>"Studies showed that Kapton was far from the ideal insulator everyone had hoped it would be — it tended to develop circumferential cracks from the slightest of

>"Studies showed that Kapton was far from the ideal insulator everyone had hoped it would be — it tended to develop circumferential cracks from the slightest of nicks, exposing the conductors within. Kapton is also easily degraded by moisture, exacerbating the problem in humid environments or areas of an aircraft subject to moisture, like galleys and lavatories. Once the insulation is compromised, arcing can occur, which leads to charring of the Kapton. This changes the insulation’s dielectric properties, turning it into a conductor. In some cases, this led to overloaded circuits that were not detected by circuit breakers, since the insulation was carrying the excess current rather than the conductor." [...] >"Planes built since then generally use TKT, which is Kapton with two thin layers of Teflon to provide better resistance to mechanical abrasion and water intrusion." PDS: TKT sounds like a much better material, from a material science perspective...