3D Printing Info

Filament comparison

e-TPU vs PC-ESD

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

Foaming / expanded TPU (TPU Aero / TPU Air) guideESD-safe PC guide

2 selected · all documented properties

Open these two in the interactive comparisonMore e-TPU comparisonsMore PC-ESD comparisons
e-TPU vs PC-ESD — documented properties and sources
PropertyFoaming / expanded TPU (TPU Aero / TPU Air)FLEXESD-safe PCPC
Market snapshot
Listing priceUSD/kg; dated snapshots$52.05/kg median; $41.99–$85.29/kg across 6 dated product listings$180.00/kg median; $180.00–$180.00/kg across 1 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]Polycarbonate compounded with a conductive filler for static-dissipative parts[2]
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)[3][4]1.24 (ISO 1183, 3DXTech); Stratasys specific gravity 1.195 (ASTM D792)[2][5]
Typical priceUSD/kg1 kg-equivalent spools span 42–85; the middle of the market is about 52[6][7][8][9][10][11]1 kg-equivalent spools cluster near 180[12]
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[6][7][8][9][10][11][13]180 at 3DXTech's 750 g pricing — the most expensive material in this group[12]
Market availability1–5Available from several mainstream brands — colorFabb, Recreus, QIDI, Phaetus, Siraya Tech and FusRock all sell an active-foaming TPU[1][6][7][8][10][11]Special order, 1–2 makers worldwide[12]
Spool sizes & diameters1.75 mm; 0.7, 0.75, 0.8, 1 and 3 kg spools[1][6][8][9][11]1.75 and 2.85 mm; 750 g spools plus Stratasys-compatible cartridges[12]
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][9]Electronics fixtures and trays that need PC heat resistance and static dissipation together[2]
Diameter tolerance± mm0.03 (Siraya Tech and Roamr, 1.75 mm)[3][4]Not documented
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][3][4][10]Not documented
Bed temperature°C30–45 (QIDI and Siraya Tech), 35–50 (Roamr) — a hot bed makes the foamed part over-stick[3][4][10]Not documented
Enclosure / chamber requirement1–5Open frame is fine — Roamr states no enclosure is required[1][4]Enclosure required (passive)[14][15]
Part cooling fan100 % — cooling sets the foamed structure quickly (Siraya Tech and Roamr)[3][4]Not documented
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[16][17][3]PEI with a glue stick or a commercial adhesive[18]
Maximum volumetric flow (mm³/s; see test conditions)mm³/sUp to 12 (Siraya Tech, Flex TPU Air)[8]Not documented
Warping tendency1–5Not documentedSevere — heated chamber needed[14][15]
Bed-adhesion difficulty1–5Not documentedNeeds a specific surface plus adhesive[18][19]
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[3][10]Moderate — retraction tuning needed; Polymaker flags stringing as a common PC problem[19]
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; both density and hardness follow nozzle temperature and flow[1]Advanced — enclosure, hardware upgrades, tuning[14]
Extruder requirementDirect drive; the base material is a 92A TPU[1][20]Not documented
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely — Roamr states plainly that no hardened nozzle is needed[21][4]Hardened steel required[2]
Abrasiveness1–5Non-abrasive[21]Moderately abrasive — conductive carbon filler[2]
Nozzle clog risk1–5Not documentedModerate — needs dry filament and a clean nozzle; 3DXTech lists no special nozzle concerns but a 120 °C pre-dry[22]
Heat-creep / jam sensitivity1–5Not documentedSlightly sensitive[18]
Hotend requirementNo special hot-end required, but a direct-drive extruder is (Simplify3D)[16]All-metal hot end required (Simplify3D)[18]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate[23]Low (0.1–0.3 %) — the PC matrix takes up 0.15–0.25 % and 3DXTech specifies a 120 °C, 4 h pre-dry[24][25][22]
Equilibrium moisture content at ~50 % RH%1.09 water absorption (QIDI TPU-Aero; the standard is not stated)[10]Not documented
Drying temperature & time70–80 °C for 4–6 h; keep below 15 % RH while printing (Siraya Tech, Roamr and QIDI)[3][4][10]Not documented
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[23][3]Bubbling and popping at the nozzle, stringing and a rough surface[23]
Effect of moisture on strengthPolymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[23]No dry-versus-conditioned figures are published. Polymaker calls PC highly hygroscopic and requires a 70–80 °C dry for 6–8 h; run wet, the loss shows as surface defects and poor layer adhesion[19][23]
Storage requirementSealed with desiccant; often kept in a dryer during the print[23]Airtight containers with desiccant to prevent reabsorption[19]
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][3][10]68 at break (printed XY, ISO 527, 3DXTech) — above the 58 of 3DXTech's unfilled ezPC; Stratasys prints 47.6-49.4 at yield in XZ (ASTM D638)[2][26][5]
Young's modulusMPa50 unfoamed and 40 foamed (colorFabb, ISO 527-1A)[1]2300 (printed XY, ISO 527); Stratasys prints 1960 in XZ and 1810-1910 in ZX (ASTM D638)[2][5]
