3D Printing Info

Filament comparison

PEEK-CF vs PEI 9085

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

Fibre-reinforced PEEK guidePEI (ULTEM 9085) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PEEK-CF comparisonsMore PEI 9085 comparisons
PEEK-CF vs PEI 9085 — documented properties and sources
PropertyFibre-reinforced PEEKHIGHTEMPPEI (ULTEM 9085)HIGHTEMP
Market snapshot
Listing priceUSD/kg; dated snapshots$597.50/kg median; $448.00–$695.00/kg across 5 dated product listings$309.80/kg median; $220.00–$392.00/kg across 6 dated product listings
Identity & Market
Base polymer / chemistryShort-fibre reinforced PEEK. 3DXTech's CarbonX grade is nominally 10 wt% carbon and its FibreX grade 20 wt% glass; LEHVOSS Luvocom 3F PEEK CF 9676 is 15 wt% carbon; Ensinger's machining stock runs to 30 wt% carbon[1][2][3][4]Polyetherimide, ULTEM 9085 grade — the flame-retardant PEI used for aircraft interiors[5]
Densityg/cm³1.39 (ISO 1183)[1]1.34 (ISO 1183, 3DXTech) against 1.27 specific gravity on moulded plaques (ASTM D792, Stratasys) — the two suppliers disagree[5][6]
Typical priceUSD/kg1 kg-equivalent spools span 448–972; the middle of the market is about 598[2][3][7]1 kg-equivalent spools cluster near 298[2][8][9][3]
Price range across brandsUSD/kg448-972 across formats and filler types; IEMAI 3D CF-PEEK and GF-PEEK 448 at 1 kg, 3DXTech CarbonX PEEK+CF10 598 at 2 kg and FibreX PEEK+GF20 695 at 1 kg, Luvocom 3F PEEK CF 9676 648 at 2 kg[2][3][7][10]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[2][8][9][3][11]
Market availability1–5Niche, a handful of specialist brands[2][3]Niche, a handful of specialist brands[2][8][9][3]
Spool sizes & diameters1.75 and 2.85 mm; 200 g to 2 kg spools[2][3]1.75 and 2.85 mm; 250 g to 2 kg spools, plus Stratasys canisters[2][3][6]
Typical applicationsStiff aerospace and oil-and-gas parts where PEEK alone is not rigid enough[1]Aircraft interior parts and rail rolling stock, where the flame, smoke and toxicity rating is the requirement[5]
Printing Parameters
Bed temperature°CNot documented130–140 (3DXTech)[5]
Enclosure / chamber requirement1–5Actively heated chamber required[12][13]Actively heated chamber required[12][13]
Warping tendency1–5Moderate — needs adhesion aid or draught shield; the fibre cuts PEEK's crystallisation shrinkage[1]Severe — heated chamber needed[12]
Overall printing difficulty1–5Expert / industrial hardware only[12][13]Expert / industrial hardware only[12][13]
Hardware Wear & Reliability
Nozzle hardness required1–4Hardened steel required[1]Brass fine indefinitely for unfilled grades, but brass softens near these nozzle temperatures — hardened or plated hot ends are the norm[12]
Abrasiveness1–5Highly abrasive — standard CF composite[1]Non-abrasive when unfilled[5]
Nozzle clog risk1–5High — jams from moisture, heat creep or particles; 3DXTech adds a hardened 0.4 mm minimum nozzle and 0.25 mm layers to the mandatory 120 °C pre-dry[14][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
Equilibrium moisture content at ~50 % RH%0.06 in 24 h on extruded CF30 stock (ASTM D570)[4]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[14]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)MPa105 at break (printed XY, ISO 527, CF10); 121 at yield on extruded CF30 stock (ASTM D638)[1][4]63-77 at break (printed XZ, ASTM D638, Stratasys F900/F3300/Fortus 450mc, three tips and two colours); 54 (printed XY, ISO 527, 3DXTech)[6][5]
Young's modulusMPa8100 (printed XY, ISO 527, CF10) — more than double unfilled PEEK; 6343 on extruded CF30 stock (ASTM D638)[1][4]2040-2540 (printed XZ, ASTM D638, Stratasys); 2050 (printed XY, ISO 527, 3DXTech)[6][5]
Elongation at break%3 at break (printed XY, ISO 527), against 28 for unfilled PEEK[1][17]5.4-9.1 at break (printed XZ, ASTM D638, Stratasys); 1.9-4.3 in ZX; 3DXTech quotes 3 (ISO 527)[6][5]
Flexural strengthMPa136 (printed XY, ISO 178, CF10); 193 on extruded CF30 stock (ASTM D790)[1][4]104-116 at break (printed XZ, ASTM D790 Procedure A, Stratasys); 72-98 in ZX; 3DXTech quotes 90 (ISO 178)[6][5]
Flexural modulusMPa8300 (printed XY, ISO 178, CF10); 7171 on extruded CF30 stock (ASTM D790)[1][4]2400-2550 (printed XZ, ASTM D790, Stratasys F900 T16 and T16A) against 2120-2130 in ZX; 3DXTech quotes 2170 (ISO 178)[6][5]
Other impact dataIzod notched 61.9 J/m on extruded CF30 stock, converted from 1.16 ft-lb/in (ASTM D256)[4]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)[6]
Layer adhesion / Z tensileMPaNot documented39-63 at break (printed ZX, ASTM D638, Stratasys); the low end is the F900 T16 baseline, the high end the F3300 N500 hot end[6]
Brittleness1–5Brittle — snaps with little warning; elongation falls from 28 % to 3 %[1][17]Brittle — snaps with little warning[5]
Hardness (scale-specific)Shore A / Shore D / RockwellRockwell M107 on extruded PEEK-CF30 stock (ASTM D785), against M100 unfilled[4][18]Rockwell M110 / R126 on extruded PEI stock (ASTM D785)[19]
Creep resistance / sustained load1–5Excellent — holds load for years. Ensinger rates carbon-fibre PEEK stock as very highly creep resistant and specifies 260 °C continuous service[4]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[6][19]
Fatigue / repeated-flex resistance1–5Good. Victrex rates PEEK for long-term fatigue as well as creep; the fibre cuts elongation at break from 28 % to 3 %, which limits repeated large-strain flexing[20][1][17]Not documented
Elasticity / flexibility1–5Rigid[1]Rigid[5]
Z strength as % of XY%Not documented56-86 (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[6]
Thermal Properties
HDT at 0.45 MPa°C265 (printed XY, ISO 75 at 0.45 MPa, CarbonX PEEK+CF10) against 140 for unfilled PEEK[1][17]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[5][6]
HDT at 1.8 MPa°C316 on extruded CF30 stock, converted from 600 °F at 264 psi (ASTM D648)[4]170-173 (printed XY 170.2 and ZX 172.6, ASTM D648 Method B at 264 psi); moulded 172.9[6]
Glass transition (Tg)°C143 (DSC, CarbonX PEEK+CF10) — the fibre does not move the glass transition[1]177 (moulded plaque, ASTM D7426 inflection point, Stratasys); 186 (DSC, 3DXTech)[6][5][21]
Melting point / Vicat°C334 melting on extruded CF30 stock, converted from 633 °F[4]Not documented
Continuous service temperature°C260 long-term on extruded CF30 stock, converted from 500 °F; 300 short term[4]170 long-term service on extruded PEI stock, converted from 338 °F; 200 short term[19]
Thermal expansion (CTE)µm/m·K14.4 (extruded PEEK-CF30 stock, ASTM D696; source states 0.80e-5 in/in/°F) — about a third of unfilled PEEK[4][18]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[6]
Flammability / UL 94UL 94 V-0 on the base resin; Ensinger lists extruded PEEK-CF30 stock as inherently flame resistant[17][4]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[5][6]
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[6]
Electrical & ESD propertiesSurface resistance above 10⁹ ohm/sq — not static-dissipative (ASTM D257)[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[22]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[22]
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[22]Ventilated room or enclosure recommended[22]
Dust & fibre handling hazardCarbon fibre is bound in the matrix; sanding dust should not be inhaled[1]Not documented
Solvents & Solubility
Soluble in95–98 wt% sulphuric acid dissolves the matrix at 40–70 °C and leaves the fibre. Nothing else touches PEEK.[23][24]Chlorinated hydrocarbons — dichloromethane and chloroform — are solvents for polyetherimide. Laboratory reagents.[25][24]
Softened or crazed byConcentrated nitric, hydrofluoric, hydrobromic and hydriodic acids attack it; DCM, DMSO and THF swell thin-walled sections.[26][24]Acetone, MEK, benzene, toluene and butyl acetate craze or stress-crack it; alcohols, fuels and dilute acids do not.[24][25]
Solvent welding & smoothing agentNone — no solvent softens PEEK, so parts are joined thermally or mechanically, never chemically.[26][24]Dichloromethane is the only welding route, and it is a controlled carcinogen rather than a workshop material.[25][24]

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. CarbonX Carbon Fiber PEEK Technical Data Sheet v3 3DXTech · 2026-08 · tds
  2. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  3. 3D4Makers product catalogue 3D4Makers · 2026-08 · vendor
  4. TECAPEEK CF30 black (PEEK-CF30) — stock shape properties Ensinger · 2026-08 · tds
  5. ThermaX PEI 9085 Technical Data Sheet v4 3DXTech · 2026-08 · tds
  6. ULTEM 9085 Resin — FDM Material Data Sheet Stratasys · 2026-04 · tds
  7. IEMAI 3D CF-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 GF-PEEK 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  11. IEMAI 3D PEI 9085 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  12. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  13. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  14. CARBONX PEEK+CF10 — product page (print recommendations) 3DXTech · 2026-08 · doc
  15. Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
  16. THERMAX PEI 9085 — product page (print recommendations) 3DXTech · 2026-08 · doc
  17. ThermaX PEEK Technical Data Sheet v3 3DXTech · 2026-08 · tds
  18. TECAPEEK natural (PEEK) — stock shape properties Ensinger · 2026-08 · tds
  19. TECAPEI natural (PEI) — stock shape properties Ensinger · 2026-08 · tds
  20. PEEK polymers — product overview Victrex · 2026-08 · doc
  21. ThermaX PEI 1010 Technical Data Sheet v4 3DXTech · 2026-08 · tds
  22. 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
  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
  24. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  25. Radel PPSU, Veradel PESU, Acudel modified PPSU Design Guide — environmental stress cracking tables Solvay Specialty Polymers · 2026-08 · tds
  26. What solvents are not compatible with PEEK? — fluidics technical FAQ IDEX Health & Science · 2026-08 · doc