3D Printing Info

Filament comparison

rPETG vs PPA

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

Recycled PETG (rPETG) guidePPA (polyphthalamide) guide

2 selected · all documented properties

Open these two in the interactive comparisonMore rPETG comparisonsMore PPA comparisons
rPETG vs PPA — documented properties and sources
PropertyRecycled PETG (rPETG)PETGPPA (polyphthalamide)PA
Market snapshot
Listing priceUSD/kg; dated snapshots$28.99/kg median; $17.24–$39.98/kg across 4 dated product listings$45.49/kg median; $45.49–$45.49/kg across 1 dated product listings
Identity & Market
Base polymer / chemistryPETG regranulated from recycled polyester waste; Polymaker's Fiberon PETG-rCF08 adds 8 wt% recycled carbon fibre[1][2][3]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[4][5]
Densityg/cm³1.27 (Prusament) and 1.30 (Fiberon PETG-rCF08), ISO 1183[1][3]1.21 (ISO 1183, Siraya Tech Fibreheart PPA)[6]
Typical priceUSD/kg1 kg spools cluster near 29[7][8][9][10]One 1 kg listing on the market, at 45[11]
Price range across brandsUSD/kg17–40 across brands; Filament PM RePETG 17, 3DXTech ECOMAX 26, GreenGate3D 32, Fiberon rCF08 40[7][8][9][10]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[11]
Market availability1–5Available from several mainstream brands[7][8][9]Special order, 1–2 makers worldwide — Siraya Tech is the only brand found selling unfilled PPA filament[11]
Spool sizes & diameters1.75 and 2.85 mm; 0.5, 1 and 3 kg spools[9][8]1.75 mm, 1 kg[11]
Typical applicationsNot documentedGears, bearings and tooling that must hold load above the reach of PA6 or PA12, and parts exposed to fuels and industrial chemicals[6]
Diameter tolerance± mm±0.05 (Prusament PETG Recycled), against ±0.02 for virgin Prusament PETG[1][12]Not documented
Printing Parameters
Nozzle temperature°C250 ± 10 (Prusament); 230–255 (Spectrum)[1][2]280–300 (Siraya Tech)[6]
Bed temperature°C80 ± 10 (Prusament); 60–80 (Spectrum)[1][2]70–80 (Siraya Tech)[6]
Enclosure / chamber requirement1–5Open frame is fine — Spectrum states a closed chamber is not necessary[2]Enclosure recommended — Siraya Tech advises an enclosure to hold temperature and limit warping on larger prints[6]
Part cooling fan50 % (Prusament); up to 100 % (Spectrum)[1][2]20–60 % (Siraya Tech)[6]
Bed surface & adhesion aidTextured PEI, satin or powder-coated sheets; on smooth PEI a glue stick acts as a release agent[12][13]PEI sheet with a glue stick, or a PVP glue coating[6]
Bed-adhesion difficulty1–5Needs the right surface or a thin adhesive — the problem is releasing the part, not sticking it[12][13]Not documented
Stringing / oozing tendency1–5Moderate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[13]Not documented
Overall printing difficulty1–5Easy — minor profile tuning; Spectrum describes printing as similar to standard PETG[2]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[1]Brass fine indefinitely — Siraya Tech states a hardened steel nozzle is not needed for the unfilled grade[6]
Abrasiveness1–5Not documentedNon-abrasive when unfilled[6]
Nozzle clog risk1–5Low — recycled PETG prints on the same hardware as virgin PETG: no special hot-end, no drybox and no hardened nozzle[14][15]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 sensitivity1–5Slightly sensitive[14]Not documented
Hotend requirementNo special hot-end required[14]High-quality metal nozzle, 0.4–1.0 mm; hardened steel not required (Siraya Tech)[6]
Moisture Behaviour
Moisture absorption (hygroscopicity)1–5Moderate (0.3–0.8 %) — recycled PETG shares the virgin matrix, which reaches 0.40 % saturated at 25 °C / 55 % RH[12]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][5][16]
Equilibrium moisture content at ~50 % RH%0.07 after 24 h and 0.10 after 7 days at 24 °C / 22 % RH (Prusa Polymers)[1]2.59 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 & timeNot documented80–100 °C for 4–6 h (Siraya Tech)[6]
Symptoms when wetBubbling and popping at the nozzle, stringing and a rough surface[17]Oozing, bubbles and a rough surface finish (Siraya Tech)[6]
Effect of moisture on strengthPolymaker 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[17]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][11]
Storage requirementSealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[17][13]Dry box below 15 % RH (Siraya Tech)[6]
Mechanical Properties
Tensile strength (XY)MPa43 ± 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[1][12][2]72 at break (printed, ASTM D638, Siraya Tech); the product page quotes 70 dry and 60 saturated[6][11]
Young's modulusMPa1500 printed horizontal, 1600 printed vertical (Prusament, ISO 527-1) — the same as virgin Prusament PETG[1][12]3600 (printed, ASTM D638, Siraya Tech)[6]
Elongation at break%4.5 at yield printed (Prusament); Spectrum quotes 400 at break on moulded specimens[1][2]10.5 at break (printed, ASTM D638, Siraya Tech)[6]
Flexural strengthMPa63 ± 1 printed horizontal, ISO 178 (Prusament), against 66 ± 2 for virgin Prusament PETG[1][12]115 (printed, ISO 178, Siraya Tech); 114 dry against 87 saturated on the product page[6][11]
Flexural modulusMPa1800 printed horizontal, ISO 178 (Prusament)[1]3350 (printed, ISO 178, Siraya Tech)[6]
Charpy impact, notchedkJ/m²12 ± 1 printed horizontal and 15 ± 3 printed vertical, ISO 179-1 notched (Prusament)[1]10.1 Charpy (printed, ISO 179, Siraya Tech); the data sheet does not state whether the specimen was notched[6]
Other impact dataCharpy unnotched 25 ± 3 printed horizontal and 38 ± 11 printed vertical (Prusament, ISO 179-1)[1]Not documented
Layer adhesion / Z tensileMPa15 ± 5 (Prusa Polymers interlayer adhesion test), against 18 ± 4 for virgin Prusament PETG[1][12]Not documented
Brittleness1–5Moderate[1]Moderate — 10.5 % elongation at break puts it between PA6 and the fibre-filled grades[6]
Hardness (scale-specific)Shore A / Shore D / Rockwell74 Shore D (Prusa Polymers method) — the same as virgin Prusament PETG[1][12]Not documented
Creep resistance / sustained load1–5Below average — no recycled-grade creep test; virgin PETG sagged from 12 to 17.1–20.4 mm over 5 days at 1.25 kg[18][19][20][21]Good — Raise3D cites high creep resistance as a reason to choose the PPA matrix over other nylons[4]
Fatigue / repeated-flex resistance1–5Moderate — no recycled-grade S-N curve; virgin printed PETG ran 79 000–193 000 cycles at 30 % of tensile strength[22]Not documented
Elasticity / flexibility1–5Slightly flexible in thin sections[1]Rigid — 3.6 GPa tensile modulus[6]
Wear resistance & frictionNot documentedSiraya Tech describes the unfilled grade as low-friction and self-lubricating, aimed at gears and bearings[6][11]
Thermal Properties
HDT at 0.45 MPa°C68 (ISO 75, 0.45 MPa) — the same as virgin Prusament PETG; Spectrum quotes 70[1][12][2]81 dry and 61 saturated (printed, ISO 75 Method B at 0.45 MPa, Siraya Tech)[6]
HDT at 1.8 MPa°C68 (ISO 75, 1.8 MPa)[1]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][5]
Glass transition (Tg)°CNot documented80 (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][11][23]
Flammability / UL 94Flammable; no UL 94 rating published for standard grades[24]Not documented
Environment & Chemical
Chemical resistanceWithstands acids, alkalis, oils and UV exposure[13]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][5]
Water / humidity resistance in service1–5Not documentedAbsorbs water, properties shift — a saturated specimen loses about 15 % of its tensile strength and 25 °C of heat-deflection temperature[6][11]
Food contactNot certified for food contact as filament[13]Not documented
Biodegradability / compostabilityNot biodegradable[13]Not documented
RecyclabilityThe feedstock itself — Spectrum describes collecting, shredding and re-homogenising PETG waste[2]Not documented
Health & Safety
Fume toxicity1–5Moderate — measurable VOCs and UFPs, ventilation advised[25]Not documented
Ventilation / filtration requirement1–5Open a window / occasional ventilation[25]Not documented
Post-Processing
Sanding & machiningSands poorly — the material is tough and gums rather than powders[14]Not documented
Gluing & solvent weldingCyanoacrylate; no common solvent welds PETG cleanly[14]Not documented
Vapour / chemical smoothingNo practical vapour smoothing[14]Not documented
Support material pairingPrints its own supports; Polymaker rates PolyDissolve S1 for PETG[14]Compatible with quick-release support materials (Siraya Tech)[6]
Solvents & Solubility
Soluble inNo common workshop solvent; 1,2-dichloroethane destroys it inside a week and dichloromethane — a carcinogen — dissolves the surface.[26][27]Dissolved at 23 °C by formic acid, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — all laboratory reagents.[28]
Softened or crazed byAcetone (+16 % weight over 1 year at 23 °C), ethyl acetate, toluene and DMF swell and soften it; methanol crazes it.[26]Mineral acids, oxidants, halogens and zinc chloride solutions attack the amide bond; ordinary solvents do not.[28]
Solvent welding & smoothing agentDichloromethane brushed on is the only agent that smooths PETG — a controlled carcinogen, not workshop stock.[27]None — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[28]

