3D Printing Info

Filament comparison

PEI 9085 vs TPU soft

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

PEI (ULTEM 9085) guideSoft TPU (below 85A) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PEI 9085 comparisonsMore TPU soft comparisons
PEI 9085 vs TPU soft — documented properties and sources
PropertyPEI (ULTEM 9085)HIGHTEMPSoft TPU (below 85A)FLEX
Market snapshot
Listing priceUSD/kg; dated snapshots$309.80/kg median; $220.00–$392.00/kg across 6 dated product listings$114.04/kg median; $109.80–$122.27/kg across 4 dated product listings
Identity & Market
Base polymer / chemistryPolyetherimide, ULTEM 9085 grade — the flame-retardant PEI used for aircraft interiors[1]Very soft thermoplastic elastomers below 85 Shore A. Fiberlogy's FiberFlex 30D measures 81 Shore A, the softest grade with a published datasheet found here[2]
Densityg/cm³1.34 (ISO 1183, 3DXTech) against 1.27 specific gravity on moulded plaques (ASTM D792, Stratasys) — the two suppliers disagree[1][3]1.07 (Fiberlogy FiberFlex 30D, ISO 1183)[2]
Typical priceUSD/kg1 kg-equivalent spools cluster near 298[4][5][6][7]1 kg-equivalent spools cluster near 115[8][9][10]
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[4][5][6][7][11]110–122 at 1 kg-equivalent; Recreus 70A 110 and 60A 116 at 500 g, NinjaTek Edge 83A 112, NinjaTek Chinchilla 75A 122; the Recreus 3 kg spools fall to 70–73[8][10][9]
Market availability1–5Niche, a handful of specialist brands[4][5][6][7]Niche, a handful of specialist brands[2][12][8]
Spool sizes & diameters1.75 and 2.85 mm; 250 g to 2 kg spools, plus Stratasys canisters[4][7][3]1.75, 2.85 and 3 mm; 0.5, 0.85, 1, 2 and 3 kg spools[2][8][13][9]
Typical applicationsAircraft interior parts and rail rolling stock, where the flame, smoke and toxicity rating is the requirement[1]Highly compliant seals, soft grips and prosthetic liners[2]
Printing Parameters
Bed temperature°C130–140 (3DXTech)[1]50–70 (Fiberlogy FiberFlex 30D)[2]
Enclosure / chamber requirement1–5Actively heated chamber required[14][15]Open frame is fine[2]
Bed surface & adhesion aidNot documentedPEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[16][17]
Warping tendency1–5Severe — heated chamber needed[14]Not documented
Overall printing difficulty1–5Expert / industrial hardware only[14][15]Expert / industrial hardware only — below 85 Shore A the filament buckles in almost any feed path that is not a short, constrained direct drive[13][17]
Extruder requirementNot documentedDirect drive only, with a constrained filament path; Bowden is not viable at this hardness[13][12]
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[14]Brass fine indefinitely[18]
Abrasiveness1–5Non-abrasive when unfilled[1]Non-abrasive[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[19]High — jams from moisture, heat creep or particles; below 85 Shore A the filament buckles and compresses, and Simplify3D warns that raised feed rates most likely end in a jam[16][17][20]
Heat-creep / jam sensitivity1–5Not documentedVery high — softens in the cold zone readily[17]
Hotend requirementNot documentedNo special hot-end required, but a direct-drive extruder is (Simplify3D)[16]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Not documentedModerate[20]
Symptoms when wetNot documentedBubbling and popping at the nozzle, stringing and a rough surface[20]
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[19]Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[20]
Storage requirementNot documentedSealed with desiccant; often kept in a dryer during the print[20]
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)[3][1]Not documented
Young's modulusMPa2040-2540 (printed XZ, ASTM D638, Stratasys); 2050 (printed XY, ISO 527, 3DXTech)[3][1]Not documented
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)[3][1]870 at break (Fiberlogy FiberFlex 30D, ISO 527) — the highest elongation in the dataset[2]
Flexural strengthMPa104-116 at break (printed XZ, ASTM D790 Procedure A, Stratasys); 72-98 in ZX; 3DXTech quotes 90 (ISO 178)[3][1]Not documented
Flexural modulusMPa2400-2550 (printed XZ, ASTM D790, Stratasys F900 T16 and T16A) against 2120-2130 in ZX; 3DXTech quotes 2170 (ISO 178)[3][1]Not documented
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)[3]Not documented
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[3]Not documented
Brittleness1–5Brittle — snaps with little warning[1]Very ductile — bends far before failing[2]
Hardness (scale-specific)Shore A / Shore D / RockwellRockwell M110 / R126 on extruded PEI stock (ASTM D785)[21]81 Shore A and 30 Shore D (Fiberlogy FiberFlex 30D, ISO 7619)[2]
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[3][21]Poor — no creep test at this hardness; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[22]
Fatigue / repeated-flex resistance1–5Not documentedExcellent — living hinges viable[17]
Elasticity / flexibility1–5Rigid[1]Rubbery / highly elastic[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[3]Not documented
Wear resistance & frictionNot documentedTear strength 95 kN/m (Fiberlogy FiberFlex 30D, ISO 34-1)[2]
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][3]Not documented
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[3]Not documented
Glass transition (Tg)°C177 (moulded plaque, ASTM D7426 inflection point, Stratasys); 186 (DSC, 3DXTech)[3][1][23]Not documented
Melting point / Vicat°CNot documented170 melting (Fiberlogy FiberFlex 30D, DSC)[2]
Continuous service temperature°C170 long-term service on extruded PEI stock, converted from 338 °F; 200 short term[21]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[3]Not documented
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][3]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[3]Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[17]
Chemical resistanceNot documentedWithstands industrial solvents and UV exposure (Polymaker)[17]
Food contactNot documentedNot food safe without specific certification (Polymaker)[17]
Biodegradability / compostabilityNot documentedNot biodegradable[17]
RecyclabilityNot documentedNot accepted in household plastic collection[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[24]Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[24]
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[24]Open a window / occasional ventilation[24]
Post-Processing
Sanding & machiningNot documentedDifficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[17]
Gluing & solvent weldingNot documentedCyanoacrylate bonds TPU; no common solvent welds it[17]
Vapour / chemical smoothingNot documentedNo practical vapour smoothing[17]
Support material pairingNot documentedPolymaker warns TPU supports are often very difficult to remove[17]
Solvents & Solubility
Soluble inChlorinated hydrocarbons — dichloromethane and chloroform — are solvents for polyetherimide. Laboratory reagents.[25][26]DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[27]
Softened or crazed byAcetone, MEK, benzene, toluene and butyl acetate craze or stress-crack it; alcohols, fuels and dilute acids do not.[26][25]Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[27]
Solvent welding & smoothing agentDichloromethane is the only welding route, and it is a controlled carcinogen rather than a workshop material.[25][26]None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[27]

