3D Printing Info

Filament comparison

PSU vs TPU soft

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

PSU guideSoft TPU (below 85A) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PSU comparisonsMore TPU soft comparisons
PSU vs TPU soft — documented properties and sources
PropertyPSUHIGHTEMPSoft TPU (below 85A)FLEX
Market snapshot
Listing priceUSD/kg; dated snapshots$168.00/kg median; $168.00–$168.00/kg across 1 dated product listings$114.04/kg median; $109.80–$122.27/kg across 4 dated product listings
Identity & Market
Base polymer / chemistryPolysulfone — the lowest-temperature and cheapest of the sulfone family[1]Very soft thermoplastic elastomers below 85 Shore A. Fiberlogy's FiberFlex 30D measures 81 Shore A, the softest grade with a published datasheet found here[2]
Densityg/cm³1.24 (ISO 1183)[1]1.07 (Fiberlogy FiberFlex 30D, ISO 1183)[2]
Typical priceUSD/kg1 kg-equivalent spools cluster near 250[3]1 kg-equivalent spools cluster near 115[4][5][6]
Price range across brandsUSD/kg168-250 across formats; 250 g spool $42 (168/kg), 500 g $125 (250/kg) — 3DXTech is the only filament supplier found[3]110–122 at 1 kg-equivalent; Recreus 70A 110 and 60A 116 at 500 g, NinjaTek Edge 83A 112, NinjaTek Chinchilla 75A 122; the Recreus 3 kg spools fall to 70–73[4][6][5]
Market availability1–5Special order, 1–2 makers worldwide[3]Niche, a handful of specialist brands[2][7][4]
Spool sizes & diameters1.75 mm; 250 g and 500 g spools[3]1.75, 2.85 and 3 mm; 0.5, 0.85, 1, 2 and 3 kg spools[2][4][8][5]
Typical applicationsTransparent high-temperature housings, medical trays and hot-water fittings[1]Highly compliant seals, soft grips and prosthetic liners[2]
Printing Parameters
Bed temperature°C120–140 (3DXTech)[1]50–70 (Fiberlogy FiberFlex 30D)[2]
Enclosure / chamber requirement1–5Actively heated chamber required[9][10]Open frame is fine[2]
Bed surface & adhesion aidNot documentedPEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[11][12]
Overall printing difficulty1–5Expert / industrial hardware only[9][10]Expert / industrial hardware only — below 85 Shore A the filament buckles in almost any feed path that is not a short, constrained direct drive[8][12]
Extruder requirementNot documentedDirect drive only, with a constrained filament path; Bowden is not viable at this hardness[8][7]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely for unfilled grades, but brass softens near these nozzle temperatures — hardened or plated hot ends are the norm[9]Brass fine indefinitely[13]
Abrasiveness1–5Non-abrasive when unfilled[1]Non-abrasive[13]
Nozzle clog risk1–5Moderate — needs dry filament and a clean nozzle; 3DXTech lists no special nozzle concerns but a mandatory 120 °C pre-dry before every print[14]High — jams from moisture, heat creep or particles; below 85 Shore A the filament buckles and compresses, and Simplify3D warns that raised feed rates most likely end in a jam[11][12][15]
Heat-creep / jam sensitivity1–5Not documentedVery high — softens in the cold zone readily[12]
Hotend requirementNot documentedNo special hot-end required, but a direct-drive extruder is (Simplify3D)[11]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Not documentedModerate[15]
Equilibrium moisture content at ~50 % RH%0.30 in 24 h on extruded stock (ASTM D570)[16]Not documented
Symptoms when wetNot documentedBubbling and popping at the nozzle, stringing and a rough surface[15]
Effect of moisture on strengthNo dry-versus-conditioned figures are published; 3DXTech mandates a 120 °C, 4 h pre-dry before every print because trapped water flashes to steam at these nozzle temperatures[14]Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[15]
Storage requirementNot documentedSealed with desiccant; often kept in a dryer during the print[15]
Mechanical Properties
Tensile strength (XY)MPa52 (printed XY, ISO 527, 3DXTech); 81 at break on extruded stock (ASTM D638)[1][16]Not documented
Young's modulusMPa2100 (printed XY, ISO 527)[1]Not documented
Elongation at break%8 (printed XY, ISO 527) against 50 on extruded stock — nearly three times PPSU's printed 3 %[1][17][16]870 at break (Fiberlogy FiberFlex 30D, ISO 527) — the highest elongation in the dataset[2]
Flexural strengthMPa87 (printed XY, ISO 178)[1]Not documented
Flexural modulusMPa2050 (printed XY, ISO 178)[1]Not documented
Other impact dataIzod notched 69 J/m on extruded PSU stock, converted from 1.3 ft-lb/in (ASTM D256)[16]Not documented
Brittleness1–5Moderate[1]Very ductile — bends far before failing[2]
Hardness (scale-specific)Shore A / Shore D / RockwellRockwell M120 on extruded PSU stock (ASTM D785)[16]81 Shore A and 30 Shore D (Fiberlogy FiberFlex 30D, ISO 7619)[2]
Creep resistance / sustained load1–5Good. Ensinger lists high creep resistance as a headline property of extruded PSU stock, which is rated to 173 °C heat deflection at 1.8 MPa[16]Poor — no creep test at this hardness; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[18]
Fatigue / repeated-flex resistance1–5Not documentedExcellent — living hinges viable[12]
Elasticity / flexibility1–5Rigid[1]Rubbery / highly elastic[2]
Wear resistance & frictionNot documentedTear strength 95 kN/m (Fiberlogy FiberFlex 30D, ISO 34-1)[2]
Thermal Properties
HDT at 0.45 MPa°C172 (printed XY, ISO 75 at 0.45 MPa, 3DXTech); 181 on extruded stock, converted from 358 °F at 66 psi[1][16]Not documented
HDT at 1.8 MPa°C174 on extruded PSU stock, converted from 345 °F at 264 psi (ASTM D648)[16]Not documented
Glass transition (Tg)°C187 (DSC, 3DXTech) and 185 on extruded stock (ASTM D3418), against 230 for PPSU[1][17][16]Not documented
Melting point / Vicat°CNot documented170 melting (Fiberlogy FiberFlex 30D, DSC)[2]
Continuous service temperature°C141 long-term service on extruded PSU stock, converted from 285 °F[16]Not documented
Thermal expansion (CTE)µm/m·K55.8 (extruded PSU stock, ASTM D696; source states 3.1e-5 in/in/°F)[16]Not documented
Flammability / UL 94UL 94 V-0 on extruded PSU stock[16]Not documented
Environment & Chemical
UV resistance1–5Not documentedGood — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[12]
Chemical resistanceNot documentedWithstands industrial solvents and UV exposure (Polymaker)[12]
Food contactNot documentedNot food safe without specific certification (Polymaker)[12]
Biodegradability / compostabilityNot documentedNot biodegradable[12]
RecyclabilityNot documentedNot accepted in household plastic collection[12]
Electrical & ESD propertiesSurface resistance above 10¹³ ohm/sq — an insulator (IEC 60093)[1]Not documented
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised. None of these polymers was in the chamber study, and all are processed far above the temperatures it covered[19]Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[19]
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[19]Open a window / occasional ventilation[19]
Post-Processing
Sanding & machiningNot documentedDifficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[12]
Gluing & solvent weldingNot documentedCyanoacrylate bonds TPU; no common solvent welds it[12]
Vapour / chemical smoothingNot documentedNo practical vapour smoothing[12]
Support material pairingNot documentedPolymaker warns TPU supports are often very difficult to remove[12]
Solvents & Solubility
Soluble inChlorinated hydrocarbons — dichloromethane, chloroform — dissolve polysulfone; ketones and esters attack it as well.[20][21]DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[22]
Softened or crazed byAcetone, MEK, ethyl acetate, benzene and toluene craze or stress-crack it; methanol and isopropanol only marginally.[21][20]Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[22]
Solvent welding & smoothing agentDichloromethane cement welds PSU and NMP softens residual resin. Both are laboratory reagents.[20]None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[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

  1. ThermaX PSU Technical Data Sheet v3 3DXTech · 2026-08 · tds
  2. FiberFlex 30D Technical Data Sheet Fiberlogy · 2026-08 · tds
  3. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  4. Recreus product catalogue Recreus · 2026-08 · vendor
  5. Chinchilla product page — print guidelines, spool sizes and price NinjaTek · 2026-08 · vendor
  6. NinjaFlex Edge product page — durometer, print guidelines and price NinjaTek · 2026-08 · vendor
  7. Filaflex 82A product page (Shore hardness and elongation) Recreus · 2026-08 · vendor
  8. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  9. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  10. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  11. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  12. TPU — material basics Polymaker Wiki · 2026-08 · doc
  13. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  14. THERMAX PSU — product page (print recommendations) 3DXTech · 2026-08 · doc
  15. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  16. TECASON S natural (PSU) — stock shape properties Ensinger · 2026-08 · tds
  17. ThermaX PPSU Technical Data Sheet v3 3DXTech · 2026-08 · tds
  18. BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
  19. 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
  20. Radel PPSU, Veradel PESU, Acudel modified PPSU Design Guide — environmental stress cracking tables Solvay Specialty Polymers · 2026-08 · tds
  21. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds
  22. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds