ASTM_D_1238_-_20.pdf

Designation:D123820Standard Test Method forMelt Flow Rates of Thermoplastics by ExtrusionPlastometer1This standard is issued under the fixed designation D1238;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope*1.1 This test method covers the determination of the rate ofextrusion of molten thermoplastic resins using an extrusionplastometer.1.2 The values stated in SI units are to be regarded asstandard.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.NOTE1This standard and ISO 1133 address the same subject matter,but differ in technical content.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:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD3364 Test Method for Flow Rates for Poly(Vinyl Chloride)with Molecular Structural ImplicationsD4000 Classification System for Specifying Plastic Materi-alsD5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensE456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ANSI Standard:B46.1 on Surface Texture32.3 ISO Standard:ISO 1133 Determination of the Melt-Mass Flow Rate(MFR)and the Melt Volume-Flow Rate(MVR)of Thermoplas-tics33.Terminology3.1 Terms used in this standard are defined in accordancewith Terminology D883,unless otherwise specified.For termsrelating to precision and bias and associated issues,the termsused in this standard are defined in accordance with Terminol-ogy E456.4.Summary of Test Method4.1 After a specified preheating time,resin is extrudedthrough a die with a specified length and orifice diameter underprescribed conditions of temperature,load,and piston positionin the barrel.Four procedures are described.Comparableresults have been obtained by these procedures in interlabora-tory round-robin measurements of several materials and aredescribed in Section 16.4.2 Procedure A is used to determine the melt flow rate(MFR)of a thermoplastic material.The units of measure aregrams of material/10 minutes(g/10 min).It is based on themeasurement of the mass of material that extrudes from the dieover a given period of time.It is generally used for materialshaving melt flow rates that fall between 0.15 and 50 g/10 min(see Note 2).4.3 Procedure B is an automatically timed measurementused to determine the melt flow rate(MFR)as well as the meltvolume rate(MVR)of thermoplastic materials.MFR measure-ments made with Procedure B are reported in g/10 minutes.MVR measurements are reported in cubic centimeters/ten1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.30 on Thermal Properties(Section D20.30.08).Current edition approved July 1,2020.Published August 2020.Originallyapproved in 1965.Last previous edition approved in 2013 as D1238-13.DOI:10.1520/D1238-20.2For 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.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright 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.1minutes(cm3/10 min).Procedure B measurements are basedon the determination of the volume of material extruded fromthe die over a given period of time.The volume is converted toa mass measurement by multiplying the result by the meltdensity value for the material(see Note 3).Procedure B isgenerally used with materials having melt flow rates from 0.50to 1500 g/10 min.4.4 Procedure C is an autom