Symbol: PEI
Crystallinity: Amorphous
Trade Names: Ultem, RTP, LNP, EnCom

Learn more about Polyetherimide.


PEI Spatula Fotolia_29120773_S.jpgPEI is a high performance material introduced by GE Plastics as ULTEM. It has high strength and rigidity at elevated temperatures, heat resistance, chemical resistance, and has highly stable dimensional and electrical properties. It is also very flame resistant.

Processing Considerations:

  • Residence Time: Residence time ranges from 2 to 4 minutes.
  • Back Pressure: Back pressure runs 150 PSI (or 1500 plastic pressure) or less.
  • Drying: PEI must be dried.
  • RPM: RPM is typically 30 to 200.

Screw Design Based on:

  • Medium Compression Ratio
  • Medium Transition Length
  • Medium Meter Channel Depth

Other Information:

  • Mixer: A low shear, mixing screw can be used to run PEI. Reiloy Westland Corporation’s Eagle mixer has been proven to successfully process this resin.
  • Barrier: Barrier screws are typically not recommended.
  • Custom Design: A general purpose screw design will process this resin.
  • Recommended Valve: A three piece free-flow valve is recommended.
  • Screw & Barrel Material Recommendation: Processed very HOT and chrome-plated components are not recommended. Do not run nitrided surface with PEI. It will pit per GE Plastics.

PEI is processed at very high temperatures.

Various additives and/or fillers can have an effect on a resin’s process behavior. For more detailed information, please contact Reiloy Westland Corporation.

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Industry Applications - Resins

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