Insulation
Types
|
Advantages
|
Disadvantages
|
FEP and PTFE
(Dupont TM
Teflon)
|
- Excellent high
temperature properties. PTFE Teflon is preferred for solder applications.
FEP is preferred for jacket material.
- Non-flammable
- Good outgassing
characteristics
- Most flexible
of all insulations
- Good weatherability,
resists moisture absorption and atomic oxygen erosion
|
- Susceptible to
cold flow when stressed (bent) over tight radius or when laced too tightly.
- Degraded by solar
radiation above 5 x 105 RADS.
- FEP has poor cut
through resistance
- Heaviest insulation
|
ETFE
(Dupont TM
Tefzel)
|
- Withstands physical
abuse during and after installation
- Good high and
low temperature properties
- High flex life
- Good outgassing
characteristics
- Fair cold flow
properties
|
- Some ETFE insulations
fail flammability in a 30% oxygen environment
- Insulation tends
to soften at high temperature
- Degraded by gamma
radiation above 106 RADS
|
Crosslinked ETFE
(Dupont TM
Tefzel)
|
- Higher strength
than normal ETFE
- Resistant to cold
flow and abrasion
- More resistant
to radiation effects
(to 5 x 107 RADS)
- Higher maximum
temperature than normal ETFE
- Tin Coating
= 150°C Max.
- Silver Coating
= 200°C Max.
- Good outgassing
characteristics
|
- Some ETFE insulations
fail flammability in a 30% oxygen environment
- Less flexible
than extruded ETFE
- More difficult
to work with than PTFE Teflon
|
Polyimide
(Dupont TM
Kapton)
|
- Lightest weight
wire insulation material. Commonly used with FEP or PTFE
Teflon to form layered insulation tapes
- Excellent physical
thermal and electric properties. Excellent cut-through resistance
and cold flow resistance
- Excellent radiation
resistance
(to 5 x 109 RADS)
- Good outgassing
characteristics
|
- Inflexibility
- difficult to strip.
- Absorbs moisture.
Degraded by atomic oxygen. Poor weatherability
- Prone to wet-arc
and dry-arc tracking from abrasions and cuts
- More difficult
to flex
- Not stable to
ultraviolet radiation
|
Crosslinked
Polyalkene
|
- Dual extrusion
which is fused by sintering. Combines excellent abrasion and cut
through resistance of Polyvinylidene Fluoride (PVDF, PVF2-Penwalt
Corp. TM Kynar) with Polyolefin for greater flexibility and
improved heat resistance. Polyalkene is used mainly as a primary
insulation under an outer jacket such as crosslinked ETFE or crosslinked
PVDF/PVF2
- High dielectric
constant, used in high voltage applications
- PVDF has good
radiation resistance
(to 108 RADS)
- More resistant
to cold flow
- Good outgassing
characteristics
|
- Lower maximum
conductor temperature rating
- (135°C for
GSFC S-311-P-13)
- (150°C for
MIL-W-81044)
- Reduced flexibility
|
Silicon Rubber
|
- Excellent flexibility
at low temperatures
- Excellent high
voltage corona resistance
- Good radiation
resistance (to 108 RADS)
- Good cold flow
resistance
|
- Poor cut through
resistance, mechanical toughness, and fluid resistance
- Must be processed
for outgassing control
- Flammable
- No standard silicon
rubber insulated wire or cable
|