PEI · grade
PEI 9085
Properties of the 9085 condition, compared with the other PEI grades.
Pick for aircraft interior parts and FDM filament where FAR 25.853 heat-release/smoke compliance and better toughness/flow matter more than peak Tg.
What is PEI 9085?
PEI 9085 is PEI in the 9085 grade — pick for aircraft interior parts and FDM filament where FAR 25.853 heat-release/smoke compliance and better toughness/flow matter more than peak Tg. PEI 9085 has a yield strength of 105 MPa (15.2 ksi) and a tensile strength of 72 MPa (10.4 ksi) — stronger than 97% of polymer grades. Elongation at break is 30% and the elastic modulus is 2.2 GPa (0.319 Msi). PEI 9085 has a density of 1.34 g/cm³ (0.0484 lb/in³), heavier than 74% of polymer grades. Its glass-transition temperature is 186°C (367 °F). Unfilled (1000) is the default condition FabDigit quotes; 9085 is available on request or by drawing note.
Advantages
- High strength — 105 MPa (15.2 ksi), better than 97% of polymer grades
- High service temperature — 155°C (311 °F), better than 81% of polymer grades
- Polishes to a fine finish — 70/100, better than 78% of polymer grades
Limitations
- High embodied carbon — 9 kg CO₂/kg, worse than 88% of polymer grades
PEI 9085 properties
Typical room-temperature values for PEI 9085 — 13 properties are specific to this condition; the rest are grade-level values shared by every PEI grade. Each bar shows where the value sits among the polymer grades in FabDigit's library — further right is higher.
Physical6
PEI 9085 has a density of 1.34 g/cm³ (0.0484 lb/in³), heavier than 74% of polymer grades. Its glass-transition temperature is 186°C (367 °F).
Mechanical17
PEI 9085 has a yield strength of 105 MPa (15.2 ksi) and a tensile strength of 72 MPa (10.4 ksi) — stronger than 97% of polymer grades. Elongation at break is 30% and the elastic modulus is 2.2 GPa (0.319 Msi).
Thermal11
PEI 9085 is rated for continuous service to 155°C (311 °F). It conducts heat at 0.22 W/m·K (0.127 BTU/hr·ft·°F), better than 60% of polymer grades. Thermal expansion is 55 µm/m·K (30.6 µin/in·°F).
Electrical7
PEI 9085 is an electrical insulator with a dielectric strength of 33 kV/mm (838.2 V/mil) and a resistivity of 1×10¹⁵ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 63% of polymer grades. UV resistance is fair.
Sustainability4
Producing a kilogram of PEI 9085 takes about 230 MJ of energy and emits 9 kg of CO₂ — more than 91% of polymer grades. Typical recycled content is 0%.
Manufacturability8
PEI 9085's machinability is good (65/100, better than 66% of polymer grades); weldability good (60/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other PEI grades and fills
PEI is also supplied in 14 other conditions. The full side-by-side table is on the PEI overview.
- Unfilled (1000)DefaultDefault choice for transparent, tough, high-Tg parts and stock shapes where isotropic properties and machinability matter.105 MPa tensile
- UnfilledDefaultUse when a supplier only states 'unfilled PEI' (domestic Chinese resin or extruded/machined stock) without a SABIC grade number.100 MPa tensile
- CF30Choose for maximum specific stiffness, low CTE and static-dissipative structural parts (semiconductor handling, aerospace fixtures).200 MPa tensile
- GF40Maximum stiffness and lowest CTE PEI compound for metal-replacement structures; brittle and abrasive to tooling.190 MPa tensile
- GF30 (2300)The benchmark commercial 30% GF PEI for machined stock shapes, semiconductor fixtures and high-load electrical parts.169 MPa tensile
- GF30Standard high-stiffness structural PEI: use where load, creep resistance and low CTE dominate and surface finish/ductility can be sacrificed.165 MPa tensile
- GF20Balanced stiffness/toughness reinforcement for structural brackets and connectors at elevated temperature.145 MPa tensile
- GF10Lightly reinforced option when moderate stiffness gain and reduced shrinkage are needed but some ductility must be retained.120 MPa tensile
- MedicalChoose for reusable surgical instrument bodies, trays and dental parts needing ISO 10993/USP Class VI compliance and hundreds of steam autoclave cycles.105 MPa tensile
- 1010Choose for thin-wall/complex moldings, food-contact and biocompatible applications, and high-temperature FDM (Tg ≈ 217 °C, best flow of unfilled PEI).105 MPa tensile
- ESDUse for wafer/electronics handling tooling where surface resistivity must sit in the 1e4–1e9 Ω dissipative window at high temperature.95 MPa tensile
- LubricatedSelect for unlubricated sliding parts (bushings, wear pads, valve seats) needing low friction at 150–170 °C.90 MPa tensile
- Standard (FAA Approved)Specify when documentation (FAR 25.853 flammability/smoke/toxicity, lot traceability) is required for aircraft cabin parts.72 MPa tensile
- 9085Pick for aircraft interior parts and FDM filament where FAR 25.853 heat-release/smoke compliance and better toughness/flow matter more than peak Tg.72 MPa tensile
- As PrintedUse for design allowables of FDM-printed PEI parts: expect 60–80% of molded strength in-plane and much lower Z-axis strength.69 MPa tensile
Working with PEI 9085
Is PEI easy to machine?
