Active Standard ASTM D4441 | Developed by Subcommittee: D20.15
Book of Standards Volume: 08.02
Historical (view previous versions of standard)
This specification establishes the properties and test methods for aqueous dispersions of polytetrafluoroethylene (PTFE) resins, and is used to determine if a shipment, lot, or container of PTFE dispersions is suitable for its intended use. These resins are homopolymers of tetrafluoroethylene, or in some cases modified homopolymers containing not more than 1% by weight of other fluoromonomers, and the dispersions are usually stabilized by one or more surfactants. Other non-PTFE materials may be present in total at 5% or less by weight for special purposes. This specification is for virgin materials only, and does not cover PTFE copolymers or filled dispersions, and recycled materials as they are not appropriate for dispersions. Materials shall be appropriately sampled for testing on the following: pH value; solid and surfactant content by gravimetric weight loss; solid content by hydrometer; test for coagulated polymer; specific gravity; and melting characteristics.
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.
1.1 This specification covers aqueous dispersions of polytetrafluoroethylene (PTFE) resins. These resins are homopolymers of tetrafluoroethylene, or in some cases modified homopolymers containing not more than 1 % by weight of other fluoromonomers.
1.1.1 The dispersion is usually stabilized by one or more surfactants. Other non-PTFE materials may be present in total at 5 % or less by weight for special purposes.
1.1.2 This specification is for virgin material only and does not address recycled material as it is not appropriate for dispersions.
1.2 This specification is used to determine if a shipment, lot, or container of PTFE dispersion is suitable for its intended use. It covers only aqueous dispersions of polytetrafluoroethylene. It does not cover PTFE copolymers or filled dispersions. This specification includes test methods for both aqueous dispersion and the PTFE in the dispersion.
Note 1—Uses for the PTFE dispersion covered by this specification include, but are not limited to, casting of their films, impregnation of mechanical packings and other materials, surface coatings on various substrates, combined impregnation and coating of fibrous materials, and co-coagulation with other materials for subsequent processing into films, sheets, rods, and tubes.
Note 2—Information in this specification is technically equivalent to related information in ISO 12086-1 and ISO 12086-2.
1.4 The following precautionary caveat pertains only to the test method portions 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. Specific precautionary information is given in Notes 5 and 6.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D883 Terminology Relating to Plastics
D3892 Practice for Packaging/Packing of Plastics
D4464 Test Method for Particle Size Distribution of Catalytic Material by Laser Light Scattering
D4591 Test Method for Determining Temperatures and Heats of Transitions of Fluoropolymers by Differential Scanning Calorimetry
D4894 Specification for Polytetrafluoroethylene (PTFE) Granular Molding and Ram Extrusion Materials
D4895 Specification for Polytetrafluoroethylene (PTFE) Resin Produced From Dispersion
E70 Test Method for pH of Aqueous Solutions With the Glass Electrode
ICS Number Code 83.080.20 (Thermoplastic materials)