3D Printing Info

Filament comparison

PEI 9085 vs rPLA

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

PEI (ULTEM 9085) guideRecycled PLA (rPLA) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PEI 9085 comparisonsMore rPLA comparisons
PEI 9085 vs rPLA — documented properties and sources
PropertyPEI (ULTEM 9085)HIGHTEMPRecycled PLA (rPLA)PLA
Market snapshot
Listing priceUSD/kg; dated snapshots$309.80/kg median; $220.00–$392.00/kg across 6 dated product listings$20.79/kg median; $16.05–$40.64/kg across 8 dated product listings
Identity & Market
Base polymer / chemistryPolyetherimide, ULTEM 9085 grade — the flame-retardant PEI used for aircraft interiors[1]PLA regranulated from post-industrial PLA manufacturing waste; post-consumer feedstock is rare[2][3][4]
Densityg/cm³1.34 (ISO 1183, 3DXTech) against 1.27 specific gravity on moulded plaques (ASTM D792, Stratasys) — the two suppliers disagree[1][5]1.24 (ISO 1183)[2]
Typical priceUSD/kg1 kg-equivalent spools cluster near 298[6][7][8][9]1 kg spools run 20–22[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]16–41 across brands; Fiberlogy refill 16, Filamentive 750 g 41[14][15]
Market availability1–5Niche, a handful of specialist brands[6][7][8][9]Available from several mainstream brands[3][4][12]
Spool sizes & diameters1.75 and 2.85 mm; 250 g to 2 kg spools, plus Stratasys canisters[6][9][5]1.75 and 2.85 mm; 0.75, 0.85 and 1 kg spools plus spool-less refills[16][14][3]
Typical applicationsAircraft interior parts and rail rolling stock, where the flame, smoke and toxicity rating is the requirement[1]General-purpose printing where the feedstock's recycled content matters more than an exact colour match[3][4]
Diameter tolerance± mmNot documented±0.03 guaranteed by Prusa Research today; the 2021 datasheet specified ±0.05, against ±0.02 for virgin Prusament PLA[3][2][17]
Printing Parameters
Nozzle temperature°CNot documented210 ± 10 (Prusament); 200 ± 15 (Filamentive)[2][4]
Bed temperature°C130–140 (3DXTech)[1]40–60 (Prusament); up to 60 (Filamentive)[2][4]
Enclosure / chamber requirement1–5Actively heated chamber required[18][19]Open frame is fine[2][20]
Part cooling fanNot documented100 %[2]
Warping tendency1–5Severe — heated chamber needed[18]None — brim not generally needed[2]
Bed-adhesion difficulty1–5Not documentedSticks to anything[21]
Overall printing difficulty1–5Expert / industrial hardware only[18][19]Beginner — prints on any machine out of the box[2][20]
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[18]Brass fine indefinitely[20]
Abrasiveness1–5Non-abrasive when unfilled[1]Non-abrasive[22][20]
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[23]Very low[20]
Heat-creep / jam sensitivity1–5Not documentedModerate — good heatbreak cooling needed; PLA softens below 60 °C[24]
Hotend requirementNot documentedNo special hot-end required[21]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Not documentedModerate — 0.3 % after both 24 h and 7 days at 28 °C / 37 % RH (Prusa Polymers method), against 0.19 % in 7 days for virgin Prusament PLA[2][17]
Equilibrium moisture content at ~50 % RH%Not documented0.3 after 24 h and 7 days at 28 °C / 37 % RH (Prusa Polymers method)[2]
Symptoms when wetNot documentedBubbling and popping at the nozzle, stringing, rough surface and weak layers[25]
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[23]Polymaker rates PLA low-sensitivity — the loss shows as poor layer adhesion and brittle layers rather than a published strength figure[25]
Storage requirementNot documentedSealed with desiccant below 20 % RH; shelf life at ambient is long[26][21]
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)[5][1]49 printed horizontal and 55 printed vertical XZ (ISO 527-1, yield); virgin Prusament PLA gives 51 and 59 by the same method[2][17]
Young's modulusMPa2040-2540 (printed XZ, ASTM D638, Stratasys); 2050 (printed XY, ISO 527, 3DXTech)[5][1]2100 printed horizontal, 2300 printed vertical XZ (ISO 527-1); virgin Prusament PLA 2300 and 2400[2][17]
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)[5][1]3.1 at yield printed horizontal (ISO 527-1); virgin Prusament PLA 2.9[2][17]
Flexural strengthMPa104-116 at break (printed XZ, ASTM D790 Procedure A, Stratasys); 72-98 in ZX; 3DXTech quotes 90 (ISO 178)[5][1]82 printed horizontal, 87 printed vertical XZ (ISO 178); virgin Prusament PLA 83 and 99[2][17]