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][3][4][10]6 at break (printed XY, ISO 527), against 14 for the unfilled grade[2][26]
Flexural strengthMPaNot documented95 (printed XY, ISO 178); Stratasys prints 82.6-83.2 at break in XZ against 46.3-49.5 in ZX (ASTM D790)[2][5]
Flexural modulusMPa50 unfoamed and 40 foamed flexural modulus (colorFabb, ISO 178)[1]2310 (printed XY, ISO 178)[2]
Layer adhesion / Z tensileMPaNot documented32.5-37.9 at yield printed ZX (Stratasys, ASTM D638 on the Fortus 450mc and F900)[5]
Brittleness1–5Very ductile — bends far before failing[1]Moderate[2]
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][3][4][27]Rockwell 70 (118) — the source does not name the scales and Shore D 79 on extruded unfilled PC stock (ASTM D785, D2240); no figure is published for an ESD grade[28]
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[29]Excellent — holds load for years. Moulded unfilled PC was still running unbroken under 41 MPa tensile creep at room temperature when the test was stopped, and the conductive filler leaves the glass transition unchanged at 142 °C, so the creep mechanism is polycarbonate's[30][5]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[17]Not documented
Elasticity / flexibility1–5Rubbery / highly elastic[1]Rigid[2]
Z strength as % of XY%Not documented68-77 (Stratasys ZX against XZ tensile yield, ASTM D638)[5]
Thermal Properties
HDT at 0.45 MPa°CNot documented143-146 printed in XY, XZ and ZX (Stratasys, ASTM D648 Method B at 66 psi); 135 moulded[5]
HDT at 1.8 MPa°CNot documented140-144 printed in XY, XZ and ZX (Stratasys, ASTM D648 Method B at 264 psi); 124 moulded[5]
Glass transition (Tg)°CNot documented143 (DSC, 3DXTech) and 142 (Stratasys, ASTM D7426)[2][5]
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[3][10]Not documented
Continuous service temperature°CNot documented113 — Prusa publishes this as the temperature resistance of Prusament PC Blend[25]
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][3]Not documented
Thermal expansion (CTE)µm/m·KNot documented68.4 on extruded unfilled PC stock (ASTM D696; source states 3.8e-5 in/in/°F); no figure is published for a conductive-filled grade[28]
Environment & Chemical
UV resistance1–5Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[17]Not documented
Chemical resistanceWithstands industrial solvents and UV exposure (Polymaker)[17]Withstands oils, solvents and fuels; Polymaker rates it good against weak acids[19]
Food contactNot food safe without specific certification (Polymaker)[17]Bisphenol-A polycarbonate is not offered as food-contact filament[19]
Biodegradability / compostabilityNot biodegradable[17]Not biodegradable[19]
RecyclabilityNot accepted in household plastic collection[17]Mechanically recyclable but not accepted in household plastic collection[19]
Electrical & ESD propertiesNot documentedSurface resistance 10⁷–10⁹ ohm/sq, the static-dissipative band (ASTM D257), against above 10¹³ for unfilled ezPC[2][26]
Health & Safety
Fume toxicity1–5Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[31]Moderate — measurable VOCs and UFPs, ventilation advised[31]
Ultrafine-particle emission rateparticles/minNot documented≈4 × 10¹⁰ median — the highest ultrafine-particle rate of the nine filaments in the chamber study, above every ABS tested[31]
Ventilation / filtration requirement1–5Open a window / occasional ventilation[31]Ventilated room or enclosure recommended[31][14]
Dust & fibre handling hazardNot documentedConductive carbon filler is bound in the matrix; avoid inhaling sanding dust[2]
Post-Processing
Sanding & machiningDifficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[17]Sands and machines well; the toughness means it cuts rather than chips[18]
Gluing & solvent weldingCyanoacrylate bonds TPU; no common solvent welds it[17]Cyanoacrylate; dichloromethane solvent-welds PC but is a laboratory reagent[18]
Vapour / chemical smoothingNo practical vapour smoothing[17]No practical vapour smoothing[18]
Support material pairingPolymaker warns TPU supports are often very difficult to remove[17]Prints its own supports; 3DXTech sells a dedicated PC break-away support[18]
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][3]Not documented
Solvents & Solubility
Soluble inDMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[32]Dichloromethane, chloroform, DMF and dioxane dissolve it outright (Covestro, 6 days at 23 °C). Laboratory reagents.[33]
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.[32]Methanol, butyl acetate, ether, 1 % NaOH and phthalate plasticisers stress-crack it; acetone, MEK and xylene swell it.[33]
Solvent welding & smoothing agentNone practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[32]Dichloromethane cement welds PC — 16.5 MPa lap shear at one week (IPS Weld-On 3). A controlled carcinogen.[34]

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. 3DXSTAT ESD-PC Technical Data Sheet 3DXTech · 2026-08 · tds
  3. Siraya Tech Flex TPU Air Technical Data Sheet Siraya Tech · 2026-08 · tds
  4. Roamr TPU Air HR 80A Technical Data Sheet Siraya Tech · 2026-08 · tds
  5. PC-ESD — FDM Material Data Sheet Stratasys · 2024-10 · tds
  6. Recreus product catalogue Recreus · 2026-08 · vendor
  7. varioShore TPU Natural — product page colorFabb US · 2026-08 · vendor
  8. Siraya Tech Flex TPU Air Black Filament — lightweight foaming flexible, product page Siraya Tech · 2026-08 · vendor
  9. Roamr TPU Air HR 80A Filament — product page Siraya Tech · 2026-08 · vendor
  10. TPU-Aero Lightweight TPU Filament — product page with specification tables QIDI Tech · 2026-08 · vendor
  11. aeFlex TPU-Aero — active foaming low weight TPU, product page Phaetus · 2026-08 · vendor
  12. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  13. Phaetus aeWorthy TPU-Aero — reseller listing West3D · 2026-08 · vendor
  14. ABS / ASA / PC Usage Guide Bambu Lab Wiki · 2026-08 · doc
  15. PolyLite PC Technical Data Sheet V5.4 Polymaker · 2024-11 · tds
  16. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  17. TPU — material basics Polymaker Wiki · 2026-08 · doc
  18. Polycarbonate — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  19. PC — material basics Polymaker Wiki · 2026-08 · doc
  20. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  21. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  22. 3DXSTAT ESD-PC — product page (print recommendations) 3DXTech · 2026-08 · doc
  23. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  24. Bambu Filament Technical Data Sheet V2.0 — PC Bambu Lab · 2026-08 · tds
  25. Prusament PC Blend Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  26. ezPC Polycarbonate Technical Data Sheet 3DXTech · 2026-08 · tds
  27. Roamr TPU Air HR 85A Technical Data Sheet Siraya Tech · 2026-08 · tds
  28. TECANAT natural (PC) — stock shape properties Ensinger · 2026-08 · tds
  29. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  30. Experimental data for creep and dynamic mechanical properties of polycarbonate and polycarbonate/ABS Data in Brief 42:108264 · 2022-06 · paper
  31. 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
  32. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds
  33. Makrolon — The chemical resistance (Makrolon 2800, 6 days at 23 °C and 50 °C) Covestro · 2016-12 · tds
  34. Weld-On 3 Acrylic Plastic Cement — technical data sheet (shipped as dichloromethane) IPS Corporation · 2002-07 · tds