Wire Insulation Selection Guidelines
 
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