Introduction
Polyetherimide (PEI), commonly known by its brand name Ultem®, is a high-performance thermoplastic that boasts remarkable thermal, mechanical, and chemical resistance properties. PEI filament is predominately utilized in industries that require durable, high-strength components capable of operating under extreme conditions, such as aerospace, automotive, and medical applications. Its inherent flame retardancy, transparency, and ability to maintain performance over a wide temperature range make PEI an excellent choice for demanding engineering applications that necessitate precision, reliability, and advanced material properties.
Printing with PEI requires careful handling due to its high extrusion temperature and the necessity for a heated print bed and chamber to minimize warping and ensure proper layer adhesion. For those equipped with high-temperature-capable 3D printers and seeking to push the boundaries of additive manufacturing, PEI offers the opportunity to create parts with exceptional durability and resistance to harsh environments.
About PEI Filament
PEI’s standout features include its high heat resistance, with a continuous service temperature above 180°C, and its strength and stiffness, which remain consistent across its operating temperature range. Additionally, PEI’s resistance to common aerospace and automotive fluids makes it particularly valuable for applications exposed to challenging chemical environments. Its biocompatibility also opens opportunities for use in medical devices and components requiring sterilization.
Successfully printing with PEI involves maintaining high chamber temperatures to achieve optimal results, necessitating advanced 3D printing setups designed to handle high-performance materials accurately and safely.
Possible Applications of PEI Filament
Aerospace and Automotive Parts
PEI is used to produce lightweight, heat-resistant components, including interior cabin parts, ducting systems, and electrical connectors that require exceptional performance.
Medical Devices
Due to its biocompatibility and ability to undergo sterilization, PEI is suitable for surgical instruments, medical imaging devices, and components for diagnostic equipment.
Electrical and Electronic Insulation
The material’s inherent flame resistance and electrical insulation properties make it ideal for electronic housings, circuit boards, and connectors.
High-Performance Prototypes
Engineers and designers favor PEI for prototyping parts that need to withstand rigorous testing and simulate the conditions of final production materials accurately.
Pros and Cons of PEI Filament
Pros:
- Superior Thermal Resistance: Maintains mechanical properties at high temperatures, surpassing most other 3D printing materials.
- Chemical and Flame Resistance: Provides safety and durability in environments exposed to flames and harsh chemicals.
- Biocompatibility: Suitable for medical applications requiring sterility and compatibility with human tissue.
- High Strength and Stiffness: Ensures part reliability under mechanical stress and strain.
Cons:
- Printing Challenges: Requires 3D printers capable of reaching and maintaining high extrusion and bed temperatures.
- Cost: As a specialized engineering material, PEI comes at a higher cost compared to standard 3D printing filaments.
- Specialized Equipment: Demands a 3D printer with a heated chamber and precise temperature control to minimize warping.
- Moisture Sensitivity: Like many high-performance polymers, PEI must be properly dried before printing to ensure optimal quality.
Material Settings of PEI Filament
| Setting | Value |
|---|---|
| Print Temperature [°C] | 340 – 450 |
| Build Plate Temperature [°C] | 120 – 190 |
| Print Speed [mm/s] | 10 – 50 |
| Cooling Fan [%] | 0 – 10 |
| Enclosed Build Chamber | Required |
| Air Management | Required |
| Min Active Heated Build Chamber Temperature [°C] | 90 |
| Drying | Required |
| Annealing | Required |
To achieve the highest quality prints with PEI, a printer equipped with the capability to reach and regulate elevated temperatures throughout the printing process is essential, along with stringent moisture control.
Mechanical Properties of PEI Filament
| Property | Value |
|---|---|
| Shore Hardness | D85 – D90 |
| Specific Gravity [g/cc] | 1.27 – 1.38 |
| Tensile Strength at Break [Mpa] | 95 – 105 |
| Elongation at Break [%] | 3 – 75 |
| Flexural Strength [Mpa] | 90 – 140 |
| Flexural Modulus [Mpa] | 2,000 – 3,500 |
| Impact Strength Charpy 23˚C [kJ/m²] | 10 – 15 |
| HDT B [°C] | 155 – 210 |
| Tg [°C] | 180 – 217 |
| UV Resistance | High |
PEI’s mechanical properties underscore its exceptional rigidity, toughness, and suitability for producing parts that require longevity and reliability under challenging operational conditions.
Material Comparison
| Material | PLA | ABS | PEI |
|---|---|---|---|
| Print Temperature [°C] | 180 – 235 | 230 – 270 | 340 – 380 |
| Durability | Moderate | High | Highest |
| Ease of Printing | High | Moderate | Difficult |
| UV Resistance | Low | Moderate | High |
| Heat Resistance | Low | Moderate | Highest |
PEI distinguishes itself with unparalleled heat resistance and mechanical properties, presenting a challenging but rewarding option for advanced applications that exceed the capabilities of materials like PLA and ABS. Its UV resistance and biocompatibility further enhance its applicability in demanding environments.
FAQ´s about PEI Filament
How does PEI compare to PEEK in terms of applications?
Both PEI and PEEK offer outstanding thermal and mechanical properties, but PEI generally provides better flame resistance, making it more suitable for applications requiring strict flame retardancy standards.
Can PEI be used for consumer-grade 3D printing?
PEI usually requires industrial-grade 3D printers capable of very high temperatures, making it less accessible for typical consumer-grade printing setups.
How can warping be minimized when printing with PEI?
Utilizing a heated print bed, enclosed chamber, and specific surface adhesives aids in reducing warping, alongside ensuring the material is thoroughly dried before use.
Is PEI recyclable?
Yes, PEI is recyclable, though its specialized nature means it should be processed at facilities that can handle high-performance engineering plastics.
How does PEI handle long-term outdoor exposure?
PEI exhibits high UV resistance, maintaining its mechanical and thermal properties over prolonged outdoor exposure, making it excellent for exterior aerospace and automotive applications.
