ASTM D4895-18(2023)

Standard Specification for Polytetrafluoroethylene (PTFE) Resin Produced From Dispersion

ABSTRACT
This specification covers dry-powder resins of polytetrafluoroethylene (PTFE) resin produced from dispersion. PTFE mixtures with additives are not covered in this specification. This specification covers type I and type II PTFE. The resins shall be tested for bulk density, particle size, water content, melting peak temperature, tensile strength, elongation at break, standard specific gravity, extrusion pressure, thermal instability index, and stretching void index. Specimen preparation, testing, inspection, and packaging shall be in accordance to the procedures indicated in this specification.
SCOPE
1.1 This specification2 covers polytetrafluoroethylene (PTFE) prepared by coagulation of a dispersion. These PTFE resins are homopolymers of tetrafluoroethylene or modified homopolymers containing not more than 1 % by weight of other fluoromonomers. The materials covered herein do not include mixtures of PTFE with additives such as colors, fillers, or plasticizers; nor do they include reprocessed or reground resin or any fabricated articles because the properties of such materials have been irreversibly changed when they were fibrillated or sintered.  
1.2 The values stated in SI units as detailed in IEEE/ASTM SI-10 are to be regarded as standard. The values given in parentheses are for information only.  
1.3 The following safety hazards 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. See Warning note in 9.1.1 for a specific hazards statement.
Note 1: Information in this specification is technically equivalent to related information in ISO 20568-1 and ISO 20568-2.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Apr-2023
• ICS: 83.080.10 - Thermosetting materials
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.15 - Thermoplastic Materials

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4895 − 18 (Reapproved 2023)
Standard Specification for
Polytetrafluoroethylene (PTFE) Resin Produced From
1
Dispersion
This standard is issued under the fixed designation D4895; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2. Referenced Documents
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2
2.1 ASTM Standards:
1.1 This specification covers polytetrafluoroethylene
D618 Practice for Conditioning Plastics for Testing
(PTFE) prepared by coagulation of a dispersion. These PTFE
D638 Test Method for Tensile Properties of Plastics
resins are homopolymers of tetrafluoroethylene or modified
D792 Test Methods for Density and Specific Gravity (Rela-
homopolymers containing not more than 1 % by weight of
tive Density) of Plastics by Displacement
other fluoromonomers. The materials covered herein do not
D883 Terminology Relating to Plastics
include mixtures of PTFE with additives such as colors, fillers,
D1708 Test Method for Tensile Properties of Plastics by Use
or plasticizers; nor do they include reprocessed or reground
of Microtensile Specimens
resin or any fabricated articles because the properties of such
D1895 Test Methods for Apparent Density, Bulk Factor, and
materials have been irreversibly changed when they were
Pourability of Plastic Materials
fibrillated or sintered.
D3892 Practice for Packaging/Packing of Plastics
1.2 The values stated in SI units as detailed in IEEE/ASTM
D4052 Test Method for Density, Relative Density, and API
SI-10 are to be regarded as standard. The values given in
Gravity of Liquids by Digital Density Meter
parentheses are for information only.
D4441 Specification for Aqueous Dispersions of Polytet-
1.3 The following safety hazards caveat pertains only to the
rafluoroethylene
Specimen Preparation Section, Section 9, and the Test Methods
D4591 Test Method for Determining Temperatures and
Section, Section 10, of this specification: This standard does
Heats of Transitions of Fluoropolymers by Differential
not purport to address all of the safety concerns, if any,
Scanning Calorimetry
associated with its use. It is the responsibility of the user of this
D4894 Specification for Polytetrafluoroethylene (PTFE)
standard to establish appropriate safety, health, and environ-
Granular Molding and Ram Extrusion Materials
mental practices and determine the applicability of regulatory
E11 Specification for Woven Wire Test Sieve Cloth and Test
limitations prior to use. See Warning note in 9.1.1 for a specific
Sieves
hazards statement.
E29 Practice for Using Significant Digits in Test Data to
Determine Conformance with Specifications
NOTE 1—Information in this specification is technically equivalent to
E177 Practice for Use of the Terms Precision and Bias in
related information in ISO 20568-1 and ISO 20568-2.
ASTM Test Methods
1.4 This international standard was developed in accor-
IEEE/ASTM SI-10 Use of the International System of Units
dance with internationally recognized principles on standard-
(SI): The Modern Metric System
ization established in the Decision on Principles for the
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2.2 ISO Standards:
Development of International Standards, Guides and Recom-
ISO 20568-1 Plastics Fluoropolymer Dispersions and Mold-
mendations issued by the World Trade Organization Technical
ing and Extrusion Materials—Part 1: Designation and
Barriers to Trade (TBT) Committee.
Specification
ISO 20568-2 Plastics Fluoropolymer Dispersions and
Molding and Extrusion Materials—Part 2: Preparation of
1
This specification is under the jurisdiction of ASTM Committee D20 on
Plastics and is the direct responsibility of Subcommittee D20.15 on Thermoplastic
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Materials. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved May 1, 2023. Published May 2023. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1989. Last previous edition approved in 2018 as D4895 – 18. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D4895-18R23. the ASTM website.
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Specifications for other forms of polytetrafluoroethylene are found in Specifi- Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
cations D4441 and D4894. 4th Floor, New York, NY 10036, http://www.ansi.org.
*A Summary of Changes section appears at the end of this standard
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