3D Printing Info

Filament comparison

PET-CF vs TPU 85A

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

Carbon-fibre PET (PET-CF) guideTPU 85A guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PET-CF comparisonsMore TPU 85A comparisons
PET-CF vs TPU 85A — documented properties and sources
PropertyCarbon-fibre PET (PET-CF)PETGTPU 85AFLEX
Market snapshot
Listing priceUSD/kg; dated snapshots$39.99/kg median; $26.00–$49.98/kg across 4 dated product listings$89.89/kg median; $31.99–$106.05/kg across 6 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]Soft thermoplastic polyurethane at 82–85 Shore A[3][4][5]
Densityg/cm³1.29 (Bambu Lab) and 1.34 (Fiberon PET-CF17), ISO 1183[1][2]1.11 (BASF Ultrafuse 85A) to 1.19 (NinjaFlex 85A), ISO 1183 / ASTM D792[5][3]
Typical priceUSD/kg1 kg spools cluster near 45[1][6]1 kg-equivalent spools span 32–106; the middle of the market is about 90[7][8][3]
Price range across brandsUSD/kg26–50 across brands; ELEGOO 26 in a 5 kg pack, Bambu Lab 45, Fiberon 50[9][1][6]32–106 across brands; Siraya Tech Flex TPU 85A 32 at 1 kg, add:north TPU Pro Matte 85A 72, Recreus Filaflex 82A 90 at 500 g, Proto-pasta Clear Flexible TPU 90, 3DXTech 3DXFLEX 85A 96, NinjaTek NinjaFlex 106[10][7][8][11][3]
Market availability1–5Available from several mainstream brands[1][6][9]Available from several mainstream brands[7][10]
Spool sizes & diameters1.75 mm; 0.5 and 1 kg spools[6][1]1.75, 2.85 and 3 mm; 0.5, 1 and 2 kg spools[7][10][3]
Typical applicationsLoad-bearing parts that must survive above PETG's 70 °C ceiling without moving to PA or PC[1][2]Soft-touch grips, seals, wearables and anything that must compress and rebound[3][4]
Printing Parameters
Nozzle temperature°C260–290 (Bambu Lab)[1]200–220 (BASF Ultrafuse 85A, 210 typical)[5]
Bed temperature°C80–100 (Bambu Lab)[1]40 (BASF Ultrafuse 85A)[5]
Enclosure / chamber requirement1–5Enclosure recommended — Bambu Lab specifies a 45–60 °C chamber[1]Open frame is fine[5]
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[12][13]PEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[14][15]
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][16]1.2–3.2 at the 15–40 mm/s BASF specifies on a 0.4 mm nozzle at 0.2 mm layer[5]
Warping tendency1–5Not documentedNone[5]
Bed-adhesion difficulty1–5Needs the right surface or a thin adhesive — the problem is releasing the part, not sticking it[12][13]Sticks to anything — Recreus states its 82A grade has excellent bed adhesion without a heated bed or additives[4]
Stringing / oozing tendency1–5Moderate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[13]High — drying plus tuning needed[17][15]
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning[1]Advanced — enclosure, hardware upgrades, tuning; at this hardness the filament will not push through a Bowden tube[3][4]
Extruder requirementNot documentedDirect drive only. NinjaTek calls its 85A grade ideal for direct-drive extruders and Recreus specifies direct-drive printers for 82A; BASF caps print speed at 15–40 mm/s with a nozzle of 0.4 mm or larger[3][4][5]
Hardware Wear & Reliability
Nozzle hardness required1–4Hardened steel required[1]Brass fine indefinitely[18]
Abrasiveness1–5Highly abrasive — standard CF composite[1]Non-abrasive[18]
Nozzle clog risk1–5Moderate — needs dry filament and a clean nozzle; Prusa lists higher risk of nozzle clogging for carbon-filled composites[19]High — jams from moisture, heat creep or particles[17][15]
Heat-creep / jam sensitivity1–5Slightly sensitive[20]Very high — softens in the cold zone readily; soft filament buckles between the drive gear and the melt zone[15][3]
Hotend requirementNo special hot-end required[20]No special hot-end required, but a direct-drive extruder is (Simplify3D)[14]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate — 0.37 % saturated at 25 °C / 55 % RH (Bambu Lab); 0.53 % equilibrium (Fiberon)[1][2]Moderate — NinjaTek measures 0.22 % in 24 h (ASTM D570) and BASF specifies a 70 °C dry for at least 5 h[3][5]
Equilibrium moisture content at ~50 % RH%0.37 saturated at 25 °C / 55 % RH (Bambu Lab); 0.53 equilibrium (Fiberon PET-CF17)[1][2]0.22 after 24 h water immersion (NinjaFlex 85A, ASTM D570) — an immersion figure, not an equilibrium moisture content at 50 % RH[3]
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]70 °C for at least 5 h in a hot-air dryer or vacuum oven (BASF)[5]
Symptoms when wetBubbling and popping at the nozzle, stringing and a rough surface[17]Bubbling and popping at the nozzle, stringing and a rough surface[17]
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; wet TPU prints with poor layer adhesion and weak, brittle layers[17]
Storage requirementSealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[17][13]Sealed with desiccant; often kept in a dryer during the print[17]
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]26 ultimate (NinjaFlex 85A, ASTM D638)[3]
Young's modulusMPa4730 ± 260 (Bambu Lab) and 5481 ± 224 (Fiberon) printed XY, ISO 527[1][2]12 (NinjaFlex 85A, ASTM D638) — two orders of magnitude below any rigid filament; NinjaTek's 95A Cheetah reaches 26 by the same method[3][21]
Elongation at break%2.4 ± 0.5 printed XY, ISO 527 (Fiberon PET-CF17)[2]650 at break (Filaflex 82A) and 660 (NinjaFlex 85A); BASF measures 600 in XY and 320 in ZX[4][3][5]
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 documented29 Shore D / 85 Shore A (BASF Ultrafuse 85A, ISO 7619-1); 85 Shore A (NinjaFlex, ASTM D2240); 82 A nominal for Filaflex[3][5][4]
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]Poor — no 85A creep test; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg, and softer grades creep more[22]
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]Excellent — living hinges viable[15]
Elasticity / flexibility1–5Rigid[1]Rubbery / highly elastic[3][4]
Z strength as % of XY%42 (Fiberon) to 47 (Bambu Lab), printed[1][2]53 — BASF measures 320 % elongation at break in ZX against 600 % in XY[5]
Wear resistance & frictionNot documentedAbrasion 0.08 g mass loss over 10 000 cycles (NinjaFlex, ASTM D4060); 82 mm³ (BASF, ISO 4649)[3][5]
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]Not documented
Melting point / Vicat°C241.3 (Fiberon) and 250 (Bambu Lab) melting, DSC; Vicat 226–238[1][2]216 melting (NinjaFlex 85A, DSC)[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[23]Not documented
Environment & Chemical
UV resistance1–5Not documentedGood — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[15]
Chemical resistanceWithstands acids, alkalis, oils and UV exposure[13]Withstands industrial solvents and UV exposure (Polymaker)[15]
Food contactNot certified for food contact as filament[13]Not food safe without specific certification (Polymaker)[15]
Biodegradability / compostabilityNot biodegradable[13]Not biodegradable[15]
RecyclabilityNot accepted in household plastic collection[13]Not accepted in household plastic collection[15]
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[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][1]Open a window / occasional ventilation[24]
Dust & fibre handling hazardCarbon fibre is bound in the matrix; sanding dust should not be inhaled[2]Not documented
Post-Processing
Sanding & machiningSands poorly — the material is tough and gums rather than powders[20]Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[15]
Gluing & solvent weldingCyanoacrylate; no common solvent welds PETG cleanly[20]Cyanoacrylate bonds TPU; no common solvent welds it[15]
Vapour / chemical smoothingNo practical vapour smoothing[20]No practical vapour smoothing[15]
Support material pairingPrints its own supports; Polymaker rates PolyDissolve S1 for PETG[20]Polymaker warns TPU supports are often very difficult to remove[15]
Dimensional accuracy & detailBambu Lab markets it on low warping and shrinkage relative to other high-temperature composites[1]Not documented
Solvents & Solubility
Soluble inNone common; fluorinated solvents such as hexafluoroisopropanol dissolve linear polyester at 23 °C. Laboratory only.[25][26]DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[27]
Softened or crazed byEnsinger rates polyester not resistant to chloroform or dichloromethane and only conditionally resistant to acetone and MEK.[26]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 attacks polyester and can be brushed on, but the carbon fibre blocks any useful surface flow.[26][28]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. 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. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  4. Filaflex 82A product page (Shore hardness and elongation) Recreus · 2026-08 · vendor
  5. Ultrafuse TPU 85A Technical Data Sheet (Version 3.0) BASF Forward AM · 2022-08 · tds
  6. Polymaker product catalogue Polymaker · 2026-08 · vendor
  7. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  8. Siraya Tech Flex TPU 85A Filament — product page Siraya Tech · 2026-08 · vendor
  9. ELEGOO product catalogue ELEGOO · 2026-08 · vendor
  10. Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
  11. add:north TPU Pro Matte 85A product page add:north · 2026-08 · vendor
  12. Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  13. PETG — material basics Polymaker Wiki · 2026-08 · doc
  14. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  15. TPU — material basics Polymaker Wiki · 2026-08 · doc
  16. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  17. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  18. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  19. Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
  20. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  21. NinjaTek technical specs comparison chart (Cheetah, NinjaFlex, Armadillo, Alloy 910, Nylon 645) NinjaTek · 2026-08 · tds
  22. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  23. Prusament PETG V0 Technical Datasheet Prusa Polymers · 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. Resistance of Ultramid, Ultraform and Ultradur to chemicals (TI-KTU/AS-28 e) BASF · 2000-10 · 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
  28. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc