3D Printing Info

Filament comparison

PA6 vs PP

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

PA6 (Nylon 6) guidePolypropylene (PP) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore PA6 comparisonsMore PP comparisons
PA6 vs PP — documented properties and sources
PropertyPA6 (Nylon 6)PAPolypropylene (PP)POLYOLEFIN
Market snapshot
Listing priceUSD/kg; dated snapshots$104.00/kg median; $38.99–$136.00/kg across 3 dated product listings$46.56/kg median; $31.99–$53.00/kg across 4 dated product listings
Identity & Market
Base polymer / chemistryPolyamide 6, ring-opened from caprolactam — the most hygroscopic of the common nylons[1][2]Polypropylene — a semi-crystalline polyolefin with no polar groups, so it neither absorbs water nor bonds to most bed surfaces[3][4]
Densityg/cm³1.06 (ISO 1183, 3DXTech iOn PA6 alloy)[5]0.91 (Prusa PP composite, ISO 1183) — the lightest common filament[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]1 kg-equivalent spools span 27–53; the middle of the market is about 44[9][10][11][12]
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]27–53 across brands; Reli3D 32 on Amazon, SUNLU 44 at 0.8 kg, Fiberlogy 49 at 750 g, IEMAI 3D 53, and the 3DJake PP listing spans 27–49[9][13][10][11][12]
Market availability1–5Niche, a handful of specialist brands[7]Available from several mainstream brands[13][10][9]
Spool sizes & diameters1.75 and 2.85 mm; 500 g and 750 g spools[7]1.75 and 2.85 mm; 0.75 kg spools are common[10]
Typical applicationsWear parts, bushings and gears where PA6's toughness and abrasion resistance matter more than dimensional stability[1]Living hinges, chemical-resistant containers, automotive clips and packaging prototypes[3]
Printing Parameters
Nozzle temperature°C220–260 (Polymaker); 225–265 (Simplify3D)[1][14]210–230 (Braskem-type PE/PP window); Formfutura's Centaur PP melts at 205 ± 15 °C[3]
Bed temperature°C70–100 (Polymaker); 70–90 (Simplify3D)[1][14]Not documented
Enclosure / chamber requirement1–5Enclosure required (passive)[15][1]Enclosure recommended — Simplify3D lists an enclosure as a hardware requirement and Polymaker advises one below 70 °C ambient to stop warping and cracking[16][4]
Part cooling fanPart cooling fan not required (Simplify3D)[14]Part cooling fan required (Simplify3D)[16]
Bed surface & adhesion aidPEI sheet with a glue stick, or a dedicated adhesive such as Magigoo[14][1]Packing tape, a polypropylene sheet, or a PP-specific adhesive such as Magigoo PP — ordinary PLA and ABS adhesives do not hold it[16][4]
Warping tendency1–5Not documentedHigh — enclosure needed for reliable large parts; PP's crystallinity drives shrinkage and Prusa recommends a brim on its PP grades[6][17]
Bed-adhesion difficulty1–5Needs a specific surface plus adhesive[14][1]Very difficult — special plates or slurry required. PP bonds to almost nothing; a polypropylene-specific tape or adhesive is the normal answer[6][4]
Stringing / oozing tendency1–5Moderate — retraction tuning needed[1]Slight — Polymaker advises 1–2 mm retraction at 20–30 mm/s[4]
Overall printing difficulty1–5Advanced — enclosure, hardware upgrades, tuning; the filament must be kept dry throughout the print[1][18]Advanced — enclosure, hardware upgrades, tuning; bed adhesion is the whole problem[4][6]
Hardware Wear & Reliability
Nozzle hardness required1–4Brass fine indefinitely for unfilled grades[1]Brass fine indefinitely for unfilled grades — Simplify3D states no special hotend is required[16]
Abrasiveness1–5Non-abrasive when unfilled[1]Non-abrasive when unfilled[16]
Nozzle clog risk1–5Very high — frequent jams without careful setup; wet nylon pops and cracks in the melt[19][18]Low — Simplify3D lists no special hotend requirement for PP and clogging is not among its listed drawbacks[18][16]
Heat-creep / jam sensitivity1–5Moderate — good heatbreak cooling needed[14]Slightly sensitive[16]
Hotend requirementMay require an all-metal hot end (Simplify3D)[14]No special hot-end required (Simplify3D)[16]
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[18][20]Negligible (<0.1 % EMC) — Prusa measures 0.03 % in 24 h and 0.04 % in 7 days on its PP composite, the lowest figures it publishes for any filament[6]
Equilibrium moisture content at ~50 % RH%Not documented0.03 after 24 h and 0.04 after 7 days at 24 °C / 22 % RH (Prusa Polymers, measured on its PP composite)[6]
Drying temperature & time100 °C for 8 h (Polymaker CoPA); storage below 20 % RH[15][21]No drying step is published for PP; uptake is below the level that affects printing[6]
Symptoms when wetPopping and cracking during extrusion, then defects that Polymaker describes as very hard to diagnose[19]Bubbling and popping at the nozzle; Polymaker still advises a 70 °C dry for 4–6 h despite the low uptake[4]
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 %[15][19]Not applicable in practice — with equilibrium uptake at 0.04 %, there is no moisture-driven strength loss to measure. Polymaker's sensitivity tiers put polyolefins below even PLA[6][18]
Storage requirementSealed below 20 % RH with desiccant; Polymaker says nylon often needs to stay in a dryer while printing[21][18]No special storage needed[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[15][21]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][22]12 at yield (Formfutura Centaur PP, ASTM D638)[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)[5][22]724 on extruded PP stock (ASTM D638; converted from 105,000 psi)[23]
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][22]Above 600 at break (Formfutura Centaur PP, ASTM D638)[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)[5][22]31.0 on extruded PP stock (ASTM D790; converted from 4500 psi)[23]
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][22]402 flexural modulus (Formfutura Centaur PP, ASTM D790) — an order of magnitude below any rigid filament[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[22]Izod notched 112 J/m on extruded PP stock, converted from 2.1 ft-lb/in (ASTM D256)[23]
Layer adhesion / Z tensileMPa36.5 ultimate and 28.9 at yield printed ZX (Stratasys FDM Nylon 6, conditioned 20 °C / 50 % RH, ASTM D638)[22]Not documented
Brittleness1–5Tough — absorbs impact, yields before breaking[1]Very ductile — bends far before failing[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[24]Rockwell R102 (and M95) on extruded PP stock (ASTM D785)[23]
Creep resistance / sustained load1–5Moderate[1]Below average[3]
Fatigue / repeated-flex resistance1–5Excellent — living hinges viable[1]Excellent — living hinges viable, the classic polypropylene application[3]
Elasticity / flexibility1–5Semi-flexible[19]Semi-flexible[3]
Z strength as % of XY%54 (Stratasys FDM Nylon 6 conditioned, ZX against XZ ultimate tensile, ASTM D638); 59 on the yield figures[22]Not documented
Wear resistance & friction3DXTech sells a dedicated wear-resistant PA6 grade; abrasion resistance is the usual reason to choose PA6 over PA12[7]Not documented
Thermal Properties
HDT at 0.45 MPa°CNot documented74 on extruded PP stock (ASTM D648 at 66 psi; converted from 165 °F)[23]
HDT at 1.8 MPa°C93 (Stratasys FDM Nylon 6, conditioned, ASTM D648 at 264 psi)[22]Not documented
Glass transition (Tg)°C105 (DSC, 3DXTech iOn PA6 alloy)[5]Not documented
Melting point / Vicat°CNot documented205 ± 15 melting (Formfutura Centaur PP)[3]
Continuous service temperature°CNot documentedBounded by a melting point of 205 ± 15 °C and by the 158 °C heat deflection of the carbon-filled grade; no loaded-bar service figure is published for unfilled PP[3][6]
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[24]Not documented
Flammability / UL 94Flammable; no UL 94 rating published for the unfilled filament grades surveyed[5]Flammable; no UL 94 rating published for the grades surveyed[6]
Environment & Chemical
UV resistance1–5Months outdoors before embrittlement — unstabilised polyamide yellows and chalks under UV[1]Months outdoors before embrittlement — unstabilised polypropylene chalks under UV[4]
Chemical resistanceWithstands oils, fuels and alkalis — the usual reason to choose a polyamide[1]Excellent against acids, alkalis and most solvents — the usual reason to choose PP[4]
Water / humidity resistance in service1–5Absorbs water, properties shift — a conditioned part is measurably softer and larger than the same part dry[19][15]Excellent — essentially unaffected[6]
Food contactPolymaker notes medical-grade variants exist, but standard filament is not food-contact certified[1]Polypropylene is a common food-packaging polymer, but no filament here carries a food-contact certification[4]
Biodegradability / compostabilityNot biodegradable[1]Not biodegradable[4]
RecyclabilityMechanically recyclable but not accepted in household plastic collection[1]Mechanically recyclable as resin code 5, but printed waste is not accepted in household collection[4]
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[2]Low hazard — minimal VOC and particle emission. Inferred: no polyolefin was among the nine filaments in the Azimi chamber study, so this is a family-level judgement rather than a measurement[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]Open a window / occasional ventilation. Inferred — no polyolefin was measured in the chamber study[2]
Post-Processing
Sanding & machiningSands poorly — the toughness makes it gum rather than powder[14]Sands poorly — the waxy surface loads abrasive paper[16]
Painting & finishingNot documentedPaint and adhesives do not key to untreated PP; flame or plasma treatment is normally needed first[4]
Gluing & solvent weldingCyanoacrylate; no common solvent welds polyamide[14]Nothing common bonds untreated PP; flame or plasma treatment is needed before adhesives key[4]
Vapour / chemical smoothingNo practical vapour smoothing[14]No practical vapour smoothing[16]
Support material pairingPVA dissolves cleanly against nylon; Polymaker sells a break-away PolySupport for PA12[14]Prints its own supports; no soluble support is rated for PP[16]
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[19]Shrinkage and warping dominate; the low modulus means parts flex rather than hold tolerance[6]
Solvents & Solubility
Soluble inDissolved at 23 °C by formic acid above ~50 %, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — laboratory reagents.[25]None at room temperature; chloroform dissolves it at 60 °C and xylene at about 118 °C — the xylene-solubles route.[26][27]
Softened or crazed byZinc chloride solutions stress-crack it — 10 % marginal, 37 % not resistant; alcoholic calcium chloride dissolves it.[25]Xylene, decalin, CCl4 and chlorobenzene are heavily absorbed at 20 °C; oleum, chlorosulphonic acid and bromine destroy it.[26]
Solvent welding & smoothing agentNone — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[25]None — nothing softens PP at room temperature, so joints have to be welded thermally rather than chemically.[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. 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. Centaur PP Technical Data Sheet Formfutura · 2026-08 · tds
  4. PP — material basics Polymaker Wiki · 2026-08 · doc
  5. iOn PA6-based Nylon Alloy Technical Data Sheet v2.0 3DXTech · 2026-08 · tds
  6. Prusament PP Carbon Fiber Technical Datasheet v1.0 Prusa Polymers · 2024-11 · tds
  7. 3DXTech product catalogue 3DXTech · 2026-08 · vendor
  8. YXPOLYER PA6 Black 1 kg — product page YXPOLYER · 2026-08 · vendor
  9. SUNLU product catalogue SUNLU · 2026-08 · vendor
  10. Fiberlogy PP Natural — product page 3DJake International · 2026-08 · vendor
  11. Reli3D Low Warp PP Filament 1.75 mm 1 kg Black — Amazon listing Amazon.com · 2026-08 · vendor
  12. IEMAI 3D PP 3D Printing Filament — store page IEMAI 3D · 2026-08 · vendor
  13. PP filament listing 3DJake International · 2026-08 · vendor
  14. Nylon — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  15. PolyMide CoPA Technical Data Sheet V5.4 (dry and wet status blocks) Polymaker · 2024-11 · tds
  16. Polypropylene — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
  17. Prusament PP Glass Fiber Technical Datasheet v1.0 Prusa Polymers · 2024-11 · tds
  18. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  19. Moisture Conditioning — effect on printed nylon properties Polymaker Wiki · 2026-08 · doc
  20. Fiberon PA612-CF15 Technical Data Sheet V1.1 Polymaker · 2024-12 · tds
  21. PolyMide CoPA — Technical Data Sheet page Polymaker Wiki · 2026-08 · tds
  22. FDM Nylon 6 — data sheet (conditioned 20 °C / 50 % RH) Stratasys · 2017-11 · tds
  23. TECAFINE PP natural — stock shape properties Ensinger · 2026-08 · tds
  24. TECAMID 66 natural (PA66) — stock shape properties Ensinger · 2026-08 · tds
  25. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
  26. Pro-fax and Moplen polypropylene — Chemical Resistance Guide (20, 60 and 100 °C) LyondellBasell · 2026-08 · tds
  27. US 5,278,282 Polymer recycling by selective dissolution — xylene dissolution temperatures Nauman & Lynch, Rensselaer Polytechnic Institute · 1994-01 · paper