Fluoropolymer-Insulated
Aircraft Wiring

The same people who are putting geese out of the parka-insulation business have developed an electrical insulation that may help keep aircraft on the wing a bit longer. W.L. Gore & Associates, Inc., Newark, DE, makers of GORE-TEX fabrics and a wide range of electronic, industrial and medical products, has developed a high strength, flexible and abrasion-resistant fluoropolymer insulation for aircraft wiring, which possesses important properties critical to both electrical performance and safety.

In several highly publicized reports, consumer and safety advocates have raised concerns about the performance of current insulation systems for wiring in aircraft. Current aircraft wiring involves the use of crosslinked ETFE (such as TEFZEL), polyimide (such as KAPTON), or a composite insulation system of PTFE/Polyimide over the conductor. The crosslinked ETFE exhibits poor performance at elevated temperatures and produces smoke. The composite insulation system was developed to address the electrically conductive carbon char that develops when the polyimide is subjected to a high voltage arc. However, the composite has an outer layer of PTFE that exhibits poor cut-through, creep and abrasion characteristics.

The High Strength Toughened Fluoropolymer (HSTF) does not exhibit creep and cut-through properties typically associated with PTFE insulation. The Gore fluoropolymer insulation also does not form an electrically conductive carbon char when subjected to an arc, as occurs with polyimide insulation. Gore HSTF insulated wire can be used in all parts of the aircraft, from fuel probe cables to general purpose hook-up wires, due to the wide temperature performance (260°) and chemical inertness of the material.

Gore is currently engaged in programs with several aircraft manufacturers (both military and commercial), airlines and aircraft component suppliers regarding testing and potential utilization of HSTF insulated wires.

--RM

For more information, contact W.L. Gore & Associates, Inc., 555 Papermill Rd, Newark, DE 19714. 302-738-7880. http://www.gorefabrics.com Circle 555.