3D Printing Info

Filament comparison

e-TPU vs PETG-CF

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

Foaming / expanded TPU (TPU Aero / TPU Air) guideCarbon-fibre PETG (PETG-CF) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore e-TPU comparisonsMore PETG-CF comparisons
e-TPU vs PETG-CF — documented properties and sources
PropertyFoaming / expanded TPU (TPU Aero / TPU Air)FLEXCarbon-fibre PETG (PETG-CF)PETG
Market snapshot
Listing priceUSD/kg; dated snapshots$52.05/kg median; $41.99–$85.29/kg across 6 dated product listings$29.99/kg median; $16.00–$74.22/kg across 11 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]PETG reinforced with chopped carbon fibre[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]1.25 (Bambu Lab) to 1.34 (3DXTech), ISO 1183; Prusament 1.27[2][6][3]
Typical priceUSD/kg1 kg-equivalent spools span 42–85; the middle of the market is about 52[7][8][9][10][11][12]1 kg-equivalent spools span 16–74; the middle of the market is about 29[2][13][14][15][16][17][18][19]
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[7][8][9][10][11][12][20]16–74 across brands; ELEGOO 16 in a 5 kg pack, Reli3D 17, SUNLU 20, IEMAI 22, Siraya Tech 25, Bambu Lab 32, Sakata 3D 53, 3DXTech 67, Prusament 70, Filament PM 74 on 0.5 kg spools[21][2][22][13][14][15][16][17][18][19]
Market availability1–5Available from several mainstream brands — colorFabb, Recreus, QIDI, Phaetus, Siraya Tech and FusRock all sell an active-foaming TPU[1][7][8][9][11][12]Stocked by most mainstream brands[2][22][13][21]
Spool sizes & diameters1.75 mm; 0.7, 0.75, 0.8, 1 and 3 kg spools[1][7][9][10][12]1.75 and 2.85 mm; 0.75 and 1 kg spools[22][2]
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][10]Stiff functional parts and fixtures where PETG's toughness is traded for rigidity and a matte finish[2][3]
Diameter tolerance± mm0.03 (Siraya Tech and Roamr, 1.75 mm)[4][5]±0.02 (Prusament)[3]
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][11]240–270 (Bambu Lab); 265 ± 10 (Prusament)[2][3]
Bed temperature°C30–45 (QIDI and Siraya Tech), 35–50 (Roamr) — a hot bed makes the foamed part over-stick[4][5][11]65–75 (Bambu Lab); 90 ± 10 (Prusament)[2][3]
Enclosure / chamber requirement1–5Open frame is fine — Roamr states no enclosure is required[1][5]Open frame fine; draught shield helps — Bambu Lab specifies a 35–50 °C chamber[2]
Recommended chamber temperature°CNot documented35–50 (Bambu Lab)[2]
Part cooling fan100 % — cooling sets the foamed structure quickly (Siraya Tech and Roamr)[4][5]0–60 % (Bambu Lab); 50 % (Prusament)[2][3]
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[23][24][4]Textured PEI or engineering plate with glue (Bambu Lab)[2]
Maximum volumetric flow (mm³/s; see test conditions)mm³/sUp to 12 (Siraya Tech, Flex TPU Air)[9]11.5 on My Tech Fun's Bambu Lab PETG-CF profile[25]
Bed-adhesion difficulty1–5Not documentedNeeds the right surface or a thin adhesive[2]
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][11]Slight — the fibre reduces stringing against unfilled PETG[2][26]
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; both density and hardness follow nozzle temperature and flow[1]Intermediate — dry filament and a tuned profile; hardened nozzle mandatory[2]
Extruder requirementDirect drive; the base material is a 92A TPU[1][27]Not documented
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely — Roamr states plainly that no hardened nozzle is needed[28][5]Hardened steel required[2]
Abrasiveness1–5Non-abrasive[28]Highly abrasive — standard CF composite[2]
Nozzle clog risk1–5Not documentedModerate — needs dry filament and a clean nozzle; 3DXTech specifies a hardened 0.4 mm minimum nozzle and 0.25 mm layers or higher, and Prusa lists composites as a higher clogging risk[29][30]
Heat-creep / jam sensitivity1–5Not documentedSlightly sensitive[26]
Hotend requirementNo special hot-end required, but a direct-drive extruder is (Simplify3D)[23]Hardened steel nozzle; no high-temperature hot-end needed[2][26]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate[31]Low — 0.30 % saturated at 25 °C / 55 % RH (Bambu Lab)[2]
Equilibrium moisture content at ~50 % RH%1.09 water absorption (QIDI TPU-Aero; the standard is not stated)[11]0.30 saturated at 25 °C / 55 % RH (Bambu Lab); Prusa measures 0.10 after 7 days at 22 % RH[2][3]
Drying temperature & time70–80 °C for 4–6 h; keep below 15 % RH while printing (Siraya Tech, Roamr and QIDI)[4][5][11]65 °C for 8 h (Bambu Lab)[2]
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[31][4]Bubbling and popping at the nozzle, stringing and a rough surface[31]
Effect of moisture on strengthPolymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[31]No dry-versus-conditioned figures published; Bambu Lab states PETG-CF must be properly dried before printing and stored dry after use[2][31]
Storage requirementSealed with desiccant; often kept in a dryer during the print[31]Sealed with desiccant; Bambu Lab says store dry after use[2][31]
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][11]35 ± 5 (Bambu Lab) and 47 ± 2 at yield (Prusament) printed XY, ISO 527; 56 at break for 3DXTech[2][3][6]
Young's modulusMPa50 unfoamed and 40 foamed (colorFabb, ISO 527-1A)[1]2460 ± 230 (Bambu Lab) and 1700 (Prusament) printed XY, ISO 527[2][3]
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][11]4.3 at yield (Prusament, printed XY, ISO 527); 3 at break for 3DXTech[3][6]
Flexural strengthMPaNot documented68 ± 3 printed horizontal, ISO 178 (Prusament)[3]
Flexural modulusMPa50 unfoamed and 40 foamed flexural modulus (colorFabb, ISO 178)[1]2300 printed horizontal, 3100 printed vertical, ISO 178 (Prusament)[3]
Other impact dataNot documentedCharpy unnotched 29 ± 6 printed horizontal and 43 ± 8 printed vertical (Prusament, ISO 179-1); Izod 4.91 kJ/m² on My Tech Fun bars[3][25]
Layer adhesion / Z tensileMPaNot documented29 ± 4 printed Z (Bambu Lab, ISO 527); 18 ± 3 by Prusa's interlayer adhesion test; 10.7 on My Tech Fun bars[2][3][25]
Brittleness1–5Very ductile — bends far before failing[1]Brittle — snaps with little warning[6]
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][32]77 Shore D (Prusa Polymers method)[3]
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[33]Below average — a 12 mm bar sagged to 16.4 mm over 5 days at 1.25 kg, less than plain PETG's 19.4[25]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[24]Moderate — no CF-grade S-N curve; unfilled printed PETG ran 79 000–193 000 cycles at 30 % of tensile strength[34]
Elasticity / flexibility1–5Rubbery / highly elastic[1]Rigid[2]
Z strength as % of XY%Not documented83 (Bambu Lab, printed Z against XY tensile)[2]
Thermal Properties
HDT at 0.45 MPa°CNot documented74 (Bambu Lab) and 96 (Prusament), ISO 75 at 0.45 MPa[2][3]
HDT at 1.8 MPa°CNot documented68 (Bambu Lab) and 80 (Prusament), ISO 75 at 1.8 MPa[2][3]
Glass transition (Tg)°CNot documented68 (Bambu Lab) and 80 (3DXTech), DSC[2][6]
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][11]225 melting (Bambu Lab, DSC) — the carbon fibre lets the PET fraction crystallise[2]
Continuous service temperature°CNot documented77 — loaded bars begin to move at this temperature, against 61 for Bambu Lab PETG Basic[25]
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
Flammability / UL 94Not documentedFlammable; no UL 94 rating published[2]
Environment & Chemical
UV resistance1–5Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[24]Moderate — a season or two; the carbon fibre does not add UV stabilisation[35]
Chemical resistanceWithstands industrial solvents and UV exposure (Polymaker)[24]Withstands acids, alkalis, oils and UV exposure, as for unfilled PETG[35]
Food contactNot food safe without specific certification (Polymaker)[24]Not certified for food contact[35]
Biodegradability / compostabilityNot biodegradable[24]Not biodegradable[35]
RecyclabilityNot accepted in household plastic collection[24]Fibre-filled PETG is not accepted in household plastic collection[35]
Electrical & ESD propertiesNot documentedSurface resistance above 10⁹ ohm/sq — carbon fibre at this loading is not static-dissipative (3DXTech)[6]
Health & Safety
Fume toxicity1–5Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[36]Moderate — measurable VOCs and UFPs, ventilation advised[36]
Ventilation / filtration requirement1–5Open a window / occasional ventilation[36]Open a window / occasional ventilation[36]
Dust & fibre handling hazardNot documentedCarbon fibre is bound in the matrix; sanding dust should not be inhaled[6]
Post-Processing
Sanding & machiningDifficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[24]Sands to a matte finish more readily than unfilled PETG[26]
Gluing & solvent weldingCyanoacrylate bonds TPU; no common solvent welds it[24]Cyanoacrylate; no common solvent welds it[26]
Vapour / chemical smoothingNo practical vapour smoothing[24]No practical vapour smoothing[26]
Support material pairingPolymaker warns TPU supports are often very difficult to remove[24]Support for PLA or its own material (Bambu Lab)[2]
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]Matte finish hides layer lines; stringing is reduced against unfilled PETG[2]
Solvents & Solubility
Soluble inDMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[37]No common workshop solvent; dichloromethane — a carcinogen — dissolves the matrix surface, 1,2-dichloroethane destroys it in a week.[38][39]
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.[37]Acetone (+16 % weight over 1 year at 23 °C), ethyl acetate, toluene and DMF swell and soften it; methanol crazes it.[38]
Solvent welding & smoothing agentNone practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[37]Dichloromethane reaches only the resin, so the fibre is left standing proud of the surface. Controlled carcinogen.[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. varioShore TPU Technical Data Sheet colorFabb · 2026-08 · tds
  2. Bambu Filament Technical Data Sheet — PETG-CF Bambu Lab · 2026-08 · tds
  3. Prusament PETG Carbon Fiber Technical Datasheet Prusa Polymers · 2026-08 · 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. CarbonX Carbon Fiber PETG Technical Data Sheet 3DXTech · 2026-08 · tds
  7. Recreus product catalogue Recreus · 2026-08 · vendor
  8. varioShore TPU Natural — product page colorFabb US · 2026-08 · vendor
  9. Siraya Tech Flex TPU Air Black Filament — lightweight foaming flexible, product page Siraya Tech · 2026-08 · vendor
  10. Roamr TPU Air HR 80A Filament — product page Siraya Tech · 2026-08 · vendor
  11. TPU-Aero Lightweight TPU Filament — product page with specification tables QIDI Tech · 2026-08 · vendor
  12. aeFlex TPU-Aero — active foaming low weight TPU, product page Phaetus · 2026-08 · vendor
  13. Printed Solid product catalogue Printed Solid · 2026-08 · vendor
  14. SUNLU PETG-CF (PETG Carbon Fiber) 3D Printer Filament 1 kg SUNLU · 2026-08 · vendor
  15. Fibreheart PETG-CF Pro Filament product page Siraya Tech · 2026-08 · vendor
  16. IEMAI CF-PETG 3D Printing Filament product page IEMAI 3D · 2026-08 · vendor
  17. Reli3D Carbon Fiber PETG Filament 1.75 mm, 1 kg Reli3D (Amazon US) · 2026-08 · vendor
  18. PET-G CF15 Sakata 3D Filaments · 2026-08 · vendor
  19. Filament PM CFJet technical data sheet (TDS CFJet ENG.pdf) Filament PM (Plasty Mladec) · 2026-08 · tds
  20. Phaetus aeWorthy TPU-Aero — reseller listing West3D · 2026-08 · vendor
  21. ELEGOO product catalogue ELEGOO · 2026-08 · vendor
  22. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  23. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  24. TPU — material basics Polymaker Wiki · 2026-08 · doc
  25. BambuLab PETG Basic vs Translucent vs PETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  26. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  27. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  28. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  29. CARBONX PETG+CF — product page (print recommendations) 3DXTech · 2026-08 · doc
  30. Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
  31. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  32. Roamr TPU Air HR 85A Technical Data Sheet Siraya Tech · 2026-08 · tds
  33. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  34. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  35. PETG — material basics Polymaker Wiki · 2026-08 · doc
  36. 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
  37. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds
  38. Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
  39. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc