PEI – Polyetherimid

PEI is an amorphous, high temperature material with relatively low cost compared to other high temperature materials. It has excellent elongation and Impact Strength, and can be molded to tight tolerances. Its chemical resistance is not as good as crystalline materials but is excellent for an amorphous material. PEI behaves similar to polycarbonate, but can perform at higher temperatures.

Applications: Commercial aircraft interiors, healthcare products, cooking utensils, fiber optics, electrical and electronic applications.

Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
14,000-28,000 psi 480,000-1,300,000 psi 2 ft-lb/in notched izod 375°-420° F Fair to Good


  • High heat resistance
  • Exceptional strength and impact modulus
  • High dielectric strength
  • Broad chemical resistance
  • Biocompatible
  • Excellent machinability and finishing characteristic
  • Outstanding processability on conventional molding equipment
  • Flame resistance with low smoke evolution


  • Translucent and opaque-clear is not available
  • High cost
  • Notch sensitive
  • High processing temps required

Brand Names: Ultem.