Kapton®: High-performance polyimide films for harsh environments

Kapton® refers to the range of polyimide films historically developed by DuPont, now marketed by Qnity Electronics. ADDEV Materials distributes and processes Kapton® films for the energy, mobility, and aerospace industries. As a Qnity Authorized Distributor Kapton®, ADDEV offers a multi-location stock in Europe and North America, integrated converting capabilities (slitting, die-cutting, laminating), and technical support through ADDEV’TECH from the feasibility stage.

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Kapton®: the polyimide standard since 1965

Kapton® is a polyimide film developed by DuPont in the 1960s. This material does not melt; it chars at 815°C. Its glass transition temperature (Tg) exceeds 350°C. The brand now belongs to Qnity Electronics (formerly DuPont Electronics & Industrial), an entity resulting from DuPont's 2024-2025 spin-off.

The Kapton® film covers thicknesses from 7.5 to 175 µm. It offers a dielectric strength of 280 kV/mm (based on 23 µm), radiation resistance and chemical resistance to oils, greases and aromatic derivatives. Its UL 94 rating is validated at 240 °C (thermal class H+).

ADDEV Materials distributes Kapton® HN, FN, MT, MT+, RS and HPP-ST grades. The proprietary ADDEV laminate Nokamex® (Nomex®/Kapton®/Nomex® NKN) completes the range for high-temperature combined insulation applications.

Why Kapton® remains a benchmark for extreme environments

Kapton® is the go-to material for critical applications due to four verifiable properties, recognised by insulation engineers and aerospace design offices:

Tg > 350 °C — carbonises at 815 °C, does not melt

Operating range: -269 °C to +400 °C

Dielectric strength 280 kV/mm (23 µm base)

UL 94 — Thermal rating at 240 °C

Kapton® range available from ADDEV Materials

ADDEV Materials distributes six grades of Kapton® covering electrical insulation, thermal management, heaters, and corona resistance:

Grade	Description	Thicknesses (µm)	Main applications
Kapton® HN	Pure polyimide film — Reference standard grade	7,5 – 175	Engine insulation, transformers, stator slots, flat cables
Kapton® FN	Polyimide + Teflon™ FEP (1 or 2 sides) — heat-seal, moisture barrier	12,5 – 125	Winding wrappings, heat-sealable insulation, chemical barrier
Kapton® MT	Thermally conductive polyimide	25 – 125	Thermal interface, electronic substrates, heat dissipation
Kapton® MT+	~2× thermal conductivity of MT - UL 94 V-0, RoHS	25 – 125	Heater circuits, power supplies, replacement ceramic plates
Kapton® RS	Conductive electrical polyimide film	25 – 75	Flexible polyimide heaters, custom heating elements
Kapton® HPP-ST	Improved partial discharge resistance	25 – 125	High-voltage motors, inverters, variable frequency drives

For applications combining polyimide insulation and superior thermal resistance, ADDEV Materials offers its proprietary laminate Nokamex® (Nomex®/Kapton®/Nomex® NKN), manufactured in its European workshops.

Principales propriétés techniques du Kapton® HN

The values below correspond to standard Kapton® HN, manufacturer Qnity (formerly DuPont) data.

Dielectric strength

280 kV/mm

base 23 µm

UL 94 Classification

240 °C

Thermal class H+

Glass transition temperature (Tg)

350 °C

Carbonisation

815°C

doesn't melt

Temperature range

-269 to +400 °C

Thickness range

7.5 to 175 µm

Chemical resistance

Oils, fats, flavourings

Special resistors

Radiations, bending, corona

HPP-ST and RS grades

Industrial applications of Kapton® films

Kapton® films are used in environments where temperature, radiation or chemical stress precludes conventional polymers:

Data centres & Power electronics

Flexible Printed Circuit Board (FPCB) substrate
Kapton® RS for flexible polyimide heaters
Kapton® MT+ as a thermal interface substrate
Replacement of ceramic plates (Kapton® MT+, UL 94 V-0)
Isolation for high-density inverters and power supplies

Power & Electricity Generation: Transport and Distribution

High-voltage cable insulation and overhead lines
Kapton® HPP-ST for power transformers
Insulation of generator and alternator windings
Long-term standoff to partial discharges (corona)
Resistance to cumulative thermal and electrical stresses

Automotive & Electric Mobility: Engines and Batteries

Isolation nicks stator and EV motor phase separation (Kapton® HN)
Thermal Runaway Barrier Film between battery cells
Wrapping coils with heat-sealable Kapton® FN
Nokamex® NKN Laminate for High-Temperature Combined Insulation
IATF 16949 Compliance (Pittsburgh, USA site)

Energy & BESS: Battery thermal management

Kapton® MT and MT+ for thermal dissipation between modules
High-temperature isolation busbar
Lightweight and fire-retardant thermal barrier (Thermal Runaway Barrier)
Kapton® RS for heaters integrated into battery packs
Kapton® HN for cell-to-cell insulation

Rail: motor insulation and on-board electronics

Traction motor insulation and high-voltage windings
Kapton® HPP-ST corona resistant for inverters and variable speed drives
Class H insulation for on-board transformers
Kapton® FN for high-temperature cable wrapping
Compatible with EN 45545 requirements

Bespoke transformation of Kapton® films by ADDEV

Beyond distribution, ADDEV Materials transforms Kapton® films at its 15 industrial sites in Europe and North America. The ADDEV’TECH technical support accompanies the client through 4 phases: feasibility, study & development, pre-industrialisation, and series production.

Slitting

CNC cutting

Nokamex® Lamination

Complexing

Sheeting

Parting

Why choose ADDEV Materials for your Kapton® films

Four tangible reasons distinguish ADDEV Materials as a Kapton® partner:

Qnity Authorised Distributor Kapton® — Direct access to the six grades HN, FN, MT, MT+, RS, HPP-ST
Multi-local stock In Europe and North America – short lead time on standard references
Integrated conversion capabilities — Rereeling, CNC cutting, Nokamex® NKN laminating and bespoke laminating
ADDEV'TECH Application Expertise — Engineering support in 4 phases, from prototyping to series production

ADDEV Materials is certified ISO 9001, ISO 13485, IATF 16949 and ISO 14001 (site Pittsburgh, USA), EN 45545 for the railway, and obtained the ranking EcoVadis Platinum — Top 1 % in February 2025.

Need a Kapton® film solution?

Are you looking for a Kapton® grade for your applications in high-temperature insulation, electrical mobility, aerospace, or thermal management? Speak with an ADDEV expert to identify the right product for your specifications.

Quick response from a technical expert
Recommendation for grade and thickness
Support from R&D to production

What to remember

Kapton® is a polyimide film (Qnity, formerly DuPont) with a Tg > 350 °C and a dielectric strength of 280 kV/mm.
Six grades cover standard insulation (HN), heat-seal (FN), thermal management (MT, MT+), heaters (RS), and corona resistance (HPP-ST).
Operating temperature range: -269 °C to +400 °C. UL 94 rating at 240 °C.
ADDEV Materials is a Qnity Authorised Distributor of Kapton® with stock in Europe and North America.
The proprietary Nokamex® laminate (Nomex®/Kapton®/Nomex® NKN) complements the offering for combined high-temperature insulation.

FAQ — Kapton® Films and Industrial Applications

What is the difference between Kapton® HN and Kapton® FN?

Kapton® HN is a pure polyimide film, used as a benchmark insulation for motors and transformers. Kapton® FN is a polyimide + Teflon™ FEP composite on one or two sides. The FEP coating gives Kapton® FN the ability to be heat-sealed, a barrier against moisture and increased chemical resistance.

Does Kapton® resist space radiation?

Yes. Kapton® film has recognised radiation resistance in aerospace. It is used as a component of MLI (multi-layer insulation) on satellites and launchers. Its aluminised version serves as thermal shielding in orbit.

Which Kapton® grade to choose for thermal management in batteries?

Kapton® MT and MT+ are designed for thermal dissipation. MT+ offers approximately twice the thermal conductivity of MT while retaining electrical insulation properties. It is UL 94 V-0 rated and RoHS compliant. ADDEV Materials recommends MT+ for thermal interfaces in BESS and EV battery packs.

Can ADDEV Materials transform Kapton® to my dimensions?

Yes. ADDEV Materials integrates converting operations: slitting, CNC cutting, kiss-cut, Nokamex® NKN (Nomex®/Kapton®/Nomex®) lamination, and spooling. Parts are delivered in rolls, sheets or individual formats according to your process.

DuPont owns Qnity. Kapton is a brand of polyimide film produced by DuPont.

Kapton® was developed by DuPont in the 1960s. In 2024-2025, DuPont created Qnity Electronics, an independent entity bringing together its electronics activities. Kapton® is part of the Qnity portfolio alongside Pyralux®, Kalrez®, Laird™ and Riston®. ADDEV Materials is a Qnity Authorized Distributor for Kapton®.

Is Kapton® HPP-ST suitable for variable frequency drives?

Yes. Kapton® HPP-ST offers improved partial discharge (corona resistant) performance. This grade is designed for inverter and variable frequency drive powered motors, where repeated voltage spikes accelerate the degradation of conventional insulators.