,for example 55,60,65.4.2 Target values may be expressed in any of the customaryunits(specimen preparation,rotor size,warm-up time,runningtime and temperature).4.3 With targets established at intervals of 5 units,themaximum difference which could occur between a target valueand the midpoint of an established specification range is 2units.A change this small should be able to be accommodatedby most users of SBR.4.3.1 Illustration:Producers Mooney viscositytarget value70 UML1+4(100C)Users specification range6282 UML1+4(100C)Users specification midpoint72 UML1+4(100C)User would choose a Mooney viscosity target value of 70.Ifthe users midpoint had been 73,he would have chosen a targetvalue of 75.1This practice is under the jurisdiction ofASTM Committee D11 on Rubber andRubber-like Materials and is the direct responsibility of Subcommittee D11.23 onSynthetic Rubbers.Current edition approved Nov.1,2021.Published January 2022.Originallyapproved in 1994.Last previous edition approved in 2016 as D5605 94(2016).DOI:10.1520/D5605-94R21.2For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1?5.Keywords5.1 Mooney viscosity;SBR;target valuesASTM International takes no position respecting the validity of any patent rights as