3D Printing Info

Filament comparison

PEI 9085 vs PLA

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

PEI (ULTEM 9085) guidePLA (standard) guide

2 selected · all documented properties

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PEI 9085 vs PLA — documented properties and sources
PropertyPEI (ULTEM 9085)HIGHTEMPPLA (standard)PLA
Market snapshot
Listing priceUSD/kg; dated snapshots$309.80/kg median; $220.00–$392.00/kg across 6 dated product listings$19.74/kg median; $9.99–$32.99/kg across 24 dated product listings
Identity & Market
Base polymer / chemistryPolyetherimide, ULTEM 9085 grade — the flame-retardant PEI used for aircraft interiors[1]Poly(lactic acid), a thermoplastic aliphatic polyester from fermented plant starch[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]1.17–1.24 (ISO 1183)[2][5][3]
Typical priceUSD/kg1 kg-equivalent spools cluster near 298[6][7][8][9]Mainstream 1 kg spools cluster near 20[10][11][12]
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[6][7][8][9][13]10–33 across brands; budget house brands 10–14, premium European 26–33[14][15][16][17]
Market availability1–5Niche, a handful of specialist brands[6][7][8][9]Ubiquitous, every brand and retailer[18][19]
Spool sizes & diameters1.75 and 2.85 mm; 250 g to 2 kg spools, plus Stratasys canisters[6][9][4]1.75 and 2.85 mm; 0.75, 0.85, 1 and 1.1 kg spools plus spool-less refills[10][20][21][16][22]
Typical applicationsAircraft interior parts and rail rolling stock, where the flame, smoke and toxicity rating is the requirement[1]Concept models, functional prototypes, low-wear toys, jigs used at room temperature[23]
Diameter tolerance± mmNot documented±0.02 (Prusament) to ±0.03 (Bambu Lab, Prusa Research standard)[2][10][24]
Printing Parameters
Nozzle temperature°CNot documented190–230; Prusament specifies 210 ± 10[2][5][3]
Bed temperature°C130–140 (3DXTech)[1]25–60; Prusament 40–60, Bambu Lab 35–45[2][5][3]
Enclosure / chamber requirement1–5Actively heated chamber required[25][26]Open frame is fine[5][18]
Part cooling fanNot documented100 % from the second layer; reduce on the first one or two layers for bed adhesion[2][19]
Bed surface & adhesion aidNot documentedSmooth or textured PEI, glass or painter's tape; glue stick only where release is a problem[5][27][19]
Maximum volumetric flow (mm³/s; see test conditions)mm³/sNot documented12–20 (PrusaSlicer max volumetric speed guidance for PLA)[28]
Warping tendency1–5Severe — heated chamber needed[25]None[29][18]
Bed-adhesion difficulty1–5Not documentedSticks to anything — glue only needed on smooth PEI[5][3][19]
Stringing / oozing tendency1–5Not documentedSlight — 1–3 mm retraction handles it; oozing rises with nozzle temperature[5][19][30]
Overall printing difficulty1–5Expert / industrial hardware only[25][26]Beginner — prints on any machine out of the box[18][19]
Extruder requirementNot documentedAny extruder; Bowden and direct drive both fine, no hardware upgrades[18]
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[25]Brass fine indefinitely[18]
Abrasiveness1–5Non-abrasive when unfilled[1]Non-abrasive[29][18]
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[31]Very low[18][19]
Heat-creep / jam sensitivity1–5Not documentedModerate — good heatbreak cooling needed; softens below 60 °C so it deforms in a warm cold zone[27][32]
Hotend requirementNot documentedAny standard hotend; PTFE-lined is fine at PLA temperatures[18]
Other hardware wearNot documentedNone — brass nozzles and standard drive gears are unaffected[29][18]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Not documentedModerate — 0.40–0.51 % saturated at 23–25 °C and 55–70 % RH[3][5][33]
Equilibrium moisture content at ~50 % RH%Not documented0.43 saturated at 25 °C / 55 % RH (Bambu Lab); 0.51 equilibrium (Polymaker)[3][5]
Drying temperature & timeNot documented50–55 °C for 6–8 h in a forced-air dryer; 45 °C for 12 h in the Bambu Lab AMS HT[5][3][32]
Symptoms when wetNot documentedBubbling and popping at the nozzle, stringing, rough surface and weak layers[34]
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[31]Polymaker rates PLA low-sensitivity — it absorbs moisture slowly and the loss shows as poor layer adhesion and brittle layers rather than a published strength figure[34]
Storage requirementNot documentedSealed with desiccant below 20 % RH; shelf life at ambient is long[3][19]
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]35–52 (printed XY, ISO 527); 55 mean across 16 brands and 53 for the reference PLA in a later run, both on 4×4 mm printed bars[2][5][3][35][36]
Young's modulusMPa2040-2540 (printed XZ, ASTM D638, Stratasys); 2050 (printed XY, ISO 527, 3DXTech)[4][1]2300–3427 (printed XY, ISO 527)[2][5][3]
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]6.3–12.2 (printed XY, ISO 527); Prusament quotes 2.9 at yield[5][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]76–87 (printed XY, ISO 178); Fiberlogy quotes 81 by ASTM D790[2][5][3][37]
Flexural modulusMPa2400-2550 (printed XZ, ASTM D790, Stratasys F900 T16 and T16A) against 2120-2130 in ZX; 3DXTech quotes 2170 (ISO 178)[4][1]2750–3230 (printed XY, ISO 178); Fiberlogy quotes 3800 by ASTM D790[2][5][3][37]
Charpy impact, notchedkJ/m²Not documented3.3–7.9 (printed XY, ISO 179, notched)[5][3]
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]Charpy unnotched, printed: 13–14 (Prusament, ISO 179-1), 26.6 (Bambu Lab PLA Basic)[2][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]17–31 (Prusa interlayer test and printed Z tensile); 23 mean on My Tech Fun 4×4 mm bars[2][3][36]
Brittleness1–5Brittle — snaps with little warning[1]Brittle — snaps with little warning[27][29]
Hardness (scale-specific)Shore A / Shore D / RockwellRockwell M110 / R126 on extruded PEI stock (ASTM D785)[38]81 Shore D (Prusa Polymers in-house method); 75.3 Shore D measured on printed bars (My Tech Fun, Sunlu PLA)[2][39]
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][38]Poor — deforms under load at room temperature; 12 mm bar sagged to 20.3 mm over 5 days at 1.25 kg[40][41]
Fatigue / repeated-flex resistance1–5Not documentedPoor — 38 000–49 000 cycles at 30 % of tensile strength, against 79 000–193 000 for PETG (printed, R = 0.2, 7 Hz)[42][27]
Elasticity / flexibility1–5Rigid[1]Rigid[29]
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]77–89 on TDS specimens; ≈44 on My Tech Fun 4×4 mm bars[5][3][36]
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]55–60 (ISO 75, 0.45 MPa)[2][5][3]
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]54–58 (ISO 75, 1.8 MPa)[2][5][3]
Glass transition (Tg)°C177 (moulded plaque, ASTM D7426 inflection point, Stratasys); 186 (DSC, 3DXTech)[4][1][43]55–61 (DSC)[2][5][3]
Melting point / Vicat°CNot documented145–160 peak melt (Prusament, ISO 11357); 150 and 160 by DSC (PolyLite, Bambu Lab); Vicat 57–63 (ISO 306)[23][5][3]
Continuous service temperature°C170 long-term service on extruded PEI stock, converted from 338 °F; 200 short term[38]50–55 — loaded bars begin to move at this temperature[29][36]
