|
PTFE Moulded & Machined Finished Products:
Property
|
Units
|
Unfilled
|
25% w/w Glass
|
15% w/w Graphite
|
25% w/w Carbon
|
55% w/w Bronze + 5% MoS2
|
Relative Density
|
-
|
2.17
|
2.25
|
2.2
|
2.1
|
3.7 - 3.9
|
Maximum Tensile Strength
|
kg/cm2
|
105 - 300
|
125 - 200
|
140 - 210
|
120 - 155
|
105 - 140
|
Elongation at Break
|
%
|
200 - 400
|
200 - 300
|
200 - 300
|
100 - 150
|
90 - 130
|
Hardness
|
Shore D
|
50 - 55
|
55 - 70
|
55 - 65
|
60 - 65
|
66 - 70
|
Volume Resistivity
|
ohm, cm
|
1018
|
2 x 1015
|
106 |
104 |
107 |
| Surface Resistivity |
ohm
|
1017 |
1015 |
1014 |
107 |
109 |
Permittivity at 23oC; 105-107 Hx dry
Liner Thermal Expansion
|
-
|
2.02 - 2.09
|
2.25 - 2.50
|
Conducting Filler
|
Conducting Filler |
Conducting Filler |
Parallel to direction of Moulding
|
%
|
2.35
|
2.20
|
2.14
|
1.88
|
1.50
|
Perpendicular to direction of Moulding
|
%
|
2.30
|
1.00
|
1.58
|
1.12
|
1.10
|
Thermal Conductivity
|
10-4Cal/cms
deg. C
|
6
|
9
|
11
|
13
|
19
|
Continuous Service Temperature
|
oC
oF
|
-250 to + 260
-420 to + 500
|
-250 to + 260
-420 to + 500 |
-250 to + 260
-420 to + 500 |
-250 to + 260
-420 to + 500 |
-250 to + 260
-420 to + 500 |
Coefficient of Friction (Dynamic)
|
-
|
0.06
|
0.12
|
0.07
|
0.13
|
0.13
|
Flammability
|
|
Non Flammable
|
Non Flammable |
Non Flammable |
Non Flammable |
|
Resistance to Weathering
|
-
|
Excellent
|
Excellent |
Excellent |
Excellent |
|
| Chemical Resistance |
PTFE is
chemically inert and unaffected by all known chemicals, except alkali
metals, fluorine under certain conditions and some fluorine compounds
at elevated temperatures. Filled PTFE has inferior chemical resistance
because of the presence of particular fillers, but superior mechanical
and electrical properties, as compared to unfilled PTFE.
|
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