ASTM_D_4894_-_15.pdf

Designation:D489415Standard Specification forPolytetrafluoroethylene(PTFE)Granular Molding and RamExtrusion Materials1This standard is issued under the fixed designation D4894;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.Scope*1.1 This specification covers granular resins and test meth-ods for polytetrafluoroethylene(PTFE)that have never beenpreformed or molded and are normally processed by methodssimilar to those used in powder metallurgy or ceramics,or byspecial extrusion processes.These PTFE resins are homopoly-mers of tetrafluoroethylene,or,in some cases,modified ho-mopolymers containing not more than one percent by weight ofother fluoromonomers.The usual methods of processing ther-moplastics generally are not applicable to these materialsbecause of their viscoelastic properties at processing tempera-tures.The materials included herein do not include mixtures ofPTFE resin with additives such as colorants,fillers or plasti-cizers;nor do they include reprocessed or reground resin or anyfabricated articles.The methods and properties included arethose required to identify the various types of resins.Addi-tional procedures are provided in the Appendix for furthercharacterization of the resins.1.2 The values stated in SI units as detailed in IEEE/ASTMSI-10 are to be regarded as the standard,and the practices ofIEEE/ASTM SI-10 are incorporated herein.1.3 The following precautionary caveat pertains only to theSpecimen Preparation section,Section 9,and the Test Methodssection,Section 10,of this specification:This specificationdoes not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility of the user of thisstandard to establish appropriate safety and health practicesand determine the applicability of regulatory limitations priorto use.See Notes 3 and 9 for specific cautionary statements.NOTE1Information in this specification is technically equivalent torelated information in ISO 12086-1 and ISO 12086-2.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD792 Test Methods for Density and Specific Gravity(Rela-tive Density)of Plastics by DisplacementD883 Terminology Relating to PlasticsD1708 Test Method for Tensile Properties of Plastics by Useof Microtensile SpecimensD1895 Test Methods for Apparent Density,Bulk Factor,andPourability of Plastic MaterialsD3295 Specification for PTFE Tubing,Miniature Beadingand Spiral Cut TubingD3892 Practice for Packaging/Packing of PlasticsD4441 Specification for Aqueous Dispersions of Polytetra-fluoroethyleneD4591 Test Method for Determining Temperatures andHeats of Transitions of Fluoropolymers by DifferentialScanning CalorimetryD4745 Classification System and Basis for Specification forFilled Polytetrafluoroethlyene(PTFE)Molding and Extru-sion Materials Using ASTM MethodsD4895 Specification for Polytetrafluoroethylene(PTFE)Resin Produced From DispersionE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsIEEE/ASTM SI-10 Standard for Use of the InternationalSystem of Units(SI):The Modern Metric System2.2 ISO Standards:3ISO 12086-1 PlasticsFluoropolymer Dispersions andMoulding and Extrusion MaterialsPart 1:Designation1This specification is under the jurisdiction of ASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved May 1,2015.Published June 2015.Originallyapproved in 1989.Last previous edition approved in 2012 as D4894-07(2012).DOI:10.1520/D4894-15.2For 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 System and Basis for SpecificationISO 12086-2 Test Methods for Fluoropolymers3.Terminology3.1 Definitions:3.1.1 The terminology given in Terminology D883 is appli-cable to this specification.3.2 Descriptions of Terms Specific to This Standard:3.2.1 bulk densitythe mass(in grams)per litre of resinmeasured under the conditions of the test.3.2.2 extended specific gravity(ESG)the specific gravityof a specimen of PTFE material molded as described in thisspecification and sintered(g.v.)for an extended period of time,compared to the sintering time for the measurement of standardspecific gravity(SSG),using the appropriate si