What are Kapton Tapes?
Kapton is a polyimide film developed by DuPont in the late 1960s that remains stable (in isolation) across a wide range of temperatures, from 4 to 673 K (−269°C to +400 °C). Kapton is used in, among other things, flexible printed circuits (flexible electronics) and space blankets, which are used on spacecraft, satellites, and various space instruments.
The chemical name for Kapton K and HN is poly(4,4'-oxydiphenylene-pyromellitimide). It is produced from the condensation of pyromellitic dianhydride and 4,4'- oxydiphenylamine. Kapton synthesis is an example of the use of a dianhydride in step polymerization. The intermediate polymer, known as a poly(amic acid), is soluble because of strong hydrogen bonds to the polar solvents usually employed in the reaction. The ring closure is carried out at high temperatures of 470–570 K (200–300 °C).
The thermal conductivity of Kapton at temperatures from 0.5 to 5 kelvins is rather high for such low temperatures, κ = 4.638×10−3 T0.5678 W·m^−1·K^−1.
This, together with its good dielectric qualities and its availability as thin sheets have made it a favorite material in cryogenics, as it provides electrical insulation at low thermal gradients. Kapton is regularly used as an insulator in ultra-high-vacuum environments due to its low outgassing rate.
Simply put, Kapton tape is a brand-name version of polyimide tape. Kapton tape is a type of polyimide tape, but it's far from the only one. It may, however, be the most popular variant used across industries. Kapton tape has strong hydrogen bonds to the polar solvents used in when manufacturing it. These bonds are made at temperatures as high as 300°C, preparing the final product for high temperatures when applied. Like other polyimide tapes, Kapton tape is used for insulation, heat control, and chemical resistance.
Since Kapton tape is a type of polyimide tape, all the same things that make polyimide tape special make Kapton tape special. It's heat and chemical resistant, it's strong, and it's available in very thin sheets.
Kapton tape has excellent adhesion properties and leaves nothing behind when peeled off. It's particularly hard to puncture and can stick to difficult surfaces that other tapes and adhesives simply can't. Very little pressure is needed for a good stick, making the applicator's job a lot easier.
- Kapton tape is used across the spectrum of the electrical field. It's mostly used as insulation. This includes capacitor and transformer insulation, coil insulation, and magnetic wire insulation. It can also be used during powder coatings as a temperature mask.
- Many car manufacturers use Kapton tape for both insulation, and general heat resistance.
- Kapton tape is commonly used in the manufacturing of both commercial and military aircraft. The aircraft industry chooses Kapton tape for its strength, heat resistance, and weight.
- Kapton is used in spaceships and satellites to keep certain systems running at a consistent temperature.