3D Printing Info

Filament comparison

PET-CF vs TPU-CF

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

Carbon-fibre PET (PET-CF) guideCarbon-fibre TPU guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PET-CF comparisonsMore TPU-CF comparisons
PET-CF vs TPU-CF — documented properties and sources
PropertyCarbon-fibre PET (PET-CF)PETGCarbon-fibre TPUFLEX
Market snapshot
Listing priceUSD/kg; dated snapshots$39.99/kg median; $26.00–$49.98/kg across 4 dated product listings$107.05/kg median; $107.05–$107.05/kg across 1 dated product listings
Identity & Market
Base polymer / chemistrySemi-crystalline PET reinforced with carbon fibre — a different polymer from PETG-CF, with the glycol modifier removed so the matrix can crystallise[1][2]Carbon-fibre reinforced thermoplastic polyurethane at the hard end of the range[3]
Densityg/cm³1.29 (Bambu Lab) and 1.34 (Fiberon PET-CF17), ISO 1183[1][2]1.22 (Extrudr FLEX HARD CF, ISO 2781)[3]
Typical priceUSD/kg1 kg spools cluster near 45[1][4]107 for the only retail listing found (Extrudr 0.5 kg coil, incl. VAT)[5]
Price range across brandsUSD/kg26–50 across brands; ELEGOO 26 in a 5 kg pack, Bambu Lab 45, Fiberon 50[6][1][4]One listing only: EUR 49.56 incl. VAT per 0.5 kg coil, direct from Extrudr; no reseller or second brand found[5]
Market availability1–5Available from several mainstream brands[1][4][6]Niche, a handful of specialist brands — Extrudr's FLEX HARD CF is the only carbon-filled flexible with a published datasheet found here[3]
Spool sizes & diameters1.75 mm; 0.5 and 1 kg spools[4][1]1.75 mm; 0.5 and 2 kg coils[5]
Typical applicationsLoad-bearing parts that must survive above PETG's 70 °C ceiling without moving to PA or PC[1][2]Stiffened flexible parts — damping mounts and semi-rigid brackets[3]
Printing Parameters
Nozzle temperature°C260–290 (Bambu Lab)[1]230–260 (Extrudr FLEX HARD CF)[3]
Bed temperature°C80–100 (Bambu Lab)[1]50–90 (Extrudr FLEX HARD CF)[3]
Enclosure / chamber requirement1–5Enclosure recommended — Bambu Lab specifies a 45–60 °C chamber[1]Open frame is fine[3]
Recommended chamber temperature°C45–60 (Bambu Lab)[1]Not documented
Part cooling fan0–60 % (Bambu Lab)[1]Not documented
Bed surface & adhesion aidTextured PEI, satin or powder-coated sheets; on smooth PEI a glue stick acts as a release agent[7][8]PEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[9][10]
Maximum volumetric flow (mm³/s; see test conditions)mm³/s8 at Bambu Lab's 100 mm/s cap on a 0.4 mm nozzle at 0.2 mm layer — half the speed it allows for PETG-CF[1][11]1.6–8 at the 20–100 mm/s Extrudr specifies on a 0.4 mm nozzle at 0.2 mm layer[3]
Bed-adhesion difficulty1–5Needs the right surface or a thin adhesive — the problem is releasing the part, not sticking it[7][8]Not documented
Stringing / oozing tendency1–5Moderate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[8]Not documented
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning[1]Advanced — enclosure, hardware upgrades, tuning; hardened nozzle needed[3]
Hardware Wear & Reliability
Nozzle hardness required1–4Hardened steel required[1]Hardened steel required — Extrudr marks FLEX HARD CF as needing a hardened nozzle where its unfilled FLEX grades do not[3]
Abrasiveness1–5Highly abrasive — standard CF composite[1]Highly abrasive — standard CF composite[3]
Nozzle clog risk1–5Moderate — needs dry filament and a clean nozzle; Prusa lists higher risk of nozzle clogging for carbon-filled composites[12]High — jams from moisture, heat creep or particles; a flexible base plus chopped carbon fibre, which Prusa lists as a higher nozzle-clogging risk, and Extrudr requires a hardened nozzle[12][3][9]
Heat-creep / jam sensitivity1–5Slightly sensitive[13]Not documented
Hotend requirementNo special hot-end required[13]No special hot-end required, but a direct-drive extruder is (Simplify3D)[9]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate — 0.37 % saturated at 25 °C / 55 % RH (Bambu Lab); 0.53 % equilibrium (Fiberon)[1][2]Moderate[14]
