ASTM D4894-98a
Historical Standard: ASTM D4894-98a Standard Specification for Polytetrafluoroethylene (PTFE) Granular Molding and Ram Extrusion Materials
SUPERSEDED (see Active link, below)
ASTM D4894
1. Scope
1.1 This specification covers granular resins of 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 materials covered by this specification formerly were covered in Specification D1457 as Types I, IV, V, VI, VII and VIII.
1.3 The values stated in SI units as detailed in Practice E380 are to be regarded as the standard, and the practices of E380 are incorporated herein.
1.4 The following precautionary caveat pertains only to the Specimen Preparation section, Section 9, and the Test Methods section, Section 10, of this specification: This standard 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 1, 3 and 9 for specific cautionary statements.
Note 1-Most of the technical content of this standard is included as part of ISO 12086-1 and ISO 12086-2 Part 2. These standards have been approved for publication and are in the final editing process.
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 FluoropolymersKeywords
fluoropolymers; granular polytetrafluoroethylene; polytetrafluoroethylene; PTFE;
ICS Code
ICS Number Code 83.080.20 (Thermoplastic materials)
DOI: 10.1520/D4894-98A
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