Characteristics of the PEI


High heat stability.

Exceptional mechanical strength and elastic


High dielectric strength.

Stable dielectric constant and dissipation factor.

Good chemical resistance.

Flame resistance inherent to the molecular

structure, low smoke emission.

Good machining and finishing characteristics.



PEI has excellent resistance against gamma

radiation, 6% loss of tensile strength after

cumulative exposure to 500 megarads at a rate of

1 Mrad/h using cobalt 60.

A 1000-hour ageing test with a xenon lamp had

no effect on tensile strength.


- DIN4102 Flammability Class B1

- Class M1 under the CSTB standard

- Class 0 under the BS 476 standard

Easily to metallise.


Excellent electrical insulator, high dielectric

strength (33 KV/mm at a thickness of 1.6 mm).

Good dielectric constant, remains stable

throughout PEI's usage temperature range.

Arc resistance value of 128s when subjected to

the ASTM-D495 test.

• Mil - C 55 302 • Mil - C - 83 513 • Mil - S - 83

734. • Mil - S - 83 502 • Mil S 83 505 • Mil - M -

245 19 B (EC)




PEI has an exceptional flexural modulus (3300

N/mm² at room temperature), which remains

excellent at high temperatures.

Yield point at elastic limit exceeds 105 N/mm².

Furthermore, PEI's tensile strength is still approx.

40 N/mm² at 175°C, with a flexural modulus of

2300 N/mm².

PEI has remarkable toughness.


PEI's continuous use temperature is 180°C.

Its heat distortion temperature under a load of

1.82 N/mm² is 200°C.

Glass transition temperature (Tg) of 215°C.


PEI is inert with regard to most hydrocarbons,

although it is soluble in partially halogenated

hydrocarbons (methylene chloride and


It resists well against freon-based cleaning

agents, refrigerants, and vapour phase soldering


PEI resists against:

- mineral acids

- mineral saline solutions

- diluted bases (pH below 9)

Prolonged immersion in water, even at 100°C,

has practically no effect on its properties.

PEI is UV-resistant.


Under the UL 94 standard, PEI has V0

classification under 0.8 mm thick and 5V

classification under 1.9 mm thick.


It gives off very little smoke, and its products of

combustion are no more toxic than those

released by wood. They consist mainly of CO,

CO², and gaseous H²O.