Equilibrium moisture content at ~50 % RH%0.37 saturated at 25 °C / 55 % RH (Bambu Lab); 0.53 equilibrium (Fiberon PET-CF17)[1][2]Not documented
Drying temperature & time80 °C for 8–12 h (Bambu Lab) — the longest and hottest dry in the polyester family; Fiberon specifies 100 °C for 10 h[1][2]60 °C for 6 h (Extrudr FLEX HARD CF)[3]
Symptoms when wetBubbling and popping at the nozzle, stringing and a rough surface[14]Bubbling and popping at the nozzle, stringing and a rough surface[14]
Effect of moisture on strengthBambu Lab publishes its whole mechanical table under the heading "Mechanical Properties (Dry state)" — the quoted figures apply only to dried filament[1]Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[14]
Storage requirementSealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[14][8]Sealed with desiccant; often kept in a dryer during the print[14]
Hydrolysis at melt temperatureThe 80–100 °C dry both suppliers mandate is far above the 55–65 °C used for PETG, consistent with a melt-hydrolysis risk in the semi-crystalline PET matrix; neither publishes a molecular-weight loss figure[1][2]Not documented
Mechanical Properties
Tensile strength (XY)MPa65.9 (Fiberon) to 74 (Bambu Lab) printed XY, ISO 527[1][2]Not documented
Young's modulusMPa4730 ± 260 (Bambu Lab) and 5481 ± 224 (Fiberon) printed XY, ISO 527[1][2]35 (Extrudr FLEX HARD CF, ISO 527-2/5A/500)[3]
Elongation at break%2.4 ± 0.5 printed XY, ISO 527 (Fiberon PET-CF17)[2]380 ultimate elongation (Extrudr FLEX HARD CF, ISO 527-2/5A/500), against 490 for the unfilled FLEX HARD[3]
Flexural strengthMPa109.3 ± 2.0 printed XY, ISO 178 (Fiberon PET-CF17)[2]Not documented
Flexural modulusMPa4744 ± 136 printed XY, ISO 178 (Fiberon PET-CF17)[2]Not documented
Charpy impact, notchedkJ/m²5.1 ± 0.2 printed XY, ISO 179 notched (Fiberon PET-CF17); unnotched 25.1 ± 2.8[2]Not documented
Layer adhesion / Z tensileMPa27.9 (Fiberon) and 35 ± 5 (Bambu Lab) printed Z, ISO 527[1][2]Not documented
Brittleness1–5Very brittle — elongation at break 2.4 % in XY and 0.8 % in Z[2]Very ductile — bends far before failing[3]
Hardness (scale-specific)Shore A / Shore D / RockwellNot documented70 Shore D (Extrudr FLEX HARD CF, ISO 868), against 58 Shore D for the unfilled FLEX HARD[3]
Creep resistance / sustained load1–5Good — no creep test found; annealed PET-CF holds a 105 °C HDT at 1.8 MPa and a 4730–5481 MPa modulus against 1500–2311 for PETG[2][1]Below average — no CF-grade creep test; the grade is 70 Shore D where a 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[3][15]
Fatigue / repeated-flex resistance1–5Below average — no S-N curve; elongation at break is 2.4 % in XY and 0.8 % in Z, against 5.2–9.3 % for unfilled PETG[2]Good — 380 % ultimate elongation and a damping application set (Extrudr cites longboard wheels), below the unfilled grades[3]
Elasticity / flexibility1–5Rigid[1]Semi-flexible[3]
Z strength as % of XY%42 (Fiberon) to 47 (Bambu Lab), printed[1][2]Not documented
Wear resistance & frictionNot documentedAbrasion 26 mm³ (Extrudr FLEX HARD CF, ISO 4649-A) — the same as the unfilled FLEX HARD[3]
Thermal Properties
HDT at 0.45 MPa°C147.5 (Fiberon) and 205 (Bambu Lab), ISO 75 at 0.45 MPa[1][2]Not documented
HDT at 1.8 MPa°C105 (Fiberon) and 182 (Bambu Lab), ISO 75 at 1.8 MPa[1][2]Not documented
Glass transition (Tg)°C75 (Bambu Lab) and 79.3 (Fiberon), DSC[1][2]-24 (Extrudr FLEX HARD CF)[3]
Melting point / Vicat°C241.3 (Fiberon) and 250 (Bambu Lab) melting, DSC; Vicat 226–238[1][2]Vicat A 140 (Extrudr FLEX HARD CF, ISO 306)[3]
Annealing responseThe PET matrix crystallises on annealing, which is what separates this grade from PETG-CF[2][1]Not documented
Flammability / UL 94Flammable; no UL 94 rating published for standard grades[16]Not documented
Environment & Chemical
UV resistance1–5Not documentedGood — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[10]
Chemical resistanceWithstands acids, alkalis, oils and UV exposure[8]Withstands industrial solvents and UV exposure (Polymaker)[10]
Food contactNot certified for food contact as filament[8]Not food safe without specific certification (Polymaker)[10]
Biodegradability / compostabilityNot biodegradable[8]Not biodegradable[10]
RecyclabilityNot accepted in household plastic collection[8]Not accepted in household plastic collection[10]
Electrical & ESD propertiesSurface resistivity above 10¹² ohm — insulating (Fiberon PET-CF17, ANSI/ESD S11.11)[2]Not documented
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[17]Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[17]
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[17][1]Open a window / occasional ventilation[17]
Dust & fibre handling hazardCarbon fibre is bound in the matrix; sanding dust should not be inhaled[2]Carbon fibre is bound in the matrix; sanding dust should not be inhaled[3]
Post-Processing
Sanding & machiningSands poorly — the material is tough and gums rather than powders[13]Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[10]
Gluing & solvent weldingCyanoacrylate; no common solvent welds PETG cleanly[13]Cyanoacrylate bonds TPU; no common solvent welds it[10]
Vapour / chemical smoothingNo practical vapour smoothing[13]No practical vapour smoothing[10]
Support material pairingPrints its own supports; Polymaker rates PolyDissolve S1 for PETG[13]Polymaker warns TPU supports are often very difficult to remove[10]
Dimensional accuracy & detailBambu Lab markets it on low warping and shrinkage relative to other high-temperature composites[1]Tear strength 165 kN/m (Extrudr FLEX HARD CF, ISO 34-1B)[3]
Solvents & Solubility
Soluble inNone common; fluorinated solvents such as hexafluoroisopropanol dissolve linear polyester at 23 °C. Laboratory only.[18][19]DMF, DMSO, NMP and THF dissolve the TPU matrix and leave the fibre; ketones are partial solvents. Laboratory reagents.[20]
Softened or crazed byEnsinger rates polyester not resistant to chloroform or dichloromethane and only conditionally resistant to acetone and MEK.[19]Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[20]
Solvent welding & smoothing agentDichloromethane attacks polyester and can be brushed on, but the carbon fibre blocks any useful surface flow.[19][21]None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[20]

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. Bambu Filament Technical Data Sheet — PET-CF Bambu Lab · 2026-08 · tds
  2. Fiberon PET-CF17 Technical Data Sheet V1.0 Polymaker · 2026-08 · tds
  3. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  4. Polymaker product catalogue Polymaker · 2026-08 · vendor
  5. Extrudr TPU FLEX Hard CF — product page (1.75 mm, 0.5 and 2 kg coils, price) Extrudr (FD3D GmbH) · 2026-08 · vendor
  6. ELEGOO product catalogue ELEGOO · 2026-08 · vendor
  7. Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  8. PETG — material basics Polymaker Wiki · 2026-08 · doc
  9. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  10. TPU — material basics Polymaker Wiki · 2026-08 · doc
  11. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  12. Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
  13. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  14. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  15. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  16. Prusament PETG V0 Technical Datasheet Prusa Polymers · 2026-08 · tds
  17. 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
  18. Resistance of Ultramid, Ultraform and Ultradur to chemicals (TI-KTU/AS-28 e) BASF · 2000-10 · tds
  19. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  20. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds
  21. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc