ASTM D3308-97

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 3308 – 97 An American National Standard
Standard Specification for
PTFE Resin Skived Tape
This standard is issued under the fixed designation D 3308; 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 (e) 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 D 882 Test Methods for Tensile Properties of Thin Plastic
Sheeting
1.1 This specification covers skived tape in thicknesses
D 1389 Methods for Dielectric Proof-Voltage Testing of
from 0.013 to 6.35 mm (0.0005 to 0.250 in.) manufactured by
Thin Solid Electrical Insulating Materials
skiving (Note 1) from PTFE resin molding and extrusion
D 1505 Test Method for Density of Plastics by the Density-
materials.
Gradient Technique
NOTE 1—Skiving is the process of continuously shaving a film on a
D 1600 Terminology for Abbreviated Terms Relating to
lathe from the outer surface to the core of a molded cylindrical tube of
4 3
Plastics Microtensile Specimens
material.
D 1898 Practice for Sampling of Plastics
NOTE 2—Abbreviations have been approved from Terminology
D 3892 Practice for Packaging/Packing of Plastics
D 1600.
D 4894 Specification for Polytetrafluoroethylene (PTFE)
1.2 The values stated in inch-pound units are to be regarded
Granular Molding and Ram Extrusion Materials
as the standard. The values given in parentheses are for
E 691 Practice for Conducting an Interlaboratory Study to
information only.
Determine the Precision of a Test Method
1.3 The following hazard caveat pertains only to the test
2.2 ISO Standards:
method portion, Section 7, of this specification: This standard
ISO/FDIS 13000-1 Plastics—Polytetrafluorethylene
does not purport to address all of the safety concerns, if any,
(PTFE) Semi-Finished Products Part 1: Requirements and
associated with its use. It is the responsibility of the user of this
Designation
standard to establish appropriate safety and health practices
ISO/FDIS 13000-2 Plastics—Polytetrafluorethylene
and determine the applicability of regulatory limitations prior
(PTFE) Semi-Finished Products Part 2: Preparation of
to use.
Specimens and Determination of Properties
NOTE 3—This specification and ISO/FDIS 13000-1 and ISO/FDIS
3. Classification
13000-2 differ in approach or detail, and data obtained using either may
not be technically equivalent.
3.1 This specification covers four types of PTFE resin
skived tape:
2. Referenced Documents
3.1.1 Type I—Premium; normally used for exacting electri-
2.1 ASTM Standards:
cal, mechanical, or chemical applications.
D 149 Test Methods for Dielectric Breakdown Voltage and
3.1.2 Type II—General purpose; for electrical, mechanical,
Dielectric Strength of Solid Electrical Insulating Materials
and chemical applications not requiring premium material.
at Commercial Power Frequencies
3.1.3 Type III—Commercial; for non-critical chemical,
D 374 Test Methods for Thickness of Solid Electrical Insu-
electrical, and mechanical applications.
lation
3.1.4 Type IV—Utility; having no electrical requirements,
D 618 Practice for Conditioning Plastics and Electrical
and with mechanical properties at lower level.
Insulating Materials for Testing
3.2 Types I, II, III, and IV may be subdivided into two
D 638 Test Method for Tensile Properties of Plastics
grades according to the base resin used as follows:
D 792 Test Method for Specific Gravity (Relative Density)
3.2.1 Grade 1—Made only from virgin resin.
and Density of Plastics by Displacement
3.2.2 Grade 2—May be made using reprocessed resin, or a
mixture of virgin and reprocessed resin.
This specification is under the jurisdiction of ASTM Committee D-20 on
Plastics and is the direct responsibility of Subcommittee D20.15 on Thermoplastic
Materials (Section D20.15.12). Annual Book of ASTM Standards, Vols 08.01 and 08.04.
Current edition approved Nov. 10, 1997. Published April 1998. Originally Annual Book of ASTM Standards, Vol 08.02.
published as D 3308 – 74. Last previous edition D 3308 – 91a. Annual Book of ASTM Standards, Vol 14.02.
2 7
Annual Book of ASTM Standards, Vol 10.02. Available from American National Standards Institute, 11 W. 42nd St., 13th
Annual Book o ASTM Standards, Vol 08.01. Floor, New York, NY 10036.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 3308
TABLE 1 Width Tolerances for Skived Tape
3.3 A one-line system may be used to specify materials
covered by this specification. The system uses predefined cells Width Tolerance
to refer to specific aspects of this specification, asillustrated
mm in. mm in.
