3D Printing Info

Filament comparison

e-TPU vs PP-CF

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

Foaming / expanded TPU (TPU Aero / TPU Air) guideCarbon-fibre PP (PP-CF) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore e-TPU comparisonsMore PP-CF comparisons
e-TPU vs PP-CF — documented properties and sources
PropertyFoaming / expanded TPU (TPU Aero / TPU Air)FLEXCarbon-fibre PP (PP-CF)POLYOLEFIN
Market snapshot
Listing priceUSD/kg; dated snapshots$52.05/kg median; $41.99–$85.29/kg across 6 dated product listings$107.68/kg median; $57.13–$120.00/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]Polypropylene reinforced with chopped carbon fibre[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]0.91 (Prusament PP Carbon Fiber, 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-equivalent spools span 57–138; the middle of the market is about 108[12][13][14]
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][15]57–138 across brands; Reli3D 57 at 700 g on Amazon, Prusament 108 direct from Prusa and 138 at Printed Solid, 3DXTech CarbonX PP+CF 120[12][16][13][14]
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[13][16]
Spool sizes & diameters1.75 mm; 0.7, 0.75, 0.8, 1 and 3 kg spools[1][6][8][9][11]1.75 mm; 0.65 kg spools[16][13]
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]Lightweight chemical-resistant parts, automotive clips and ducting that must survive above 150 °C[17]
Diameter tolerance± mm0.03 (Siraya Tech and Roamr, 1.75 mm)[4][5]±0.04 (Prusament)[2]
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]270 ± 10 (Prusament)[2]
Bed temperature°C30–45 (QIDI and Siraya Tech), 35–50 (Roamr) — a hot bed makes the foamed part over-stick[4][5][10]85 ± 10 (Prusament)[2]
Enclosure / chamber requirement1–5Open frame is fine — Roamr states no enclosure is required[1][5]Enclosure recommended — Simplify3D lists an enclosure as a hardware requirement and Polymaker advises one below 70 °C ambient to stop warping and cracking[18][19]
Part cooling fan100 % — cooling sets the foamed structure quickly (Siraya Tech and Roamr)[4][5]Off — Prusa runs 0 % except 100 % on bridges[2]
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[20][21][4]Not documented
Maximum volumetric flow (mm³/s; see test conditions)mm³/sUp to 12 (Siraya Tech, Flex TPU Air)[8]3.2 at Prusa's 40 mm/s cap on a 0.4 mm nozzle at 0.2 mm layer[2][22]
Warping tendency1–5Not documentedHigh — enclosure needed for reliable large parts; Prusa recommends a brim[2]
Bed-adhesion difficulty1–5Not documentedVery difficult — special plates or slurry required[2]
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]Advanced — enclosure, hardware upgrades, tuning; hardened nozzle mandatory[2]
Extruder requirementDirect drive; the base material is a 92A TPU[1][23]Prusa states a hardened nozzle is necessary and recommends a brim[2]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely — Roamr states plainly that no hardened nozzle is needed[24][5]Hardened steel required — Prusa states plainly that a hardened nozzle is necessary[2]
Abrasiveness1–5Non-abrasive[24]Highly abrasive — standard CF composite[2]
Nozzle clog risk1–5Not documentedModerate — needs dry filament and a clean nozzle; 3DXTech specifies a hardened 0.4 mm minimum nozzle and 0.25 mm layers or higher, and Prusa lists composites as a higher clogging risk[3][25]
Hotend requirementNo special hot-end required, but a direct-drive extruder is (Simplify3D)[20]Not documented
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate[26]Negligible (<0.1 % EMC) — Prusa measures 0.03 % in 24 h and 0.04 % in 7 days on its PP composite, the lowest figures it publishes for any filament[2]
Equilibrium moisture content at ~50 % RH%1.09 water absorption (QIDI TPU-Aero; the standard is not stated)[10]0.03 after 24 h and 0.04 after 7 days at 24 °C / 22 % RH (Prusa Polymers)[2]
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[26][4]Not documented
Effect of moisture on strengthPolymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[26]Not applicable in practice at 0.04 % equilibrium uptake[2]
Storage requirementSealed with desiccant; often kept in a dryer during the print[26]No special storage needed[2]
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]21 ± 0.4 filament tensile yield (Prusament, ISO 527)[2]
Young's modulusMPa50 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][4][5][10]Not documented
Flexural modulusMPa50 unfoamed and 40 foamed flexural modulus (colorFabb, ISO 178)[1]Not documented
Charpy impact, notchedkJ/m²Not documented14.5 ± 0.3 printed horizontal and 10.5 ± 0.8 printed vertical XZ (ISO 179-1, notched)[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][27]Rockwell R102 (and M95) on extruded unfilled PP stock (ASTM D785); no figure is published for a carbon-fibre PP filament[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]Not documented
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[21]Good[30]
Elasticity / flexibility1–5Rubbery / highly elastic[1]Slightly flexible in thin sections[2]
Thermal Properties
HDT at 0.45 MPa°CNot documented158 (ISO 75, 0.45 MPa) — far above unfilled PP and above most engineering filaments[2]
HDT at 1.8 MPa°CNot documented115 (ISO 75, 1.8 MPa)[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]Not documented
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
Environment & Chemical
UV resistance1–5Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[21]Not documented
Chemical resistanceWithstands industrial solvents and UV exposure (Polymaker)[21]Excellent against acids, alkalis and most solvents[19]
Water / humidity resistance in service1–5Not documentedExcellent — essentially unaffected[2]
Food contactNot food safe without specific certification (Polymaker)[21]Not documented
Biodegradability / compostabilityNot biodegradable[21]Not documented
RecyclabilityNot accepted in household plastic collection[21]Not documented
Health & Safety
Fume toxicity1–5Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[31]Low hazard — minimal VOC and particle emission. Inferred: no polyolefin was among the nine filaments in the Azimi chamber study, so this is a family-level judgement rather than a measurement[31]
Ventilation / filtration requirement1–5Open a window / occasional ventilation[31]Open a window / occasional ventilation. Inferred — no polyolefin was measured in the chamber study[31]
Dust & fibre handling hazardNot documentedCarbon fibre is bound in the matrix; sanding dust should not be inhaled[2]
Post-Processing
Sanding & machiningDifficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[21]Not documented
Gluing & solvent weldingCyanoacrylate bonds TPU; no common solvent welds it[21]Not documented
Vapour / chemical smoothingNo practical vapour smoothing[21]Not documented
Support material pairingPolymaker warns TPU supports are often very difficult to remove[21]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.[32]None at room temperature; chloroform dissolves the matrix at 60 °C and xylene at about 118 °C, leaving the fibre.[33][34]
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]Xylene, decalin, CCl4 and chlorobenzene are heavily absorbed at 20 °C; oleum, chlorosulphonic acid and bromine destroy it.[33]
Solvent welding & smoothing agentNone practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[32]None — nothing softens PP at room temperature, so joints have to be welded thermally rather than chemically.[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. Prusament PP Carbon Fiber Technical Datasheet v1.0 Prusa Polymers · 2024-11 · tds
  3. CarbonX PP+CF — 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. Prusament PP Carbon Fiber Black 650g — product page Prusa Research · 2026-08 · vendor
  13. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  14. Reli3D Carbon Fiber PP Filament 1.75 mm 700 g Black — Amazon listing Amazon.com · 2026-08 · vendor
  15. Phaetus aeWorthy TPU-Aero — reseller listing West3D · 2026-08 · vendor
  16. Printed Solid product catalogue Printed Solid · 2026-08 · vendor
  17. Prusament PP Carbon Fiber — material page Prusa Polymers · 2026-08 · doc
  18. Polypropylene — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  19. PP — material basics Polymaker Wiki · 2026-08 · doc
  20. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  21. TPU — material basics Polymaker Wiki · 2026-08 · doc
  22. Max volumetric speed Prusa Knowledge Base · 2026-08 · doc
  23. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  24. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  25. Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
  26. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  27. Roamr TPU Air HR 85A Technical Data Sheet Siraya Tech · 2026-08 · tds
  28. TECAFINE PP natural — 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. Centaur PP Technical Data Sheet Formfutura · 2026-08 · tds
  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. Pro-fax and Moplen polypropylene — Chemical Resistance Guide (20, 60 and 100 °C) LyondellBasell · 2026-08 · tds
  34. US 5,278,282 Polymer recycling by selective dissolution — xylene dissolution temperatures Nauman & Lynch, Rensselaer Polytechnic Institute · 1994-01 · paper