3D Printing Info

Filament comparison

e-TPU vs PLA

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

Foaming / expanded TPU (TPU Aero / TPU Air) guidePLA (standard) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore e-TPU comparisonsMore PLA comparisons
e-TPU vs PLA — documented properties and sources
PropertyFoaming / expanded TPU (TPU Aero / TPU Air)FLEXPLA (standard)PLA
Market snapshot
Listing priceUSD/kg; dated snapshots$52.05/kg median; $41.99–$85.29/kg across 6 dated product listings$19.74/kg median; $9.99–$32.99/kg across 24 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]Poly(lactic acid), a thermoplastic aliphatic polyester from fermented plant starch[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]1.17–1.24 (ISO 1183)[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]Mainstream 1 kg spools cluster near 20[13][14][15]
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][16]10–33 across brands; budget house brands 10–14, premium European 26–33[17][18][19][20]
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]Ubiquitous, every brand and retailer[21][22]
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, 0.85, 1 and 1.1 kg spools plus spool-less refills[13][23][24][19][25]
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]Concept models, functional prototypes, low-wear toys, jigs used at room temperature[26]
Diameter tolerance± mm0.03 (Siraya Tech and Roamr, 1.75 mm)[4][5]±0.02 (Prusament) to ±0.03 (Bambu Lab, Prusa Research standard)[2][13][27]
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]190–230; Prusament specifies 210 ± 10[2][6][3]
Bed temperature°C30–45 (QIDI and Siraya Tech), 35–50 (Roamr) — a hot bed makes the foamed part over-stick[4][5][11]25–60; Prusament 40–60, Bambu Lab 35–45[2][6][3]
Enclosure / chamber requirement1–5Open frame is fine — Roamr states no enclosure is required[1][5]Open frame is fine[6][21]
Part cooling fan100 % — cooling sets the foamed structure quickly (Siraya Tech and Roamr)[4][5]100 % from the second layer; reduce on the first one or two layers for bed adhesion[2][22]
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[28][29][4]Smooth or textured PEI, glass or painter's tape; glue stick only where release is a problem[6][30][22]
Maximum volumetric flow (mm³/s; see test conditions)mm³/sUp to 12 (Siraya Tech, Flex TPU Air)[9]12–20 (PrusaSlicer max volumetric speed guidance for PLA)[31]
Warping tendency1–5Not documentedNone[32][21]
Bed-adhesion difficulty1–5Not documentedSticks to anything — glue only needed on smooth PEI[6][3][22]
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 — 1–3 mm retraction handles it; oozing rises with nozzle temperature[6][22][33]
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; both density and hardness follow nozzle temperature and flow[1]Beginner — prints on any machine out of the box[21][22]
Extruder requirementDirect drive; the base material is a 92A TPU[1][34]Any extruder; Bowden and direct drive both fine, no hardware upgrades[21]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely — Roamr states plainly that no hardened nozzle is needed[35][5]Brass fine indefinitely[21]
Abrasiveness1–5Non-abrasive[35]Non-abrasive[32][21]
Nozzle clog risk1–5Not documentedVery low[21][22]
Heat-creep / jam sensitivity1–5Not documentedModerate — good heatbreak cooling needed; softens below 60 °C so it deforms in a warm cold zone[30][36]
Hotend requirementNo special hot-end required, but a direct-drive extruder is (Simplify3D)[28]Any standard hotend; PTFE-lined is fine at PLA temperatures[21]
Other hardware wearNot documentedNone — brass nozzles and standard drive gears are unaffected[32][21]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate[37]Moderate — 0.40–0.51 % saturated at 23–25 °C and 55–70 % RH[3][6][38]
Equilibrium moisture content at ~50 % RH%1.09 water absorption (QIDI TPU-Aero; the standard is not stated)[11]0.43 saturated at 25 °C / 55 % RH (Bambu Lab); 0.51 equilibrium (Polymaker)[3][6]
Drying temperature & time70–80 °C for 4–6 h; keep below 15 % RH while printing (Siraya Tech, Roamr and QIDI)[4][5][11]50–55 °C for 6–8 h in a forced-air dryer; 45 °C for 12 h in the Bambu Lab AMS HT[6][3][36]
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[37][4]Bubbling and popping at the nozzle, stringing, rough surface and weak layers[37]
Effect of moisture on strengthPolymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[37]Polymaker rates PLA low-sensitivity — it absorbs moisture slowly and the loss shows as poor layer adhesion and brittle layers rather than a published strength figure[37]
Storage requirementSealed with desiccant; often kept in a dryer during the print[37]Sealed with desiccant below 20 % RH; shelf life at ambient is long[3][22]
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]35–52 (printed XY, ISO 527); 55 mean across 16 brands and 53 for the reference PLA in a later run, both on 4×4 mm printed bars[2][6][3][39][40]
Young's modulusMPa50 unfoamed and 40 foamed (colorFabb, ISO 527-1A)[1]2300–3427 (printed XY, ISO 527)[2][6][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]6.3–12.2 (printed XY, ISO 527); Prusament quotes 2.9 at yield[6][3][2]
Flexural strengthMPaNot documented76–87 (printed XY, ISO 178); Fiberlogy quotes 81 by ASTM D790[2][6][3][41]
Flexural modulusMPa50 unfoamed and 40 foamed flexural modulus (colorFabb, ISO 178)[1]2750–3230 (printed XY, ISO 178); Fiberlogy quotes 3800 by ASTM D790[2][6][3][41]
Charpy impact, notchedkJ/m²Not documented3.3–7.9 (printed XY, ISO 179, notched)[6][3]
Other impact dataNot documentedCharpy unnotched, printed: 13–14 (Prusament, ISO 179-1), 26.6 (Bambu Lab PLA Basic)[2][3]
Layer adhesion / Z tensileMPaNot documented17–31 (Prusa interlayer test and printed Z tensile); 23 mean on My Tech Fun 4×4 mm bars[2][3][40]
Brittleness1–5Very ductile — bends far before failing[1]Brittle — snaps with little warning[30][32]
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][42]81 Shore D (Prusa Polymers in-house method); 75.3 Shore D measured on printed bars (My Tech Fun, Sunlu PLA)[2][43]
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[44]Poor — deforms under load at room temperature; 12 mm bar sagged to 20.3 mm over 5 days at 1.25 kg[45][46]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[29]Poor — 38 000–49 000 cycles at 30 % of tensile strength, against 79 000–193 000 for PETG (printed, R = 0.2, 7 Hz)[47][30]
Elasticity / flexibility1–5Rubbery / highly elastic[1]Rigid[32]
Z strength as % of XY%Not documented77–89 on TDS specimens; ≈44 on My Tech Fun 4×4 mm bars[6][3][40]
Thermal Properties
HDT at 0.45 MPa°CNot documented55–60 (ISO 75, 0.45 MPa)[2][6][3]
HDT at 1.8 MPa°CNot documented54–58 (ISO 75, 1.8 MPa)[2][6][3]
Glass transition (Tg)°CNot documented55–61 (DSC)[2][6][3]
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]145–160 peak melt (Prusament, ISO 11357); 150 and 160 by DSC (PolyLite, Bambu Lab); Vicat 57–63 (ISO 306)[26][6][3]
Continuous service temperature°CNot documented50–55 — loaded bars begin to move at this temperature[32][40]
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]Bambu Lab conditions specimens at 55 °C for 8 h; annealing at 50–60 °C for 6–12 h raises crystallinity but can warp parts[3][48]
Thermal expansion (CTE)µm/m·KNot documented96 ± 5 at 0° and 99 ± 5 at 90° raster (printed PLA, fibre Bragg grating, 25–50 °C)[49]
Flammability / UL 94Not documentedFlammable; no UL 94 rating published by the major brands[3][6]
Environment & Chemical
UV resistance1–5Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[29]Degrades within weeks outdoors[30][26]
Outdoor durabilityNot documentedNot suitable for long-term outdoor use — UV embrittlement plus softening above 55 °C in direct sun[26][30]
Chemical resistanceWithstands industrial solvents and UV exposure (Polymaker)[29]Good against weak acids, oils and grease; poor against strong acids and alkalis; dissolved by chloroform, THF and hot benzene[6][30]
Water / humidity resistance in service1–5Not documentedGood — insoluble in water, absorbs 0.4–0.5 % at equilibrium[3][50]
Food contactNot food safe without specific certification (Polymaker)[29]Base resin is food-contact grade and EN 71-3 certified by some brands, but printed layer grooves harbour bacteria; Prusa advises against food use[30][50]
Biodegradability / compostabilityNot biodegradable[29]Industrially compostable only — needs sustained 55 °C and specific microbial conditions; not home compostable[50][30][3]
RecyclabilityNot accepted in household plastic collection[29]Mechanically recyclable; not accepted in household plastic collection, so brand take-back schemes are the practical route[50]
Health & Safety
Fume toxicity1–5Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[51]Low hazard — minimal VOC and particle emission[51]
VOC emission rateµg/minNot documented4–5 lactide, the dominant VOC (chamber study, three printers)[51]
Ultrafine-particle emission rateparticles/minNot documented≈1 × 10⁸ median across three printers; only laywood ≈8 × 10⁷ and laybrick ≈6 × 10⁷ were lower[51]
Hazardous species emittedNot documentedLactide (3,6-dimethyl-1,4-dioxane-2,5-dione) dominates; no styrene or caprolactam as a leading species[51]
Ventilation / filtration requirement1–5Open a window / occasional ventilation[51]None needed in a normal room[51]
Post-Processing
Sanding & machiningDifficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[29]Wet sanding — dry sanding heats the surface by friction and smears it[26][30]
Gluing & solvent weldingCyanoacrylate bonds TPU; no common solvent welds it[29]Cyanoacrylate for most joints; some grades partially dissolve and bond with acetone, depending on additives and colour[30][27]
Vapour / chemical smoothingNo practical vapour smoothing[29]No practical vapour smoothing — only chloroform, hot benzene or THF, which are laboratory-only[30]
Support material pairingPolymaker warns TPU supports are often very difficult to remove[29]PolySupport and PolyDissolve S1 (Polymaker); Support for PLA (Bambu Lab)[6][3]
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]Good — low shrinkage and features under 0.2 mm resolve; 55° overhangs and 30 mm bridges[32][3][22]
Solvents & Solubility
Soluble inDMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[52]Chloroform: 10 % w/v in 2–4 h at 23 °C, every grade and morphology; THF and DMF only at 65 °C. Laboratory reagents.[53]
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.[52]Acetone, ethyl acetate and toluene plasticise it but dissolve <1 % even at 65 °C; submersion in acetone crazes and destroys parts.[53][54]
Solvent welding & smoothing agentNone practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[52]Chloroform vapour smooths and welds PLA at the cost of tensile strength; acetone does not smooth it at all.[55][54]

