3D Printing Info

Filament comparison

ASA Aero vs TPU soft

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

Foaming ASA (ASA Aero) guideSoft TPU (below 85A) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore ASA Aero comparisonsMore TPU soft comparisons
ASA Aero vs TPU soft — documented properties and sources
PropertyFoaming ASA (ASA Aero)ASASoft TPU (below 85A)FLEX
Market snapshot
Listing priceUSD/kg; dated snapshots$49.99/kg median; $49.99–$49.99/kg across 1 dated product listings$114.04/kg median; $109.80–$122.27/kg across 4 dated product listings
Identity & Market
Base polymer / chemistryASA with a heat-activated blowing agent that expands at the nozzle[1][2]Very soft thermoplastic elastomers below 85 Shore A. Fiberlogy's FiberFlex 30D measures 81 Shore A, the softest grade with a published datasheet found here[3]
Densityg/cm³0.99 filament (Bambu Lab, ISO 1183); Formfutura's grade reaches 0.33 g/cm³ fully expanded[1][2]1.07 (Fiberlogy FiberFlex 30D, ISO 1183)[3]
Typical priceUSD/kg1 kg spools cluster near 50[4]1 kg-equivalent spools cluster near 115[5][6][7]
Price range across brandsUSD/kg50 at Bambu Lab's 1 kg listing[4]110–122 at 1 kg-equivalent; Recreus 70A 110 and 60A 116 at 500 g, NinjaTek Edge 83A 112, NinjaTek Chinchilla 75A 122; the Recreus 3 kg spools fall to 70–73[5][7][6]
Market availability1–5Niche, a handful of specialist brands[4][2]Niche, a handful of specialist brands[3][8][5]
Spool sizes & diameters1.75 mm; 1 kg spools[4]1.75, 2.85 and 3 mm; 0.5, 0.85, 1, 2 and 3 kg spools[3][5][9][6]
Typical applicationsDrone airframes, RC parts and floating or outdoor applications where mass matters and UV exposure rules out LW-PLA[2]Highly compliant seals, soft grips and prosthetic liners[3]
Printing Parameters
Nozzle temperature°C240–280 (Bambu Lab); 220–285 (Formfutura), with foaming activating near 230 °C and peaking between 270 and 285 °C[1][2]Not documented
Bed temperature°C80–90 (Bambu Lab); 50–90 (Formfutura)[1][2]50–70 (Fiberlogy FiberFlex 30D)[3]
Enclosure / chamber requirement1–5Enclosure recommended — Bambu Lab specifies a 45–60 °C chamber[1][10]Open frame is fine[3]
Recommended chamber temperature°C45–60 (Bambu Lab)[1]Not documented
Part cooling fan0–80 % (Bambu Lab); 0–50 % (Formfutura)[1][2]Not documented
Bed surface & adhesion aidPEI sheet, BuildTak or an adhesion aid such as Magigoo (Polymaker); Simplify3D also lists Kapton tape and ASA slurry[11][12]PEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[13][14]
Maximum volumetric flow (mm³/s; see test conditions)mm³/s12 at Bambu Lab's 150 mm/s cap on a 0.4 mm nozzle at 0.2 mm layer[1][15]Not documented
Bed-adhesion difficulty1–5Needs a specific surface plus adhesive[11]Not documented
Stringing / oozing tendency1–5Slight — Polymaker advises 1–2 mm retraction at 20–30 mm/s[11]Not documented
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; flow has to be cut to match the expansion and the density follows nozzle temperature[2][1]Expert / industrial hardware only — below 85 Shore A the filament buckles in almost any feed path that is not a short, constrained direct drive[9][14]
Extruder requirementNot documentedDirect drive only, with a constrained filament path; Bowden is not viable at this hardness[9][8]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely[10]Brass fine indefinitely[16]
Abrasiveness1–5Non-abrasive[10]Non-abrasive[16]
Nozzle clog risk1–5Not documentedHigh — jams from moisture, heat creep or particles; below 85 Shore A the filament buckles and compresses, and Simplify3D warns that raised feed rates most likely end in a jam[13][14][17]
Heat-creep / jam sensitivity1–5Slightly sensitive[12]Very high — softens in the cold zone readily[14]
Hotend requirementNo special hotend required[12]No special hot-end required, but a direct-drive extruder is (Simplify3D)[13]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5High — 0.80 % saturated at 25 °C / 55 % RH, nearly double unfilled Bambu Lab ASA[1][18]Moderate[17]
Equilibrium moisture content at ~50 % RH%0.80 saturated at 25 °C / 55 % RH (Bambu Lab)[1]Not documented
Drying temperature & time80 °C for 8 h (Bambu Lab)[1]Not documented
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 strengthNo dry-versus-conditioned figures are published; Polymaker groups the styrenics as moderate-sensitivity and absorbed water shows as bubbling and poor layer adhesion[17]Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[17]
Storage requirementSealed with desiccant; Polymaker rates the styrenics moderate-sensitivity[17]Sealed with desiccant; often kept in a dryer during the print[17]
Mechanical Properties
Tensile strength (XY)MPa32 ± 4 printed XY, ISO 527 (Bambu Lab)[1]Not documented
Young's modulusMPa2010 ± 260 printed XY, ISO 527 (Bambu Lab)[1]Not documented
Elongation at break%5.1 ± 1.6 printed XY, ISO 527 (Bambu Lab)[1]870 at break (Fiberlogy FiberFlex 30D, ISO 527) — the highest elongation in the dataset[3]
Flexural strengthMPa58 ± 6 printed XY, ISO 178 (Bambu Lab)[1]Not documented
Flexural modulusMPa1510 ± 120 printed XY, ISO 178 (Bambu Lab)[1]Not documented
Charpy impact, notchedkJ/m²8.2 ± 1.6 printed XY, ISO 179, notched (Bambu Lab)[1]Not documented
Other impact dataCharpy unnotched 32.0 ± 2.5 printed XY (Bambu Lab, ISO 179)[1]Not documented
Layer adhesion / Z tensileMPa21 ± 4 printed Z, ISO 527 (Bambu Lab); flexural Z falls to 24 against 58 in XY[1]Not documented
Brittleness1–5Moderate[1]Very ductile — bends far before failing[3]
Hardness (scale-specific)Shore A / Shore D / RockwellNot documented81 Shore A and 30 Shore D (Fiberlogy FiberFlex 30D, ISO 7619)[3]
Creep resistance / sustained load1–5Below average — no creep test found; the foamed structure drops modulus to 2010 MPa and load is carried by a lower solid fraction[1][18]Poor — no creep test at this hardness; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[19]
Fatigue / repeated-flex resistance1–5Moderate — no foamed-grade S-N curve; unfilled printed ASA holds a fatigue limit at 25 % of tensile strength[1][20]Excellent — living hinges viable[14]
Elasticity / flexibility1–5Rigid[1]Rubbery / highly elastic[3]
Z strength as % of XY%66 by tensile, 41 by flexural (printed, Bambu Lab)[1]Not documented
Wear resistance & frictionNot documentedTear strength 95 kN/m (Fiberlogy FiberFlex 30D, ISO 34-1)[3]
Thermal Properties
HDT at 0.45 MPa°C85 (ISO 75, 0.45 MPa, Bambu Lab) against 100 for unfilled Bambu Lab ASA[1][18]Not documented
HDT at 1.8 MPa°C78 (ISO 75, 1.8 MPa, Bambu Lab) against 92 for unfilled Bambu Lab ASA[1][18]Not documented
Melting point / Vicat°CNot documented170 melting (Fiberlogy FiberFlex 30D, DSC)[3]
Continuous service temperature°C93 — Prusa publishes this as the temperature resistance of Prusament ASA[21]Not documented
Flammability / UL 94Flammable; no UL 94 rating published[18]Not documented
Environment & Chemical
UV resistance1–5Excellent — designed for permanent outdoor use; Formfutura states the foaming grade retains ApolloX's UV resistance[2][22]Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[14]
Chemical resistanceGood against weak acids, weak alkalis, oils and grease; dissolved by acetone[23]Withstands industrial solvents and UV exposure (Polymaker)[14]
Food contactNot food safe[11]Not food safe without specific certification (Polymaker)[14]
Biodegradability / compostabilityNot biodegradable[11]Not biodegradable[14]
RecyclabilityNot accepted in household plastic collection[11]Not accepted in household plastic collection[14]
Health & Safety
Fume toxicity1–5High — hazardous VOC such as styrene; enclosure and filtration needed[24][10]Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[24]
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[10][24]Not documented
Ventilation / filtration requirement1–5Enclosure with carbon and HEPA filtration[24][10]Open a window / occasional ventilation[24]
Post-Processing
Sanding & machiningSands well and takes filler before painting[11]Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[14]
Painting & finishingPaints readily; ASA holds colour outdoors so many parts are left unpainted[11]Not documented
Gluing & solvent weldingSolvent-welds with acetone[23]Cyanoacrylate bonds TPU; no common solvent welds it[14]
Vapour / chemical smoothingAcetone vapour smoothing works[23]No practical vapour smoothing[14]
Support material pairingHIPS breaks away or dissolves in d-limonene; Bambu Lab sells a Support for ABS that also serves ASA[10]Polymaker warns TPU supports are often very difficult to remove[14]
Dimensional accuracy & detailMatte, textured surface that hides layer lines; colour lightens as the foaming degree rises, which doubles as a visual density cue[2]Not documented
Solvents & Solubility
Soluble inAcetone dissolves it (Polymaker); MEK, THF, ethyl acetate and the chlorinated solvents dissolve the styrenic backbone.[25][23]DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[26]
Softened or crazed byLimonene attacks some grades — Prusa reports Prusament ASA Orange flaking apart as layer adhesion fails.[27]Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[26]
Solvent welding & smoothing agentAcetone vapour, ~20 min at 80 °C over 5 mm of liquid; the foamed wall absorbs solvent, so cut the exposure well short.[28]None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[26]

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 Aero Bambu Lab · 2026-08 · tds
  2. ApolloX Foaming Technical Data Sheet Formfutura · 2025-07 · tds
  3. FiberFlex 30D Technical Data Sheet Fiberlogy · 2026-08 · tds
  4. ASA Aero — product page Bambu Lab US Store · 2026-08 · vendor
  5. Recreus product catalogue Recreus · 2026-08 · vendor
  6. Chinchilla product page — print guidelines, spool sizes and price NinjaTek · 2026-08 · vendor
  7. NinjaFlex Edge product page — durometer, print guidelines and price NinjaTek · 2026-08 · vendor
  8. Filaflex 82A product page (Shore hardness and elongation) Recreus · 2026-08 · vendor
  9. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  10. ABS / ASA / PC Usage Guide Bambu Lab Wiki · 2026-08 · doc
  11. ASA — material basics Polymaker Wiki · 2026-08 · doc
  12. ASA — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  13. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  14. TPU — material basics Polymaker Wiki · 2026-08 · doc
  15. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  16. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  17. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  18. Bambu Filament Technical Data Sheet V3.0 — ASA Bambu Lab · 2026-08 · tds
  19. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  20. Mechanical, Fatigue, and Thermal Characterization of ASA, Nylon 12, PC and PC-ABS Manufactured by Fused Filament Fabrication (FFF) Polymers 18(2):302 · 2026-01 · paper
  21. Prusament ASA — material page Prusa Polymers · 2026-08 · doc
  22. ASA — FDM Material Data Sheet (includes 1000 h QUV exposure results) Stratasys · 2026-08 · tds
  23. PolyLite ASA Technical Data Sheet Polymaker · 2024-11 · 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. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  26. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds
  27. HIPS — Knowledge Base Prusa Research · 2026-08 · doc
  28. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc