Performance of partially fluorinated polyimide insulation for aerospace applications

Polyimide has been used extensively as the primary wiring insulation in commercial planes, military aircraft and space vehicles due to its low weight high service temperature and good dielectric strength. New failure modes, however, have been associated with the use of polyimide because of the susceptibility of the insulation to pyrolization and arc tracking. A new wiring construction utilizing partially fluorinated polyimide insulation has been tested and compared with the standard military polyimide wire. Electrical properties which were investigated include AC corona inception and extinction voltages (sea level and 60,000 feet), time/current to smoke and wire fusing time. The two constructions were also characterized in terms of their mechanical properties including abrasion resistance, dynamic cut through and notch propagation. In this paper, these test efforts and the results obtained are presented and discussed.