Resin
Compound |
PVC |
Polyethylene
(Unfilled) |
Polypropylene
(Unfilled) |
Nylon |
Fluorocarbon |
Low-density |
High-density |
TFE |
FEP |
| Specific Gravity |
1.35 |
0.920 |
0.947 |
0.902 |
|
2.18 |
2.16 |
| Ultimate Tensile Strength,
psi |
3000 |
2200 |
3400 |
5000 |
8000 |
3500 |
3000 |
| Ultimate Elongation, % |
200 |
625 |
250 |
200 |
200 |
300 |
250 |
| Rated Max Temp, °C |
105 |
75 |
- |
- |
105 |
260 |
175 |
| Rated Min Temp,°C |
-40 |
-65 |
-65 |
10 |
-40 |
-65 |
-65 |
| Volume Resistivity, ohm-cm |
8 x 10 |
1 x 10 |
1 x 10 |
1 x 10 |
1 x 10 |
1 x 10 |
1 x 10 |
| Dielectric Constant, 1k hz |
5.0 |
2.25 |
2.32 |
2.22 |
4.5 |
2.0 |
2.1 |
| Dissipation Factor |
0.10 |
0.0002 |
0.0002 |
0.0003
|
0.04 |
0.0002 |
0.0003 |
PVC
Because of its wide range of properties, PVC is typically
used either as a dielectric or sheathing or both in applications
such as: power distribution cables, building wiring, appliances
wiring, flexible cords, high temperature wiring, industrial
wiring, coaxial cables.
Polyethylene (PE)
All of the polyethylenes are excellect dielectrics. Outstanding
electrical properties include high insulation resistance,
high dielectric strength, low dielectric constant, low dielectric
loss at all frequencies, excellent resistance to cold flow,
and good abrasion resistance.
Polyethylene is widely used for insulation on telephone signal
and control cables, high frequency electronic cables, high
and low voltage power cables, line wire, neutral supported
secondary and service drop cable.
Low Density Polyethylene (LDPE)
LDPE exhibits good fluid resistance at room temperature. It
also has very low water absorption. The mechanical properties
of LDPE are not outstanding. Generally, where mechanical abuse
is anticipated on relatively thin-walled hook-up wire constructions,
a nylon jacket or some other suitable outer covering is usually
recommended to improve abrasion and cut-through resistance.
The electrical properties of LDPE are outstanding. It is a low loss material and is used as the dielectric for many coaxial cables in involving high frequency applications. It exhibits good resistance to breakdown under corona and is often used in high voltage applications.
High Density Polyethylene (HDPE)
High density polyethylene has chemical and electrical properties
similar to the lox density resins. Its fluid resistance is
somewhat better. The major difference between the two types
lies in the mechanical area. High density resisn are harder,
stiffer, and better in abrasion and cut-through resistance
than the low density resins. These resins are suitable for
jackets or sheaths since they have good resistance to environmental
degradation.
Polypropylene Polypropylene has a lower density
than the polyethylene resins. The chemical and electrical
and electrical properties of this polymer are similar to those
of the polyethylenes. Its fluid resistance is somewhat superior.
Its dielectric constant is somewhat lower than that of LDPE.
Polypropylene is considerable harder and stiffer than polyethylene.
It also has relatively poor low-temperature flexibility. It
can be degraded by heat and light unless protected by antioxidants.
Nylon
Nylon generally carries a high temperature rating of 150C for continuous service. Its low temperature limit is dependent upon the wall thickness and the diameter of the construction. As both of these parameters increase, the susceptibleness to cracking or flexing at low temperatures also increases.
TFE
It is non-polar and has outstanding electrical properties.
The good electrical properties are combined with very high
resistance to chemicals and temperature: service operation
up to 260C is possible and flexibility remains at very low
temperatures. Polymers of TFE possess unexcelled fluid resistance
and are attacked only by alkali metals such as barium, sodium,
potassium, and by fluorine at high tempertures and pressures.
Fluorinated Ethylene Propylene (FEP) The low temperature properties of FEP are similiar to the TFE and result in a -65C rating. The mechanical and electric properties of FEP are also similiar to TFE. However, they deteriorate faster under adverse conditions.
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