Ordinary PVC tape starts to soften not far above 80°C. Inside a motor, transformer, heater or battery pack, temperatures run well past that, and the tape still has to insulate, hold its shape and stay stuck for years. That is the job of high-temperature insulation tape.
There are several kinds, and they are not interchangeable. This guide compares the main types of high temperature insulation tape, sometimes called heat insulation tape, and explains how to choose one. If you are still deciding between everyday tapes, start with our comparison of PVC vs glass cloth vs polyester insulation tape.
What Makes a Tape High-Temperature?
Two parts decide how hot a tape can go: the backing and the adhesive.
The backing carries the electrical and mechanical load. High-temperature backings include polyimide film, woven glass, aramid paper, PTFE and mica.
The adhesive is often the weak link. Rubber adhesives soften early. Acrylic adhesives handle moderate heat. Silicone adhesives keep their grip at the highest temperatures. A tape with a heat-proof film but the wrong adhesive will lift and unwind long before the film itself is in trouble. Some tapes use thermosetting adhesives that cure during processing and then hold firmly.
Polyimide (Kapton) Tape
Polyimide tape is a thin amber film, usually with a silicone adhesive. The film handles around 260°C, and the adhesive decides the final rating of the tape. It offers high dielectric strength in very little thickness and usually peels off cleanly.
Typical uses include coil and lead wrapping, transformer insulation, battery pack insulation and masking circuit boards during soldering. See our polyimide tape, our post on polyimide tape uses, and the comparison of polyimide tape vs Kapton tape.
Glass Cloth Tape
Glass cloth tape is woven fiberglass with a silicone or thermosetting adhesive, typically rated around Class H (180°C). It is very strong, does not stretch and does not burn. It is used for wrapping motor coils, insulating generator leads and binding high-temperature harnesses. Plain woven glass tape without adhesive is also wound on and then varnished. See our fiberglass tape and our post on fiberglass tape uses.
Aramid Paper (Nomex) Tape
Aramid paper tape uses an aramid paper backing with an adhesive and is rated Class H. It conforms well and soaks up varnish, so it suits coil wrapping, lead insulation and layer insulation in transformers. See our Class H aramid paper adhesive tapes, and our guide to Nomex 410 vs 411 for the papers behind it.
PTFE Tape
PTFE tape is made from skived PTFE film or PTFE-coated glass cloth, usually with a silicone adhesive. It handles up to around 260°C, is non-stick and chemically inert, and has very low friction. It is used on heat-sealing jaws, as a release surface and for wrapping wires where chemical resistance matters. It resists cut-through less well than glass cloth. For more on the material, see our guide to types of PTFE sheet.
Mica Tape
Mica tape bonds mica paper to glass cloth or film. Mica withstands flame and resists partial discharge, so the tape is used in fire-resistant cables that must keep working during a fire and in high-voltage coil insulation. Our fiberglass mica cable uses mica for the same reason.
Resin-Impregnated Fiberglass Banding Tape
This tape is glass fibre impregnated with polyester resin. It is wound on under tension and then cured into a rigid band that holds armature and rotor windings against centrifugal force, often replacing steel wire banding. See our polyester resin fiberglass tape.
High-Temperature Tapes Compared
| Tape | Backing | Typical temperature | Main strengths | Typical uses |
| Polyimide | Polyimide film | Film around 260°C; adhesive sets the tape rating | Thin, high dielectric strength, clean removal | Coil wrapping, battery packs, PCB masking |
| Glass cloth | Woven fiberglass | Around 180°C | Very strong, no stretch, does not burn | Motor coils, generator leads |
| Aramid paper | Aramid paper | Class H | Conformable, absorbs varnish | Coil wrapping, transformer layers |
| PTFE | PTFE film or PTFE-coated glass | Up to around 260°C | Non-stick, chemically inert | Heat sealing, release, chemical areas |
| Mica | Mica on glass or film | Very high, fire resistant | Flame and corona resistance | Fire-resistant cables, HV coils |
| Resin banding tape | Glass with polyester resin | Depends on resin system | Very high tensile strength once cured | Armature and rotor banding |
These are typical figures. Ratings vary by product, so check the datasheet.
How to Choose a High-Temperature Tape
- Check the full tape rating. Look at the temperature class of the whole tape, adhesive included, not just the backing.
- Look at the electrical demand. Thin, high-dielectric layers point to polyimide. High-voltage coils and partial discharge point to mica.
- Look at the mechanical demand. Choose glass cloth for strength and resin banding tape for rotating parts.
- Think about the process. Windings that will be varnished or VPI suit aramid paper or glass. Masking during soldering needs clean removal, so polyimide fits.
- Consider the environment. Chemicals and sticky process residues call for PTFE.
- Think about fire. Where a circuit must survive a fire, use mica.
Getting the Choice Right
Polyimide is the go-to thin, high-temperature film tape. Glass cloth is the strong choice for coils and leads, aramid paper tape suits varnished Class H windings, PTFE handles chemicals and non-stick jobs, and mica is the answer for fire and high voltage.
Harnawa supplies a full range of high temperature insulation tapes, including polyester woven tape for binding. For general guidance, see insulation tape uses and applications. Contact us with your temperature, voltage and process to find the right tape.
Frequently Asked Questions
What is the best high temperature insulation tape?
It depends on the job. Polyimide tape is the most common thin high-temperature tape, glass cloth tape is best for strength, and mica tape is used where fire resistance matters.
What temperature can Kapton tape withstand?
The polyimide film itself handles around 260°C. The adhesive decides the final rating, so check the datasheet for the tape you are buying.
What is the difference between polyimide tape and glass cloth tape?
Polyimide tape is a thin film with high dielectric strength in very little space. Glass cloth tape is thicker and woven, much stronger mechanically, and typically rated around Class H.
Which tape is used for motor coil wrapping?
Glass cloth tape, aramid paper tape, polyimide tape and woven polyester tape are all used, depending on the insulation class and whether the coil will be varnished.
What is heat insulation tape?
The term is used both for high-temperature electrical tapes and for thermal tapes used on AC pipes and ducts. This guide covers electrical insulation tapes for motors, transformers and other hot equipment.
Why does the adhesive matter on a high temperature tape?
The adhesive often fails before the backing. A tape with a heat-resistant film but an unsuitable adhesive can lift and unwind at temperatures the film could easily handle.
