PEI Film

PEI Film delivers high thermal endurance, dielectric performance, and dimensional stability, making it ideal for precision electrical insulation, optical substrates, and thermal barriers in demanding environments. Resistant to hydrolysis and many solvents, it performs reliably in aerospace, automotive, and electronics industries. Applications include flexible printed circuits, capacitor dielectrics, and transparent thermal shields. Specific uses range from flexible connectors in avionics to moisture-resistant dielectric layers in battery systems and optical interlayers in high-temperature glazing. In research, PEI film is used to explore thin-film polymer optics, high-temperature dielectric behavior, and fabrication of microelectronic substrates. Its combination of clarity, stability, and heat resistance ensures it remains a preferred choice for advanced engineering and scientific applications.

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Tolerance

Properties

Reference & Citations

each

Tolerances

Foil

Thickness		±20%

Material Properties for Polymers

Chemical Resistance

Element	Value
Acids - concentrated	Good(-Fair?)
Acids - dilute	Good
Alcohols	Good
Alkalis	Good-Poor
Aromatic hydrocarbons	Poor
Greases and Oils	Good
Halogenated Hydrocarbons	Good-Poor
Ketones	Poor

Electrical Properties

Element	Value
Dielectric constant @1kHz	3.1
Dissipation factor @ 1MHz	0.0013@1
Dielectric strength( kV mm⁻¹ )	30@1.6mm
Surface resistivity( Ohm/sq )	4.10¹³
Volume resistivity( Ohmcm )	7.10¹⁵

Physical Properties

Element	Value
Flammability	V-0 @ 0.4mm
Radiation resistance	Good
Resistance to Ultra-violet	Good/Fair
Limiting oxygen index( % )	47
Water absorption - equilibrium( % )	1.3
Water absorption - over 24 hours( % )	0.25
Density( gcm⁻³ )	1.27

Mechanical Properties

Element	Value
Hardness - Rockwell	R125
Poisson's ratio	0.44
Elongation at break( % )	60
Compressive modulus( GPa )	2.9
Tensile modulus( GPa )	2.9
Izod impact strength( J m⁻¹ )	50
Abrasive resistance - ASTM D1044( mg/1000 cycles )	10
Tensile strength( MPa )	85

Thermal Properties

Element	Value
Heat-deflection temperature - 0.45MPa( C )	200
Heat-deflection temperature - 1.8MPa( C )	190
Upper working temperature( C )	170-200
Specific heat( J K⁻¹ kg⁻¹ )	2000
Thermal conductivity( W m⁻¹ K⁻¹ )	0.22@23°C
Coefficient of thermal expansion( x10⁻⁶ K⁻¹ )	56