Filament comparison
e-TPU vs TPE SEBS
Compare printing settings, strength, heat resistance, dated prices and sources.
2 selected · all documented properties
| Property | Foaming / expanded TPU (TPU Aero / TPU Air)FLEX | TPE (SEBS)FLEX |
|---|---|---|
| Market snapshot | ||
| Listing priceUSD/kg; dated snapshots | $52.05/kg median; $41.99–$85.29/kg across 6 dated product listings | $98.25/kg median; $76.50–$120.00/kg across 2 dated product listings |
| Identity & Market | ||
| Base polymer / chemistry | Foaming thermoplastic polyurethane — a blowing agent expands the extrudate so the printed Shore hardness can be tuned by flow rate[1] | Styrene-ethylene-butadiene-styrene thermoplastic elastomer — a styrenic rubber, not a polyurethane[2] |
| Densityg/cm³ | 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)[3][4] | 1.044 printed part density (BASF Ultrafuse TPS 90A, ISO 1183-1) — the lightest elastomer here[2] |
| Typical priceUSD/kg | 1 kg-equivalent spools span 42–85; the middle of the market is about 52[5][6][7][8][9][10] | 1 kg-equivalent spools cluster near 77[5] |
| Price range across brandsUSD/kg | 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[5][6][7][8][9][10][11] | 77 for the Recreus 600 g spool; Proto-pasta only lists a 50 g coil, which prices at 120[5][12] |
| Market availability1–5 | Available from several mainstream brands — colorFabb, Recreus, QIDI, Phaetus, Siraya Tech and FusRock all sell an active-foaming TPU[1][5][6][7][9][10] | Niche, a handful of specialist brands[2][12][5] |
| Spool sizes & diameters | 1.75 mm; 0.7, 0.75, 0.8, 1 and 3 kg spools[1][5][7][8][10] | 1.75 and 2.85 mm; 0.05 and 0.6 kg spools[2][5] |
| Typical applications | 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[1][8] | Soft-touch overmoulds and skin-contact parts where a non-polyurethane elastomer is wanted[2] |
| Diameter tolerance± mm | 0.03 (Siraya Tech and Roamr, 1.75 mm)[3][4] | Not documented |
| Printing Parameters | ||
| Nozzle temperature°C | 230–270 (QIDI and Siraya Tech), 220–260 (Roamr); foaming activates near 230 °C and is strongest at the top of the range[1][3][4][9] | 260–280 (BASF Ultrafuse TPS 90A) — far hotter than any TPU here[2] |
| Bed temperature°C | 30–45 (QIDI and Siraya Tech), 35–50 (Roamr) — a hot bed makes the foamed part over-stick[3][4][9] | 70–90 (BASF Ultrafuse TPS 90A)[2] |
| Enclosure / chamber requirement1–5 | Open frame is fine — Roamr states no enclosure is required[1][4] | Open frame is fine[2] |
| Part cooling fan | 100 % — cooling sets the foamed structure quickly (Siraya Tech and Roamr)[3][4] | Not documented |
| Bed surface & adhesion aid | 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[13][14][3] | 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/s | Up to 12 (Siraya Tech, Flex TPU Air)[7] | 0.8–2.4 at the 10–30 mm/s BASF specifies on a 0.4 mm nozzle at 0.2 mm layer — the slowest material in this group[2] |
| Stringing / oozing tendency1–5 | 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[3][9] | Not documented |
| Overall printing difficulty1–5 | Advanced — enclosure, hardware upgrades, tuning; both density and hardness follow nozzle temperature and flow[1] | Advanced — enclosure, hardware upgrades, tuning[2] |
| Extruder requirement | Direct drive; the base material is a 92A TPU[1][15] | Nozzle 0.4 mm or larger; BASF caps print speed at 10–30 mm/s[2] |
| Hardware Wear & Reliability | ||
| Nozzle hardness required1–4 | Brass fine indefinitely — Roamr states plainly that no hardened nozzle is needed[16][4] | Brass fine indefinitely[16] |
| Abrasiveness1–5 | Non-abrasive[16] | Non-abrasive[16] |
| Nozzle clog risk1–5 | Not documented | Moderate — needs dry filament and a clean nozzle; BASF caps print speed at 10–30 mm/s and Simplify3D warns that raised feed rates on flexibles most likely end in a jam[13][2] |
| Hotend requirement | No special hot-end required, but a direct-drive extruder is (Simplify3D)[13] | No special hot-end required, but a direct-drive extruder is (Simplify3D)[13] |
| Moisture Behaviour | ||
| Moisture absorption (hygroscopicity)1–5 | Moderate[17] | Negligible (<0.1 % EMC) — BASF states drying is not necessary, unique among the elastomers here[2] |
| Equilibrium moisture content at ~50 % RH% | 1.09 water absorption (QIDI TPU-Aero; the standard is not stated)[9] | Not documented |
| Drying temperature & time | 70–80 °C for 4–6 h; keep below 15 % RH while printing (Siraya Tech, Roamr and QIDI)[3][4][9] | None — BASF states Ultrafuse TPS 90A arrives in a printable condition and drying is not necessary[2] |
| Symptoms when wet | Bubbling and popping at the nozzle, stringing and a rough surface; Siraya Tech adds that moisture wrecks the foaming itself, not only the surface[17][3] | Bubbling and popping at the nozzle, stringing and a rough surface[17] |
| Effect of moisture on strength | Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[17] | Not applicable — the SEBS chemistry has no amide or ester linkages to take up water, and BASF specifies no drying at all[2] |
| Storage requirement | Sealed with desiccant; often kept in a dryer during the print[17] | Sealed with desiccant; often kept in a dryer during the print[17] |
| Mechanical Properties | ||
| Tensile strength (XY)MPa | 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)[1][3][9] | Not documented |
| Young's modulusMPa | 50 unfoamed and 40 foamed (colorFabb, ISO 527-1A)[1] | Not documented |
| 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][9] | Not documented |
| Flexural modulusMPa | 50 unfoamed and 40 foamed flexural modulus (colorFabb, ISO 178)[1] | Not documented |
| Brittleness1–5 | Very ductile — bends far before failing[1] | Very ductile — bends far before failing[2] |
| Hardness (scale-specific)Shore A / Shore D / Rockwell | Tunable 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][18] | 89 Shore A and 29 Shore D (BASF Ultrafuse TPS 90A, ISO 7619-1)[2] |
| Creep resistance / sustained load1–5 | 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[19] | Poor — no SEBS creep test; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[19] |
| Fatigue / repeated-flex resistance1–5 | Excellent — living hinges viable[14] | Excellent — living hinges viable[14] |
| Elasticity / flexibility1–5 | Rubbery / highly elastic[1] | Rubbery / highly elastic[2] |
| Wear resistance & friction | Not documented | Abrasion 111 mm³ (ISO 4649) — the poorest abrasion resistance in this group, well behind TPU[2] |
| Thermal Properties | ||
| Melting point / Vicat°C | Vicat softening drops as the foam expands: 83 printed at 240 °C to 53 at 270 °C (Siraya Tech, ISO 306); QIDI 70.4[3][9] | 242–249 melting (BASF Ultrafuse TPS 90A, ISO 11357-3)[2] |
| Annealing response | Foaming 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 |
| Environment & Chemical | ||
| UV resistance1–5 | Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[14] | Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[14] |
| Chemical resistance | Withstands industrial solvents and UV exposure (Polymaker)[14] | Withstands industrial solvents and UV exposure (Polymaker)[14] |
| Water / humidity resistance in service1–5 | Not documented | Excellent — essentially unaffected[2] |
| Food contact | Not food safe without specific certification (Polymaker)[14] | Not food safe without specific certification (Polymaker)[14] |
| Biodegradability / compostability | Not biodegradable[14] | Not biodegradable[14] |
| Recyclability | Not accepted in household plastic collection[14] | Not accepted in household plastic collection[14] |
| Health & Safety | ||
| Fume toxicity1–5 | Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[20] | Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[20] |
| Ventilation / filtration requirement1–5 | Open a window / occasional ventilation[20] | Open a window / occasional ventilation[20] |
| Post-Processing | ||
| Sanding & machining | Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[14] | Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[14] |
| Gluing & solvent welding | Cyanoacrylate bonds TPU; no common solvent welds it[14] | Cyanoacrylate bonds TPU; no common solvent welds it[14] |
| Vapour / chemical smoothing | No practical vapour smoothing[14] | No practical vapour smoothing[14] |
| Support material pairing | Polymaker warns TPU supports are often very difficult to remove[14] | Polymaker warns TPU supports are often very difficult to remove[14] |
| Dimensional accuracy & detail | 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[1][3] | Not documented |
| Solvents & Solubility | ||
| Soluble in | DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[21] | Toluene dissolves SEBS at room temperature — Kraton quotes solution viscosity at 25 % mass in toluene, 25 °C.[22] |
| Softened or crazed by | Toluene and benzene swell it up to +50 % by weight at 23 °C; the foamed wall soaks up esters and alcohols faster still.[21] | Soaking in hydrocarbon solvents and oils deteriorates it; short exposures are tolerated. Resists water, acids and bases.[22] |
| Solvent welding & smoothing agent | None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[21] | Toluene will weld it, though the joint stays soft; no workshop-safe agent, and vapour smoothing is not practical.[22] |
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
- varioShore TPU Technical Data Sheet colorFabb · 2026-08 · tds
- Ultrafuse TPS 90A Technical Data Sheet (Version 1.1, SEBS) BASF Forward AM · 2020-12 · tds
- Siraya Tech Flex TPU Air Technical Data Sheet Siraya Tech · 2026-08 · tds
- Roamr TPU Air HR 80A Technical Data Sheet Siraya Tech · 2026-08 · tds
- Recreus product catalogue Recreus · 2026-08 · vendor
- varioShore TPU Natural — product page colorFabb US · 2026-08 · vendor
- Siraya Tech Flex TPU Air Black Filament — lightweight foaming flexible, product page Siraya Tech · 2026-08 · vendor
- Roamr TPU Air HR 80A Filament — product page Siraya Tech · 2026-08 · vendor
- TPU-Aero Lightweight TPU Filament — product page with specification tables QIDI Tech · 2026-08 · vendor
- aeFlex TPU-Aero — active foaming low weight TPU, product page Phaetus · 2026-08 · vendor
- Phaetus aeWorthy TPU-Aero — reseller listing West3D · 2026-08 · vendor
- Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
- Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
- TPU — material basics Polymaker Wiki · 2026-08 · doc
- NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
- Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
- Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
- Roamr TPU Air HR 85A Technical Data Sheet Siraya Tech · 2026-08 · tds
- BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
- 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
- Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds
- KRATON polymers Grade Range — chemical resistance and toluene solution data Kraton Corporation · 2025-07 · tds