3D Printing Info

Filament comparison

PA6/66 vs TPU 85A

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

PA66 (Nylon 66) guideTPU 85A guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PA6/66 comparisonsMore TPU 85A comparisons
PA6/66 vs TPU 85A — documented properties and sources
PropertyPA66 (Nylon 66)PATPU 85AFLEX
Market snapshot
Listing priceUSD/kg; dated snapshotsNot documented$89.89/kg median; $31.99–$106.05/kg across 6 dated product listings
Identity & Market
Base polymer / chemistryPolyamide 66, condensed from hexamethylenediamine and adipic acid; melts around 40 °C above PA6[1]Soft thermoplastic polyurethane at 82–85 Shore A[2][3][4]
Densityg/cm³1.14 (extruded unfilled PA66 stock)[5]1.11 (BASF Ultrafuse 85A) to 1.19 (NinjaFlex 85A), ISO 1183 / ASTM D792[4][2]
Typical priceUSD/kgNot documented1 kg-equivalent spools span 32–106; the middle of the market is about 90[6][7][2]
Price range across brandsUSD/kgNot documented32–106 across brands; Siraya Tech Flex TPU 85A 32 at 1 kg, add:north TPU Pro Matte 85A 72, Recreus Filaflex 82A 90 at 500 g, Proto-pasta Clear Flexible TPU 90, 3DXTech 3DXFLEX 85A 96, NinjaTek NinjaFlex 106[8][6][7][9][2]
Market availability1–5Special order, 1–2 makers worldwide — no unfilled PA66 filament appeared in any catalogue searched, and the 3DXTech nylon range offers PA6, PA12 and a 6/66 copolymer but no straight PA66[6][10]Available from several mainstream brands[6][8]
Spool sizes & diametersNot documented1.75, 2.85 and 3 mm; 0.5, 1 and 2 kg spools[6][8][2]
Typical applicationsNot documentedSoft-touch grips, seals, wearables and anything that must compress and rebound[2][3]
Printing Parameters
Nozzle temperature°CNot documented200–220 (BASF Ultrafuse 85A, 210 typical)[4]
Bed temperature°CNot documented40 (BASF Ultrafuse 85A)[4]
Enclosure / chamber requirement1–5Enclosure required (passive)[1]Open frame is fine[4]
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]
Maximum volumetric flow (mm³/s; see test conditions)mm³/sNot documented1.2–3.2 at the 15–40 mm/s BASF specifies on a 0.4 mm nozzle at 0.2 mm layer[4]
Warping tendency1–5Not documentedNone[4]
Bed-adhesion difficulty1–5Not documentedSticks to anything — Recreus states its 82A grade has excellent bed adhesion without a heated bed or additives[3]
Stringing / oozing tendency1–5Not documentedHigh — drying plus tuning needed[13][12]
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning[1]Advanced — enclosure, hardware upgrades, tuning; at this hardness the filament will not push through a Bowden tube[2][3]
Extruder requirementNot documentedDirect drive only. NinjaTek calls its 85A grade ideal for direct-drive extruders and Recreus specifies direct-drive printers for 82A; BASF caps print speed at 15–40 mm/s with a nozzle of 0.4 mm or larger[2][3][4]
Hardware Wear & Reliability
Nozzle hardness required1–4Not documentedBrass fine indefinitely[14]
Abrasiveness1–5Not documentedNon-abrasive[14]
Nozzle clog risk1–5Very high — frequent jams without careful setup[15][13]High — jams from moisture, heat creep or particles[13][12]
Heat-creep / jam sensitivity1–5Not documentedVery high — softens in the cold zone readily; soft filament buckles between the drive gear and the melt zone[12][2]
Hotend requirementNot documentedNo special hot-end required, but a direct-drive extruder is (Simplify3D)[11]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Very high (>2 %)[13]Moderate — NinjaTek measures 0.22 % in 24 h (ASTM D570) and BASF specifies a 70 °C dry for at least 5 h[2][4]
Equilibrium moisture content at ~50 % RH%8.5 at saturation on extruded PA66 stock (ASTM D570) — the highest uptake of any polymer in this dataset[5]0.22 after 24 h water immersion (NinjaFlex 85A, ASTM D570) — an immersion figure, not an equilibrium moisture content at 50 % RH[2]
Drying temperature & timeNot documented70 °C for at least 5 h in a hot-air dryer or vacuum oven (BASF)[4]
Symptoms when wetNot documentedBubbling and popping at the nozzle, stringing and a rough surface[13]
Effect of moisture on strengthMeasured dry against wet on printed specimens at 6.16 % moisture (Polymaker CoPA): tensile 78.0 → 34.3 MPa, Young's modulus 2703 → 724 MPa, flexural strength 109.8 → 22.6 MPa, while notched Charpy rises 6.9 → 27.7 kJ/m² and elongation 12.7 → 13.2 %[16][15]Polymaker groups TPU with the highly hygroscopic materials; wet TPU prints with poor layer adhesion and weak, brittle layers[13]
Storage requirementNot documentedSealed with desiccant; often kept in a dryer during the print[13]
Mechanical Properties
Tensile strength (XY)MPa82.7 at yield and 84.8 at break on extruded PA66 stock (ASTM D638; converted from 12,000 and 12,300 psi) — no printed figure exists because no unfilled PA66 filament was found[5]26 ultimate (NinjaFlex 85A, ASTM D638)[2]
Young's modulusMPa2413 on extruded PA66 stock (ASTM D638; converted from 350,000 psi)[5]12 (NinjaFlex 85A, ASTM D638) — two orders of magnitude below any rigid filament; NinjaTek's 95A Cheetah reaches 26 by the same method[2][17]
Elongation at break%50 at break on extruded PA66 stock (ASTM D638)[5]650 at break (Filaflex 82A) and 660 (NinjaFlex 85A); BASF measures 600 in XY and 320 in ZX[3][2][4]
Flexural strengthMPa113.8 on extruded PA66 stock (ASTM D790; converted from 16,500 psi)[5]Not documented
Flexural modulusMPa3034 on extruded PA66 stock (ASTM D790; converted from 440,000 psi)[5]Not documented
Other impact dataIzod 53 J/m on extruded PA66 stock, converted from 1.0 ft-lb/in (ASTM D256)[5]Not documented
Brittleness1–5Not documentedVery ductile — bends far before failing[2]
Hardness (scale-specific)Shore A / Shore D / RockwellShore D 86 and Rockwell 85 (108) — the source does not name the scales on extruded PA66 stock (ASTM D2240, D785)[5]29 Shore D / 85 Shore A (BASF Ultrafuse 85A, ISO 7619-1); 85 Shore A (NinjaFlex, ASTM D2240); 82 A nominal for Filaflex[2][4][3]
Creep resistance / sustained load1–5Not documentedPoor — no 85A creep test; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg, and softer grades creep more[18]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[1]Excellent — living hinges viable[12]
Elasticity / flexibility1–5Semi-flexible[15]Rubbery / highly elastic[2][3]
Z strength as % of XY%Not documented53 — BASF measures 320 % elongation at break in ZX against 600 % in XY[4]
Wear resistance & frictionWear factor 200e-10 in3*min/(ft*lb*h) on extruded PA66 stock (ASTM D3702); Ensinger lists very good slide and wear properties[5]Abrasion 0.08 g mass loss over 10 000 cycles (NinjaFlex, ASTM D4060); 82 mm³ (BASF, ISO 4649)[2][4]
Thermal Properties
HDT at 0.45 MPa°C232 on extruded PA66 stock (ASTM D648 at 66 psi; converted from 450 °F)[5]Not documented
HDT at 1.8 MPa°C90 on extruded PA66 stock (ASTM D648 at 264 psi; converted from 194 °F) — the gap to the 0.45 MPa figure is the widest in the dataset[5]Not documented
Melting point / Vicat°C255 melting on extruded PA66 stock (ASTM D2133; converted from 491 °F)[5]216 melting (NinjaFlex 85A, DSC)[2]
Continuous service temperature°C85 long term and 149 short term on extruded PA66 stock (converted from 185 °F and 300 °F)[5]Not documented
Thermal expansion (CTE)µm/m·K81.0 (extruded PA66 stock, ASTM D696; source states 4.5e-5 in/in/°F)[5]Not documented
Flammability / UL 94UL 94 V-2 on extruded PA66 stock[5]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 propertiesVolume resistance 1e15 ohm-cm and dielectric constant 4 on extruded PA66 stock (ASTM D257, D150)[5]Not documented
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[19]Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[19]
VOC emission rateµg/minUp to 180 caprolactam, the dominant VOC from nylon; total VOC reached nearly 200 µg/min, the highest of the nine filaments tested[19]Not documented
Ultrafine-particle emission rateparticles/min≈2 × 10⁸ median — low for ultrafine particles despite the highest VOC mass of any filament tested[19]Not documented
Hazardous species emittedCaprolactam, at up to 180 µg/min from nylon filament — the largest single-VOC emission rate measured in the study[19]Not documented
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 inDissolved at 23 °C by formic acid above ~80 %, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — laboratory reagents.[20]DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[21]
Softened or crazed byZinc chloride solutions stress-crack it — 10 % marginal, 37 % not resistant; alcoholic calcium chloride dissolves it.[20]Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[21]
Solvent welding & smoothing agentNone — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[20]None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[21]

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. PA (Nylon) — material basics Polymaker Wiki · 2026-08 · doc
  2. NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
  3. Filaflex 82A product page (Shore hardness and elongation) Recreus · 2026-08 · vendor
  4. Ultrafuse TPU 85A Technical Data Sheet (Version 3.0) BASF Forward AM · 2022-08 · tds
  5. TECAMID 66 natural (PA66) — stock shape properties Ensinger · 2026-08 · tds
  6. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  7. Siraya Tech Flex TPU 85A Filament — product page Siraya Tech · 2026-08 · vendor
  8. Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
  9. add:north TPU Pro Matte 85A product page add:north · 2026-08 · vendor
  10. Polymaker product catalogue Polymaker · 2026-08 · vendor
  11. Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  12. TPU — material basics Polymaker Wiki · 2026-08 · doc
  13. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  14. Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
  15. Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
  16. PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
  17. NinjaTek technical specs comparison chart (Cheetah, NinjaFlex, Armadillo, Alloy 910, Nylon 645) NinjaTek · 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. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
  21. Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds