ASTM_D_4020_-_11.pdf

Designation:D402011Standard Specification forUltra-High-Molecular-Weight Polyethylene Molding andExtrusion Materials1This standard is issued under the fixed designation D4020;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 specification provides for the identification ofvirgin,natural color,unmodified homopolymer ultra-high-molecular-weight polyethylene(UHMW-PE)plastics moldingand extrusion materials.This identification is made in such amanner that the seller and purchaser can agree on the accept-ability of different commercial lots or shipments.1.2 This specification also provides guidance for the char-acterization of UHMWPE materials based on variousmechanical,thermal,electrical,and other analyses.1.3 It is not intended to differentiate between variousmolecular weight grades of ultra-high-molecular-weight poly-ethylene commercially available.1.4 It is not the function of this specification to providespecific engineering data for design purposes.1.5 Ultra-high-molecular-weight polyethylenes,as definedin this specification,are those linear polymers of ethylenewhich have a relative viscosity of 1.44 or greater,in accor-dance with the test procedures described herein.1.6 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.7 The following precautionary caveat pertains only to thetest method portions in Section 7 and the Annex andAppendixes,of this specification:This standard does not pur-port to address all of the safety concerns,if any,associatedwith its use.It is the responsibility of the user of this standardto establish appropriate safety and health practices anddetermine the applicability of regulatory limitations prior touse.NOTE1This standard and ISO 11542-1 address the same subjectmatter,but differ in technical content.ISO 11542-1 provides a classifica-tion system based on various characteristics and a range of viscositynumbers determined in accordance with ISO 1628-3.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1601 Test Method for Dilute Solution Viscosity of Ethyl-ene Polymers2.2 ISO Standards:3ISO 11542-1 PlasticsUltra High Molecular-Weight Poly-ethylene(PE-UHMW)MouldingandExtrusionMaterialsPart 1:Designation System and Basis forSpecificationISO 1628-3 PlasticsDetermination of Viscosity Numberand Limiting Viscosity NumberPart 3:Polyethylenesand Polypropylenes3.Terminology3.1 DefinitionsDefinitions of terms used in this specifica-tion are in accordance with Terminology D883.3.2 Definitions of Terms Specific to This Standard:3.2.1 ultra-high-molecular-weight polyethylene moldingand extrusion materialsas defined by this specification,thosesubstantially linear polyethylenes which have a relative viscos-ity of 1.44 or greater,at a concentration of 0.02%,at 135C,indecahydronaphthalene.3.2.1.1 DiscussionIt has been common practice to refer tothe“molecular weight”of UHMW-PE resins.The followingcalculations shall be used to approximate the specific viscosity(sp),reduced viscosity(red or R.S.V.),intrinsic viscosity(or I.V.),and the approximate nominal viscosity average mo-lecular weight of virgin resin.The calculations are shown asfollows:1This specification is under the jurisdiction of ASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved Sept.1,2011.Published October 2011.Originallyapproved in 1981.Last previous edition approved in 2005 as D4020-05.DOI:10.1520/D4020-11.2For 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 States1 Relative viscosity5 r5Sts2ktsD/Sto2ktoD(1)Specific viscosity5 sp5 r2 1Reduced viscosity5 red5spCThe intrinsic viscosity is calculated by determining thereduced viscosity and extrapolating to infinite dilution,thatis,0%concentration.Intrinsic viscosity=(2sp 2 ln rel)1/2 cNominal viscosity molecular weight=5.37 1041.37where:k=kinetic energy correction constant for the particularviscometer used,ts=flow time of solution at 135C,s,to=flow time of pure solvent at 135C,s,andC=concentration.NOTE2There are other equations being used in industry to calculatethe nominal viscosity average molecular weights.Re