3DXTech ThermaX PEI 9085: ULTEM 9085-Based PEI Filament for High-Temperature Parts (500g, 1.75mm)
ThermaX PEI 9085 is 3DXTech's filament formulated with SABIC ULTEM 9085 resin. It's an amorphous PEI with a Tg of 186°C — slightly tougher and more forgiving to print than PEI 1010, with low smoke emission according to the manufacturer. Available here in natural color, 500g, 1.75mm. A high-temperature printer is an absolute requirement: nozzle at 350–380°C, bed at 140–160°C, and an actively heated enclosure.
Key Specs
- Compounded with ULTEM 9085 resin, per 3DXTech.
- Tg of 186°C and HDT of 158°C at 0.45 MPa (per TDS).
- Base resin rated UL94 V-0 at 1.5mm, with low smoke emission and low smoke toxicity.
- Excellent dimensional stability and minimal creep at elevated temperatures.
- Nozzle: 350–380°C | Bed: 140–160°C | Heated enclosure recommended.
- Dry at 120°C for 4 hours before printing.
Will My Printer Handle This Filament?
Only if it's a true high-temperature machine. You need a hotend that runs reliably at 350–380°C, a bed capable of 140–160°C, and a heated enclosure — which 3DXTech recommends. A closed printer without active chamber heating isn't enough for any part of real size: PEI shrinks and lifts off the bed. If your printer doesn't meet these requirements, this is not the filament for you.
PEI 9085 vs. PEI 1010 — Which One Do You Need?
According to 3DXTech's datasheets, PEI 1010 handles higher temperatures (Tg 217°C vs. 186°C, HDT 208°C vs. 158°C) and is stiffer. PEI 9085 is slightly less demanding on nozzle temperature and a bit easier to print. If your part won't see service temperatures above 150°C, 9085 is typically the right choice.
Does It Have Aerospace Certifications?
3DXTech does not cite any FST standards or aerospace certifications on this filament's product page, so we won't make that claim either. What they do state is low smoke emission and toxicity, plus UL94 V-0 classification for the base resin. Browse more options in our technical filaments collection.
Technical Specifications
| Property |
Value |
| Material |
PEI (ULTEM 9085) |
| Diameter |
1.75 mm |
| Net Weight |
500 g |
| Color |
Natural |
| Nozzle Temperature |
350–380 °C |
| Bed Temperature |
140–160 °C |
| Enclosure |
Recommended |
| Nozzle |
No special requirements per 3DXTech |
| Drying |
120 °C, 4 h |
| Density (ISO 1183) |
1.34 g/cm³ |
| Tensile Strength (ISO 527) |
54 MPa |
| Tensile Modulus |
2050 MPa |
| Elongation at Break |
3% |
| Flexural Strength (ISO 178) |
90 MPa |
| Flexural Modulus |
2170 MPa |
| Tg (DSC) |
186 °C |
| HDT at 0.45 MPa (ISO 75) |
158 °C |
| Flammability |
UL94 V-0 at 1.5 mm (base resin) |
Printing Tips
- Dry at 120 °C for 4 hours immediately before printing. If your dryer doesn't reach 120 °C, check out our filament dryers.
- 3DXTech's test specimens were printed at 365–385 °C with a 130–140 °C bed, 0.25 mm layer height, and 100% infill.
- Keep the part cooling fan at minimum or off. PEI needs ambient heat around the print, not airflow.
- Let the enclosure fully heat-soak before starting, and don't open the door until the part has cooled down completely.
- For bed adhesion, use the surface your printer manufacturer recommends for PEI. Printing directly on a smooth PEI sheet may cause the part to bond so strongly it tears the surface off.
Frequently Asked Questions
What format does it come in?
1.75 mm diameter, 500 g spool, natural color. Part number PEI01UN200500NAT0, verified on 3dxtech.com.
What nozzle temperature should I use?
350–380 °C per the 3DXTech product data sheet.
Do I need a heated enclosure?
3DXTech recommends one. Without it, medium-to-large prints are prone to warping.
How much heat can printed parts handle?
HDT of 158 °C at 0.45 MPa and a Tg of 186 °C per the TDS.
Is it flame retardant?
The base resin is rated UL94 V-0 at 1.5 mm per the TDS, and 3DXTech notes low smoke emission.
Does it meet FST requirements for aerospace?
3DXTech does not specify FST compliance on this product's page, so we cannot confirm it.
Do I need a hardened nozzle?
No — this filament contains no abrasive fillers. 3DXTech lists no special nozzle requirements.
Is it chemical resistant?
3DXTech cites good resistance to automotive fluids, fully halogenated hydrocarbons, alcohols, and aqueous solutions.
