3D Printing Info

Filament comparison

ASA-CF vs e-TPU

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

Carbon-fibre ASA (ASA-CF) guideFoaming / expanded TPU (TPU Aero / TPU Air) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore ASA-CF comparisonsMore e-TPU comparisons
ASA-CF vs e-TPU — documented properties and sources
PropertyCarbon-fibre ASA (ASA-CF)ASAFoaming / expanded TPU (TPU Aero / TPU Air)FLEX
Market snapshot
Listing priceUSD/kg; dated snapshots$36.99/kg median; $25.00–$90.00/kg across 5 dated product listings$52.05/kg median; $41.99–$85.29/kg across 6 dated product listings
Identity & Market
Base polymer / chemistryASA reinforced with chopped carbon fibre — Formfutura's ApolloX CF10 is 10 wt%[1][2][3]Foaming thermoplastic polyurethane — a blowing agent expands the extrudate so the printed Shore hardness can be tuned by flow rate[4]
Densityg/cm³1.02 (Bambu Lab), 1.1 (Formfutura ApolloX CF10) and 1.11 (3DXTech), ISO 1183[1][2][3]1.15 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)[5][6]
Typical priceUSD/kg1 kg spools cluster near 37[7][8]1 kg-equivalent spools span 42–85; the middle of the market is about 52[9][10][11][12][13][14]
Price range across brandsUSD/kg25–90 across brands; IEMAI 25, Ambrosia 33, Bambu Lab 37, Polymaker Fiberon 40, 3DXTech 90[15][7][8][16][17]42–85 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[9][10][11][12][13][14][18]
Market availability1–5Available from several mainstream brands[7][8][16][15]Available from several mainstream brands — colorFabb, Recreus, QIDI, Phaetus, Siraya Tech and FusRock all sell an active-foaming TPU[4][9][10][11][13][14]
Spool sizes & diameters1.75 and 2.85 mm; 0.5, 0.75 and 1 kg spools[8][16][7]1.75 mm; 0.7, 0.75, 0.8, 1 and 3 kg spools[4][9][11][12][14]
Typical applicationsOutdoor structural parts, drone and antenna mounts where stiffness and UV stability both matter[1][2]Cushioning, 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[4][12]
Diameter tolerance± mmNot documented0.03 (Siraya Tech and Roamr, 1.75 mm)[5][6]
Printing Parameters
Nozzle temperature°C250–280 (Bambu Lab)[1]230–270 (QIDI and Siraya Tech), 220–260 (Roamr); foaming activates near 230 °C and is strongest at the top of the range[4][5][6][13]
Bed temperature°C80–100 (Bambu Lab)[1]30–45 (QIDI and Siraya Tech), 35–50 (Roamr) — a hot bed makes the foamed part over-stick[5][6][13]
Enclosure / chamber requirement1–5Enclosure recommended — Bambu Lab specifies a 45–60 °C chamber[1][19]Open frame is fine — Roamr states no enclosure is required[4][6]
Recommended chamber temperature°C45–60 (Bambu Lab)[1]Not documented
Part cooling fanFan on (Bambu Lab)[1]100 % — cooling sets the foamed structure quickly (Siraya Tech and Roamr)[5][6]
Bed surface & adhesion aidPEI sheet, BuildTak or an adhesion aid such as Magigoo (Polymaker); Simplify3D also lists Kapton tape and ASA slurry[20][21]PEI 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[22][23][5]
Maximum volumetric flow (mm³/s; see test conditions)mm³/s20 at Bambu Lab's 250 mm/s cap on a 0.4 mm nozzle at 0.2 mm layer[1][24]Up to 12 (Siraya Tech, Flex TPU Air)[11]
Warping tendency1–5Moderate — needs adhesion aid or draught shield; the fibre reduces warping against unfilled ASA[19]Not documented
Bed-adhesion difficulty1–5Needs a specific surface plus adhesive[20]Not documented
Stringing / oozing tendency1–5Slight — Polymaker advises 1–2 mm retraction at 20–30 mm/s[20]Severe — 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[5][13]
Overall printing difficulty1–5Intermediate — dry filament and a tuned profile; hardened nozzle mandatory[19]Advanced — enclosure, hardware upgrades, tuning; both density and hardness follow nozzle temperature and flow[4]
Extruder requirementNot documentedDirect drive; the base material is a 92A TPU[4][25]
Hardware Wear & Reliability
Nozzle hardness required1–4Hardened steel required[19]Brass fine indefinitely — Roamr states plainly that no hardened nozzle is needed[26][6]
Abrasiveness1–5Highly abrasive — standard CF composite[19]Non-abrasive[26]
Nozzle clog risk1–5Moderate — needs dry filament and a clean nozzle; Prusa lists higher risk of nozzle clogging for fibre-filled composites and Simplify3D a higher tendency to clog[27][28]Not documented
Heat-creep / jam sensitivity1–5Slightly sensitive[21]Not documented
Hotend requirementNo special hotend required[21]No special hot-end required, but a direct-drive extruder is (Simplify3D)[22]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate — 0.33 % saturated at 25 °C / 55 % RH (Bambu Lab)[1]Moderate[29]
Equilibrium moisture content at ~50 % RH%0.33 saturated at 25 °C / 55 % RH (Bambu Lab)[1]1.09 water absorption (QIDI TPU-Aero; the standard is not stated)[13]
Drying temperature & time80 °C for 8 h (Bambu Lab)[1]70–80 °C for 4–6 h; keep below 15 % RH while printing (Siraya Tech, Roamr and QIDI)[5][6][13]
Symptoms when wetBubbling and popping at the nozzle, stringing and a rough surface[29]Bubbling and popping at the nozzle, stringing and a rough surface; Siraya Tech adds that moisture wrecks the foaming itself, not only the surface[29][5]
Effect of moisture on strengthNo dry-versus-conditioned figures are published; Polymaker groups the styrenics as moderate-sensitivity and absorbed water shows as bubbling and poor layer adhesion[29]Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[29]
Storage requirementSealed with desiccant; Polymaker rates the styrenics moderate-sensitivity[29]Sealed with desiccant; often kept in a dryer during the print[29]
Mechanical Properties
Tensile strength (XY)MPa34 ± 3 printed XY, ISO 527 (Bambu Lab); 3DXTech quotes 48 at break and Formfutura 79 at 23 °C[1][2][3]Falls 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)[4][5][13]
Young's modulusMPa4200 ± 270 printed XY, ISO 527 (Bambu Lab); 3DXTech quotes 5355 and Formfutura 7580[1][2][3]50 unfoamed and 40 foamed (colorFabb, ISO 527-1A)[4]
Elongation at break%9.6 ± 1.4 printed XY, ISO 527 (Bambu Lab); 3DXTech quotes 3 at break and Formfutura 1.8[1][2][3]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)[4][5][6][13]
Flexural strengthMPa72 ± 5 printed XY, ISO 178 (Bambu Lab); 3DXTech quotes 78[1][2]Not documented
Flexural modulusMPa3740 ± 130 printed XY, ISO 178 (Bambu Lab); 3DXTech quotes 5210[1][2]50 unfoamed and 40 foamed flexural modulus (colorFabb, ISO 178)[4]
Charpy impact, notchedkJ/m²6.2 ± 1.4 printed XY, ISO 179, notched (Bambu Lab) — a third of unfilled Bambu Lab ASA's 19.6[1][30]Not documented
Other impact dataCharpy unnotched 14.0 ± 2.2 printed XY (Bambu Lab, ISO 179), against 41.0 for unfilled Bambu Lab ASA[1][30]Not documented
Layer adhesion / Z tensileMPa30 ± 4 printed Z, ISO 527 (Bambu Lab); flexural Z falls to 33 against 72 in XY[1]Not documented
Brittleness1–5Brittle — snaps with little warning[1][2]Very ductile — bends far before failing[4]
Hardness (scale-specific)Shore A / Shore D / RockwellNot documentedTunable 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)[4][5][6][31]
Creep resistance / sustained load1–5Good — no creep test found; chopped carbon fibre lifts modulus to 4200 MPa against 2379–2450 for unfilled ASA[1][32]Poor — 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]
Fatigue / repeated-flex resistance1–5Below average — no CF-grade S-N curve; notched Charpy falls to 6.2 kJ/m² against 19.6 for unfilled Bambu Lab ASA[1][30]Excellent — living hinges viable[23]
Elasticity / flexibility1–5Rigid[1]Rubbery / highly elastic[4]
Z strength as % of XY%88 by tensile, 46 by flexural (printed, Bambu Lab)[1]Not documented
Thermal Properties
HDT at 0.45 MPa°C110 (ISO 75, 0.45 MPa, Bambu Lab) against 100 for unfilled Bambu Lab ASA[1][30]Not documented
HDT at 1.8 MPa°C102 (ISO 75, 1.8 MPa, Bambu Lab) against 92 for unfilled Bambu Lab ASA[1][30]Not documented
Melting point / Vicat°CNot documentedVicat softening drops as the foam expands: 83 printed at 240 °C to 53 at 270 °C (Siraya Tech, ISO 306); QIDI 70.4[5][13]
Continuous service temperature°C93 — Prusa publishes this as the temperature resistance of Prusament ASA[34]Not documented
Annealing responseNot documentedFoaming 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[4][5]
Flammability / UL 94Flammable; no UL 94 rating published[30]Not documented
Environment & Chemical
UV resistance1–5Excellent — designed for permanent outdoor use; the acrylate rubber phase is unchanged by the fibre[35][20]Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[23]
Chemical resistanceGood against weak acids, weak alkalis, oils and grease; dissolved by acetone[32]Withstands industrial solvents and UV exposure (Polymaker)[23]
Food contactNot food safe[20]Not food safe without specific certification (Polymaker)[23]
Biodegradability / compostabilityNot biodegradable[20]Not biodegradable[23]
RecyclabilityNot accepted in household plastic collection[20]Not accepted in household plastic collection[23]
Electrical & ESD propertiesSurface resistance above 10⁹ ohm/sq — not static-dissipative (3DXTech, ASTM D257)[2]Not documented
Health & Safety
Fume toxicity1–5High — hazardous VOC such as styrene; enclosure and filtration needed[36][19]Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[36]
Hazardous species emittedStyrene. Bambu Lab states ABS and ASA release harmful gases such as styrene at printing temperature, which can be toxic and cause dizziness or nausea. Azimi et al. measured styrene from every styrenic filament tested but did not test ASA itself[19][36]Not documented
Ventilation / filtration requirement1–5Enclosure with carbon and HEPA filtration[36][19]Open a window / occasional ventilation[36]
Dust & fibre handling hazardCarbon fibre is bound in the matrix; sanding dust should not be inhaled[2]Not documented
Post-Processing
Sanding & machiningSands well and takes filler before painting[20]Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[23]
Painting & finishingPaints readily; ASA holds colour outdoors so many parts are left unpainted[20]Not documented
Gluing & solvent weldingSolvent-welds with acetone[32]Cyanoacrylate bonds TPU; no common solvent welds it[23]
Vapour / chemical smoothingAcetone vapour smoothing works[32]No practical vapour smoothing[23]
Support material pairingHIPS breaks away or dissolves in d-limonene; Bambu Lab sells a Support for ABS that also serves ASA[19]Polymaker warns TPU supports are often very difficult to remove[23]
Dimensional accuracy & detailMatte fibre-filled finish hides layer lines[1]Foamed 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[4][5]
Solvents & Solubility
Soluble inAcetone dissolves the resin and leaves the fibre; MEK, THF, ethyl acetate and chlorinated solvents attack the styrenic backbone.[37][32]DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[38]
Softened or crazed byLimonene attacks some grades — Prusa reports Prusament ASA Orange flaking apart as layer adhesion fails.[39]Toluene and benzene swell it up to +50 % by weight at 23 °C; the foamed wall soaks up esters and alcohols faster still.[38]
Solvent welding & smoothing agentAcetone vapour reaches only the resin fraction, so the fibre is left standing proud of the smoothed surface.[40][32]None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[38]

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 V1.0 — ASA-CF Bambu Lab · 2026-08 · tds
  2. CarbonX Carbon Fiber ASA Technical Data Sheet 3DXTech · 2026-08 · tds
  3. ApolloX CF10 Technical Data Sheet Formfutura · 2026-08 · tds
  4. varioShore TPU Technical Data Sheet colorFabb · 2026-08 · tds
  5. Siraya Tech Flex TPU Air Technical Data Sheet Siraya Tech · 2026-08 · tds
  6. Roamr TPU Air HR 80A Technical Data Sheet Siraya Tech · 2026-08 · tds
  7. ASA-CF — product page Bambu Lab US Store · 2026-08 · vendor
  8. Polymaker product catalogue Polymaker · 2026-08 · vendor
  9. Recreus product catalogue Recreus · 2026-08 · vendor
  10. varioShore TPU Natural — product page colorFabb US · 2026-08 · vendor
  11. Siraya Tech Flex TPU Air Black Filament — lightweight foaming flexible, product page Siraya Tech · 2026-08 · vendor
  12. Roamr TPU Air HR 80A Filament — product page Siraya Tech · 2026-08 · vendor
  13. TPU-Aero Lightweight TPU Filament — product page with specification tables QIDI Tech · 2026-08 · vendor
  14. aeFlex TPU-Aero — active foaming low weight TPU, product page Phaetus · 2026-08 · vendor
  15. Filastruder product catalogue Filastruder · 2026-08 · vendor
  16. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  17. IEMAI CF-ASA 3D Printing Filament product page IEMAI 3D · 2026-08 · vendor
  18. Phaetus aeWorthy TPU-Aero — reseller listing West3D · 2026-08 · vendor
  19. ABS / ASA / PC Usage Guide Bambu Lab Wiki · 2026-08 · doc
  20. ASA — material basics Polymaker Wiki · 2026-08 · doc
  21. ASA — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  22. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  23. TPU — material basics Polymaker Wiki · 2026-08 · doc
  24. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  25. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  26. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  27. Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
  28. Carbon Fiber Filled — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  29. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  30. Bambu Filament Technical Data Sheet V3.0 — ASA Bambu Lab · 2026-08 · tds
  31. Roamr TPU Air HR 85A Technical Data Sheet Siraya Tech · 2026-08 · tds
  32. PolyLite ASA Technical Data Sheet Polymaker · 2024-11 · tds
  33. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  34. Prusament ASA — material page Prusa Polymers · 2026-08 · doc
  35. ASA — FDM Material Data Sheet (includes 1000 h QUV exposure results) Stratasys · 2026-08 · tds
  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. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  38. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds
  39. HIPS — Knowledge Base Prusa Research · 2026-08 · doc
  40. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc