Materials / PEI
ULTEM (PEI) 3D printing in India
Print Forge 3D prints PEI parts, including ULTEM™ materials, in Bengaluru for engineering teams across India. PEI is the pragmatic high-temperature polymer: strong, heat-resistant and light, for housings, ducting, brackets and durable tooling. This page gives the ULTEM 9085 reference data with its test conditions and explains when to choose PEI over PEEK or PEKK.
- ±0.3% (min ±0.3 mm)Printed tolerance
- from 1 business dayPrinted lead time
- to ±0.020 mmMachined interfaces
- within 24 h of a complete briefQuote
These are starting capabilities. Geometry, material, quantity and finishing determine the final tolerances and lead time in the quotation.
What is ULTEM (PEI)?
Polyetherimide (PEI) is an amorphous thermoplastic sold under the ULTEM™ name. Because it does not crystallise, it shrinks predictably, holds its shape well through the thermal cycle of printing and needs no anneal to develop its properties. ULTEM 9085 is a PEI-based formulation widely used for extrusion printing; other formulations, such as ULTEM 1010, have different properties, so name the one your specification calls for.
Typical printed PEI parts: transport housings, air ducting, cabin brackets, assembly tools and heat-resistant functional prototypes.
ULTEM 9085 reference data
| Property | Value | Orientation and standard |
|---|---|---|
| Tensile yield strength | 69.2 MPa | XZ · ASTM D638 |
| Tensile modulus | 2.52 GPa | XZ · ASTM D638 |
| Heat deflection temperature | 172.6 °C | XZ · 1.82 MPa (264 psi) · ASTM D648 B |
Named grades are manufacturer references, not a Print Forge stock list or Print Forge test results. Specify the grade your application requires; the quotation confirms the material supplied. The printer, tip and layer height are the manufacturer's test set-up, given as context; they are not a statement of Print Forge equipment.
Why build orientation matters for PEI parts
The values above are for XZ specimens, where the specimen lies on its edge and the tensile load runs along the deposited beads. Stand the same specimen upright (ZX) and the load pulls the layers apart, so strength falls. Manufacturer datasheets typically report more than one orientation, and the gap applies to every extruded polymer. Orient brackets and duct flanges so the beads carry the load, and give any feature loaded across layers more section.
PEI, PEEK or PEKK: which should you specify?
| Material | Structure | Reference data | Choose it when |
|---|---|---|---|
| PEI (ULTEM 9085) | Amorphous | 69.2 MPa tensile yield, XZ, ASTM D638; HDT 172.6 °C at 1.82 MPa, XZ | Heat resistance, dimensional stability and flame, smoke and toxicity documentation matter more than chemical resistance |
| PEEK (VICTREX 450G) | Semi-crystalline PAEK | 98 MPa tensile yield, resin, 23 °C, ISO 527-2; HDT 152 °C at 1.8 MPa, unannealed | Chemical resistance, wear, electrical insulation or a machined-from-stock route matter most |
| PEKK (Antero 800NA) | Semi-crystalline PAEK | 86.7 MPa tensile yield, XZ, ASTM D638; HDT 157 °C at 1.82 MPa, XY | You want PAEK chemical resistance in a formulation designed for extrusion printing |
A useful rule: amorphous PEI is more vulnerable than the semi-crystalline PAEKs to some solvents, fuels and stress cracking. If the part sits in hot oil, aggressive cleaning agents or fuel, list the chemicals and exposure time in the brief before settling on PEI.
Flame, smoke and toxicity requirements
ULTEM 9085 is often chosen for transport interiors where flame, smoke and toxicity (FST) test evidence is part of the specification. Treat the datasheet as the manufacturer's results for their specimens. If your programme needs FST evidence for the finished part, name the test standard and the documentation you need in the brief; the quotation states the documentation supplied.
Design and finishing notes for ULTEM parts
- PEI absorbs moisture, so material is dried before printing; write drying into the build specification if your quality plan needs it.
- Plan where supports will be removed. Support contact leaves witness marks, so keep them off sealing faces and cosmetic surfaces.
- For ducting or enclosures that must hold pressure, specify a leak test or a sealing treatment; printed walls can contain small voids.
- Use threaded inserts, or post-machine bores and threads, where the fit matters. Machining starts at ±0.020 mm.
What to send for an ULTEM quote
- CAD: STEP or IGES for design review and quoting; STL or 3MF if you only have print-ready mesh geometry.
- A PDF drawing with units, revision, datums, the critical dimensions and their tolerances, threads and fits.
- Material: the PEI formulation (for example ULTEM 9085 or ULTEM 1010) and any flame, smoke and toxicity standard the part must meet.
- Build requirements: load direction, sealing or pressure requirements and surfaces to be machined.
- Quantity and timing: the first batch, expected repeat volumes and a target delivery date.
- Inspection and documents: whether you need a dimensional inspection report, material traceability or other records.
- Confidential designs: tick discuss an NDA before sharing files in the quote form. You can start the conversation without attaching CAD.
Quotes are returned within 24 hours of a complete brief. The design-review checklist lists the questions an engineering review will ask.
Frequently asked questions
Is ULTEM 9085 the same as ULTEM 1010?
No. They are different PEI formulations with different thermal and mechanical data. Name the formulation your drawing or specification requires; the ULTEM 9085 figures on this page do not apply to other grades.
Does printed ULTEM meet aircraft flammability requirements?
That depends on the formulation, the process and the specific test your programme requires. The manufacturer's datasheet reports its own specimen results; qualification of your part and process is a separate step. State the standard in your brief and the quotation sets out the documentation.
What tolerances can printed PEI parts hold?
The starting capability for 3D printing is ±0.3% with a ±0.3 mm minimum. Interfaces can be post-machined, starting at ±0.020 mm. Geometry, material, quantity and finishing determine the final tolerances and lead time in the quotation.
When is PEEK a better choice than ULTEM?
When chemical resistance, wear or long exposure to hot fluids drive the design, or when you need a machined-from-stock or implant-grade route. PEI suits heat-resistant housings, ducting and tooling where those factors matter less.
Start a project
Quote an ULTEM part
Send the drawing, the formulation and the test standards that apply. The brief is reviewed for geometry, orientation and documentation before the quotation is issued.
Start a project brief info@printforge.co.in+91 98441 14767