Annealing responseNot documentedBambu Lab conditions specimens at 55 °C for 8 h; annealing at 50–60 °C for 6–12 h raises crystallinity but can warp parts[3][44]
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]96 ± 5 at 0° and 99 ± 5 at 90° raster (printed PLA, fibre Bragg grating, 25–50 °C)[45]
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]Flammable; no UL 94 rating published by the major brands[3][5]
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]Degrades within weeks outdoors[27][23]
Outdoor durabilityNot documentedNot suitable for long-term outdoor use — UV embrittlement plus softening above 55 °C in direct sun[23][27]
Chemical resistanceNot documentedGood against weak acids, oils and grease; poor against strong acids and alkalis; dissolved by chloroform, THF and hot benzene[5][27]
Water / humidity resistance in service1–5Not documentedGood — insoluble in water, absorbs 0.4–0.5 % at equilibrium[3][46]
Food contactNot documentedBase resin is food-contact grade and EN 71-3 certified by some brands, but printed layer grooves harbour bacteria; Prusa advises against food use[27][46]
Biodegradability / compostabilityNot documentedIndustrially compostable only — needs sustained 55 °C and specific microbial conditions; not home compostable[46][27][3]
RecyclabilityNot documentedMechanically recyclable; not accepted in household plastic collection, so brand take-back schemes are the practical route[46]
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[47]Low hazard — minimal VOC and particle emission[47]
VOC emission rateµg/minNot documented4–5 lactide, the dominant VOC (chamber study, three printers)[47]
Ultrafine-particle emission rateparticles/minNot documented≈1 × 10⁸ median across three printers; only laywood ≈8 × 10⁷ and laybrick ≈6 × 10⁷ were lower[47]
Hazardous species emittedNot documentedLactide (3,6-dimethyl-1,4-dioxane-2,5-dione) dominates; no styrene or caprolactam as a leading species[47]
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[47]None needed in a normal room[47]
Post-Processing
Sanding & machiningNot documentedWet sanding — dry sanding heats the surface by friction and smears it[23][27]
Gluing & solvent weldingNot documentedCyanoacrylate for most joints; some grades partially dissolve and bond with acetone, depending on additives and colour[27][24]
Vapour / chemical smoothingNot documentedNo practical vapour smoothing — only chloroform, hot benzene or THF, which are laboratory-only[27]
Support material pairingNot documentedPolySupport and PolyDissolve S1 (Polymaker); Support for PLA (Bambu Lab)[5][3]
Dimensional accuracy & detailNot documentedGood — low shrinkage and features under 0.2 mm resolve; 55° overhangs and 30 mm bridges[29][3][19]
Solvents & Solubility
Soluble inChlorinated hydrocarbons — dichloromethane and chloroform — are solvents for polyetherimide. Laboratory reagents.[48][49]Chloroform: 10 % w/v in 2–4 h at 23 °C, every grade and morphology; THF and DMF only at 65 °C. Laboratory reagents.[50]
Softened or crazed byAcetone, MEK, benzene, toluene and butyl acetate craze or stress-crack it; alcohols, fuels and dilute acids do not.[49][48]Acetone, ethyl acetate and toluene plasticise it but dissolve <1 % even at 65 °C; submersion in acetone crazes and destroys parts.[50][51]
Solvent welding & smoothing agentDichloromethane is the only welding route, and it is a controlled carcinogen rather than a workshop material.[48][49]Chloroform vapour smooths and welds PLA at the cost of tensile strength; acetone does not smooth it at all.[52][51]

