3D Printing Info

Filament comparison

PA6 vs PEI 9085

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

PA6 (Nylon 6) guidePEI (ULTEM 9085) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PA6 comparisonsMore PEI 9085 comparisons
PA6 vs PEI 9085 — documented properties and sources
PropertyPA6 (Nylon 6)PAPEI (ULTEM 9085)HIGHTEMP
Market snapshot
Listing priceUSD/kg; dated snapshots$104.00/kg median; $38.99–$136.00/kg across 3 dated product listings$309.80/kg median; $220.00–$392.00/kg across 6 dated product listings
Identity & Market
Base polymer / chemistryPolyamide 6, ring-opened from caprolactam — the most hygroscopic of the common nylons[1][2]Polyetherimide, ULTEM 9085 grade — the flame-retardant PEI used for aircraft interiors[3]
Densityg/cm³1.06 (ISO 1183, 3DXTech iOn PA6 alloy)[4]1.34 (ISO 1183, 3DXTech) against 1.27 specific gravity on moulded plaques (ASTM D792, Stratasys) — the two suppliers disagree[3][5]
Typical priceUSD/kg1 kg-equivalent spools span 39–136; the middle of the market is about 104, though budget unfilled PA6 has now arrived at 39[6][7]1 kg-equivalent spools cluster near 298[6][8][9][10]
Price range across brandsUSD/kg39–136 across brands; YXPOLYER 39, 3DXTech iOn Nylon 6 Alloy 104, WearX Nylon 6 136. Unfilled PA6 filament stays rare — most PA6 reaches the market glass- or carbon-filled[6][7]220-392 across brands and formats; 3DXTech ThermaX PEI 9085 220 at 2 kg, 3D4Makers 270 at 2 kg, Fiberlogy 298 at 500 g, Kimya 321 at 500 g, IEMAI 3D 385 at 1 kg, 3DXTech CarbonX PEI 9085+CF 392[6][8][9][10][11]
Market availability1–5Niche, a handful of specialist brands[6]Niche, a handful of specialist brands[6][8][9][10]
Spool sizes & diameters1.75 and 2.85 mm; 500 g and 750 g spools[6]1.75 and 2.85 mm; 250 g to 2 kg spools, plus Stratasys canisters[6][10][5]
Typical applicationsWear parts, bushings and gears where PA6's toughness and abrasion resistance matter more than dimensional stability[1]Aircraft interior parts and rail rolling stock, where the flame, smoke and toxicity rating is the requirement[3]
Printing Parameters
Nozzle temperature°C220–260 (Polymaker); 225–265 (Simplify3D)[1][12]Not documented
Bed temperature°C70–100 (Polymaker); 70–90 (Simplify3D)[1][12]130–140 (3DXTech)[3]
Enclosure / chamber requirement1–5Enclosure required (passive)[13][1]Actively heated chamber required[14][15]
Part cooling fanPart cooling fan not required (Simplify3D)[12]Not documented
Bed surface & adhesion aidPEI sheet with a glue stick, or a dedicated adhesive such as Magigoo[12][1]Not documented
Warping tendency1–5Not documentedSevere — heated chamber needed[14]
Bed-adhesion difficulty1–5Needs a specific surface plus adhesive[12][1]Not documented
Stringing / oozing tendency1–5Moderate — retraction tuning needed[1]Not documented
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; the filament must be kept dry throughout the print[1][16]Expert / industrial hardware only[14][15]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely for unfilled grades[1]Brass fine indefinitely for unfilled grades, but brass softens near these nozzle temperatures — hardened or plated hot ends are the norm[14]
Abrasiveness1–5Non-abrasive when unfilled[1]Non-abrasive when unfilled[3]
Nozzle clog risk1–5Very high — frequent jams without careful setup; wet nylon pops and cracks in the melt[17][16]Moderate — needs dry filament and a clean nozzle; 3DXTech lists no special nozzle concerns but a mandatory 120 °C pre-dry before every print[18]
Heat-creep / jam sensitivity1–5Moderate — good heatbreak cooling needed[12]Not documented
Hotend requirementMay require an all-metal hot end (Simplify3D)[12]Not documented
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Very high (>2 %) — Polymaker groups nylon with PVA as the most moisture-prone class, and its own PA6-based composites reach 2.35–3.33 % equilibrium[16][19]Not documented
Drying temperature & time100 °C for 8 h (Polymaker CoPA); storage below 20 % RH[13][20]Not documented
Symptoms when wetPopping and cracking during extrusion, then defects that Polymaker describes as very hard to diagnose[17]Not documented
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 %[13][17]No 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[18]
Storage requirementSealed below 20 % RH with desiccant; Polymaker says nylon often needs to stay in a dryer while printing[20][16]Not documented
Hydrolysis at melt temperaturePolymaker requires a 100 °C dry for 8 h and storage below 20 % RH; no molecular-weight loss figure is published, and the published wet data is conditioning rather than melt hydrolysis[13][20]Not documented
Mechanical Properties
Tensile strength (XY)MPa62 at break (printed XY, ISO 527, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned to 20 °C / 50 % RH gives 67.6 ultimate and 49.3 at yield printed XZ (ASTM D638)[4][21]63-77 at break (printed XZ, ASTM D638, Stratasys F900/F3300/Fortus 450mc, three tips and two colours); 54 (printed XY, ISO 527, 3DXTech)[5][3]
Young's modulusMPa2110 (printed XY, ISO 527, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 2232 printed XZ and 1817 ZX (ASTM D638)[4][21]2040-2540 (printed XZ, ASTM D638, Stratasys); 2050 (printed XY, ISO 527, 3DXTech)[5][3]
Elongation at break%9 at break (printed XY, ISO 527, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 38 printed XZ against 3.2 in ZX (ASTM D638)[4][21]5.4-9.1 at break (printed XZ, ASTM D638, Stratasys); 1.9-4.3 in ZX; 3DXTech quotes 3 (ISO 527)[5][3]
Flexural strengthMPa78 (printed XY, ISO 178, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 97.2 printed XZ and 82 ZX (ASTM D790)[4][21]104-116 at break (printed XZ, ASTM D790 Procedure A, Stratasys); 72-98 in ZX; 3DXTech quotes 90 (ISO 178)[5][3]
Flexural modulusMPa2200 (printed XY, ISO 178, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 2196 printed XZ and 1879 ZX (ASTM D790)[4][21]2400-2550 (printed XZ, ASTM D790, Stratasys F900 T16 and T16A) against 2120-2130 in ZX; 3DXTech quotes 2170 (ISO 178)[5][3]
Other impact dataIzod notched 106 J/m printed XZ against 43 J/m in ZX; unnotched 2873 against 192 J/m (Stratasys FDM Nylon 6, conditioned 20 °C / 50 % RH, ASTM D256 Method A) — a 15x anisotropy unnotched[21]Izod notched 88.5-140 J/m XZ against 37-80 J/m ZX; unnotched 647-2260 J/m XZ against 169-633 J/m ZX (printed, ASTM D256/D4812, Stratasys, across three printers and three tips)[5]
Layer adhesion / Z tensileMPa36.5 ultimate and 28.9 at yield printed ZX (Stratasys FDM Nylon 6, conditioned 20 °C / 50 % RH, ASTM D638)[21]39-63 at break (printed ZX, ASTM D638, Stratasys); the low end is the F900 T16 baseline, the high end the F3300 N500 hot end[5]
Brittleness1–5Tough — absorbs impact, yields before breaking[1]Brittle — snaps with little warning[3]
Hardness (scale-specific)Shore A / Shore D / RockwellShore D 86 and Rockwell 85 (108) — the source does not name the scales on extruded unfilled PA66 stock (ASTM D2240, D785); no figure is published for a PA6 filament[22]Rockwell M110 / R126 on extruded PEI stock (ASTM D785)[23]
Creep resistance / sustained load1–5Moderate[1]Excellent — holds load for years. Printed ZX coupons keep 87 % of room-temperature tensile strength at 104 °C and 70 % at 132 °C (ASTM D638); extruded PEI stock is rated 170 °C long-term service[5][23]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[1]Not documented
Elasticity / flexibility1–5Semi-flexible[17]Rigid[3]
Z strength as % of XY%54 (Stratasys FDM Nylon 6 conditioned, ZX against XZ ultimate tensile, ASTM D638); 59 on the yield figures[21]56-86 (Stratasys ZX against XZ tensile at break, ASTM D638, across F900/F3300/Fortus 450mc and T16/T20/T40A tips); 58 on the F900 T16 baseline[5]
Wear resistance & friction3DXTech sells a dedicated wear-resistant PA6 grade; abrasion resistance is the usual reason to choose PA6 over PA12[6]Not documented
Thermal Properties
HDT at 0.45 MPa°CNot documented158 (printed XY, ISO 75 at 0.45 MPa, 3DXTech) to 178 (printed XY 178.2 and ZX 178.4, ASTM D648 Method B at 66 psi, Stratasys); moulded 176.9[3][5]
HDT at 1.8 MPa°C93 (Stratasys FDM Nylon 6, conditioned, ASTM D648 at 264 psi)[21]170-173 (printed XY 170.2 and ZX 172.6, ASTM D648 Method B at 264 psi); moulded 172.9[5]
Glass transition (Tg)°C105 (DSC, 3DXTech iOn PA6 alloy)[4]177 (moulded plaque, ASTM D7426 inflection point, Stratasys); 186 (DSC, 3DXTech)[5][3][24]
Continuous service temperature°CNot documented170 long-term service on extruded PEI stock, converted from 338 °F; 200 short term[23]
Thermal expansion (CTE)µm/m·K81.0 on extruded unfilled PA66 stock (ASTM D696; source states 4.5e-5 in/in/°F); no figure is published for a PA6 filament, and PA6 and PA66 expand almost identically[22]44.9 (printed XY, -50 to 80 °C, ASTM E831), falling to 31.4 over 80-160 °C; ZX gives 44.5 over -50 to 60 °C. Black pigment raises it to 51.9[5]
Flammability / UL 94Flammable; no UL 94 rating published for the unfilled filament grades surveyed[4]UL 94 V-0 at 1.5 mm on the base resin. Printed parts are tested to 14 CFR 25.853, BSS 7238 and 7239 and AITM 2.0007B and 3.0005 covering 60 s and 12 s vertical burn, 15 s horizontal burn, smoke density, toxic gas emission and OSU heat release[3][5]
Environment & Chemical
UV resistance1–5Months outdoors before embrittlement — unstabilised polyamide yellows and chalks under UV[1]Good — years with some colour shift. 1000 h of QUV cycling to ASTM G154 left printed ZX coupons at 55.5 MPa yield against 56.0 unexposed, with elongation and modulus unchanged[5]
Chemical resistanceWithstands oils, fuels and alkalis — the usual reason to choose a polyamide[1]Not documented
Water / humidity resistance in service1–5Absorbs water, properties shift — a conditioned part is measurably softer and larger than the same part dry[17][13]Not documented
Food contactPolymaker notes medical-grade variants exist, but standard filament is not food-contact certified[1]Not documented
Biodegradability / compostabilityNot biodegradable[1]Not documented
RecyclabilityMechanically recyclable but not accepted in household plastic collection[1]Not documented
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[2]Moderate — 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[2]
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[2]Not documented
Ultrafine-particle emission rateparticles/min≈2 × 10⁸ median — low for ultrafine particles despite the highest VOC mass of any filament tested[2]Not documented
Hazardous species emittedCaprolactam, at up to 180 µg/min from nylon filament — the largest single-VOC emission rate measured in the study[2]Not documented
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[2]Ventilated room or enclosure recommended[2]
Post-Processing
Sanding & machiningSands poorly — the toughness makes it gum rather than powder[12]Not documented
Gluing & solvent weldingCyanoacrylate; no common solvent welds polyamide[12]Not documented
Vapour / chemical smoothingNo practical vapour smoothing[12]Not documented
Support material pairingPVA dissolves cleanly against nylon; Polymaker sells a break-away PolySupport for PA12[12]Not documented
Dimensional accuracy & detailParts grow as they absorb moisture after printing; Polymaker declines to publish a standard dimensional allowance because it depends on geometry and infill[17]Not documented
Solvents & Solubility
Soluble inDissolved at 23 °C by formic acid above ~50 %, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — laboratory reagents.[25]Chlorinated hydrocarbons — dichloromethane and chloroform — are solvents for polyetherimide. Laboratory reagents.[26][27]
Softened or crazed byZinc chloride solutions stress-crack it — 10 % marginal, 37 % not resistant; alcoholic calcium chloride dissolves it.[25]Acetone, MEK, benzene, toluene and butyl acetate craze or stress-crack it; alcohols, fuels and dilute acids do not.[27][26]
Solvent welding & smoothing agentNone — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[25]Dichloromethane is the only welding route, and it is a controlled carcinogen rather than a workshop material.[26][27]

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. 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
  3. ThermaX PEI 9085 Technical Data Sheet v4 3DXTech · 2026-08 · tds
  4. iOn PA6-based Nylon Alloy Technical Data Sheet v2.0 3DXTech · 2026-08 · tds
  5. ULTEM 9085 Resin — FDM Material Data Sheet Stratasys · 2026-04 · tds
  6. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  7. YXPOLYER PA6 Black 1 kg — product page YXPOLYER · 2026-08 · vendor
  8. Kimya PEI-9085 Natural 2.85 mm 500 g igo3d · 2026-08 · vendor
  9. Fiberlogy PEI 9085 Natural, 1.75 mm / 500 g 3DJAKE · 2026-08 · vendor
  10. 3D4Makers product catalogue 3D4Makers · 2026-08 · vendor
  11. IEMAI 3D PEI 9085 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  12. Nylon — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  13. PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
  14. Prusament PEI 1010 Technical Datasheet v1.0 Prusa Polymers · 2024-09 · tds
  15. Prusament PEI 1010 — material page Prusa Polymers · 2026-08 · doc
  16. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  17. Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
  18. THERMAX PEI 9085 — product page (print recommendations) 3DXTech · 2026-08 · doc
  19. Fiberon PA612-CF15 Technical Data Sheet V1.1 Polymaker · 2024-12 · tds
  20. PolyMide CoPA — Technical Data Sheet page Polymaker Wiki · 2026-08 · tds
  21. FDM Nylon 6 — data sheet (conditioned 20 °C / 50 % RH) Stratasys · 2017-11 · tds
  22. TECAMID 66 natural (PA66) — stock shape properties Ensinger · 2026-08 · tds
  23. TECAPEI natural (PEI) — stock shape properties Ensinger · 2026-08 · tds
  24. ThermaX PEI 1010 Technical Data Sheet v4 3DXTech · 2026-08 · tds
  25. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
  26. Radel PPSU, Veradel PESU, Acudel modified PPSU Design Guide — environmental stress cracking tables Solvay Specialty Polymers · 2026-08 · tds
  27. Chemical resistance — resistance of Ensinger plastics to chemicals (DIN 50 014, 23/50) Ensinger · 2026-08 · tds