3D Printing Info

Filament comparison

PEEK vs PEI 9085

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

PEEK guidePEI (ULTEM 9085) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PEEK comparisonsMore PEI 9085 comparisons
PEEK vs PEI 9085 — documented properties and sources
PropertyPEEKHIGHTEMPPEI (ULTEM 9085)HIGHTEMP
Market snapshot
Listing priceUSD/kg; dated snapshots$531.87/kg median; $296.14–$770.00/kg across 5 dated product listings$309.80/kg median; $220.00–$392.00/kg across 6 dated product listings
Identity & Market
Base polymer / chemistryPolyether ether ketone — a semi-crystalline polyaryletherketone[1]Polyetherimide, ULTEM 9085 grade — the flame-retardant PEI used for aircraft interiors[2]
Densityg/cm³1.30 (ISO 1183)[1][3]1.34 (ISO 1183, 3DXTech) against 1.27 specific gravity on moulded plaques (ASTM D792, Stratasys) — the two suppliers disagree[2][4]
Typical priceUSD/kg1 kg-equivalent spools span 296–770; the middle of the market is about 532[5][6][7]1 kg-equivalent spools cluster near 298[5][8][9][6]
Price range across brandsUSD/kg296-770 across brands and spool sizes; 3D4Makers recycled R-PEEK 296 at 750 g, IEMAI 3D 420 at 1 kg, LEHVOSS Luvocom 3F PEEK 9581 532 at 2 kg, 3DXTech ThermaX PEEK 770 at 500 g[5][6][7]220-392 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][8][9][6][10]
Market availability1–5Niche, a handful of specialist brands[5][6][3]Niche, a handful of specialist brands[5][8][9][6]
Spool sizes & diameters1.75 and 2.85 mm; 200 g to 2 kg spools[5][6][3]1.75 and 2.85 mm; 250 g to 2 kg spools, plus Stratasys canisters[5][6][4]
Typical applicationsAerospace brackets, semiconductor handling, sterilisable medical tooling and downhole parts[1]Aircraft interior parts and rail rolling stock, where the flame, smoke and toxicity rating is the requirement[2]
Printing Parameters
Nozzle temperature°C380-400 (3DXTech printed-specimen conditions); Victrex quotes a 340-450 melt range for AM 450 FIL[1][3]Not documented
Bed temperature°C130–140 (3DXTech)[1]130–140 (3DXTech)[2]
Enclosure / chamber requirement1–5Actively heated chamber required[11][12]Actively heated chamber required[11][12]
Recommended chamber temperature°CNot less than 150 for semi-crystalline printing (Victrex AM 450 FIL); bed above 150[3]Not documented
Warping tendency1–5Severe — heated chamber needed[11]Severe — heated chamber needed[11]
Bed-adhesion difficulty1–5Very difficult — special plates or slurry required[11]Not documented
Overall printing difficulty1–5Expert / industrial hardware only[11][12]Expert / industrial hardware only[11][12]
Extruder requirementAn all-metal hot end rated above 400 °C and a heated chamber; 3DXTech tests at 0.25 mm layer height on a 0.4 mm nozzle[1][11]Not documented
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[11]Brass fine indefinitely for unfilled grades, but brass softens near these nozzle temperatures — hardened or plated hot ends are the norm[11]
Abrasiveness1–5Non-abrasive when unfilled[1]Non-abrasive when unfilled[2]
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[13]Moderate — needs dry filament and a clean nozzle; 3DXTech lists no special nozzle concerns but a mandatory 120 °C pre-dry before every print[14]
Moisture Behaviour
Equilibrium moisture content at ~50 % RH%0.45 at saturation, 23 °C (ISO 62); 0.55 at 100 °C[3]Not documented
Drying temperature & time120 °C for 5 h, target below 0.020 % moisture (Victrex AM 450 FIL)[3]Not documented
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[13]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[14]
Mechanical Properties
Tensile strength (XY)MPa60-100 (printed XY): Victrex AM 450 FIL 60-80 at yield and 3DXTech 100, both ISO 527; 98 at yield injection-moulded[1][3]63-77 at break (printed XZ, ASTM D638, Stratasys F900/F3300/Fortus 450mc, three tips and two colours); 54 (printed XY, ISO 527, 3DXTech)[4][2]
Young's modulusMPa3000-4000 (printed XY, ISO 527, Victrex AM 450 FIL); 3720 (3DXTech); 4000 injection-moulded[1][3]2040-2540 (printed XZ, ASTM D638, Stratasys); 2050 (printed XY, ISO 527, 3DXTech)[4][2]
Elongation at break%28 (printed XY, ISO 527) — remarkably ductile for a high-temperature polymer[1]5.4-9.1 at break (printed XZ, ASTM D638, Stratasys); 1.9-4.3 in ZX; 3DXTech quotes 3 (ISO 527)[4][2]
Flexural strengthMPa130 (printed XY, ISO 178)[1]104-116 at break (printed XZ, ASTM D790 Procedure A, Stratasys); 72-98 in ZX; 3DXTech quotes 90 (ISO 178)[4][2]
Flexural modulusMPa2700 (printed XY, ISO 178)[1]2400-2550 (printed XZ, ASTM D790, Stratasys F900 T16 and T16A) against 2120-2130 in ZX; 3DXTech quotes 2170 (ISO 178)[4][2]
Charpy impact, notchedkJ/m²6.0 (injection-moulded, ISO 179/1eA); unnotched does not break[3]Not documented
Other impact dataIzod notched 7.0 kJ/m2 injection-moulded (ISO 180/A). Printed anisotropy is extreme: VICTREX AM 200 on a Stratasys F900 gives Izod notched 1380-1530 J/m XZ against 30-62 J/m ZX (ASTM D256)[3][15]Izod 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]
Layer adhesion / Z tensileMPa20-85 at yield (printed ZX, ISO 527, Victrex AM 450 FIL); the spread is set by chamber temperature and weld quality[3]39-63 at break (printed ZX, ASTM D638, Stratasys); the low end is the F900 T16 baseline, the high end the F3300 N500 hot end[4]
Brittleness1–5Tough — absorbs impact, yields before breaking[1]Brittle — snaps with little warning[2]
Hardness (scale-specific)Shore A / Shore D / RockwellShore D 84.5 (injection-moulded, ISO 868); Rockwell M100 / R125 on extruded PEEK stock (ASTM D785)[3][16]Rockwell M110 / R126 on extruded PEI stock (ASTM D785)[17]
Creep resistance / sustained load1–5Excellent — holds load for years. Victrex rates PEEK for long-term creep; injection-moulded flexural stress at 3.5 % strain falls only from 125 MPa at 23 °C to 85 MPa at 125 °C, and extruded stock is rated to 249 °C continuous[18][3][16]Excellent — 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][17]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable. Victrex rates PEEK for long-term fatigue as well as creep[18]Not documented
Elasticity / flexibility1–5Rigid[1]Rigid[2]
Z strength as % of XY%71-84 (VICTREX AM 200 LMPAEK printed on the Stratasys F900 and Fortus 450mc, ZX against XZ tensile yield, ASTM D638); unfilled PEEK's own ZX spread is wider[15]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]
Thermal Properties
HDT at 0.45 MPa°C140 (printed XY, ISO 75 at 0.45 MPa, 3DXTech)[1]158 (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[2][4]
HDT at 1.8 MPa°C152 (unannealed, ISO 75-2/Af, Victrex AM 450 FIL); 160 on extruded stock (ASTM D648 at 264 psi)[3][16]170-173 (printed XY 170.2 and ZX 172.6, ASTM D648 Method B at 264 psi); moulded 172.9[4]
Glass transition (Tg)°C143 (DSC, 3DXTech); Victrex gives onset 143 and midpoint 150 (ISO 11357-2)[1][3]177 (moulded plaque, ASTM D7426 inflection point, Stratasys); 186 (DSC, 3DXTech)[4][2][19]
Melting point / Vicat°C343 melting (ISO 11357-3, Victrex); VICTREX AM 200 LMPAEK melts at 303[3][15]Not documented
Continuous service temperature°C240 UL 746B relative thermal index, strength (RTI electrical 260, impact 180); Ensinger rates extruded PEEK stock at 249 long term[3][16]170 long-term service on extruded PEI stock, converted from 338 °F; 200 short term[17]
Thermal expansion (CTE)µm/m·K37.8 (extruded PEEK stock, 23-60 °C, ASTM E831; source states 2.1e-5 in/in/°F), rising to 41.9 at 60-100 °C and 55.8 at 100-150 °C[16]44.9 (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]
Flammability / UL 94UL 94 V-0 at 1.5 mm on the base resin; glow-wire flammability index 960 °C at 2.0 mm (IEC 60695-2-12)[1][3]UL 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[2][4]
Environment & Chemical
UV resistance1–5Not documentedGood — 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]
Chemical resistanceOutstanding — resistant to almost all solvents and to steam sterilisation[1]Not documented
Water / humidity resistance in service1–5Excellent — essentially unaffected; 0.45 % water at saturation and resistant to steam sterilisation[3][1]Not documented
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]
Solvents & Solubility
Soluble in95–98 wt% sulphuric acid dissolves it — 10 g per 100 mL at 40–70 °C gives a dark red solution. Laboratory route only.[21][22]Chlorinated hydrocarbons — dichloromethane and chloroform — are solvents for polyetherimide. Laboratory reagents.[23][22]
Softened or crazed byConcentrated nitric, hydrofluoric, hydrobromic and hydriodic acids attack it; DCM, DMSO and THF swell thin-walled sections.[24][22]Acetone, MEK, benzene, toluene and butyl acetate craze or stress-crack it; alcohols, fuels and dilute acids do not.[22][23]
Solvent welding & smoothing agentNone — no solvent softens PEEK, so parts are joined thermally or mechanically, never chemically.[24][22]Dichloromethane is the only welding route, and it is a controlled carcinogen rather than a workshop material.[23][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 PEEK Technical Data Sheet v3 3DXTech · 2026-08 · tds
  2. ThermaX PEI 9085 Technical Data Sheet v4 3DXTech · 2026-08 · tds
  3. VICTREX AM 450 FIL — datasheet Victrex · 2025-12 · tds
  4. ULTEM 9085 Resin — FDM Material Data Sheet Stratasys · 2026-04 · tds
  5. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  6. 3D4Makers product catalogue 3D4Makers · 2026-08 · vendor
  7. IEMAI 3D PEEK 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  8. Kimya PEI-9085 Natural 2.85 mm 500 g igo3d · 2026-08 · vendor
  9. Fiberlogy PEI 9085 Natural, 1.75 mm / 500 g 3DJAKE · 2026-08 · vendor
  10. IEMAI 3D PEI 9085 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  11. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  12. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  13. ThermaX PEEK — product page 3DXTech · 2026-08 · vendor
  14. THERMAX PEI 9085 — product page (print recommendations) 3DXTech · 2026-08 · doc
  15. VICTREX AM 200 — FDM Material Data Sheet Stratasys · 2024-04 · tds
  16. TECAPEEK natural (PEEK) — stock shape properties Ensinger · 2026-08 · tds
  17. TECAPEI natural (PEI) — stock shape properties Ensinger · 2026-08 · tds
  18. PEEK polymers — product overview Victrex · 2026-08 · doc
  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. 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
  22. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  23. Radel PPSU, Veradel PESU, Acudel modified PPSU Design Guide — environmental stress cracking tables Solvay Specialty Polymers · 2026-08 · tds
  24. What solvents are not compatible with PEEK? — fluidics technical FAQ IDEX Health & Science · 2026-08 · doc