Ultem® is the registered trademark of Sabic, one of the world’s leading manufacturers of high-performance plastics, used to market polyetherimide (PEI). This thermoplastic resin belongs to the family of high-temperature polymers.
This material stands out for its excellent thermal resistance, as well as outstanding mechanical, chemical, and dielectric properties. It also features low moisture absorption and high resistance to radiation. Polyetherimide offers excellent wear resistance and a low coefficient of friction, contributing to the durability and reliability of components even under demanding operating conditions.
It is used in a wide range of industrial applications that require reliable materials – those capable of maintaining their mechanical, functional and electrical properties over time, even in critical environments, ensuring long-lasting high performance.
These characteristics, combined with optical transparency, make Ultem a benchmark material for sectors such as automotive, rail, marine and nautical, hydraulic fittings, medical, lighting, and manufacturing. Let’s take a closer look at the key features of this resin.
Key properties of Ultem
Thermal resistance
Maintains mechanical performance up to 200°C during continuous operation, making it ideal for applications exposed to prolonged high temperatures.
Mechanical and tribological properties (wear and friction resistance)
It ensures a good balance between stiffness and mechanical strength, delivering high performance even under harsh conditions. In particular, it offers:
- High rigidity
- High tensile strength
- Good impact resistance and the ability to absorb repeated stresses, maintaining structural integrity over time
- Excellent wear resistance and a low coefficient of friction, ideal for moving or mechanically stressed components
Chemical and corrosion resistance
Ultem shows excellent resistance to a wide range of chemical agents and corrosion, making it ideal for aggressive environments, including:
- Oils and greases
- Organic solvents
- Mild acids and bases
- Atmospheric agents such as humidity and temperature variations
Dielectric properties
Due to its excellent insulating capacity, Ultem is widely used in the electronics and energy industries, where high-voltage resistance is essential without degrading the material. Applications include:
- Printed circuit board components
- High-voltage insulators
- Electrical connectors and transformer supports
Radiation resistance
With excellent stability under gamma and UV radiation, it is suitable for applications requiring radiation resistance, such as aerospace and medical sectors.
Low moisture absorption
Unlike many other high-performance polymers, Ultem has low moisture uptake, maintaining its mechanical and electrical properties even in high-humidity environments.
Flame resistance
Ultem is a self-extinguishing material, certified according to UL 94 V-0 standards. It prevents flame spread and ensures rapid extinguishing once the fire source is removed, making it especially suitable for sectors where fire safety is critical, such as rail, aerospace, and electronics.
Dimensional stability and durability
It retains mechanical and chemical properties over time, even under thermal and mechanical stress. These features make Ultem an ideal material for applications requiring dimensional precision and long-term reliability.
Optical transparency
Available in various colours, including a transparent version that combines high optical clarity with the strength and durability typical of the material.
Biocompatibility and sterilisation resistance
It is biocompatible and can be sterilised without loss of mechanical or chemical properties, making it ideal for reusable medical devices, diagnostic components, and other healthcare applications.
Good processability and manufacturing versatility
Ultem adapts well to a wide range of manufacturing processes, including injection moulding. This allows for efficient and flexible production, even for complex parts or strict technical requiremen
Applications of Ultem in various industrial sectors
Automotive
In the automotive sector, Ultem is used for components exposed to high temperatures, constant mechanical stress and harsh environments. Thanks to its thermal resistance, dimensional stability, and flame-retardant properties, it offers a valid alternative to metals and other technical polymers – reducing weight while improving durability. Key applications include:
- Engine parts and cooling system components requiring heat and corrosion resistance
- Electrical connectors and sensors exposed to vibration, thermal stress, and aggressive environments
- Lightweight structural parts combining rigidity and resistance to reduce vehicle weight
Rail
Due to its flame resistance and dimensional stability at high temperatures, Ultem is widely used in the rail sector for components that demand top safety and durability. Common uses include:
- Electrical insulators and connectors exposed to thermal and environmental stress
- Interior components requiring high thermal resistance and flame retardancy
- Lightweight structural parts for carriages, stable and durable even in extreme operating conditions
Marine and nautical
In marine applications, Ultem is valued for its mechanical strength, resistance to corrosive environments, and long-term durability – even under exposure to moisture, saltwater, and dynamic stress. Thanks to its chemical resistance, low moisture absorption, and high rigidity, Ultem is used in:
- Hydraulic fittings and valves exposed to seawater
- Structural components subjected to mechanical stress and abrasion
- High-performance boat components
Hydraulic fittings
Thanks to its high chemical and mechanical resistance, Ultem is particularly suitable for manufacturing hydraulic valves and fittings intended for critical operating conditions, such as:
- High-temperature systems requiring long-term structural stability
- Industrial systems exposed to solvents, acids and other aggressive agents, where corrosion and hydrolysis resistance is essential
Parapharmaceutical and medical sectors
Ultem’s biocompatibility, sterilisation resistance and chemical stability make it ideal for medical and diagnostic applications, including:
- Reusable surgical instruments undergoing repeated sterilisation
- Diagnostic and imaging equipment components requiring dimensional precision and chemical resistance
- Drug delivery devices
Lighting
Its optical clarity and thermal resistance make Ultem a go-to material in lighting applications requiring stability under high temperatures. Uses include:
- Reflectors and high-performance LED lamp components
- PCB supports used in lamps operating at elevated temperatures
Manufacturing
In the manufacturing industry, Ultem is used for high-performance technical parts thanks to its thermal and mechanical stability, wear resistance, and long-term durability. It is ideal in contexts requiring lightweight and rigid materials, such as:
- Structural and functional components operating at high temperatures or under repeated loads
- Supports and insulating elements in advanced industrial processes and automation
- Lightweight, resistant structures for high-precision machinery
Comparing Ultem with other high-performance plastics
In complex industrial applications, choosing the right material often involves comparing Ultem’s technical properties with those of other high-performance polymers.
The following table compares key features such as thermal resistance, dimensional stability, chemical resistance, dielectric properties, and optical transparency.
| Material | Thermal resistance | Dimensional stability | Chemical resistance | Dielectric strength | Optical transparency |
|---|---|---|---|---|---|
| ULTEM® (PEI) | 4 (200°C) | 5 | 4 | 5 | 4 |
| PEEK | 5 (260°C) | 5 | 5 | 4 | 1 |
| PPS | 4 (220°C) | 4 | 5 | 3 | 1 |
| PAI (Torlon) | 5 (270°C) | 5 | 4 | 3 | 1 |
| PSU | 3 (160°C) | 2 | 3 | 4 | 5 |
Legend
- The numerical scale from 1 to 5 indicates performance levels, where:
- 1 = Low
- 2 = Fair
- 3 = Medium
- 4 = High
- 5 = Excellent
- The “Optical transparency” column refers to the material’s availability in transparent grades. A higher score indicates greater available optical clarity.
- The values provided are indicative and may vary depending on the material grade, additives, and operating conditions.
Pioneers in Ultem processing
Corti Srl was among the first companies in Italy to innovate with Ultem, recognising its potential as a high-performance thermoplastic resin from the outset.
In 1997, GE Plastics Italia – now part of Sabic’s Innovative Plastics business unit – awarded us the “Protagonists of the Future” certificate, recognising our pioneering role in industrial Ultem processing.
This milestone is a testament to our decades-long expertise in processing high-performance materials for specialised technical sectors.
Conclusion
Ultem is a unique thermoplastic resin, offering exceptional performance, long-term reliability, and resistance under critical conditions. Its versatility makes it a valuable asset for modern industry.
If you’re looking for custom Ultem solutions or want to explore its potential for your project, get in touch for a dedicated technical consultation. We’re ready to support you with the most advanced moulding and processing technologies.
