3D Printing Info

Filament comparison

PA6 vs PPA

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

PA6 (Nylon 6) guidePPA (polyphthalamide) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PA6 comparisonsMore PPA comparisons
PA6 vs PPA — documented properties and sources
PropertyPA6 (Nylon 6)PAPPA (polyphthalamide)PA
Market snapshot
Listing priceUSD/kg; dated snapshots$104.00/kg median; $38.99–$136.00/kg across 3 dated product listings$45.49/kg median; $45.49–$45.49/kg across 1 dated product listings
Identity & Market
Base polymer / chemistryPolyamide 6, ring-opened from caprolactam — the most hygroscopic of the common nylons[1][2]Polyphthalamide — a semi-aromatic polyamide in which aromatic diacid units replace part of the aliphatic backbone; Raise3D and Bambu Lab both label it high-temperature nylon[3][4]
Densityg/cm³1.06 (ISO 1183, 3DXTech iOn PA6 alloy)[5]1.21 (ISO 1183, Siraya Tech Fibreheart PPA)[6]
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[7][8]One 1 kg listing on the market, at 45[9]
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[7][8]45 for the only unfilled PPA filament found — Siraya Tech Fibreheart PPA at 1 kg; every other PPA in retail is carbon- or glass-filled[9]
Market availability1–5Niche, a handful of specialist brands[7]Special order, 1–2 makers worldwide — Siraya Tech is the only brand found selling unfilled PPA filament[9]
Spool sizes & diameters1.75 and 2.85 mm; 500 g and 750 g spools[7]1.75 mm, 1 kg[9]
Typical applicationsWear parts, bushings and gears where PA6's toughness and abrasion resistance matter more than dimensional stability[1]Gears, bearings and tooling that must hold load above the reach of PA6 or PA12, and parts exposed to fuels and industrial chemicals[6]
Printing Parameters
Nozzle temperature°C220–260 (Polymaker); 225–265 (Simplify3D)[1][10]280–300 (Siraya Tech)[6]
Bed temperature°C70–100 (Polymaker); 70–90 (Simplify3D)[1][10]70–80 (Siraya Tech)[6]
Enclosure / chamber requirement1–5Enclosure required (passive)[11][1]Enclosure recommended — Siraya Tech advises an enclosure to hold temperature and limit warping on larger prints[6]
Part cooling fanPart cooling fan not required (Simplify3D)[10]20–60 % (Siraya Tech)[6]
Bed surface & adhesion aidPEI sheet with a glue stick, or a dedicated adhesive such as Magigoo[10][1]PEI sheet with a glue stick, or a PVP glue coating[6]
Bed-adhesion difficulty1–5Needs a specific surface plus adhesive[10][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][12]Advanced — enclosure, hardware upgrades, tuning; needs a 300 °C-class hot end and a dry spool[6]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely for unfilled grades[1]Brass fine indefinitely — Siraya Tech states a hardened steel nozzle is not needed for the unfilled grade[6]
Abrasiveness1–5Non-abrasive when unfilled[1]Non-abrasive when unfilled[6]
Nozzle clog risk1–5Very high — frequent jams without careful setup; wet nylon pops and cracks in the melt[13][12]Moderate — needs dry filament and a clean nozzle; Siraya Tech tells users to dry only when moisture symptoms appear, rather than before every print[6]
Heat-creep / jam sensitivity1–5Moderate — good heatbreak cooling needed[10]Not documented
Hotend requirementMay require an all-metal hot end (Simplify3D)[10]High-quality metal nozzle, 0.4–1.0 mm; hardened steel not required (Siraya Tech)[6]
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[12][14]High (0.8–2 %) — Siraya Tech publishes 2.59 % by ISO 62 immersion for the unfilled grade; on the equilibrium basis Bambu Lab uses, its 15 % carbon-filled PPA reaches 1.30 % against 2.35 % for the same maker's PA6-CF[6][4][15]
Equilibrium moisture content at ~50 % RH%Not documented2.59 by ISO 62 water immersion (Siraya Tech, unfilled) — an immersion figure, not the 25 °C / 55 % RH equilibrium basis the filled grades are quoted on, so the two are not directly comparable[6]
Drying temperature & time100 °C for 8 h (Polymaker CoPA); storage below 20 % RH[11][16]80–100 °C for 4–6 h (Siraya Tech)[6]
Symptoms when wetPopping and cracking during extrusion, then defects that Polymaker describes as very hard to diagnose[13]Oozing, bubbles and a rough surface finish (Siraya Tech)[6]
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 %[11][13]Siraya Tech publishes dry against saturated for the same grade: tensile 70 → 60 MPa, flexural 114 → 87 MPa, HDT at 1.8 MPa 73.5 → 48.5 °C, while Charpy rises 10 → 14.5 kJ/m²[6][9]
Storage requirementSealed below 20 % RH with desiccant; Polymaker says nylon often needs to stay in a dryer while printing[16][12]Dry box below 15 % RH (Siraya Tech)[6]
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[11][16]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)[5][17]72 at break (printed, ASTM D638, Siraya Tech); the product page quotes 70 dry and 60 saturated[6][9]
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)[5][17]3600 (printed, ASTM D638, Siraya Tech)[6]
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)[5][17]10.5 at break (printed, ASTM D638, Siraya Tech)[6]
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)[5][17]115 (printed, ISO 178, Siraya Tech); 114 dry against 87 saturated on the product page[6][9]
Flexural modulusMPa2200 (printed XY, ISO 178, 3DXTech iOn PA6 alloy); Stratasys FDM Nylon 6 conditioned gives 2196 printed XZ and 1879 ZX (ASTM D790)[5][17]3350 (printed, ISO 178, Siraya Tech)[6]
Charpy impact, notchedkJ/m²Not documented10.1 Charpy (printed, ISO 179, Siraya Tech); the data sheet does not state whether the specimen was notched[6]
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[17]Not documented
Layer adhesion / Z tensileMPa36.5 ultimate and 28.9 at yield printed ZX (Stratasys FDM Nylon 6, conditioned 20 °C / 50 % RH, ASTM D638)[17]Not documented
Brittleness1–5Tough — absorbs impact, yields before breaking[1]Moderate — 10.5 % elongation at break puts it between PA6 and the fibre-filled grades[6]
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[18]Not documented
Creep resistance / sustained load1–5Moderate[1]Good — Raise3D cites high creep resistance as a reason to choose the PPA matrix over other nylons[3]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[1]Not documented
Elasticity / flexibility1–5Semi-flexible[13]Rigid — 3.6 GPa tensile modulus[6]
Z strength as % of XY%54 (Stratasys FDM Nylon 6 conditioned, ZX against XZ ultimate tensile, ASTM D638); 59 on the yield figures[17]Not documented
Wear resistance & friction3DXTech sells a dedicated wear-resistant PA6 grade; abrasion resistance is the usual reason to choose PA6 over PA12[7]Siraya Tech describes the unfilled grade as low-friction and self-lubricating, aimed at gears and bearings[6][9]
Thermal Properties
HDT at 0.45 MPa°CNot documented81 dry and 61 saturated (printed, ISO 75 Method B at 0.45 MPa, Siraya Tech)[6]
HDT at 1.8 MPa°C93 (Stratasys FDM Nylon 6, conditioned, ASTM D648 at 264 psi)[17]73.5 dry and 48.5 saturated (printed, ISO 75 Method A at 1.8 MPa, Siraya Tech) — unfilled PPA deflects near its Tg; the 190–227 °C figures quoted for PPA are carbon-filled grades[6][4]
Glass transition (Tg)°C105 (DSC, 3DXTech iOn PA6 alloy)[5]80 (ASTM D3418, Siraya Tech)[6]
Melting point / Vicat°CNot documented231 melting point (ASTM D3418) and 230 Vicat (ISO 306), Siraya Tech[6]
Annealing responseNot documentedSiraya Tech's product page offers annealing for strength while its own data sheet says annealing is not recommended because the print can warp; on its 15 % carbon-filled PPA, annealing lifts HDT at 1.8 MPa from 82.5 to 119 °C[6][9][19]
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[18]Not documented
Flammability / UL 94Flammable; no UL 94 rating published for the unfilled filament grades surveyed[5]Not documented
Environment & Chemical
UV resistance1–5Months outdoors before embrittlement — unstabilised polyamide yellows and chalks under UV[1]Not documented
Chemical resistanceWithstands oils, fuels and alkalis — the usual reason to choose a polyamide[1]Withstands fuels, oils and industrial chemicals; Bambu Lab rates semi-aromatic nylon better than general nylon against weak acids, weak alkalis and most organic solvents[6][4]
Water / humidity resistance in service1–5Absorbs water, properties shift — a conditioned part is measurably softer and larger than the same part dry[13][11]Absorbs water, properties shift — a saturated specimen loses about 15 % of its tensile strength and 25 °C of heat-deflection temperature[6][9]
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]Not documented
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]Not documented
Post-Processing
Sanding & machiningSands poorly — the toughness makes it gum rather than powder[10]Not documented
Gluing & solvent weldingCyanoacrylate; no common solvent welds polyamide[10]Not documented
Vapour / chemical smoothingNo practical vapour smoothing[10]Not documented
Support material pairingPVA dissolves cleanly against nylon; Polymaker sells a break-away PolySupport for PA12[10]Compatible with quick-release support materials (Siraya Tech)[6]
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[13]Not documented
Solvents & Solubility
Soluble inDissolved at 23 °C by formic acid above ~50 %, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — laboratory reagents.[20]Dissolved at 23 °C by formic acid, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — all laboratory reagents.[20]
Softened or crazed byZinc chloride solutions stress-crack it — 10 % marginal, 37 % not resistant; alcoholic calcium chloride dissolves it.[20]Mineral acids, oxidants, halogens and zinc chloride solutions attack the amide bond; ordinary solvents do not.[20]
Solvent welding & smoothing agentNone — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[20]None — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[20]

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. Raise3D Industrial PPA CF Technical Data Sheet V2.0 Raise3D · 2022-04 · tds
  4. Bambu Filament Technical Data Sheet V1.0 — PPA-CF Bambu Lab · 2026-08 · tds
  5. iOn PA6-based Nylon Alloy Technical Data Sheet v2.0 3DXTech · 2026-08 · tds
  6. Siraya Tech Fibreheart PPA Technical Data Sheet Siraya Tech · 2026-08 · tds
  7. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  8. YXPOLYER PA6 Black 1 kg — product page YXPOLYER · 2026-08 · vendor
  9. Siraya Tech Fibreheart PPA Filament — product page Siraya Tech · 2026-08 · vendor
  10. Nylon — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  11. PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
  12. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  13. Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
  14. Fiberon PA612-CF15 Technical Data Sheet V1.1 Polymaker · 2024-12 · tds
  15. Bambu Filament Technical Data Sheet V3.0 — PA6-CF Bambu Lab · 2026-08 · tds
  16. PolyMide CoPA — Technical Data Sheet page Polymaker Wiki · 2026-08 · tds
  17. FDM Nylon 6 — data sheet (conditioned 20 °C / 50 % RH) Stratasys · 2017-11 · tds
  18. TECAMID 66 natural (PA66) — stock shape properties Ensinger · 2026-08 · tds
  19. Siraya Tech Fibreheart PPA-CF Technical Data Sheet Siraya Tech · 2026-08 · tds
  20. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds