3D Printing Info

Filament comparison

e-TPU vs HIPS

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

Foaming / expanded TPU (TPU Aero / TPU Air) guideHIPS guide

2 selected · all documented properties

Open these two in the interactive comparisonMore e-TPU comparisonsMore HIPS comparisons
e-TPU vs HIPS — documented properties and sources
PropertyFoaming / expanded TPU (TPU Aero / TPU Air)FLEXHIPSABS
Market snapshot
Listing priceUSD/kg; dated snapshots$52.05/kg median; $41.99–$85.29/kg across 6 dated product listings$29.99/kg median; $27.99–$32.00/kg across 3 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]High-impact polystyrene — polystyrene toughened with a butadiene rubber phase[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]1.04 (ISO 1183)[2]
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 spools cluster near 31[12][13]
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][14]28–32 across brands; YXPOLYER 28, Push Plastic 30, 3DXTech 32[13][12][15]
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]Available from several mainstream brands[12][13]
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; 1 and 3 kg spools[13][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]Break-away and d-limonene-soluble support for ABS and ASA, and a light model material in its own right[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]230–245 (Simplify3D)[16]
Bed temperature°C30–45 (QIDI and Siraya Tech), 35–50 (Roamr) — a hot bed makes the foamed part over-stick[4][5][10]100–115 (Simplify3D)[16]
Enclosure / chamber requirement1–5Open frame is fine — Roamr states no enclosure is required[1][5]Enclosure recommended[17]
Part cooling fan100 % — cooling sets the foamed structure quickly (Siraya Tech and Roamr)[4][5]Part cooling fan not required[16]
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[18][19][4]Glue stick, glass plate, Kapton tape or PET sheets[16]
Maximum volumetric flow (mm³/s; see test conditions)mm³/sUp to 12 (Siraya Tech, Flex TPU Air)[8]Not documented
Warping tendency1–5Not documentedModerate — needs adhesion aid or draught shield[17]
Bed-adhesion difficulty1–5Not documentedNeeds a specific surface plus adhesive[16]
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]Slight — HIPS oozes less than ABS[16][20]
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; both density and hardness follow nozzle temperature and flow[1]Intermediate — dry filament and a tuned profile[17]
Extruder requirementDirect drive; the base material is a 92A TPU[1][21]Not documented
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely — Roamr states plainly that no hardened nozzle is needed[22][5]Brass fine indefinitely[17]
Abrasiveness1–5Non-abrasive[22]Non-abrasive[17]
Nozzle clog risk1–5Not documentedLow — no special hot-end required, no drybox and no hardened nozzle, and 3DXTech states drying is not needed[16][23][3]
Heat-creep / jam sensitivity1–5Not documentedSlightly sensitive[16]
Hotend requirementNo special hot-end required, but a direct-drive extruder is (Simplify3D)[18]No special hot-end required[16]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate[24]Low (0.1–0.3 %) — Simplify3D lists water resistance as a headline property[16]
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[24][4]Bubbling and popping at the nozzle, stringing and a rough surface[24]
Effect of moisture on strengthPolymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[24]Polymaker rates ABS moderate-sensitivity and publishes no dry-versus-conditioned figures; absorbed water flashes to steam in the hotend and shows as bubbling and poor layer adhesion[24]
Storage requirementSealed with desiccant; often kept in a dryer during the print[24]Sealed with desiccant; less critical than for the polyamides[24]
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]40 at break (printed XY, ISO 527)[2]
Young's modulusMPa50 unfoamed and 40 foamed (colorFabb, ISO 527-1A)[1]1350 (printed XY, ISO 527) — the lowest modulus of the styrenics here[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]18 at break (printed XY, ISO 527)[2]
Flexural strengthMPaNot documented70 (printed XY, ISO 178)[2]
Flexural modulusMPa50 unfoamed and 40 foamed flexural modulus (colorFabb, ISO 178)[1]1600 (printed XY, ISO 178)[2]
Brittleness1–5Very ductile — bends far before failing[1]Tough — absorbs impact, yields before breaking[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][25]Not documented
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[26]Moderate — no printed-HIPS creep test found; Tg of 100 °C keeps room-temperature service far below softening[2][16]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[19]Moderate[2]
Elasticity / flexibility1–5Rubbery / highly elastic[1]Rigid[2]
Thermal Properties
Glass transition (Tg)°CNot documented100 (DSC)[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]Amorphous — no melting point[2]
Continuous service temperature°CNot documentedBounded by a glass transition of 100 °C; no loaded-bar service figure is published for HIPS[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
Flammability / UL 94Not documentedFlammable; no UL 94 rating published[2]
Environment & Chemical
UV resistance1–5Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[19]Months outdoors before embrittlement — polystyrene yellows and chalks under UV[27]
Chemical resistanceWithstands industrial solvents and UV exposure (Polymaker)[19]Dissolves completely in d-limonene — the basis of its use as a soluble support[3]
Food contactNot food safe without specific certification (Polymaker)[19]Not food safe[27]
Biodegradability / compostabilityNot biodegradable[19]Not biodegradable[27]
RecyclabilityNot accepted in household plastic collection[19]Not accepted in household plastic collection[27]
Electrical & ESD propertiesNot documentedSurface resistance above 10¹³ ohm/sq — insulating (ASTM D257)[2]
Health & Safety
Fume toxicity1–5Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[28]High — hazardous VOC such as styrene; enclosure and filtration needed[28]
VOC emission rateµg/minNot documented12–113 styrene, the range measured across ABS and the one HIPS filament tested[28]
Ultrafine-particle emission rateparticles/minNot documented≈4 × 10⁹ median for the HIPS filament tested, an order of magnitude below ABS but forty times PLA[28]
Hazardous species emittedNot documentedStyrene was the only dominant VOC identified for the HIPS filament tested[28]
Ventilation / filtration requirement1–5Open a window / occasional ventilation[28]Enclosure with carbon and HEPA filtration[28]
Post-Processing
Sanding & machiningDifficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[19]Sands and paints readily, like ABS[27]
Gluing & solvent weldingCyanoacrylate bonds TPU; no common solvent welds it[19]Solvent-welds with d-limonene, and with acetone via its polystyrene backbone[16][3]
Vapour / chemical smoothingNo practical vapour smoothing[19]d-limonene attacks the surface; acetone smoothing is far less effective than on ABS[3][16]
Support material pairingPolymaker warns TPU supports are often very difficult to remove[19]Used as the support material itself — dissolves in d-limonene, or breaks away from ABS and ASA[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]Not documented
Solvents & Solubility
Soluble inDMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[29]d-limonene, 12–24 h submerged with occasional agitation; acetone also dissolves it, and xylene does so at 23 °C.[30][31][32]
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.[29]Limonene also disrupts layer adhesion in some ABS and ASA grades, so an ABS model can flake apart in the same bath.[33]
Solvent welding & smoothing agentNone practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[29]Limonene welds and lightly etches it; acetone welds through the polystyrene backbone but smooths less well than ABS.[30][33]

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. 3DXMAX HIPS Technical Data Sheet 3DXTech · 2026-08 · tds
  3. 3DXMAX HIPS — product page 3DXTech · 2026-08 · vendor
  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. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  13. Push Plastic product catalogue Push Plastic · 2026-08 · vendor
  14. Phaetus aeWorthy TPU-Aero — reseller listing West3D · 2026-08 · vendor
  15. YXPOLYER HIPS product page YXPOLYER · 2026-08 · vendor
  16. HIPS — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  17. ABS / ASA / PC Usage Guide Bambu Lab Wiki · 2026-08 · doc
  18. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  19. TPU — material basics Polymaker Wiki · 2026-08 · doc
  20. ABS — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  21. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  22. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  23. Filament Material Guide Prusa Knowledge Base · 2026-08 · doc
  24. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  25. Roamr TPU Air HR 85A Technical Data Sheet Siraya Tech · 2026-08 · tds
  26. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  27. ABS — material basics Polymaker Wiki · 2026-08 · doc
  28. 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
  29. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds
  30. D-Limonene — FDM post-processing guide Filament2Print · 2026-08 · review
  31. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  32. US 5,278,282 Polymer recycling by selective dissolution — xylene dissolution temperatures Nauman & Lynch, Rensselaer Polytechnic Institute · 1994-01 · paper
  33. HIPS — Knowledge Base Prusa Research · 2026-08 · doc