ASTM D4969-07(2012)

Standard Specification for Polytetrafluoroethylene–(PTFE) Coated Glass Fabric

ABSTRACT
This specification covers glass fabric impregnated, coated, and sintered on both sides with PTFE to a specified maximum nominal thickness. It does not pertain to structural fabric, single-sided PTFE coatings, or materials used for laminates. The PTFE-coated glass fabric is for electrical, chemical, and mechanical uses. The base material used in the manufacture of the products of this specification shall be a woven glass fabric. The glass fabric is impregnated or coated with polytetrafluoroethylene. When necessary, additives are used to aid the dispersion to achieve the required properties and performance of the final product. The glass fabric shall be tested for color, thickness, breaking strength, edge tear, conductivity, percent PTFE, smoothness, and porosity.
SCOPE
1.1 This specification covers glass fabric impregnated, coated, and sintered on both sides with PTFE to a nominal thickness of 0.318 mm (0.015 in.) or less.
1.2 The PTFE-coated glass fabric is for electrical, chemical, and mechanical uses.
1.3 The PTFE-coated glass fabric of this specification does not pertain to structural fabric, single-sided PTFE coatings, or materials used for laminates.
1.4 The values stated in SI units as detailed in .
Note 1—There is no ISO standard that covers information included in this specification. The dielectric test is mentioned in ISO 12086-2 and ISO 13000–1 and 2.

General Information

• Status: Historical
• Publication Date: 31-Mar-2012
• ICS: 59.080.40 - Coated fabrics
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.15 - Thermoplastic Materials

Relations

• Replaces: ASTM D4969-07 - Standard Specification for Polytetrafluoroethylene-(PTFE) Coated Glass Fabric
• Effective Date: 01-Apr-2012

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D4969 −07 (Reapproved 2012)
Standard Specification for
Polytetrafluoroethylene–(PTFE) Coated Glass Fabric
This standard is issued under the fixed designation D4969; 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.
1. Scope* D3892 Practice for Packaging/Packing of Plastics
D4441 Specification for Aqueous Dispersions of Polytetra-
1.1 This specification covers glass fabric impregnated,
fluoroethylene
coated, and sintered on both sides with PTFE to a nominal
IEEE/ASTM SI-10 Standard for Use of the International
thickness of 0.318 mm (0.015 in.) or less.
System of Units (SI): The Modern Metric System
1.2 The PTFE-coated glass fabric is for electrical, chemical,
2.2 ISO Standard:
and mechanical uses.
ISO 12086-2 Plastics—Fluoropolymer Dispersions and
1.3 The PTFE-coated glass fabric of this specification does
MouldingandExtrusionMaterials—Part2:Preparationof
not pertain to structural fabric, single-sided PTFE coatings, or
Test Specimens and Determination of Properties
materials used for laminates.
ISO 13000–1 and 2 Plastics—Polytetrafluoroethylene
(PTFE) Semi-Finished Products
1.4 The values stated in SI units as detailed in IEEE/ASTM
SI-10.
3. Terminology
NOTE 1—There is no ISO standard that covers information included in
3.1 Definitions:
this specification. The dielectric test is mentioned in ISO 12086-2 and
3.1.1 Definitions of terms relating to plastics used in this
ISO 13000–1 and 2.
specification shall be in accordance with Definitions D883.
2. Referenced Documents
Definitions of terms relating to textiles used in this specifica-
tion shall be in accordance with Terminology D123.
2.1 ASTM Standards:
3.1.2 structural fabric—PTFE-coated fabric to a thickness
D123 Terminology Relating to Textiles
of greater than 0.381 mm (0.015 in.).
D149 Test Method for Dielectric Breakdown Voltage and
DielectricStrengthofSolidElectricalInsulatingMaterials
3.1.3 lot, n—one production run or a uniform blend of two
at Commercial Power Frequencies or more production runs.
D257 Test Methods for DC Resistance or Conductance of
4. Classification
Insulating Materials
D374 Test Methods for Thickness of Solid Electrical Insu-
4.1 There shall be six types of PTFE-coated glass fabrics as
lation
described in Table 1.
D579 Specification for Greige Woven Glass Fabrics
4.2 Use a one-line system to specify materials covered by
D618 Practice for Conditioning Plastics for Testing
this specification. The system uses redefined cells to refer to
D737 Test Method for Air Permeability of Textile Fabrics
specific aspects of this specification, as illustrated below as
D751 Test Methods for Coated Fabrics
follows.
D883 Terminology Relating to Plastics
Specification
D902 Test Methods for Flexible Resin-Coated Glass Fabrics
Standard Number Type Grade Class Special
and Glass Fabric Tapes Used for Electrical Insulation
Block Notes
D1424 Test Method for Tearing Strength of Fabrics by
Example: ASTM D4969-XX IV – – ,
Falling-Pendulum (Elmendorf-Type) Apparatus
For this example, the line call out would be: ASTM
D4969 – XX, IV– – , Porosity 15–30 CFM, and would specify
a Type IV porous product which is referenced in Table 1 with
This specification is under the jurisdiction of Committee D20 on Plastics and is
nogradeorclasssincethesesubcategoriesdonotappearinthis
the direct responsibility of Subcommittee D20.15 on Thermoplastic Materials.
Current edition approved April 1, 2012. Published June 2012. Originally
specification. A comma is used as the separator between the
approved in 1989. Last previous edition approved in 2007 as D4969 – 07. DOI:
standard number and the type. Separators are not needed
10.1520/D4969-07R12.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4969−07 (2012)
TABLE 1 PTFE-Coated Glass Fabric Types
Type Name General Description and Common Application
I Premium Smooth, defect-free, primarily used as a dielectric application, release sheet,
and Military Specification material.
II Standard Regular-grade material primarily used for mechanical applications where
temperature and easy-release characteristics are required.
III Mechanical Regular-grade material primarily used for mechanical applications where
smoothness is not a critical requirement.
IV Porous Permeable material, with a range of porosity primarily used as a release sheet in
molding.
V Tear resistant Smooth, flexible, and tear-resistant material for mechanical applications requiring
flexible materials.
VI Conductive Regular-grade material primarily used for static discharge.
between the type, grade, and class because they are, in turn, 6.2.4 Other colors for products that contain pigments, fill-
Roman numerals, Arabic digits, and uppercase letters, as ers, and additives will be agreed upon between the suppliers
providedinSectionB8of Form and Style forASTM Standards. and the customers.
Provision for “Special Notes” is included so that other infor-
6.3 Thickness—The thickness of the glass fabric is depen-
mation can be provided when required. An example would be
dent on glass style and percent PTFE coating. Tolerances are
in this specification where porosity would be defined as 15–30
typically 610 % of the finished thickness. Thickness shall be
CFM.Whenspecialnotesareused,theyshouldbeprecededby
tested in accordance with Test Methods D374.
a comma.
NOTE2—Typically,glassandcoatedglassproductsaremanufacturedto
a weight per unit area.
5. Materials and Manufacture
6.4 Breaking Strength—When tested in accordance with
5.1 Glass Fabric—The base material used in the manufac-
Methods D902, the breaking strength shall be at least 80 % of
ture of the products of this specification shall be a woven glass
the specified value stated in Table 6 of Specification D579.
fabric produced in accordance with Specification D579.A
guideline for generally acceptable substrate fabrics for the
NOTE 3—Reduction of tensile strength is due to added heat required for
common thickness of PTFE/glass fabric products is given in coating.
Table 2.
6.5 Edge Tear Strength—(Elmendorf) Tears shall be tested
in accordance with Test Method D1424. Tear values are
5.2 Coating—Theglassfabricisimpregnatedorcoatedwith
dependent upon glass style and additives added to the PTFE.
polytetrafluoroethylene in accordance with Specification
Typical Tear Resistant (Type 5) products exhibit two times the
D4441. When necessary, use additives to aid the dispersion to
values of their counterparts. Conductive (Type 6) products
achieve the required properties and performance of the final
exhibit one half the values of their counterparts. Test values
product.
and tolerances shall be determined by the supplier and the
6. Physical Requirement
...