3D Printing Info

Filament comparison

e-TPU vs POM

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

Foaming / expanded TPU (TPU Aero / TPU Air) guidePOM (acetal) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore e-TPU comparisonsMore POM comparisons
e-TPU vs POM — documented properties and sources
PropertyFoaming / expanded TPU (TPU Aero / TPU Air)FLEXPOM (acetal)ENGINEERING
Market snapshot
Listing priceUSD/kg; dated snapshots$52.05/kg median; $41.99–$85.29/kg across 6 dated product listingsNot documented
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]Polyoxymethylene, normally the copolymer POM-C. Apium's filament grade is POM-C with antistatic additives; no unfilled POM filament was found on sale[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]1.41 (extruded POM-C stock)[2]
Typical priceUSD/kg1 kg-equivalent spools span 42–85; the middle of the market is about 52[6][7][8][9][10][11]Not documented
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][12]Not documented
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 — Apium sells a POM-C ESD filament through its own shop and states its printers are the only ones able to process POM-C; no POM filament appears in the 3DJAKE or igo3d product sitemaps, at MatterHackers or at Printed Solid[3][13][14][15]
Spool sizes & diameters1.75 mm; 0.7, 0.75, 0.8, 1 and 3 kg spools[1][6][8][9][11]Not documented
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]Gears, bushings, bearings, conveyor and food-machinery parts; Apium markets its POM-C ESD grade for semiconductor insulators, aerospace fasteners and sliding parts[2][3]
Diameter tolerance± mm0.03 (Siraya Tech and Roamr, 1.75 mm)[4][5]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][4][5][10]Not documented
Bed temperature°C30–45 (QIDI and Siraya Tech), 35–50 (Roamr) — a hot bed makes the foamed part over-stick[4][5][10]Not documented
Enclosure / chamber requirement1–5Open frame is fine — Roamr states no enclosure is required[1][5]Not documented
Part cooling fan100 % — cooling sets the foamed structure quickly (Siraya Tech and Roamr)[4][5]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][4]Not documented
Maximum volumetric flow (mm³/s; see test conditions)mm³/sUp to 12 (Siraya Tech, Flex TPU Air)[8]Not documented
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][10]Not documented
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; both density and hardness follow nozzle temperature and flow[1]Not documented
Extruder requirementDirect drive; the base material is a 92A TPU[1][18]Apium states that the adaptive heating system on its industrial machines is what makes POM-C printable, and that no other 3D printer can process it[3]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely — Roamr states plainly that no hardened nozzle is needed[19][5]Not documented
Abrasiveness1–5Non-abrasive[19]Not documented
Hotend requirementNo special hot-end required, but a direct-drive extruder is (Simplify3D)[16]Not documented
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate[20]Low (0.1-0.3 %) — extruded POM-C stock takes up 0.18 % in 24 h and 0.80 % at saturation (ASTM D570)[2]
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)[4][5][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[20][4]Not documented
Effect of moisture on strengthPolymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[20]Not documented
Storage requirementSealed with desiccant; often kept in a dryer during the print[20]Not documented
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][10]66.9 at break and 64.1 at yield (extruded POM-C stock, ASTM D638; converted from 9700 and 9300 psi)[2]
Young's modulusMPa50 unfoamed and 40 foamed (colorFabb, ISO 527-1A)[1]2275 (extruded POM-C stock, ASTM D638; converted from 330,000 psi)[2]
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][10]40 at break and 9 at yield (extruded POM-C stock, ASTM D638)[2]
Flexural strengthMPaNot documented89.6 (extruded POM-C stock, ASTM D790; converted from 13,000 psi)[2]
Flexural modulusMPa50 unfoamed and 40 foamed flexural modulus (colorFabb, ISO 178)[1]2758 (extruded POM-C stock, ASTM D790; converted from 400,000 psi)[2]
Other impact dataNot documentedIzod 53 J/m on extruded POM-C stock, converted from 1.0 ft-lb/in[2]
Brittleness1–5Very ductile — bends far before failing[1]Tough — absorbs impact, yields before breaking; extruded stock elongates 40 % before failing. No printed figure is published[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][4][5][21]Rockwell 86 (and R120) — the source names only the R scale on extruded POM-C stock (ASTM D785)[2]
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[22]Not documented
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[17]Not documented
Elasticity / flexibility1–5Rubbery / highly elastic[1]Not documented
Wear resistance & frictionNot documentedWear factor 65e-10 in3*min/(ft*lb*h) and a dynamic coefficient of friction of 0.21 at 40 psi and 50 fpm (ASTM D3702, extruded stock) — the properties that make acetal the default gear and bushing plastic; Apium lists good sliding properties as the reason for its grade[2][3]
Thermal Properties
HDT at 0.45 MPa°CNot documented158 (extruded POM-C stock, ASTM D648 at 66 psi; converted from 316 °F)[2]
HDT at 1.8 MPa°CNot documented110 (extruded POM-C stock, ASTM D648 at 264 psi; converted from 230 °F)[2]
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][10]165 melting (extruded POM-C stock; converted from 329 °F)[2]
Continuous service temperature°CNot documented91 long term and 141 intermittent (extruded POM-C stock; converted from 195 °F and 285 °F)[2]
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]Not documented
Thermal expansion (CTE)µm/m·KNot documented84.6 (extruded POM-C stock, ASTM D696; source states 4.7e-5 in/in/°F)[2]
Flammability / UL 94Not documentedUL 94 HB on extruded POM-C stock[2]
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]Good chemical resistance, particularly to bases; Apium lists resistance to bases as a headline property[2][3]
Water / humidity resistance in service1–5Not documentedGood — minor absorption; 0.80 % water at saturation (ASTM D570, extruded stock)[2]
Food contactNot food safe without specific certification (Polymaker)[17]Not documented
Biodegradability / compostabilityNot biodegradable[17]Not documented
RecyclabilityNot accepted in household plastic collection[17]Not documented
Electrical & ESD propertiesNot documentedVolume resistance 1e14 ohm-cm, dielectric strength 500 V/mil and dielectric constant 3.7 at 60 Hz on extruded stock (ASTM D257, D149, D150); Apium's filament grade adds antistatic agents[2][3]
Health & Safety
Fume toxicity1–5Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[23]Not documented
Ventilation / filtration requirement1–5Open a window / occasional ventilation[23]Not documented
Post-Processing
Sanding & machiningDifficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[17]Easy to machine — Ensinger lists machinability as a headline property of POM-C stock[2]
Gluing & solvent weldingCyanoacrylate bonds TPU; no common solvent welds it[17]Not documented
Vapour / chemical smoothingNo practical vapour smoothing[17]Not documented
Support material pairingPolymaker warns TPU supports are often very difficult to remove[17]Not documented
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]Not documented
Solvents & Solubility
Soluble inDMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[24]Hexafluoroisopropanol dissolves it at room temperature; NMP and DMF only when hot. Laboratory reagents.[25]
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.[24]Acids, oxidants, halogens and hot concentrated zinc chloride attack it; alcohols, ketones and esters do not.[25][26]
Solvent welding & smoothing agentNone practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[24]None — no solvent softens POM below its melting point, which is why it is bolted or heat-welded rather than glued.[25]

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. TECAFORM AH natural (POM-C) — stock shape properties Ensinger · 2026-08 · tds
  3. POM-C ESD 3D printing — material page Apium 3D Technologies · 2026-08 · doc
  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. 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. Phaetus aeWorthy TPU-Aero — reseller listing West3D · 2026-08 · vendor
  13. 3DJAKE product catalogue 3DJAKE · 2026-08 · vendor
  14. igo3d product sitemap (17452 product URLs) igo3d · 2026-08 · vendor
  15. Printed Solid product catalogue Printed Solid · 2026-08 · vendor
  16. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  17. TPU — material basics Polymaker Wiki · 2026-08 · doc
  18. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  19. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  20. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  21. Roamr TPU Air HR 85A Technical Data Sheet Siraya Tech · 2026-08 · tds
  22. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  23. 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
  24. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds
  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