below:
12.7 0.5 −0, +0.51 −0, +0.020
25.4 1 −0, +0.64 −0, +0.025
Specification
50.8 2 −0, +0.89 −0, +0.035
Standard Number : Type : Grade : Class : Special
76.2 3 −0, +0.89 −0, +0.075
Block : : : : Notes
152.4 6 −0, +1.91 −0, +0.125
304.8 12 −0, +3.18 −0, +0.250
:::::
609.6 24 −0, +6.35 −0, +0.250
–––––––––––– ––– ––– ––– –––––,
Example: Specification D 3308 – 97 I 2 . “Oil”
For this example, the line callout would be: Specification
6. Number of Tests and Retests
D 3308 – 97,I2, Oil and would specify a skived tape that has all
6.1 One set of test specimens as prescribed in Section 7
of the properties listed for that Type and Grade, in the
shall be considered sufficient for testing each batch. The
appropriate specified properties, tables, or both, in the specifi-
average result of the specimens shall conform to the require-
cation identified. A comma is used as the separator between the
ments of this specification.
Standard number and the Type. Separators are not needed
between the Type and Grade, because they are, in turn, Roman
numerals and Arabic digits. Provision for “Special Notes” is
TABLE 2 Thickness Tolerances for Skived Tape
included so that other information can be provided when
Thickness Tolerance
required. This example would be premium PTFE tape noting
mm in. mm in.
that the dielectric strength is to be done in oil. When Special
0.013 to 0.025 0.0005 to 0.001 60.0025 60.0001
Notes are used, they should be preceded by a comma.
0.028 to 0.048 0.0011 to 0.0019 60.008 60.0003
0.051 to 0.076 0.002 to 0.003 60.008 60.0003
4. Physical Requirements
0.089 to 0.25 0.0035 to 0.010 60.013 60.0005
0.28 to 0.38 0.011 to 0.015 60.026 60.0010
4.1 The tape shall be made from unpigmented PTFE resin.
0.41 to 1.02 0.016 to 0.040 60.038 60.0015
4.2 The length and width of the roll shall be as agreed upon
1.04 to 1.55 0.041 to 0.061 60.127 60.0050
1.58 to 3.18 0.062 to 0.125 60.13 60.0050
between the purchaser and the seller. Width tolerances shall be
>3.18 >0.125 60.254 60.010
in accordance with Table 1.
4.3 The melting point for all types of tape shall be 327 6
10°C (621 6 18°F).
7. Test Methods
4.4 The thickness tolerances for skived tape shall be as
shown in Table 2.
7.1 The properties enumerated in this specification shall be
4.5 Tensile strength and elongation shall meet the require-
determined in accordance with the following test methods:
ments shown in Table 3.
7.1.1 Conditioning—For those tests where conditioning is
4.6 The requirements for specific gravity shall be as shown
required, condition the test specimens in accordance with
in Table 3.
Procedure A of Practice D 618 for a period of at least 4 h prior
4.7 The minimum required values for dielectric strength S
to test. If the test material has been exposed to temperatures
(V/mil), shall be computed for applicable thicknesses of below 20°C within 24 h prior to test, the conditioning shall be
materials in accordance with the following formulas, where t is
for at least 24 h.
the thickness of the tape in mils.
Type I: S 5 1000 20/t
=
TABLE 3 Mechanical Requirements for Skived Tape
Type II: S 5 840 20/t
=
A
Tensile Strength, min
Elongation, Specific
Type III: S 5 500 20/t
= Type
min,% Gravity
MPa psi
Type IV: No requirement for dielectric strength
I 27.58 4000 300 2.14 to 2.19
4.8 The number of permissible electrical flaws shall be as
II 19.31 2800 200 2.14 to 2.19
agreed between the purchaser and the seller.
III 11.00 1600 75 2.14 min
IV 9.66 1400 50 2.14 min
5. Sampling
A
Tape 6.35 mm ( ⁄4 in.) or wider.
5.1 Unless agreed upon between the purchaser and the
seller, the materials shall be sampled in accordance with the
7.1.2 Test Conditions—Conduct tests at the standard labo-
sampling procedure prescribed in Practice D 1898. Adequate
ratory temperature of 23 6 2°C (70 to 77°F). The maintenance
statistical sampling shall be considered an acceptable alterna-
of constant humidity is not necessary. In reference cases, the
tive. A lot shall consist of all tape that is part of one
standard atmosphere, 50 6 5 % relative humidity, shall apply.
manufacturer’s production made from the same nominal raw
7.1.3 Thickness—Measure thickness in accordance with
material under the same conditions, and designed to meet the
Method A of Test Methods D 374.
same specifications. A lot shall not exceed 24 h.
7.1.4 Melting Point—Determine the melting point on one
specimen in accordance with the test method stated in Speci-
See the ASTM Form and Style Manual. Available from ASTM Headquarters. fication D 4894.
D 3308
TABLE 4 Precision Summary, Tensile Strength and Elongation at
7.1.5 Tensile Properties—
...