PEI (Ultem 9085 & 1010): The Superhero of 3D Printing Filaments

If 3D printing materials had a Marvel-style lineup, PEI (Polyetherimide), better known by its brand name Ultem, would be Iron Man—strong, heat-resistant, and built for high-stakes missions.

Used in everything from airplane interiors to medical sterilization trays, Ultem isn’t your average filament. It’s expensive, tricky to print, and requires a high-end 3D printer… but if you need a material that laughs in the face of fire, chemicals, and extreme heat, this is the one.

What Makes Ultem So Special?

1. Extreme Heat Resistance (Up to 217°C!)

While PLA softens around 60°C and even ABS struggles past 100°C, Ultem doesn’t flinch until 217°C (for Ultem 1010). That means:

• No warping in hot cars.

• No melting in autoclaves (medical sterilization).

• Survives inside jet engines (yes, really).

2. Naturally Flame-Resistant (UL94 V-0 Certified)

Most "fireproof" filaments rely on additives, but Ultem is inherently flame-resistant. In the UL94 burn test:

• Stops burning within 10 seconds (V-0 rating).

• No toxic fumes (unlike some fire-retardant ABS).

• Used in aircraft, military, and electrical components where safety is critical.

3. Chemical & Radiation Resistance

• Handles jet fuel, acids, and solvents that dissolve lesser plastics.

• Used in medical devices because it survives gamma radiation sterilization.

4. Stronger Than Nylon, Stiffer Than PC

• Tensile strength similar to aluminum (for its weight).

• Doesn’t creep (slowly deform) under pressure like nylon.

The Catch: Printing Ultem Isn’t for Beginners

You’ll Need:

✔ A High-Temp 3D Printer (Hotend ≥ 350°C, heated chamber recommended).
✔ An Enclosure (to prevent warping and layer splitting).
✔ A Tough Build Surface (PEI or Garolite sheets work best).
✔ Patience (this stuff is not PLA—expect trial and error).

Printing Tips:

• Nozzle Temp: 340-390°C (yes, really).

• Bed Temp: 150-180°C (with adhesive like PVA glue for sticking power).

• Print Slow: 30-50 mm/s to avoid stress cracks.

• Dry It First! Ultem absorbs moisture like crazy—bake at 150°C for 4+ hours before printing.

Who Uses Ultem?

1. Aerospace & Defense

• Airplane ducting, drone housings (lightweight + fireproof = perfect).

• Military radio components (handles extreme conditions).

2. Medical & Dental

• Surgical tools (can be sterilized repeatedly).

• Dental devices (biocompatible grades exist).

3. Industrial & Automotive

• Fuel system parts (won’t degrade from gasoline).

• Semiconductor manufacturing (resists corrosive chemicals).

Should YOU Use Ultem?

✅ Yes, if…

• You need NASA-grade heat/flame resistance.

• You’re in aerospace, medical, or automotive engineering.

• You have a high-end printer (or deep pockets for a service bureau).

❌ No, if…

• You’re printing cosplay props or desk toys (this is overkill).

• You don’t have a high-temp printer (try PC or FR-ABS instead).

Final Verdict: The “Unbreakable” Filament

Ultem is the gold standard for industrial 3D printing—strong, heatproof, and flame-resistant without compromises. But like a sports car, it’s expensive and demands the right setup.

If you’re serious about engineering-grade parts, it’s worth the investment. If not? Well, there’s always polycarbonate…