ASTM D4895-10

This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:D4895–04 Designation: D4895 – 10
Standard Specification for
Polytetrafluoroethylene (PTFE) Resin Produced From
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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 Department of Defense.
1. Scope*
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1.1 This specification covers dry-powder resins of polytetrafluoroethylene (PTFE) that have been prepared from dispersions
of PTFE by manufacturing techniques that involve controlled coagulation of the dispersion. These resins are generally known as
“fine-powder” resins or “coagulated-dispersion powder” resins. The conversion of these resins to finished products normally
involves a process called “paste extrusion,” and sometimes involves formative processes such as calendering.Avolatile liquid is
present as a processing aid during these formative stages of conversion, and is subsequently removed during the finishing stages
of conversion.These PTFE resins are homopolymers of tetrafluoroethylene, or, in some cases, modified homopolymers containing
not more than 1 % by weight of other fluoromonomers. The usual methods of processing thermoplastics generally are not
applicabletothesematerialsbecauseoftheirviscoelasticproperties.ThematerialscoveredhereindonotincludemixturesofPTFE
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. The methods and
propertiesincludedarethoserequiredtoidentifythevariousresins.Anadditionalprocedureisprovidedintheappendixforfurther
characterization of the resins.
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 and health 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 12086-1 and ISO 12086-2.
2. Referenced Documents
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2.1 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
D3892 Practice for Packaging/Packing of Plastics
D4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density Meter
D4441 Specification for Aqueous Dispersions of Polytetrafluoroethylene
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
E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
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This specification is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.15 on Thermoplastic Materials.
Current edition approved Feb.July 1, 2004.2010. Published March 2004.August 2010. Originally approved in 1989. Last previous edition approved in 19982004 as
D4895-98.D4895 - 04. DOI: 10.1520/D4895-104.
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Specifications for other forms of polytetrafluoroethylene are found in Specifications D4441 and D4894.
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For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section
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