3D Printing Info

Filament comparison

PA6/66 vs rPETG

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

PA66 (Nylon 66) guideRecycled PETG (rPETG) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PA6/66 comparisonsMore rPETG comparisons
PA6/66 vs rPETG — documented properties and sources
PropertyPA66 (Nylon 66)PARecycled PETG (rPETG)PETG
Market snapshot
Listing priceUSD/kg; dated snapshotsNot documented$28.99/kg median; $17.24–$39.98/kg across 4 dated product listings
Identity & Market
Base polymer / chemistryPolyamide 66, condensed from hexamethylenediamine and adipic acid; melts around 40 °C above PA6[1]PETG regranulated from recycled polyester waste; Polymaker's Fiberon PETG-rCF08 adds 8 wt% recycled carbon fibre[2][3][4]
Densityg/cm³1.14 (extruded unfilled PA66 stock)[5]1.27 (Prusament) and 1.30 (Fiberon PETG-rCF08), ISO 1183[2][4]
Typical priceUSD/kgNot documented1 kg spools cluster near 29[6][7][8][9]
Price range across brandsUSD/kgNot documented17–40 across brands; Filament PM RePETG 17, 3DXTech ECOMAX 26, GreenGate3D 32, Fiberon rCF08 40[6][7][8][9]
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][8]Available from several mainstream brands[6][7][8]
Spool sizes & diametersNot documented1.75 and 2.85 mm; 0.5, 1 and 3 kg spools[8][7]
Diameter tolerance± mmNot documented±0.05 (Prusament PETG Recycled), against ±0.02 for virgin Prusament PETG[2][10]
Printing Parameters
Nozzle temperature°CNot documented250 ± 10 (Prusament); 230–255 (Spectrum)[2][3]
Bed temperature°CNot documented80 ± 10 (Prusament); 60–80 (Spectrum)[2][3]
Enclosure / chamber requirement1–5Enclosure required (passive)[1]Open frame is fine — Spectrum states a closed chamber is not necessary[3]
Part cooling fanNot documented50 % (Prusament); up to 100 % (Spectrum)[2][3]
Bed surface & adhesion aidNot documentedTextured PEI, satin or powder-coated sheets; on smooth PEI a glue stick acts as a release agent[10][11]
Bed-adhesion difficulty1–5Not documentedNeeds the right surface or a thin adhesive — the problem is releasing the part, not sticking it[10][11]
Stringing / oozing tendency1–5Not documentedModerate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[11]
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning[1]Easy — minor profile tuning; Spectrum describes printing as similar to standard PETG[3]
Hardware Wear & Reliability
Nozzle hardness required1–4Not documentedBrass fine indefinitely[2]
Nozzle clog risk1–5Very high — frequent jams without careful setup[12][13]Low — recycled PETG prints on the same hardware as virgin PETG: no special hot-end, no drybox and no hardened nozzle[14][15]
Heat-creep / jam sensitivity1–5Not documentedSlightly sensitive[14]
Hotend requirementNot documentedNo special hot-end required[14]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Very high (>2 %)[13]Moderate (0.3–0.8 %) — recycled PETG shares the virgin matrix, which reaches 0.40 % saturated at 25 °C / 55 % RH[10]
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]0.07 after 24 h and 0.10 after 7 days at 24 °C / 22 % RH (Prusa Polymers)[2]
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][12]Polymaker groups PETG with nylon, PVA and TPU as highly hygroscopic; no dry-versus-conditioned strength figures are published for this grade and the loss shows as bubbling and poor layer adhesion[13]
Storage requirementNot documentedSealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[13][11]
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]43 ± 1.8 printed horizontal at yield, ISO 527-1 (Prusament), against 47 ± 2 for virgin Prusament PETG; Spectrum quotes 52 at yield on moulded specimens[2][10][3]
Young's modulusMPa2413 on extruded PA66 stock (ASTM D638; converted from 350,000 psi)[5]1500 printed horizontal, 1600 printed vertical (Prusament, ISO 527-1) — the same as virgin Prusament PETG[2][10]
Elongation at break%50 at break on extruded PA66 stock (ASTM D638)[5]4.5 at yield printed (Prusament); Spectrum quotes 400 at break on moulded specimens[2][3]
Flexural strengthMPa113.8 on extruded PA66 stock (ASTM D790; converted from 16,500 psi)[5]63 ± 1 printed horizontal, ISO 178 (Prusament), against 66 ± 2 for virgin Prusament PETG[2][10]
Flexural modulusMPa3034 on extruded PA66 stock (ASTM D790; converted from 440,000 psi)[5]1800 printed horizontal, ISO 178 (Prusament)[2]
Charpy impact, notchedkJ/m²Not documented12 ± 1 printed horizontal and 15 ± 3 printed vertical, ISO 179-1 notched (Prusament)[2]
Other impact dataIzod 53 J/m on extruded PA66 stock, converted from 1.0 ft-lb/in (ASTM D256)[5]Charpy unnotched 25 ± 3 printed horizontal and 38 ± 11 printed vertical (Prusament, ISO 179-1)[2]
Layer adhesion / Z tensileMPaNot documented15 ± 5 (Prusa Polymers interlayer adhesion test), against 18 ± 4 for virgin Prusament PETG[2][10]
Brittleness1–5Not documentedModerate[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]74 Shore D (Prusa Polymers method) — the same as virgin Prusament PETG[2][10]
Creep resistance / sustained load1–5Not documentedBelow average — no recycled-grade creep test; virgin PETG sagged from 12 to 17.1–20.4 mm over 5 days at 1.25 kg[17][18][19][20]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[1]Moderate — no recycled-grade S-N curve; virgin printed PETG ran 79 000–193 000 cycles at 30 % of tensile strength[21]
Elasticity / flexibility1–5Semi-flexible[12]Slightly flexible in thin sections[2]
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]Not documented
Thermal Properties
HDT at 0.45 MPa°C232 on extruded PA66 stock (ASTM D648 at 66 psi; converted from 450 °F)[5]68 (ISO 75, 0.45 MPa) — the same as virgin Prusament PETG; Spectrum quotes 70[2][10][3]
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]68 (ISO 75, 1.8 MPa)[2]
Melting point / Vicat°C255 melting on extruded PA66 stock (ASTM D2133; converted from 491 °F)[5]Not documented
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]Flammable; no UL 94 rating published for standard grades[22]
Environment & Chemical
Chemical resistanceNot documentedWithstands acids, alkalis, oils and UV exposure[11]
Food contactNot documentedNot certified for food contact as filament[11]
Biodegradability / compostabilityNot documentedNot biodegradable[11]
RecyclabilityNot documentedThe feedstock itself — Spectrum describes collecting, shredding and re-homogenising PETG waste[3]
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[23]Moderate — measurable VOCs and UFPs, ventilation advised[23]
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[23]Not documented
Ultrafine-particle emission rateparticles/min≈2 × 10⁸ median — low for ultrafine particles despite the highest VOC mass of any filament tested[23]Not documented
Hazardous species emittedCaprolactam, at up to 180 µg/min from nylon filament — the largest single-VOC emission rate measured in the study[23]Not documented
Ventilation / filtration requirement1–5Ventilated room or enclosure recommended[23]Open a window / occasional ventilation[23]
Post-Processing
Sanding & machiningNot documentedSands poorly — the material is tough and gums rather than powders[14]
Gluing & solvent weldingNot documentedCyanoacrylate; no common solvent welds PETG cleanly[14]
Vapour / chemical smoothingNot documentedNo practical vapour smoothing[14]
Support material pairingNot documentedPrints its own supports; Polymaker rates PolyDissolve S1 for PETG[14]
Solvents & Solubility
Soluble inDissolved at 23 °C by formic acid above ~80 %, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — laboratory reagents.[24]No common workshop solvent; 1,2-dichloroethane destroys it inside a week and dichloromethane — a carcinogen — dissolves the surface.[25][26]
Softened or crazed byZinc chloride solutions stress-crack it — 10 % marginal, 37 % not resistant; alcoholic calcium chloride dissolves it.[24]Acetone (+16 % weight over 1 year at 23 °C), ethyl acetate, toluene and DMF swell and soften it; methanol crazes it.[25]
Solvent welding & smoothing agentNone — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[24]Dichloromethane brushed on is the only agent that smooths PETG — a controlled carcinogen, not workshop stock.[26]

