What is Ultem

ULTEM is an amorphous thermoplastic polyetherimide (PEI) – essentially a type of resin. It is a flame-retardant, high-performance material that is excellent for prototyping. It offers high mechanical properties, providing design engineers exceptional flexibility and freedom. There are two types of ULTEM: ULTEM 9085 and ULTEM 1010.

ULTEM 9085 can produce fully functional parts. It’s an ideal material for advanced prototyping. Possible uses include aircraft components, electrical housings, and structural components.

ULTEM 1010 is the strongest FDM thermoplastic with the highest tensile strength. It also has the highest chemical and thermal resistances of any thermoplastic. Certified grade is biocompatible and approved for food contact with NSF 51 and ISO 10993/USP Class VI certifications.

ULTEM is an affordable material that will give you the strength you need for prototyping engineer-grade pieces. It is also proven to withstand repeated sterilization, making it perfect for medical device components.


ULTEM offers the highest tensile strength, with a high strength-to-weight ratio. It also has the highest chemical and thermal resistances of any FDM thermoplastic. It has a heat resistance up to approximately 180 °C (356 °F). Heating the material this high could cause it to burn. However, the byproducts from combustion are no more toxic than those of wood.

For more specifications, the table below shows the exact properties of ULTEM.

Printing Method

Fused Deposition Modeling, or FDM, is an extrusion-based technology. It use a temperature-controlled print head to deposit a thermoplastic filament layer by layer onto a build platform. The filament is melted due to a heated nozzle, which a motor pushes the filament through.

An FDM printer moves the print head along specified coordinates, laying down the molten material onto the build plate. Once in place, it cools and solidifies. This process continues, layer by layer, until the model is complete. Support structures are used as needed, depending of the geometry and orientation of the model.

Compared to other 3D printing methods, FDM is the most cost-effective way to prototype. It is suitable for both prototyping and non-commercial functional applications. You can choose from a wide range of thermoplastic materials. Models printed in FDM have visible layer lines and therefore require post-processing to have a smooth finish.

Design Specifications

The minimum wall thickness for this material is 0.8 mm to ensure structural integrity. If there are any protruding parts on the model, we recommend the use of support structures to maintain stability.

Included engravings optimally should have a minimum 1.0 mm line thickness, 1.5 mm depth, and 4.5 mm overall height.

For embossments, it’s important to ensure they are thick enough to survive production and shipment. For this reason, the recommended minimum dimensions are 0.8 mm line thickness, 0.8 mm depth, and 3.0 mm overall height.

If the model will be printed in parts to be assembled, a 0.5 mm width is necessary between the different pieces to ensure fit.