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. Prusament PLA Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  3. Bambu Filament Technical Data Sheet V3.0 — PLA Basic Bambu Lab · 2026-08 · tds
  4. ULTEM 9085 Resin — FDM Material Data Sheet Stratasys · 2026-04 · tds
  5. PolyLite PLA Technical Data Sheet V5.4 Polymaker · 2024-11 · tds
  6. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  7. Kimya PEI-9085 Natural 2.85 mm 500 g igo3d · 2026-08 · vendor
  8. Fiberlogy PEI 9085 Natural, 1.75 mm / 500 g 3DJAKE · 2026-08 · vendor
  9. 3D4Makers product catalogue 3D4Makers · 2026-08 · vendor
  10. PLA Basic — product page Bambu Lab US Store · 2026-08 · vendor
  11. MH Build Series PLA Filament White 1.75mm 1kg MatterHackers · 2026-08 · vendor
  12. 3DJAKE ecoPLA Black 1.75mm 1000g 3DJake International · 2026-08 · vendor
  13. IEMAI 3D PEI 9085 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  14. JAYO PLA Classic 1.1KG 1.75mm JAYO Official Store · 2026-08 · vendor
  15. ELEGOO PLA Filament 1.75mm Colored 1KG Elegoo US Official Store · 2026-08 · vendor
  16. Fillamentum PLA Extrafill Natural 1kg Fillamentum USA · 2026-08 · vendor
  17. Prusament PLA Jet Black 1kg (NFC) Prusa Research · 2026-08 · vendor
  18. Filament Material Guide Prusa Knowledge Base · 2026-08 · doc
  19. PLA — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  20. Fiberlogy rPLA Refill Anthracite 850 g 3DJake International · 2026-08 · vendor
  21. JAYO Silk PLA+ 1.75mm 1.1kg JAYO Official Store · 2026-08 · vendor
  22. ColorFabb PLA/PHA 750g 3D Universe · 2026-08 · vendor
  23. Prusament PLA Technical Data Sheet v1.0 Prusa Polymers · 2018-09 · tds
  24. Prusament rPLA Corn Pigment 1kg — product page Prusa Research · 2026-08 · vendor
  25. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  26. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  27. PLA — material guide Prusa Knowledge Base · 2026-08 · doc
  28. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  29. Prusament PLA — material page Prusa Polymers · 2026-08 · doc
  30. PLA — material basics Polymaker Wiki · 2026-08 · doc
  31. THERMAX PEI 9085 — product page (print recommendations) 3DXTech · 2026-08 · doc
  32. Filament Drying Recommendations Bambu Lab Wiki · 2026-08 · doc
  33. PolySonic PLA Technical Data Sheet V5.4 Polymaker · 2024-11 · tds
  34. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  35. 16 PLA brand comparison test — results spreadsheet My Tech Fun (Igor Gaspar) · 2022-10 · test
  36. Creality Hyper PLA filament review — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  37. Easy PLA — product and technical data Fiberlogy · 2026-08 · tds
  38. TECAPEI natural (PEI) — stock shape properties Ensinger · 2026-08 · tds
  39. Carbon Fiber PLA vs META-PLA vs PLA+ vs PLA by Sunlu — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  40. BambuLab PLA Basic vs PLA Tough vs PLA-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  41. PolyTerra PLA vs PLA+ — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  42. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  43. ThermaX PEI 1010 Technical Data Sheet v4 3DXTech · 2026-08 · tds
  44. Bambu Filament Technical Data Sheet V3.0 — PLA Matte Bambu Lab · 2026-08 · tds
  45. Characterization of Thermal Expansion Coefficient of 3D Printing Polymeric Materials Using Fiber Bragg Grating Sensors Materials 17(18):4668 · 2024-09 · paper
  46. Filamentive PLA (recycled) — product page Filamentive · 2026-08 · vendor
  47. 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
  48. Radel PPSU, Veradel PESU, Acudel modified PPSU Design Guide — environmental stress cracking tables Solvay Specialty Polymers · 2026-08 · tds
  49. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  50. Solubility Study of Ingeo Biopolymer Grades in Common Organic Solvents (NWPD003) NatureWorks · 2019-10 · tds
  51. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc
  52. Effect of vapour smoothing in trichloromethane on 3D printed PLA — surface, mechanical and chemical structure Pitale, Keche & Chopra, Engineering Research Express 6(4) 045579 · 2024-12 · paper