PEI Plastic Materials
Polyetherimide Sheet, Rod & Custom Parts
PEI (polyetherimide) is an amorphous high performance engineering plastic that combines heat resistance, inherent flame retardancy, high strength and stiffness, and stable electrical insulation in one machinable material.
Widely known through the ULTEM® trade name, PEI is specified across semiconductor, electrical, aerospace, medical and chemical-processing equipment.
Great Plastics supplies PEI sheet, rod and tube stock and manufactures custom PEI parts by CNC machining, from prototype to production volume.
machining tolerance
RFQ response after drawings and application conditions are received
fast dispatch capability for suitable stock-form orders
MOQ (Min. Order)
Overview
What Is PEI Plastic Material?
PEI is an amorphous thermoplastic engineering plastic available in different grades and stock forms for precision components. Natural, unfilled PEI typically has a transparent to translucent amber appearance, while color and performance can vary with grade, reinforcement, thickness, and processing conditions.
When specifying PEI, the material grade should be matched to the component’s operating temperature, mechanical load, electrical requirements, chemical exposure, and dimensional requirements. During the inquiry stage, please provide details regarding the material form, specifications, dimensions, and tolerance requirements, and specify whether you require raw material from stock or finished parts CNC-machined according to drawings.
Available Forms
PEI Plastic Forms & Custom Parts
Material Selection
PEI Material Grades & Filler Selection
PEI grade selection depends on stiffness, dimensional stability, electrical insulation, operating conditions, machining requirements, and applicable specifications. Common options include unfilled and glass-filled PEI. ULTEM is a trademark of SABIC; resin, stock-shape, and machined-part data are related but not identical.
Performance Data
Key PEI Performance Characteristics
PEI is an amorphous thermoplastic that combines high stiffness, thermal resistance, electrical insulation, and dimensional stability. Performance depends on the specific grade, part geometry, operating conditions, and processing method.
Manufacturing Capability
PEI CNC Machining and Custom Components
PEI machining requires control of heat, clamping pressure, residual stress, and dimensional change. Tool geometry, coolant compatibility, thin-wall features, and inspection conditions should be considered for precision parts. Transparent or specialty PEI grades may also require additional attention to surface appearance and material identification.
We support prototype development, low-volume production, and OEM manufacturing programs for precision PEI parts.
custom Selection
Custom PEI Precision Components
Custom PEI parts are manufactured from PEI sheet, rod, or tube stock according to your drawings, material grade, dimensions, tolerances, and application requirements. The part design and machining process are reviewed together to account for geometry, wall thickness, critical dimensions, and operating conditions.
Industry Use Cases
Applications of PEI Plastic Materials
PEI is used for precision components in semiconductor equipment, electrical and electronics, medical and analytical equipment, aerospace systems, and industrial machinery. Typical applications include insulating components, fixtures, connector supports, instrument components, and custom machined parts.
Material Comparison
PEI vs. Other Engineering Plastics
The table below compares PEI with commonly selected high-performance engineering plastics. Material selection depends on temperature, mechanical load, chemical exposure, wear, machinability, and cost.
| Comparison | Consider PEI when | Consider the alternative when |
|---|---|---|
| PEI vs PEEK | Dimensional control, electrical insulation, stiffness, flame performance, transparency, or overall material cost are important within the required operating range. | Higher continuous-use temperature, chemical resistance, wear performance, or demanding mechanical conditions are the primary requirements. |
| PEI vs PPS | Electrical insulation, stiffness, dimensional control, transparency, or the requirements of an amorphous thermoplastic are important. | Chemical resistance, low moisture absorption, or cost-performance is prioritized. |
| PEI vs PC | Higher temperature capability, stiffness, electrical insulation, or flame performance is required beyond typical PC applications. | Impact strength, optical clarity, or lower material cost is more important. |
| PEI vs PAI | Electrical insulation, dimensional control, machinability, and the required performance can be achieved without the higher performance level of PAI. | Severe mechanical load, wear, creep resistance, or more demanding temperature conditions dominate the application. |
PEI is often selected for applications requiring dimensional stability, electrical insulation, stiffness, heat resistance, and flame performance. PEEK is considered when higher continuous-use temperature, chemical resistance, or demanding wear performance is required, while PPS is commonly selected for chemical resistance, low moisture absorption, and cost-performance. PC is often preferred where impact strength, optical clarity, or lower material cost is more important, while PAI is used for demanding load, wear, creep, and temperature conditions. Final material selection should be confirmed against the applicable grade datasheet and actual operating conditions.
Your Partner
Why Choose Great Plastics
Great Plastics supports PEI material selection, stock-shape review, drawing review, CNC machining, dimensional inspection, and production documentation for custom PEI components.
Common Questions
Frequently Asked Questions
These questions cover common considerations related to PEI material selection, grades, machining, and custom parts. Final engineering decisions should be based on the selected grade’s technical data and actual application conditions.