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PTFE Specifications
TECHNICAL DESCRIPTION
PolyTetraFluoroEthylene is a fluorocarbon-based polymer and is
commonly abbreviated PTFE. The Teflon ® brand of
PTFE is manufactured only by DuPont. Several other manufacturers make their
own brands of PTFE which can often be used as substitute material. This
fluoroplastic family offers plastics with high chemical resistance, low and
high temperature capability, resistance to weathering, low friction,
electrical and thermal insulation, and "slipperiness".
( see also
Teflon® PTFE and
Teflon® FEP & PFA Specifications )
GENERAL PROPERTIES
PTFE's mechanical properties are low compared to other plastics,
but its properties remain at a useful level over a wide temperature range of
of -100°F to +400°F (-73°C to 204°C). Mechanical properties are often
enhanced by adding fillers (see paragraph below). It has excellent thermal
and electrical insulation properties and a low coefficient of friction. PTFE
is very dense and cannot be melt processed -- it must be compressed and
sintered to form useful shapes.
FILLED GRADES
PTFE's mechanical properties can be enhanced by adding fillers such
as glass fibers, carbon, graphite, molybdenum disulphide, and bronze.
Generally, filled PTFE's maintain their excellent chemical and high
temperature characteristics, while fillers improve mechanical strength,
stability, and wear resistance.
The properties of 25% glass-filled and 25% carbon-filled PTFE grades are
shown below for comparison purposes. There are literally dozens of different
filled PTFE products and grades -- too many to be listed here.
(see also
Semitron ESd 500 Static-Dissipative PTFE |
Fluorosint Filled PTFE |
Rulon Filled PTFE Specifications)
| TYPICAL PROPERTIES of PTFE |
| ASTM or UL test |
Property |
PTFE
(unfilled) |
PTFE
(25% glass filled) |
PTFE
(25% carbon filled) |
| PHYSICAL |
| D792 |
Density (lb/in³)
(g/cm³) |
0.078
2.16 |
0.081
2.25 |
0.075
2.08 |
| D570 |
Water Absorption, 24 hrs (%) |
< 0.01 |
0.02 |
0.05 |
| MECHANICAL |
| D638 |
Tensile Strength (psi) |
3,900 |
2,100 |
1,900 |
| D638 |
Tensile Modulus (psi) |
80,000 |
- |
- |
| D638 |
Tensile Elongation at Break (%) |
300 |
270 |
75 |
| D790 |
Flexural Strength (psi) |
No break |
1,950 |
2,300 |
| D790 |
Flexural Modulus (psi) |
72,000 |
190,000 |
160,000 |
| D695 |
Compressive Strength (psi) |
3,500 |
1,000 |
1,700 |
| D695 |
Compressive Modulus (psi) |
70,000 |
110,000 |
87,000 |
| D785 |
Hardness, Shore D |
D50 |
D60 |
D62 |
| D256 |
IZOD Notched Impact (ft-lb/in) |
3.5 |
- |
- |
| THERMAL |
| D696 |
Coefficient of Linear Thermal Expansion
(x 10 -5 in./in./°F) |
7.5 |
6.4 |
6.0 |
| D648 |
Heat Deflection Temp (°F / °C)
at 264 psi |
132 / 55 |
150 / 65 |
150 / 65 |
| D3418 |
Melting Temp (°F / °C) |
635 / 335 |
635 / 335 |
635 / 335 |
| - |
Max Operating Temp (°F / °C) |
500 / 260 |
500 / 260 |
500 / 260 |
| C177 |
Thermal Conductivity
(BTU-in/ft²-hr-°F)
(x 10 -4 cal/cm-sec-°C) |
1.70
5.86 |
3.1
10.6 |
4.5
15.5 |
| UL94 |
Flammability Rating |
V-O |
V-O |
V-O |
| ELECTRICAL |
| D149 |
Dielectric Strength (V/mil) short time, 1/8" thick |
285 |
- |
- |
| D150 |
Dielectric Constant at 1 MHz |
2.1 |
2.4 |
- |
| D150 |
Dissipation Factor at 1 MHz |
< 0.0002 |
0.05 |
- |
| D257 |
Volume Resistivity (ohm-cm)at 50% RH |
> 10 18 |
> 10 15 |
10 4 |
NOTE: The information contained herein are typical values intended
for reference and comparison purposes only. They should NOT be used as a
basis for design specifications or quality control. Contact us for
manufacturers' complete material property datasheets.
All values at 73°F (23°C) unless otherwise noted.
TEFLON ® is a registered trademark of DuPont
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