Machines cleanly with sharp carbide tools, high speed and light feeds; use air or water-soluble coolant (avoid chlorinated fluids), anneal 150–200 °C before finish cuts to prevent stress cracking, and keep generous radii because PEI is notch sensitive.
Can PEI be welded?
Joins by ultrasonic, hot-plate, spin and laser welding; solvent bonding is discouraged (stress cracking) — use epoxy or high-temperature adhesives with plasma/abrasive surface prep.
Can PEI be formed, bent or molded?
Dry to <0.02% moisture (150 °C, 4+ h), mold at 340–400 °C melt with 135–175 °C tools and hot-tip/hardened gates for glass grades; thermoformable and extrudable above Tg with high-temperature tooling.
What surface finishes work on PEI?
Takes pad printing, laser marking, vacuum metallization and EMI shielding coatings; can be polished to clear amber; primers required for durable paint adhesion and no anodizing/plating without conductive pretreatment.
PEI chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| m-phenylenediamine (MPD) unitdiamine comonomer of standard PEI (ULTEM 1000/1010) | — | — |
| polycarbonate/siloxane or alternative copresent only in copolymer grades such as ULTEM 9085 | — | — |
| glass fiber0 for unfilled; 10/20/30/40 wt% in 2100/2200/2300/2400 series | 0 – 40 | 0 |
| bisphenol A dianhydride (BPADA) unitether-imide backbone from BPADA condensation | balance | — |
PEI 9085 — frequently asked
What is PEI 9085 used for?
PEI 9085 is typically used for aircraft interior panels and ducting, electrical connectors and insulators, sterilisable medical instrument handles and trays, semiconductor wafer carriers and test fixtures, high-temperature fluid fittings and valve bodies and burn-in and test sockets. In short: high-heat aerospace standard.
What is the yield strength of PEI 9085?
PEI 9085 has a typical yield strength of 105 MPa (15.2 ksi) and a tensile strength of 72 MPa (10.4 ksi) — stronger than 97% of polymer grades. Strength varies by condition: see the 15 listed tempers.
Is PEI 9085 easy to machine?
Reasonably — machinability is rated good (65/100, better than 66% of polymer grades). Machines cleanly with sharp carbide tools, high speed and light feeds; use air or water-soluble coolant (avoid chlorinated fluids), anneal 150–200 °C before finish cuts to prevent stress cracking, and keep generous radii because PEI is notch sensitive.
Can PEI 9085 be welded?
Yes — weldability is rated good (60/100). Joins by ultrasonic, hot-plate, spin and laser welding; solvent bonding is discouraged (stress cracking) — use epoxy or high-temperature adhesives with plasma/abrasive surface prep.
What surface finishes work on PEI 9085?
Takes pad printing, laser marking, vacuum metallization and EMI shielding coatings; can be polished to clear amber; primers required for durable paint adhesion and no anodizing/plating without conductive pretreatment.
Can PEI 9085 be formed, bent or molded?
Dry to <0.02% moisture (150 °C, 4+ h), mold at 340–400 °C melt with 135–175 °C tools and hot-tip/hardened gates for glass grades; thermoformable and extrudable above Tg with high-temperature tooling.
What is the maximum service temperature of PEI 9085?
PEI 9085 is rated for continuous use to about 155°C (311 °F), and briefly to 200°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in PEI 9085?
Yes — PEI 9085 is available for CNC machining, sheet metal, injection molding and 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ULTEM 1000 / 1010 / 2300 / 9085 resin datasheets — SABIC Specialty Polymers (2023)
- TECAPEI natural / GF30 stock shape datasheets — Ensinger (2023)
- ULTEM 9085 / 1010 FDM material specification — Stratasys (2022)
- CAMPUS plastics multi-point data, polyetherimide — CWFG/CAMPUS (2024)
- ASTM D5205 Standard Classification System for Polyetherimide (PEI) Materials — ASTM (2020)
- Engineering Plastics Handbook / Plastics Design Library — high-temperature thermoplastics — McGraw-Hill / Elsevier (2006)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.