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. Prusament PETG Recycled Technical Datasheet Prusa Polymers · 2026-08 · tds
  2. Spectrum r-PETG Technical Data Sheet Spectrum Filaments · 2026-08 · tds
  3. Fiberon PETG-rCF08 Technical Data Sheet V1.0 Polymaker · 2026-08 · tds
  4. Raise3D Industrial PPA CF Technical Data Sheet V2.0 Raise3D · 2022-04 · tds
  5. Bambu Filament Technical Data Sheet V1.0 — PPA-CF Bambu Lab · 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. GreenGate3D Recycled PET-G — product data GreenGate3D · 2026-08 · vendor
  9. Polymaker product catalogue Polymaker · 2026-08 · vendor
  10. Filament PM RePETG technical data sheet Filament PM (Plasty Mladec) · 2026-08 · tds
  11. Siraya Tech Fibreheart PPA Filament — product page Siraya Tech · 2026-08 · vendor
  12. Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
  13. PETG — material basics 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. Bambu Filament Technical Data Sheet V3.0 — PA6-CF Bambu Lab · 2026-08 · tds
  17. Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
  18. PCTG vs PETG comparison — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  19. Extrudr PETG vs PCTG vs XPETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  20. Prusament PETG-CF vs PETG V0 vs PETG — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  21. BambuLab PETG Basic vs Translucent vs PETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
  22. Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
  23. Siraya Tech Fibreheart PPA-CF Technical Data Sheet Siraya Tech · 2026-08 · tds
  24. Prusament PETG V0 Technical Datasheet Prusa Polymers · 2026-08 · tds
  25. 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
  26. Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
  27. Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc
  28. Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds