Kapton tape, also generically called Polyimide Tape is made up of a high temperature polyimide film and either an acrylic or silicone PSA, pressure sensitive adhesive. Polyimide films are unique because they withstand very high temps 752ºF (400ºC) and very low temps -460ºF (-273ºC). However, keep in mind, this is only the film carrier. The acrylic PSA limits the maximum use temperature to 350ºF (177ºC) and the silicone PSA limits the maximum tape temp to 500ºF (260ºC). In addition, Kapton is a good electrical insulator and it is resistant to radiation and solvents. Because of these characteristics, in addition to tapes, polyimide films are used in the production of flexible printed circuits and they make up the outer layer of space suits!
Polyimide tapes have a unique color characteristic with a bronze of gold appearance. Standard Kapton tape thicknesses are 1 mil (.001”, .025 mm), 2 mil (.002”, .051 mm) or 5 mil (.005”, .127 mm). The tape thickness refers to the polyimide film. The pressures sensitive adhesive, typically 1.5 mil thick (.0015”, .038 mm) will add to the overall tape thickness. For high temp mounting applications double sided versions are available with silicone adhesive on both sides of a 1 mil Kapton film.
Since many Kapton tape applications are electrical or electronic in nature, these tapes are often supplied as custom die cuts. Manufacturing tapes on a rotary press, allows for intricate shapes and configuration with liners scored on the back side to facilitate ease of installation.