Flexural modulusMPa2400-2550 (printed XZ, ASTM D790, Stratasys F900 T16 and T16A) against 2120-2130 in ZX; 3DXTech quotes 2170 (ISO 178)[5][1]3100 printed horizontal (ISO 178) — the same as virgin Prusament PLA[2][17]
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)[5]Charpy unnotched 14.0 printed horizontal (ISO 179-1); virgin Prusament PLA 13[2][17]
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[5]21 ± 2 (Prusa Polymers interlayer adhesion test); virgin Prusament PLA 17 ± 3 by the same test[2][17]
Brittleness1–5Brittle — snaps with little warning[1]Brittle — snaps with little warning[24][22]
Hardness (scale-specific)Shore A / Shore D / RockwellRockwell M110 / R126 on extruded PEI stock (ASTM D785)[27]80 Shore D (Prusa Polymers in-house method); virgin Prusament PLA 81[2][17]
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[5][27]Poor — no recycled-PLA creep data published; virgin PLA sagged from 12 to 18.7–20.3 mm over 5 days at 1.25 kg[28][29]
Fatigue / repeated-flex resistance1–5Not documentedPoor — no grade-specific S-N curve; plain printed PLA ran 38 000–49 000 cycles at 30 % of tensile strength (R = 0.2)[30][24]
Elasticity / flexibility1–5Rigid[1]Rigid[22]
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[5]Not documented
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][5]55 (ISO 75, 0.45 MPa) — the same as virgin Prusament PLA[2][17]
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[5]53 (ISO 75, 1.8 MPa); virgin Prusament PLA 55[2][17]
Glass transition (Tg)°C177 (moulded plaque, ASTM D7426 inflection point, Stratasys); 186 (DSC, 3DXTech)[5][1][31]Not documented
Continuous service temperature°C170 long-term service on extruded PEI stock, converted from 338 °F; 200 short term[27]55 (Filamentive states heat resistance up to 55 °C)[4]
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[5]96–99 for plain printed PLA (fibre Bragg grating, 25–50 °C); no grade-specific measurement published[32]
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][5]Flammable; no UL 94 rating published by the major brands[26][33]
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[5]Degrades within weeks outdoors[24][34]
Chemical resistanceNot documentedGood against weak acids, oils and grease; poor against strong acids and alkalis; dissolved by chloroform, THF and hot benzene[33][24]
Water / humidity resistance in service1–5Not documentedGood — insoluble in water[26]
Food contactNot documentedFilamentive certifies its rPLA to EN 71-3 and lists it food safe; printed layer grooves still harbour bacteria[4][24]
Biodegradability / compostabilityNot documentedIndustrially compostable only — needs sustained 55 °C; not home compostable[4]
RecyclabilityNot documentedThe feedstock itself; Filamentive uses 50 % post-industrial content and runs a PLA take-back scheme[4][15]
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[35]Low hazard — minimal VOC and particle emission[35]
Hazardous species emittedNot documentedPrusament rPLA Corn Pigment uses organic waste pigments such as red algae, which give a noticeable scent while printing[3]
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[35]None needed in a normal room[35]
Post-Processing
Sanding & machiningNot documentedWet sanding — dry sanding heats the surface by friction and smears it[34][24]
Gluing & solvent weldingNot documentedSuperglue for most joints; acetone works on some grades depending on additives and colour[3]
Vapour / chemical smoothingNot documentedNo practical vapour smoothing — only chloroform, hot benzene or THF, which are laboratory-only[24]
Solvents & Solubility
Soluble inChlorinated hydrocarbons — dichloromethane and chloroform — are solvents for polyetherimide. Laboratory reagents.[36][37]Chloroform: 10 % w/v in 2–4 h at 23 °C, every grade and morphology; THF and DMF only at 65 °C. Laboratory reagents.[38]
Softened or crazed byAcetone, MEK, benzene, toluene and butyl acetate craze or stress-crack it; alcohols, fuels and dilute acids do not.[37][36]Acetone, ethyl acetate and toluene plasticise it but dissolve <1 % even at 65 °C; submersion in acetone crazes and destroys parts.[38][39]
Solvent welding & smoothing agentDichloromethane is the only welding route, and it is a controlled carcinogen rather than a workshop material.[36][37]Chloroform vapour smooths and welds PLA at the cost of tensile strength; acetone does not smooth it at all.[40][39]

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 Recycled Technical Datasheet v1.0 Prusa Polymers · 2021-12 · tds
  3. Prusament rPLA Corn Pigment 1kg — product page Prusa Research · 2026-08 · vendor
  4. Filamentive PLA (recycled) — product page Filamentive · 2026-08 · vendor
  5. ULTEM 9085 Resin — FDM Material Data Sheet Stratasys · 2026-04 · 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. 3D-Fuel ReFuel Recycled PLA 1kg 3D-Fuel · 2026-08 · vendor
  11. Proto-pasta Black Recycled PLA 1kg Proto-pasta · 2026-08 · vendor
  12. Formfutura ReForm rPLA (White) 1kg Filament2Print · 2026-08 · vendor
  13. IEMAI 3D PEI 9085 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  14. Fiberlogy rPLA Refill Anthracite 850 g 3DJake International · 2026-08 · vendor
  15. Filamentive PLA (rPLA) 750 g CREATE Education · 2026-08 · vendor
  16. Kimya PLA-R 750 g Crea3D · 2026-08 · vendor
  17. Prusament PLA Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  18. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  19. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  20. Filament Material Guide Prusa Knowledge Base · 2026-08 · doc
  21. PLA — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  22. Prusament PLA — material page Prusa Polymers · 2026-08 · doc
  23. THERMAX PEI 9085 — product page (print recommendations) 3DXTech · 2026-08 · doc
  24. PLA — material guide Prusa Knowledge Base · 2026-08 · doc
  25. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  26. Bambu Filament Technical Data Sheet V3.0 — PLA Basic Bambu Lab · 2026-08 · tds
  27. TECAPEI natural (PEI) — stock shape properties Ensinger · 2026-08 · tds
  28. BambuLab PLA Basic vs PLA Tough vs PLA-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  29. PolyTerra PLA vs PLA+ — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  30. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  31. ThermaX PEI 1010 Technical Data Sheet v4 3DXTech · 2026-08 · tds
  32. Characterization of Thermal Expansion Coefficient of 3D Printing Polymeric Materials Using Fiber Bragg Grating Sensors Materials 17(18):4668 · 2024-09 · paper
  33. PolyLite PLA Technical Data Sheet V5.4 Polymaker · 2024-11 · tds
  34. Prusament PLA Technical Data Sheet v1.0 Prusa Polymers · 2018-09 · tds
  35. 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
  36. Radel PPSU, Veradel PESU, Acudel modified PPSU Design Guide — environmental stress cracking tables Solvay Specialty Polymers · 2026-08 · tds
  37. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  38. Solubility Study of Ingeo Biopolymer Grades in Common Organic Solvents (NWPD003) NatureWorks · 2019-10 · tds
  39. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc
  40. 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