3D Printing Info

Filament comparison

e-TPU vs PEKK

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

Foaming / expanded TPU (TPU Aero / TPU Air) guidePEKK guide

2 selected · all documented properties

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e-TPU vs PEKK — documented properties and sources
PropertyFoaming / expanded TPU (TPU Aero / TPU Air)FLEXPEKKHIGHTEMP
Market snapshot
Listing priceUSD/kg; dated snapshots$52.05/kg median; $41.99–$85.29/kg across 6 dated product listings$525.00/kg median; $332.50–$771.12/kg across 6 dated product listings
Identity & Market
Base polymer / chemistryFoaming thermoplastic polyurethane — a blowing agent expands the extrudate so the printed Shore hardness can be tuned by flow rate[1]Polyether ketone ketone, amorphous grade — a polyaryletherketone that stays amorphous, so it does not need PEEK's crystallisation control. Stratasys sells it as Antero 800NA and Antero 840CN03; category numbers below are unfilled unless a carbon grade is named[2][3]
Densityg/cm³1.15 filament (Siraya Tech Flex TPU Air) and 1.05 (Roamr TPU Air HR), ISO 1183; the printed part falls to 0.51–0.93 depending on nozzle temperature (ISO 845)[4][5]1.28 unfilled (ASTM D792, Antero 800NA; 1.31 annealed) and 1.33 for CarbonX PEKK-A CF15 (ISO 1183)[3][2]
Typical priceUSD/kg1 kg-equivalent spools span 42–85; the middle of the market is about 52[6][7][8][9][10][11]1 kg-equivalent spools cluster near 550[12][13][14]
Price range across brandsUSD/kg42–85 across brands; QIDI TPU-Aero 42, Siraya Tech Flex TPU Air 45, Phaetus aeFlex TPU-Aero 49 direct and 40 at West3D, Roamr TPU Air HR 80A 55 at 800 g, Recreus Filaflex Foamy 73 at 750 g, colorFabb varioShore 85 at 700 g[6][7][8][9][10][11][15]333-771 across grades and formats; 3DXTech CarbonX PEKK-A+CF15 333 at 2 kg, 3D4Makers unfilled PEKK-A 485 at 2 kg, IEMAI 3D 500 at 1 kg, Kimya PEKK Carbon 771 at 500 g[12][13][14][16][17]
Market availability1–5Available from several mainstream brands — colorFabb, Recreus, QIDI, Phaetus, Siraya Tech and FusRock all sell an active-foaming TPU[1][6][7][8][10][11]Niche, a handful of specialist brands[12][13][14]
Spool sizes & diameters1.75 mm; 0.7, 0.75, 0.8, 1 and 3 kg spools[1][6][8][9][11]1.75 and 2.85 mm; 200 g to 2 kg spools, plus Stratasys canisters[12][13][3]
Typical applicationsCushioning, midsoles, insoles and soft-touch parts where the softness needs to vary within one print; Siraya Tech's Roamr line is aimed specifically at printed footwear[1][9]Aerospace interior and structural parts; 3DXTech labels its carbon-filled PEKK-A grade AERO and Stratasys certifies Antero 800NA for outgassing and FST[2][3]
Diameter tolerance± mm0.03 (Siraya Tech and Roamr, 1.75 mm)[4][5]Not documented
Printing Parameters
Nozzle temperature°C230–270 (QIDI and Siraya Tech), 220–260 (Roamr); foaming activates near 230 °C and is strongest at the top of the range[1][4][5][10]Not documented
Bed temperature°C30–45 (QIDI and Siraya Tech), 35–50 (Roamr) — a hot bed makes the foamed part over-stick[4][5][10]140 (3DXTech CarbonX PEKK-A CF15)[2]
Enclosure / chamber requirement1–5Open frame is fine — Roamr states no enclosure is required[1][5]Actively heated chamber required[18][19]
Part cooling fan100 % — cooling sets the foamed structure quickly (Siraya Tech and Roamr)[4][5]Not documented
Bed surface & adhesion aidPEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent, and Siraya Tech recommends PVP glue or Magigoo as a release agent on PEI[20][21][4]Not documented
Maximum volumetric flow (mm³/s; see test conditions)mm³/sUp to 12 (Siraya Tech, Flex TPU Air)[8]Not documented
Stringing / oozing tendency1–5Severe — the material expands inside the hot end, so it oozes on travel moves; QIDI states retraction tuning cannot fix it and Siraya Tech advises setting retraction distance and speed to zero[4][10]Not documented
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; both density and hardness follow nozzle temperature and flow[1]Expert / industrial hardware only[18][19]
Extruder requirementDirect drive; the base material is a 92A TPU[1][22]Not documented
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely — Roamr states plainly that no hardened nozzle is needed[23][5]Hardened steel required — the category spans unfilled PEKK, where brass is acceptable, and the carbon-filled aerospace grades that make up most of the market[2][3]
Abrasiveness1–5Non-abrasive[23]Highly abrasive — most PEKK filament sold is carbon-filled; unfilled Antero 800NA and ThermaX PEKK-A are non-abrasive[2][3]
Nozzle clog risk1–5Not documentedModerate — needs dry filament and a clean nozzle; 3DXTech lists no special nozzle concerns but a mandatory 120 °C pre-dry before every print[24]
Hotend requirementNo special hot-end required, but a direct-drive extruder is (Simplify3D)[20]Not documented
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate[25]Not documented
Equilibrium moisture content at ~50 % RH%1.09 water absorption (QIDI TPU-Aero; the standard is not stated)[10]Not documented
Drying temperature & time70–80 °C for 4–6 h; keep below 15 % RH while printing (Siraya Tech, Roamr and QIDI)[4][5][10]Not documented
Symptoms when wetBubbling and popping at the nozzle, stringing and a rough surface; Siraya Tech adds that moisture wrecks the foaming itself, not only the surface[25][4]Not documented
Effect of moisture on strengthPolymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[25]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[24]
Storage requirementSealed with desiccant; often kept in a dryer during the print[25]Not documented
Mechanical Properties
Tensile strength (XY)MPaFalls with foaming: colorFabb 24 unfoamed and 12 foamed (ISO 527-1A); Siraya Tech 10.3 at break printed at 240 °C down to 3.8 at 270 °C; QIDI 6.81 at break (ISO 527, XY)[1][4][10]86.7-90.0 at yield and 73.0 at break (printed XZ, ASTM D638, Antero 800NA on the F900 and Fortus 450mc); 88.8 at break annealed; 126 at break for CarbonX PEKK-A CF15 (printed XY, ISO 527)[3][2]
Young's modulusMPa50 unfoamed and 40 foamed (colorFabb, ISO 527-1A)[1]2640-3870 (printed XZ, ASTM D638, Antero 800NA; upper figure annealed); 9125 for CarbonX PEKK-A CF15 (printed XY, ISO 527)[3][2]
Elongation at break%465 unfoamed and 450 foamed (colorFabb, ISO 527-1A); Siraya Tech 629 at 240 °C down to 475 at 270 °C; Roamr 760 down to 540; QIDI 576 (ISO 527, XY)[1][4][5][10]6.1 at break (printed XZ, ASTM D638, Antero 800NA); 2.3 in ZX; 3.15 for CarbonX PEKK-A CF15 (ISO 527)[3][2]
Flexural strengthMPaNot documented136 at 5 % strain (printed XZ, ASTM D790, Antero 800NA); 178 for CarbonX PEKK-A CF15 (printed XY, ISO 178)[3][2]
Flexural modulusMPa50 unfoamed and 40 foamed flexural modulus (colorFabb, ISO 178)[1]3200 (printed XZ, ASTM D790, Antero 800NA); 8817 for CarbonX PEKK-A CF15 (printed XY, ISO 178)[3][2]
Other impact dataNot documentedIzod notched 41.1 J/m XZ and 33.3 J/m ZX; unnotched 1730 J/m XZ against 203 J/m ZX (printed, ASTM D256/D4812, Antero 800NA)[3]
Layer adhesion / Z tensileMPaNot documented50.1-59.4 at yield (printed ZX, ASTM D638, Antero 800NA); 56.0 for the ESD grade Antero 840CN03[3][26]
Brittleness1–5Very ductile — bends far before failing[1]Moderate unfilled — 6.1 % elongation at break in plane; brittle in the carbon-filled grades at 3.15 %[3][2]
Hardness (scale-specific)Shore A / Shore D / RockwellTunable by nozzle temperature: colorFabb 92 Shore A unfoamed; Siraya Tech 78 A printed at 240 °C falling to 63 A at 270 °C, Roamr TPU Air HR 80A 80 A down to 66 A and HR 85A 83 A down to 70 A (ISO 7619)[1][4][5][27]Not documented
Creep resistance / sustained load1–5Poor — no foamed-grade creep test; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[28]Excellent — holds load for years. Antero 800NA still holds 82 % of its room-temperature ZX tensile strength at 104 °C and 63 % at 132 °C (printed, ASTM D638)[3]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[21]Not documented
Elasticity / flexibility1–5Rubbery / highly elastic[1]Rigid[2]
Z strength as % of XY%Not documented56-82 (Antero 800NA and 840CN03 printed on the F900 and Fortus 450mc, ZX against XZ tensile yield and break, ASTM D638)[3][26]
Thermal Properties
HDT at 0.45 MPa°CNot documented158 (printed XY and ZX, ASTM D648 Method B at 66 psi, Antero 800NA); 285 for CarbonX PEKK-A CF15 (ISO 75 at 0.45 MPa)[3][2]
HDT at 1.8 MPa°CNot documented156-157 (printed, ASTM D648 Method B at 264 psi, Antero 800NA); moulded 147[3]
Glass transition (Tg)°CNot documented156 (ASTM D7426, Antero 800NA); 165 for CarbonX PEKK-A CF15 (DSC)[3][2]
Melting point / Vicat°CVicat softening drops as the foam expands: 83 printed at 240 °C to 53 at 270 °C (Siraya Tech, ISO 306); QIDI 70.4[4][10]300 melt point (ASTM D7426 peak heat, Antero 800NA); 305 for CarbonX PEKK-A CF15 (DSC)[3][2]
Annealing responseFoaming activates near 230 °C and expands the extrudate about 1.6×; colorFabb advises dropping flow to 60–70 % to realise the weight saving, and Siraya Tech publishes a flow schedule from 85–90 % at 230 °C down to 50–55 % at 270 °C[1][4]Not documented
Thermal expansion (CTE)µm/m·KNot documented36.1 in XY and 50.2 in ZX (printed, 40-140 °C, ASTM E831, Antero 800NA); 47.4 and 51.2 for the ESD grade Antero 840CN03[3][26]
Environment & Chemical
UV resistance1–5Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[21]Good — years with some colour shift. 1000 h of QUV cycling to ASTM G154 left Antero 800NA's yield strength unchanged at 57 MPa and raised stress at break 3.6 %[3]
Chemical resistanceWithstands industrial solvents and UV exposure (Polymaker)[21]Not documented
Food contactNot food safe without specific certification (Polymaker)[21]Not documented
Biodegradability / compostabilityNot biodegradable[21]Not documented
RecyclabilityNot accepted in household plastic collection[21]Not documented
Electrical & ESD propertiesNot documentedUnfilled PEKK is an insulator at above 1.4e14 ohm-cm (ASTM D257); CarbonX PEKK-A CF15 sits above 10^7 ohm/sq, and the Antero 840CN03 ESD grade is specified at 10^4-10^9 ohm-cm[3][2][26]
Health & Safety
Fume toxicity1–5Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[29]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[29]
Ventilation / filtration requirement1–5Open a window / occasional ventilation[29]Ventilated room or enclosure recommended[29]
Dust & fibre handling hazardNot documentedCarbon fibre is bound in the matrix; sanding dust should not be inhaled[2]
Post-Processing
Sanding & machiningDifficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[21]Not documented
Gluing & solvent weldingCyanoacrylate bonds TPU; no common solvent welds it[21]Not documented
Vapour / chemical smoothingNo practical vapour smoothing[21]Not documented
Support material pairingPolymaker warns TPU supports are often very difficult to remove[21]Not documented
Dimensional accuracy & detailFoamed surfaces are matte and textured; holding a consistent hardness means holding the nozzle temperature steady, and the printed density moves by nearly a factor of two across the 230–270 °C window[1][4]Not documented
Solvents & Solubility
Soluble inDMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[30]Concentrated sulphuric acid, as for PEEK; no common organic solvent touches a polyaryletherketone.[31][32]
Softened or crazed byToluene and benzene swell it up to +50 % by weight at 23 °C; the foamed wall soaks up esters and alcohols faster still.[30]Concentrated sulphuric acid and liquid Freon are the entries Ensinger marks not resistant; acetone, MEK and toluene do nothing.[31]
Solvent welding & smoothing agentNone practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[30]None — no solvent softens a polyaryletherketone.[31]

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. varioShore TPU Technical Data Sheet colorFabb · 2026-08 · tds
  2. CarbonX Carbon Fiber PEKK-A CF15 Technical Data Sheet v1 3DXTech · 2026-08 · tds
  3. Antero 800NA — FDM Material Data Sheet (PEKK-based) Stratasys · 2025-08 · tds
  4. Siraya Tech Flex TPU Air Technical Data Sheet Siraya Tech · 2026-08 · tds
  5. Roamr TPU Air HR 80A Technical Data Sheet Siraya Tech · 2026-08 · tds
  6. Recreus product catalogue Recreus · 2026-08 · vendor
  7. varioShore TPU Natural — product page colorFabb US · 2026-08 · vendor
  8. Siraya Tech Flex TPU Air Black Filament — lightweight foaming flexible, product page Siraya Tech · 2026-08 · vendor
  9. Roamr TPU Air HR 80A Filament — product page Siraya Tech · 2026-08 · vendor
  10. TPU-Aero Lightweight TPU Filament — product page with specification tables QIDI Tech · 2026-08 · vendor
  11. aeFlex TPU-Aero — active foaming low weight TPU, product page Phaetus · 2026-08 · vendor
  12. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  13. 3D4Makers product catalogue 3D4Makers · 2026-08 · vendor
  14. Kimya PEKK-A Natural 1.75 mm 500 g igo3d · 2026-08 · vendor
  15. Phaetus aeWorthy TPU-Aero — reseller listing West3D · 2026-08 · vendor
  16. Kimya PEKK Carbon Grey 1.75 mm 500 g igo3d · 2026-08 · vendor
  17. IEMAI 3D PEKK 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  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. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  21. TPU — material basics Polymaker Wiki · 2026-08 · doc
  22. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  23. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  24. THERMAX PEKK-A — product page (print recommendations) 3DXTech · 2026-08 · doc
  25. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  26. Antero 840CN03 — FDM Material Data Sheet (PEKK, ESD) Stratasys · 2024-08 · tds
  27. Roamr TPU Air HR 85A Technical Data Sheet Siraya Tech · 2026-08 · tds
  28. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  29. 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
  30. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds
  31. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  32. 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