3D Printing Info

Filament comparison

PEI 9085 vs PEKK

Compare printing settings, strength, heat resistance, dated prices and sources.

PEI (ULTEM 9085) guidePEKK guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PEI 9085 comparisonsMore PEKK comparisons
PEI 9085 vs PEKK — documented properties and sources
PropertyPEI (ULTEM 9085)HIGHTEMPPEKKHIGHTEMP
Market snapshot
Listing priceUSD/kg; dated snapshots$309.80/kg median; $220.00–$392.00/kg across 6 dated product listings$525.00/kg median; $332.50–$771.12/kg across 6 dated product listings
Identity & Market
Base polymer / chemistryPolyetherimide, ULTEM 9085 grade — the flame-retardant PEI used for aircraft interiors[1]Polyether ketone ketone, amorphous grade — a polyaryletherketone that stays amorphous, so it does not need PEEK's crystallisation control. Stratasys sells it as Antero 800NA and Antero 840CN03; category numbers below are unfilled unless a carbon grade is named[2][3]
Densityg/cm³1.34 (ISO 1183, 3DXTech) against 1.27 specific gravity on moulded plaques (ASTM D792, Stratasys) — the two suppliers disagree[1][4]1.28 unfilled (ASTM D792, Antero 800NA; 1.31 annealed) and 1.33 for CarbonX PEKK-A CF15 (ISO 1183)[3][2]
Typical priceUSD/kg1 kg-equivalent spools cluster near 298[5][6][7][8]1 kg-equivalent spools cluster near 550[5][8][9]
Price range across brandsUSD/kg220-392 across brands and formats; 3DXTech ThermaX PEI 9085 220 at 2 kg, 3D4Makers 270 at 2 kg, Fiberlogy 298 at 500 g, Kimya 321 at 500 g, IEMAI 3D 385 at 1 kg, 3DXTech CarbonX PEI 9085+CF 392[5][6][7][8][10]333-771 across grades and formats; 3DXTech CarbonX PEKK-A+CF15 333 at 2 kg, 3D4Makers unfilled PEKK-A 485 at 2 kg, IEMAI 3D 500 at 1 kg, Kimya PEKK Carbon 771 at 500 g[5][8][9][11][12]
Market availability1–5Niche, a handful of specialist brands[5][6][7][8]Niche, a handful of specialist brands[5][8][9]
Spool sizes & diameters1.75 and 2.85 mm; 250 g to 2 kg spools, plus Stratasys canisters[5][8][4]1.75 and 2.85 mm; 200 g to 2 kg spools, plus Stratasys canisters[5][8][3]
Typical applicationsAircraft interior parts and rail rolling stock, where the flame, smoke and toxicity rating is the requirement[1]Aerospace interior and structural parts; 3DXTech labels its carbon-filled PEKK-A grade AERO and Stratasys certifies Antero 800NA for outgassing and FST[2][3]
Printing Parameters
Bed temperature°C130–140 (3DXTech)[1]140 (3DXTech CarbonX PEKK-A CF15)[2]
Enclosure / chamber requirement1–5Actively heated chamber required[13][14]Actively heated chamber required[13][14]
Warping tendency1–5Severe — heated chamber needed[13]Not documented
Overall printing difficulty1–5Expert / industrial hardware only[13][14]Expert / industrial hardware only[13][14]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely for unfilled grades, but brass softens near these nozzle temperatures — hardened or plated hot ends are the norm[13]Hardened steel required — the category spans unfilled PEKK, where brass is acceptable, and the carbon-filled aerospace grades that make up most of the market[2][3]
Abrasiveness1–5Non-abrasive when unfilled[1]Highly abrasive — most PEKK filament sold is carbon-filled; unfilled Antero 800NA and ThermaX PEKK-A are non-abrasive[2][3]
Nozzle clog risk1–5Moderate — needs dry filament and a clean nozzle; 3DXTech lists no special nozzle concerns but a mandatory 120 °C pre-dry before every print[15]Moderate — needs dry filament and a clean nozzle; 3DXTech lists no special nozzle concerns but a mandatory 120 °C pre-dry before every print[16]
Moisture Behaviour
Effect of moisture on strengthNo dry-versus-conditioned figures are published; 3DXTech mandates a 120 °C, 4 h pre-dry before every print because trapped water flashes to steam at these nozzle temperatures[15]No dry-versus-conditioned figures are published; 3DXTech mandates a 120 °C, 4 h pre-dry before every print because trapped water flashes to steam at these nozzle temperatures[16]
Mechanical Properties
Tensile strength (XY)MPa63-77 at break (printed XZ, ASTM D638, Stratasys F900/F3300/Fortus 450mc, three tips and two colours); 54 (printed XY, ISO 527, 3DXTech)[4][1]86.7-90.0 at yield and 73.0 at break (printed XZ, ASTM D638, Antero 800NA on the F900 and Fortus 450mc); 88.8 at break annealed; 126 at break for CarbonX PEKK-A CF15 (printed XY, ISO 527)[3][2]
Young's modulusMPa2040-2540 (printed XZ, ASTM D638, Stratasys); 2050 (printed XY, ISO 527, 3DXTech)[4][1]2640-3870 (printed XZ, ASTM D638, Antero 800NA; upper figure annealed); 9125 for CarbonX PEKK-A CF15 (printed XY, ISO 527)[3][2]
Elongation at break%5.4-9.1 at break (printed XZ, ASTM D638, Stratasys); 1.9-4.3 in ZX; 3DXTech quotes 3 (ISO 527)[4][1]6.1 at break (printed XZ, ASTM D638, Antero 800NA); 2.3 in ZX; 3.15 for CarbonX PEKK-A CF15 (ISO 527)[3][2]
Flexural strengthMPa104-116 at break (printed XZ, ASTM D790 Procedure A, Stratasys); 72-98 in ZX; 3DXTech quotes 90 (ISO 178)[4][1]136 at 5 % strain (printed XZ, ASTM D790, Antero 800NA); 178 for CarbonX PEKK-A CF15 (printed XY, ISO 178)[3][2]
Flexural modulusMPa2400-2550 (printed XZ, ASTM D790, Stratasys F900 T16 and T16A) against 2120-2130 in ZX; 3DXTech quotes 2170 (ISO 178)[4][1]3200 (printed XZ, ASTM D790, Antero 800NA); 8817 for CarbonX PEKK-A CF15 (printed XY, ISO 178)[3][2]
Other impact dataIzod notched 88.5-140 J/m XZ against 37-80 J/m ZX; unnotched 647-2260 J/m XZ against 169-633 J/m ZX (printed, ASTM D256/D4812, Stratasys, across three printers and three tips)[4]Izod notched 41.1 J/m XZ and 33.3 J/m ZX; unnotched 1730 J/m XZ against 203 J/m ZX (printed, ASTM D256/D4812, Antero 800NA)[3]
Layer adhesion / Z tensileMPa39-63 at break (printed ZX, ASTM D638, Stratasys); the low end is the F900 T16 baseline, the high end the F3300 N500 hot end[4]50.1-59.4 at yield (printed ZX, ASTM D638, Antero 800NA); 56.0 for the ESD grade Antero 840CN03[3][17]
Brittleness1–5Brittle — snaps with little warning[1]Moderate unfilled — 6.1 % elongation at break in plane; brittle in the carbon-filled grades at 3.15 %[3][2]
Hardness (scale-specific)Shore A / Shore D / RockwellRockwell M110 / R126 on extruded PEI stock (ASTM D785)[18]Not documented
Creep resistance / sustained load1–5Excellent — holds load for years. Printed ZX coupons keep 87 % of room-temperature tensile strength at 104 °C and 70 % at 132 °C (ASTM D638); extruded PEI stock is rated 170 °C long-term service[4][18]Excellent — holds load for years. Antero 800NA still holds 82 % of its room-temperature ZX tensile strength at 104 °C and 63 % at 132 °C (printed, ASTM D638)[3]
Elasticity / flexibility1–5Rigid[1]Rigid[2]
Z strength as % of XY%56-86 (Stratasys ZX against XZ tensile at break, ASTM D638, across F900/F3300/Fortus 450mc and T16/T20/T40A tips); 58 on the F900 T16 baseline[4]56-82 (Antero 800NA and 840CN03 printed on the F900 and Fortus 450mc, ZX against XZ tensile yield and break, ASTM D638)[3][17]
Thermal Properties
HDT at 0.45 MPa°C158 (printed XY, ISO 75 at 0.45 MPa, 3DXTech) to 178 (printed XY 178.2 and ZX 178.4, ASTM D648 Method B at 66 psi, Stratasys); moulded 176.9[1][4]158 (printed XY and ZX, ASTM D648 Method B at 66 psi, Antero 800NA); 285 for CarbonX PEKK-A CF15 (ISO 75 at 0.45 MPa)[3][2]
HDT at 1.8 MPa°C170-173 (printed XY 170.2 and ZX 172.6, ASTM D648 Method B at 264 psi); moulded 172.9[4]156-157 (printed, ASTM D648 Method B at 264 psi, Antero 800NA); moulded 147[3]
Glass transition (Tg)°C177 (moulded plaque, ASTM D7426 inflection point, Stratasys); 186 (DSC, 3DXTech)[4][1][19]156 (ASTM D7426, Antero 800NA); 165 for CarbonX PEKK-A CF15 (DSC)[3][2]
Melting point / Vicat°CNot documented300 melt point (ASTM D7426 peak heat, Antero 800NA); 305 for CarbonX PEKK-A CF15 (DSC)[3][2]
Continuous service temperature°C170 long-term service on extruded PEI stock, converted from 338 °F; 200 short term[18]Not documented
Thermal expansion (CTE)µm/m·K44.9 (printed XY, -50 to 80 °C, ASTM E831), falling to 31.4 over 80-160 °C; ZX gives 44.5 over -50 to 60 °C. Black pigment raises it to 51.9[4]36.1 in XY and 50.2 in ZX (printed, 40-140 °C, ASTM E831, Antero 800NA); 47.4 and 51.2 for the ESD grade Antero 840CN03[3][17]
Flammability / UL 94UL 94 V-0 at 1.5 mm on the base resin. Printed parts are tested to 14 CFR 25.853, BSS 7238 and 7239 and AITM 2.0007B and 3.0005 covering 60 s and 12 s vertical burn, 15 s horizontal burn, smoke density, toxic gas emission and OSU heat release[1][4]Not documented
Environment & Chemical
UV resistance1–5Good — years with some colour shift. 1000 h of QUV cycling to ASTM G154 left printed ZX coupons at 55.5 MPa yield against 56.0 unexposed, with elongation and modulus unchanged[4]Good — years with some colour shift. 1000 h of QUV cycling to ASTM G154 left Antero 800NA's yield strength unchanged at 57 MPa and raised stress at break 3.6 %[3]
Electrical & ESD propertiesNot documentedUnfilled PEKK is an insulator at above 1.4e14 ohm-cm (ASTM D257); CarbonX PEKK-A CF15 sits above 10^7 ohm/sq, and the Antero 840CN03 ESD grade is specified at 10^4-10^9 ohm-cm[3][2][17]
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised. None of these polymers was in the chamber study, and all are processed far above the temperatures it covered[20]Moderate — measurable VOCs and UFPs, ventilation advised. None of these polymers was in the chamber study, and all are processed far above the temperatures it covered[20]
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[20]Ventilated room or enclosure recommended[20]
Dust & fibre handling hazardNot documentedCarbon fibre is bound in the matrix; sanding dust should not be inhaled[2]
Solvents & Solubility
Soluble inChlorinated hydrocarbons — dichloromethane and chloroform — are solvents for polyetherimide. Laboratory reagents.[21][22]Concentrated sulphuric acid, as for PEEK; no common organic solvent touches a polyaryletherketone.[22][23]
Softened or crazed byAcetone, MEK, benzene, toluene and butyl acetate craze or stress-crack it; alcohols, fuels and dilute acids do not.[22][21]Concentrated sulphuric acid and liquid Freon are the entries Ensinger marks not resistant; acetone, MEK and toluene do nothing.[22]
Solvent welding & smoothing agentDichloromethane is the only welding route, and it is a controlled carcinogen rather than a workshop material.[21][22]None — no solvent softens a polyaryletherketone.[22]

Material entries describe families or representative grades, not an interchangeable specification for every spool. Test methods, orientations and conditions may differ. Unknown values are marked “Not documented”. Prices and source dates remain historical snapshots; check the linked guide for product details. Differences highlight text, not a universal winner.

Sources for this comparison

  1. ThermaX PEI 9085 Technical Data Sheet v4 3DXTech · 2026-08 · tds
  2. CarbonX Carbon Fiber PEKK-A CF15 Technical Data Sheet v1 3DXTech · 2026-08 · tds
  3. Antero 800NA — FDM Material Data Sheet (PEKK-based) Stratasys · 2025-08 · tds
  4. ULTEM 9085 Resin — FDM Material Data Sheet Stratasys · 2026-04 · tds
  5. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  6. Kimya PEI-9085 Natural 2.85 mm 500 g igo3d · 2026-08 · vendor
  7. Fiberlogy PEI 9085 Natural, 1.75 mm / 500 g 3DJAKE · 2026-08 · vendor
  8. 3D4Makers product catalogue 3D4Makers · 2026-08 · vendor
  9. Kimya PEKK-A Natural 1.75 mm 500 g igo3d · 2026-08 · vendor
  10. IEMAI 3D PEI 9085 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  11. Kimya PEKK Carbon Grey 1.75 mm 500 g igo3d · 2026-08 · vendor
  12. IEMAI 3D PEKK 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  13. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  14. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  15. THERMAX PEI 9085 — product page (print recommendations) 3DXTech · 2026-08 · doc
  16. THERMAX PEKK-A — product page (print recommendations) 3DXTech · 2026-08 · doc
  17. Antero 840CN03 — FDM Material Data Sheet (PEKK, ESD) Stratasys · 2024-08 · tds
  18. TECAPEI natural (PEI) — stock shape properties Ensinger · 2026-08 · tds
  19. ThermaX PEI 1010 Technical Data Sheet v4 3DXTech · 2026-08 · tds
  20. Emissions of Ultrafine Particles and Volatile Organic Compounds from Commercially Available Desktop Three-Dimensional Printers with Multiple Filaments (Azimi et al.) Environmental Science & Technology 50(3) 1260-1268 · 2016-01 · paper
  21. Radel PPSU, Veradel PESU, Acudel modified PPSU Design Guide — environmental stress cracking tables Solvay Specialty Polymers · 2026-08 · tds
  22. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  23. The Effects of Sulfonated Poly(ether ether ketone) Ion Exchange Preparation Conditions on Membrane Properties Yee, Zhang & Ladewig, Membranes 3(3) 182–195 · 2013-07 · paper