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. Prusament PLA Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  3. Bambu Filament Technical Data Sheet V3.0 — PLA Basic Bambu Lab · 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. PolyLite PLA Technical Data Sheet V5.4 Polymaker · 2024-11 · 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. PLA Basic — product page Bambu Lab US Store · 2026-08 · vendor
  14. MH Build Series PLA Filament White 1.75mm 1kg MatterHackers · 2026-08 · vendor
  15. 3DJAKE ecoPLA Black 1.75mm 1000g 3DJake International · 2026-08 · vendor
  16. Phaetus aeWorthy TPU-Aero — reseller listing West3D · 2026-08 · vendor
  17. JAYO PLA Classic 1.1KG 1.75mm JAYO Official Store · 2026-08 · vendor
  18. ELEGOO PLA Filament 1.75mm Colored 1KG Elegoo US Official Store · 2026-08 · vendor
  19. Fillamentum PLA Extrafill Natural 1kg Fillamentum USA · 2026-08 · vendor
  20. Prusament PLA Jet Black 1kg (NFC) Prusa Research · 2026-08 · vendor
  21. Filament Material Guide Prusa Knowledge Base · 2026-08 · doc
  22. PLA — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  23. Fiberlogy rPLA Refill Anthracite 850 g 3DJake International · 2026-08 · vendor
  24. JAYO Silk PLA+ 1.75mm 1.1kg JAYO Official Store · 2026-08 · vendor
  25. ColorFabb PLA/PHA 750g 3D Universe · 2026-08 · vendor
  26. Prusament PLA Technical Data Sheet v1.0 Prusa Polymers · 2018-09 · tds
  27. Prusament rPLA Corn Pigment 1kg — product page Prusa Research · 2026-08 · vendor
  28. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  29. TPU — material basics Polymaker Wiki · 2026-08 · doc
  30. PLA — material guide Prusa Knowledge Base · 2026-08 · doc
  31. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  32. Prusament PLA — material page Prusa Polymers · 2026-08 · doc
  33. PLA — material basics Polymaker Wiki · 2026-08 · doc
  34. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  35. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  36. Filament Drying Recommendations Bambu Lab Wiki · 2026-08 · doc
  37. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  38. PolySonic PLA Technical Data Sheet V5.4 Polymaker · 2024-11 · tds
  39. 16 PLA brand comparison test — results spreadsheet My Tech Fun (Igor Gaspar) · 2022-10 · test
  40. Creality Hyper PLA filament review — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  41. Easy PLA — product and technical data Fiberlogy · 2026-08 · tds
  42. Roamr TPU Air HR 85A Technical Data Sheet Siraya Tech · 2026-08 · tds
  43. Carbon Fiber PLA vs META-PLA vs PLA+ vs PLA by Sunlu — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  44. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  45. BambuLab PLA Basic vs PLA Tough vs PLA-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  46. PolyTerra PLA vs PLA+ — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  47. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  48. Bambu Filament Technical Data Sheet V3.0 — PLA Matte Bambu Lab · 2026-08 · tds
  49. Characterization of Thermal Expansion Coefficient of 3D Printing Polymeric Materials Using Fiber Bragg Grating Sensors Materials 17(18):4668 · 2024-09 · paper
  50. Filamentive PLA (recycled) — product page Filamentive · 2026-08 · vendor
  51. 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
  52. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds
  53. Solubility Study of Ingeo Biopolymer Grades in Common Organic Solvents (NWPD003) NatureWorks · 2019-10 · tds
  54. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc
  55. Effect of vapour smoothing in trichloromethane on 3D printed PLA — surface, mechanical and chemical structure Pitale, Keche & Chopra, Engineering Research Express 6(4) 045579 · 2024-12 · paper