ASTM D4441-98

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 stabilized by one or more surfactants. Other non-PTFE materials may be present in total at 5% or less by weight for special purposes.

1.2 This specification may be 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 both tests on the aqueous dispersion and tests on 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.

1.3 The values stated in SI units, as detailed in Practice E 380, are to be regarded as the standard.

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.