1、Designation:D489419Standard 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
2、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 beenprefor
3、med 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 fluorom
4、onomers.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
5、 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 de
6、tailed 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 specificationdoe
7、s 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
8、statements.NOTE1Information in this specification is technically equivalent torelated information in ISO 12086-1 and ISO 12086-2.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for t
9、heDevelopment 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 TestingD792 Test Methods for Density and Specific Gravity(Rela-ti
10、ve 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 Beadinga
11、nd 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
12、 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
13、 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:DesignationSystem and Basis for Specification1This specification is
14、 under the jurisdiction of ASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved May 1,2019.Published June 2019.Originallyapproved in 1989.Last previous edition approved in 2015 as D4894-15.DOI:10.1520/D4894-19.2For r
15、eferenced 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
16、.,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 Techni
