3D Printing InfoFilament comparison
PPA vs TPU-CF
Compare printing settings, strength, heat resistance, dated prices and sources.
2 selected · all documented properties
| Property | PPA (polyphthalamide)PA | Carbon-fibre TPUFLEX |
|---|---|---|
| Market snapshot | ||
| Listing priceUSD/kg; dated snapshots | $45.49/kg median; $45.49–$45.49/kg across 1 dated product listings | $107.05/kg median; $107.05–$107.05/kg across 1 dated product listings |
| Identity & Market | ||
| Base polymer / chemistry | 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[1][2] | Carbon-fibre reinforced thermoplastic polyurethane at the hard end of the range[3] |
| Densityg/cm³ | 1.21 (ISO 1183, Siraya Tech Fibreheart PPA)[4] | 1.22 (Extrudr FLEX HARD CF, ISO 2781)[3] |
| Typical priceUSD/kg | One 1 kg listing on the market, at 45[5] | 107 for the only retail listing found (Extrudr 0.5 kg coil, incl. VAT)[6] |
| Price range across brandsUSD/kg | 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[5] | One listing only: EUR 49.56 incl. VAT per 0.5 kg coil, direct from Extrudr; no reseller or second brand found[6] |
| Market availability1–5 | Special order, 1–2 makers worldwide — Siraya Tech is the only brand found selling unfilled PPA filament[5] | Niche, a handful of specialist brands — Extrudr's FLEX HARD CF is the only carbon-filled flexible with a published datasheet found here[3] |
| Spool sizes & diameters | 1.75 mm, 1 kg[5] | 1.75 mm; 0.5 and 2 kg coils[6] |
| Typical applications | Gears, bearings and tooling that must hold load above the reach of PA6 or PA12, and parts exposed to fuels and industrial chemicals[4] | Stiffened flexible parts — damping mounts and semi-rigid brackets[3] |
| Printing Parameters | ||
| Nozzle temperature°C | 280–300 (Siraya Tech)[4] | 230–260 (Extrudr FLEX HARD CF)[3] |
| Bed temperature°C | 70–80 (Siraya Tech)[4] | 50–90 (Extrudr FLEX HARD CF)[3] |
| Enclosure / chamber requirement1–5 | Enclosure recommended — Siraya Tech advises an enclosure to hold temperature and limit warping on larger prints[4] | Open frame is fine[3] |
| Part cooling fan | 20–60 % (Siraya Tech)[4] | Not documented |
| Bed surface & adhesion aid | PEI sheet with a glue stick, or a PVP glue coating[4] | PEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[7][8] |
| Maximum volumetric flow (mm³/s; see test conditions)mm³/s | Not documented | 1.6–8 at the 20–100 mm/s Extrudr specifies on a 0.4 mm nozzle at 0.2 mm layer[3] |
| Overall printing difficulty1–5 | Advanced — enclosure, hardware upgrades, tuning; needs a 300 °C-class hot end and a dry spool[4] | Advanced — enclosure, hardware upgrades, tuning; hardened nozzle needed[3] |
| Hardware Wear & Reliability | ||
| Nozzle hardness required1–4 | Brass fine indefinitely — Siraya Tech states a hardened steel nozzle is not needed for the unfilled grade[4] | Hardened steel required — Extrudr marks FLEX HARD CF as needing a hardened nozzle where its unfilled FLEX grades do not[3] |
| Abrasiveness1–5 | Non-abrasive when unfilled[4] | Highly abrasive — standard CF composite[3] |
| Nozzle clog risk1–5 | Moderate — needs dry filament and a clean nozzle; Siraya Tech tells users to dry only when moisture symptoms appear, rather than before every print[4] | High — jams from moisture, heat creep or particles; a flexible base plus chopped carbon fibre, which Prusa lists as a higher nozzle-clogging risk, and Extrudr requires a hardened nozzle[9][3][7] |
| Hotend requirement | High-quality metal nozzle, 0.4–1.0 mm; hardened steel not required (Siraya Tech)[4] | No special hot-end required, but a direct-drive extruder is (Simplify3D)[7] |
| Moisture Behaviour | ||
| Moisture absorption (hygroscopicity)1–5 | 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[4][2][10] | Moderate[11] |
| Equilibrium moisture content at ~50 % RH% | 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[4] | Not documented |
| Drying temperature & time | 80–100 °C for 4–6 h (Siraya Tech)[4] | 60 °C for 6 h (Extrudr FLEX HARD CF)[3] |
| Symptoms when wet | Oozing, bubbles and a rough surface finish (Siraya Tech)[4] | Bubbling and popping at the nozzle, stringing and a rough surface[11] |
| Effect of moisture on strength | 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[4][5] | Polymaker groups TPU with the highly hygroscopic materials; no dry-versus-conditioned figures are published[11] |
| Storage requirement | Dry box below 15 % RH (Siraya Tech)[4] | Sealed with desiccant; often kept in a dryer during the print[11] |
| Mechanical Properties | ||
| Tensile strength (XY)MPa | 72 at break (printed, ASTM D638, Siraya Tech); the product page quotes 70 dry and 60 saturated[4][5] | Not documented |
| Young's modulusMPa | 3600 (printed, ASTM D638, Siraya Tech)[4] | 35 (Extrudr FLEX HARD CF, ISO 527-2/5A/500)[3] |
| Elongation at break% | 10.5 at break (printed, ASTM D638, Siraya Tech)[4] | 380 ultimate elongation (Extrudr FLEX HARD CF, ISO 527-2/5A/500), against 490 for the unfilled FLEX HARD[3] |
| Flexural strengthMPa | 115 (printed, ISO 178, Siraya Tech); 114 dry against 87 saturated on the product page[4][5] | Not documented |
| Flexural modulusMPa | 3350 (printed, ISO 178, Siraya Tech)[4] | Not documented |
| Charpy impact, notchedkJ/m² | 10.1 Charpy (printed, ISO 179, Siraya Tech); the data sheet does not state whether the specimen was notched[4] | Not documented |
| Brittleness1–5 | Moderate — 10.5 % elongation at break puts it between PA6 and the fibre-filled grades[4] | Very ductile — bends far before failing[3] |
| Hardness (scale-specific)Shore A / Shore D / Rockwell | Not documented | 70 Shore D (Extrudr FLEX HARD CF, ISO 868), against 58 Shore D for the unfilled FLEX HARD[3] |
| Creep resistance / sustained load1–5 | Good — Raise3D cites high creep resistance as a reason to choose the PPA matrix over other nylons[1] | Below average — no CF-grade creep test; the grade is 70 Shore D where a 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[3][12] |
| Fatigue / repeated-flex resistance1–5 | Not documented | Good — 380 % ultimate elongation and a damping application set (Extrudr cites longboard wheels), below the unfilled grades[3] |
| Elasticity / flexibility1–5 | Rigid — 3.6 GPa tensile modulus[4] | Semi-flexible[3] |
| Wear resistance & friction | Siraya Tech describes the unfilled grade as low-friction and self-lubricating, aimed at gears and bearings[4][5] | Abrasion 26 mm³ (Extrudr FLEX HARD CF, ISO 4649-A) — the same as the unfilled FLEX HARD[3] |
| Thermal Properties | ||
| HDT at 0.45 MPa°C | 81 dry and 61 saturated (printed, ISO 75 Method B at 0.45 MPa, Siraya Tech)[4] | Not documented |
| HDT at 1.8 MPa°C | 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[4][2] | Not documented |
| Glass transition (Tg)°C | 80 (ASTM D3418, Siraya Tech)[4] | -24 (Extrudr FLEX HARD CF)[3] |
| Melting point / Vicat°C | 231 melting point (ASTM D3418) and 230 Vicat (ISO 306), Siraya Tech[4] | Vicat A 140 (Extrudr FLEX HARD CF, ISO 306)[3] |
| Annealing response | Siraya 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[4][5][13] | Not documented |
| Environment & Chemical | ||
| UV resistance1–5 | Not documented | Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[8] |
| Chemical resistance | 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[4][2] | Withstands industrial solvents and UV exposure (Polymaker)[8] |
| Water / humidity resistance in service1–5 | Absorbs water, properties shift — a saturated specimen loses about 15 % of its tensile strength and 25 °C of heat-deflection temperature[4][5] | Not documented |
| Food contact | Not documented | Not food safe without specific certification (Polymaker)[8] |
| Biodegradability / compostability | Not documented | Not biodegradable[8] |
| Recyclability | Not documented | Not accepted in household plastic collection[8] |
| Health & Safety | ||
| Fume toxicity1–5 | Not documented | Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[14] |
| Ventilation / filtration requirement1–5 | Not documented | Open a window / occasional ventilation[14] |
| Dust & fibre handling hazard | Not documented | Carbon fibre is bound in the matrix; sanding dust should not be inhaled[3] |
| Post-Processing | ||
| Sanding & machining | Not documented | Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[8] |
| Gluing & solvent welding | Not documented | Cyanoacrylate bonds TPU; no common solvent welds it[8] |
| Vapour / chemical smoothing | Not documented | No practical vapour smoothing[8] |
| Support material pairing | Compatible with quick-release support materials (Siraya Tech)[4] | Polymaker warns TPU supports are often very difficult to remove[8] |
| Dimensional accuracy & detail | Not documented | Tear strength 165 kN/m (Extrudr FLEX HARD CF, ISO 34-1B)[3] |
| Solvents & Solubility | ||
| Soluble in | Dissolved at 23 °C by formic acid, phenol, m-cresol, 96 % sulphuric acid or hexafluoroisopropanol — all laboratory reagents.[15] | DMF, DMSO, NMP and THF dissolve the TPU matrix and leave the fibre; ketones are partial solvents. Laboratory reagents.[16] |
| Softened or crazed by | Mineral acids, oxidants, halogens and zinc chloride solutions attack the amide bond; ordinary solvents do not.[15] | Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[16] |
| Solvent welding & smoothing agent | None — nylon's only solvents are formic acid, phenol and HFIP, all of which degrade the part they wet.[15] | None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[16] |
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
- Raise3D Industrial PPA CF Technical Data Sheet V2.0 Raise3D · 2022-04 · tds
- Bambu Filament Technical Data Sheet V1.0 — PPA-CF Bambu Lab · 2026-08 · tds
- Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
- Siraya Tech Fibreheart PPA Technical Data Sheet Siraya Tech · 2026-08 · tds
- Siraya Tech Fibreheart PPA Filament — product page Siraya Tech · 2026-08 · vendor
- Extrudr TPU FLEX Hard CF — product page (1.75 mm, 0.5 and 2 kg coils, price) Extrudr (FD3D GmbH) · 2026-08 · vendor
- Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
- TPU — material basics Polymaker Wiki · 2026-08 · doc
- Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
- Bambu Filament Technical Data Sheet V3.0 — PA6-CF Bambu Lab · 2026-08 · tds
- Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
- BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
- Siraya Tech Fibreheart PPA-CF Technical Data Sheet Siraya Tech · 2026-08 · tds
- 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
- Ultramid Nylon Chemical Resistance guide (unmodified PA6 B27E and PA66 A27E) BASF · 2026-08 · tds
- Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds