ASTM D4894 - 07(2012)

    Standard Specification for Polytetrafluoroethylene (PTFE) Granular Molding and Ram Extrusion Materials

    Active Standard ASTM D4894 | Developed by Subcommittee: D20.15

    Book of Standards Volume: 08.02


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    ASTM D4894

    Abstract

    This specification focuses on granular polytetrafluoroethylene (PTFE) resins that have never been preformed or molded, and are normally processed by methods similar to those used in powder metallurgy or ceramics, or by special extrusion processes. These PTFE resins are homopolymers of tetrafluoroethylene, or, in some cases, modified homopolymers containing not more than one percent by weight of other fluoromonomers. The materials included herein do not include mixtures of PTFE resin with additives such as colorants, fillers or plasticizers; nor do they include reprocessed or reground resin or any fabricated articles. Included are specimen preparation, test methods and requirements for materials, melting characteristics, bulk density, particle size, water content, standard specific gravity, thermal instability index, and mechanical (tensile) properties.

    This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

    1. Scope

    1.1 This specification covers granular resins and test methods for polytetrafluoroethylene (PTFE) that have never been preformed or molded and are normally processed by methods similar to those used in powder metallurgy or ceramics, or by special extrusion processes. These PTFE resins are homopolymers of tetrafluoroethylene, or, in some cases, modified homopolymers containing not more than one percent by weight of other fluoromonomers. The usual methods of processing thermoplastics generally are not applicable to these materials because of their viscoelastic properties at processing temperatures. The materials included herein do not include mixtures of PTFE resin with additives such as colorants, fillers or plasticizers; nor do they include reprocessed or reground resin or any fabricated articles. The methods and properties included are those required to identify the various types of resins. Additional procedures are provided in the Appendix for further characterization of the resins.

    1.2 The values stated in SI units as detailed in are to be regarded as the standard, and the practices of are incorporated herein.

    1.3 The following precautionary caveat pertains only to the Specimen Preparation section, Section 9, and the Test Methods section, Section 10, of this specification: This specification does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. See Notes 3 and 9 for specific cautionary statements.

    Note 1—Information in this specification is technically equivalent to related information in ISO 12086-1 and ISO 12086-2.


    2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

    ASTM Standards

    D618 Practice for Conditioning Plastics for Testing

    D638 Test Method for Tensile Properties of Plastics

    D792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement

    D883 Terminology Relating to Plastics

    D1895 Test Methods for Apparent Density, Bulk Factor, and Pourability of Plastic Materials

    D3295 Specification for PTFE Tubing, Miniature Beading and Spiral Cut Tubing

    D3892 Practice for Packaging/Packing of Plastics

    D4441 Specification for Aqueous Dispersions of Polytetrafluoroethylene

    D4591 Test Method for Determining Temperatures and Heats of Transitions of Fluoropolymers by Differential Scanning Calorimetry

    D4745 Specification for Filled Compounds of Polytetrafluoroethylene (PTFE) Molding and Extrusion Materials

    D4895 Specification for Polytetrafluoroethylene (PTFE) Resin Produced From Dispersion

    E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves

    E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods

    ISO Standards

    ISO12086-2 Test Methods for Fluoropolymers


    ICS Code

    ICS Number Code 83.080.20 (Thermoplastic materials)

    UNSPSC Code

    UNSPSC Code 13102008(Fluoropolymers PTFE)


    DOI: 10.1520/D4894-07R12

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