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. FiberFlex 30D Technical Data Sheet Fiberlogy · 2026-08 · tds
  3. ULTEM 9085 Resin — FDM Material Data Sheet Stratasys · 2026-04 · tds
  4. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  5. Kimya PEI-9085 Natural 2.85 mm 500 g igo3d · 2026-08 · vendor
  6. Fiberlogy PEI 9085 Natural, 1.75 mm / 500 g 3DJAKE · 2026-08 · vendor
  7. 3D4Makers product catalogue 3D4Makers · 2026-08 · vendor
  8. Recreus product catalogue Recreus · 2026-08 · vendor
  9. Chinchilla product page — print guidelines, spool sizes and price NinjaTek · 2026-08 · vendor
  10. NinjaFlex Edge product page — durometer, print guidelines and price NinjaTek · 2026-08 · vendor
  11. IEMAI 3D PEI 9085 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  12. Filaflex 82A product page (Shore hardness and elongation) Recreus · 2026-08 · vendor
  13. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  14. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  15. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  16. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  17. TPU — material basics Polymaker Wiki · 2026-08 · doc
  18. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  19. THERMAX PEI 9085 — product page (print recommendations) 3DXTech · 2026-08 · doc
  20. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  21. TECAPEI natural (PEI) — stock shape properties Ensinger · 2026-08 · tds
  22. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  23. ThermaX PEI 1010 Technical Data Sheet v4 3DXTech · 2026-08 · tds
  24. 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
  25. Radel PPSU, Veradel PESU, Acudel modified PPSU Design Guide — environmental stress cracking tables Solvay Specialty Polymers · 2026-08 · tds
  26. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  27. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds