Skip to content

603-742-0164 Shop Contact Us



PEI is a high strength thermoplastic film that has outstanding temperature, chemical and electrical properties. Depending on the application, PEI can be a cost effective alternative to PEEK.

Brand Names

  • Ultem® PEI


  • High temperature resistance
  • Chemical resistance
  • Excellent mechanical strength

Common Applications

  • Thermoformed components

Data Sheets

PropertyTest MethodTypical Value
  English unitsSI Units
Available Thickness Range-2 – 20 mil51 - 508µm
Max. Operating Temp.-340ºF171°C
TgASTM D-3418423ºF217°C
Melt PointASTM D-3418426ºF219°C
Dielectric StrengthASTM D-149830 V/mil33 V/μm
Dielectric ConstantASTM D-1503.153.15
Specific GravityASTM D-7922.12 - 2.172.12 - 2.17
Tensile Strength, BreakASTM D-63815200 psi105 MPa

Ultem® is a registered trademark of GE.

Note: The information displayed on the Welch Fluorocarbon, Inc. website should be utilized for evaluation and reference purposes only, and should not be used as a definitive source. It is the user’s responsibility to test the suitability of any material for their particular end use.