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. Prusament PETG Recycled Technical Datasheet Prusa Polymers · 2026-08 · tds
  3. Spectrum r-PETG Technical Data Sheet Spectrum Filaments · 2026-08 · tds
  4. Fiberon PETG-rCF08 Technical Data Sheet V1.0 Polymaker · 2026-08 · tds
  5. TECAMID 66 natural (PA66) — stock shape properties Ensinger · 2026-08 · tds
  6. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  7. GreenGate3D Recycled PET-G — product data GreenGate3D · 2026-08 · vendor
  8. Polymaker product catalogue Polymaker · 2026-08 · vendor
  9. Filament PM RePETG technical data sheet Filament PM (Plasty Mladec) · 2026-08 · tds
  10. Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  11. PETG — material basics Polymaker Wiki · 2026-08 · doc
  12. Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
  13. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  14. PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  15. Filament Material Guide Prusa Knowledge Base · 2026-08 · doc
  16. PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
  17. PCTG vs PETG comparison — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  18. Extrudr PETG vs PCTG vs XPETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  19. Prusament PETG-CF vs PETG V0 vs PETG — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  20. BambuLab PETG Basic vs Translucent vs PETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  21. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  22. Prusament PETG V0 Technical Datasheet Prusa Polymers · 2026-08 · tds
  23. 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
  24. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
  25. Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
  26. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc