Filament comparison
PETG-GF vs TPU 85A
Compare printing settings, strength, heat resistance, dated prices and sources.
2 selected · all documented properties
| Property | Glass-fibre polyester (PETG-GF / PET-GF)PETG | TPU 85AFLEX |
|---|---|---|
| Market snapshot | ||
| Listing priceUSD/kg; dated snapshots | $27.38/kg median; $18.99–$29.99/kg across 3 dated product listings | $89.89/kg median; $31.99–$106.05/kg across 6 dated product listings |
| Identity & Market | ||
| Base polymer / chemistry | Glass-fibre reinforced polyester. Polymaker's Fiberon PET-GF15 uses a PET rather than a PETG matrix and carries 15 wt% glass fibre[1] | Soft thermoplastic polyurethane at 82–85 Shore A[2][3][4] |
| Densityg/cm³ | 1.43 (Fiberon PET-GF15, ISO 1183)[1] | 1.11 (BASF Ultrafuse 85A) to 1.19 (NinjaFlex 85A), ISO 1183 / ASTM D792[4][2] |
| Typical priceUSD/kg | 1 kg spools cluster near 25[5][6] | 1 kg-equivalent spools span 32–106; the middle of the market is about 90[7][8][2] |
| Price range across brandsUSD/kg | 19–30 across brands; ELEGOO 19, Polymaker Fiberon 30[5][6] | 32–106 across brands; Siraya Tech Flex TPU 85A 32 at 1 kg, add:north TPU Pro Matte 85A 72, Recreus Filaflex 82A 90 at 500 g, Proto-pasta Clear Flexible TPU 90, 3DXTech 3DXFLEX 85A 96, NinjaTek NinjaFlex 106[9][7][8][10][2] |
| Market availability1–5 | Niche, a handful of specialist brands[5][6] | Available from several mainstream brands[7][9] |
| Spool sizes & diameters | 1.75 mm; 0.5 and 1 kg spools[6] | 1.75, 2.85 and 3 mm; 0.5, 1 and 2 kg spools[7][9][2] |
| Typical applications | Stiff, dimensionally stable fixtures; the Fiberon grade is designed to be annealed for heat resistance[1] | Soft-touch grips, seals, wearables and anything that must compress and rebound[2][3] |
| Printing Parameters | ||
| Nozzle temperature°C | Not documented | 200–220 (BASF Ultrafuse 85A, 210 typical)[4] |
| Bed temperature°C | Not documented | 40 (BASF Ultrafuse 85A)[4] |
| Enclosure / chamber requirement1–5 | Not documented | Open frame is fine[4] |
| Bed surface & adhesion aid | Textured PEI, satin or powder-coated sheets; on smooth PEI a glue stick acts as a release agent[11][12] | PEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[13][14] |
| Maximum volumetric flow (mm³/s; see test conditions)mm³/s | Not documented | 1.2–3.2 at the 15–40 mm/s BASF specifies on a 0.4 mm nozzle at 0.2 mm layer[4] |
| Warping tendency1–5 | Not documented | None[4] |
| Bed-adhesion difficulty1–5 | Needs the right surface or a thin adhesive — the problem is releasing the part, not sticking it[11][12] | Sticks to anything — Recreus states its 82A grade has excellent bed adhesion without a heated bed or additives[3] |
| Stringing / oozing tendency1–5 | Moderate — retraction tuning needed; Polymaker names stringing as PETG's common quirk[12] | High — drying plus tuning needed[15][14] |
| Overall printing difficulty1–5 | Not documented | Advanced — enclosure, hardware upgrades, tuning; at this hardness the filament will not push through a Bowden tube[2][3] |
| Extruder requirement | Not documented | Direct drive only. NinjaTek calls its 85A grade ideal for direct-drive extruders and Recreus specifies direct-drive printers for 82A; BASF caps print speed at 15–40 mm/s with a nozzle of 0.4 mm or larger[2][3][4] |
| Hardware Wear & Reliability | ||
| Nozzle hardness required1–4 | Hardened steel required[1] | Brass fine indefinitely[16] |
| Abrasiveness1–5 | Highly abrasive — standard GF composite[1] | Non-abrasive[16] |
| Nozzle clog risk1–5 | Moderate — needs dry filament and a clean nozzle; Prusa lists higher risk of nozzle clogging for glass-filled composites[17] | High — jams from moisture, heat creep or particles[15][14] |
| Heat-creep / jam sensitivity1–5 | Slightly sensitive[18] | Very high — softens in the cold zone readily; soft filament buckles between the drive gear and the melt zone[14][2] |
| Hotend requirement | No special hot-end required[18] | No special hot-end required, but a direct-drive extruder is (Simplify3D)[13] |
| Moisture Behaviour | ||
| Moisture absorption (hygroscopicity)1–5 | Moderate (0.3–0.8 %) — the PETG matrix reaches 0.40 % saturated at 25 °C / 55 % RH; no glass-filled grade publishes its own figure[11] | Moderate — NinjaTek measures 0.22 % in 24 h (ASTM D570) and BASF specifies a 70 °C dry for at least 5 h[2][4] |
| Equilibrium moisture content at ~50 % RH% | Not documented | 0.22 after 24 h water immersion (NinjaFlex 85A, ASTM D570) — an immersion figure, not an equilibrium moisture content at 50 % RH[2] |
| Drying temperature & time | Not documented | 70 °C for at least 5 h in a hot-air dryer or vacuum oven (BASF)[4] |
| Symptoms when wet | Bubbling and popping at the nozzle, stringing and a rough surface[15] | Bubbling and popping at the nozzle, stringing and a rough surface[15] |
| Effect of moisture on strength | 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[15] | Polymaker groups TPU with the highly hygroscopic materials; wet TPU prints with poor layer adhesion and weak, brittle layers[15] |
| Storage requirement | Sealed with desiccant; Polymaker groups PETG with the highly hygroscopic materials[15][12] | Sealed with desiccant; often kept in a dryer during the print[15] |
| Mechanical Properties | ||
| Tensile strength (XY)MPa | 59.9 ± 0.8 printed XY, ISO 527 (Fiberon PET-GF15)[1] | 26 ultimate (NinjaFlex 85A, ASTM D638)[2] |
| Young's modulusMPa | 4144 ± 133 printed XY, ISO 527 (Fiberon PET-GF15)[1] | 12 (NinjaFlex 85A, ASTM D638) — two orders of magnitude below any rigid filament; NinjaTek's 95A Cheetah reaches 26 by the same method[2][19] |
| Elongation at break% | 4.0 ± 0.5 printed XY, ISO 527 (Fiberon PET-GF15)[1] | 650 at break (Filaflex 82A) and 660 (NinjaFlex 85A); BASF measures 600 in XY and 320 in ZX[3][2][4] |
| Flexural strengthMPa | 104.2 ± 2.4 printed XY, ISO 178 (Fiberon PET-GF15)[1] | Not documented |
| Flexural modulusMPa | 3705 ± 85 printed XY, ISO 178 (Fiberon PET-GF15)[1] | Not documented |
| Charpy impact, notchedkJ/m² | 8.7 ± 0.6 printed XY, ISO 179, notched (Fiberon PET-GF15)[1] | Not documented |
| Other impact data | Charpy unnotched 27.2 ± 2.0 printed XY (Fiberon PET-GF15, ISO 179)[1] | Not documented |
| Layer adhesion / Z tensileMPa | 48.2 ± 0.3 printed Z, ISO 527 (Fiberon PET-GF15)[1] | Not documented |
| Brittleness1–5 | Brittle — snaps with little warning; elongation 4.0 % in XY and 2.6 % in Z[1] | Very ductile — bends far before failing[2] |
| Hardness (scale-specific)Shore A / Shore D / Rockwell | Not documented | 29 Shore D / 85 Shore A (BASF Ultrafuse 85A, ISO 7619-1); 85 Shore A (NinjaFlex, ASTM D2240); 82 A nominal for Filaflex[2][4][3] |
| Creep resistance / sustained load1–5 | Below average — no GF-grade creep test; the CF grades sagged to 14.8–16.7 mm over 5 days at 1.25 kg against 17.1–20.4 mm unfilled[20][21][22] | Poor — no 85A creep test; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg, and softer grades creep more[23] |
| Fatigue / repeated-flex resistance1–5 | Below average — no GF-grade S-N curve; elongation at break falls to 4.0 % in XY against 5.2–9.3 % unfilled[1][24] | Excellent — living hinges viable[14] |
| Elasticity / flexibility1–5 | Rigid[1] | Rubbery / highly elastic[2][3] |
| Z strength as % of XY% | 80 (Fiberon PET-GF15, printed Z against XY tensile)[1] | 53 — BASF measures 320 % elongation at break in ZX against 600 % in XY[4] |
| Wear resistance & friction | Not documented | Abrasion 0.08 g mass loss over 10 000 cycles (NinjaFlex, ASTM D4060); 82 mm³ (BASF, ISO 4649)[2][4] |
| Thermal Properties | ||
| HDT at 0.45 MPa°C | 81.6 as printed, 133.7 after annealing (ISO 75, 0.45 MPa)[1] | Not documented |
| HDT at 1.8 MPa°C | 71.8 as printed, 87.3 after annealing (ISO 75, 1.8 MPa)[1] | Not documented |
| Glass transition (Tg)°C | 59.5 (DSC)[1] | Not documented |
| Melting point / Vicat°C | 231.6 melting (DSC); Vicat 232.6 (ISO 306)[1] | 216 melting (NinjaFlex 85A, DSC)[2] |
| Annealing response | Annealing lifts HDT at 0.45 MPa from 81.6 to 133.7 °C[1] | Not documented |
| Thermal expansion (CTE)µm/m·K | 20 along the print bead and 63–74 in the build direction at 30 °C (30 wt% GF, large-format printed, TMA)[25] | Not documented |
| Flammability / UL 94 | UL 94 HB at 1.5 mm (Fiberon PET-GF15)[1] | Not documented |
| Environment & Chemical | ||
| UV resistance1–5 | Not documented | Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[14] |
| Chemical resistance | Withstands acids, alkalis, oils and UV exposure[12] | Withstands industrial solvents and UV exposure (Polymaker)[14] |
| Food contact | Not certified for food contact as filament[12] | Not food safe without specific certification (Polymaker)[14] |
| Biodegradability / compostability | Not biodegradable[12] | Not biodegradable[14] |
| Recyclability | Not accepted in household plastic collection[12] | Not accepted in household plastic collection[14] |
| Electrical & ESD properties | Surface resistivity above 10¹² ohm — insulating (Fiberon PET-GF15, ANSI/ESD S11.11)[1] | Not documented |
| Health & Safety | ||
| Fume toxicity1–5 | Moderate — measurable VOCs and UFPs, ventilation advised[26] | Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[26] |
| Ventilation / filtration requirement1–5 | Open a window / occasional ventilation[26] | Open a window / occasional ventilation[26] |
| Dust & fibre handling hazard | Glass fibre is bound in the matrix; avoid inhaling sanding dust[1] | Not documented |
| Post-Processing | ||
| Sanding & machining | Sands poorly — the material is tough and gums rather than powders[18] | Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[14] |
| Gluing & solvent welding | Cyanoacrylate; no common solvent welds PETG cleanly[18] | Cyanoacrylate bonds TPU; no common solvent welds it[14] |
| Vapour / chemical smoothing | No practical vapour smoothing[18] | No practical vapour smoothing[14] |
| Support material pairing | Prints its own supports; Polymaker rates PolyDissolve S1 for PETG[18] | Polymaker warns TPU supports are often very difficult to remove[14] |
| Solvents & Solubility | ||
| Soluble in | No common workshop solvent; dichloromethane — a carcinogen — dissolves the matrix surface, 1,2-dichloroethane destroys it in a week.[27][28] | DMF, DMSO, NMP and THF dissolve TPU; acetone, MEK and cyclohexanone are partial solvents. All laboratory reagents.[29] |
| Softened or crazed by | Acetone (+16 % weight over 1 year at 23 °C), ethyl acetate, toluene and DMF swell and soften it; methanol crazes it.[27] | Toluene and benzene swell it up to +50 % by weight at 23 °C; esters swell it severely; ethanol and IPA soften it.[29] |
| Solvent welding & smoothing agent | Dichloromethane reaches only the resin, so the fibre is left standing proud of the surface. Controlled carcinogen.[28] | None practical — the true solvents (DMF, THF, NMP) are laboratory reagents and leave the joint swollen and weak.[29] |
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
- Fiberon PET-GF15 Technical Data Sheet V1.0 Polymaker · 2026-08 · tds
- NinjaFlex 85A Technical Specifications NinjaTek · 2026-08 · tds
- Filaflex 82A product page (Shore hardness and elongation) Recreus · 2026-08 · vendor
- Ultrafuse TPU 85A Technical Data Sheet (Version 3.0) BASF Forward AM · 2022-08 · tds
- ELEGOO product catalogue ELEGOO · 2026-08 · vendor
- Polymaker product catalogue Polymaker · 2026-08 · vendor
- 3DXTech product catalogue 3DXTech · 2026-08 · vendor
- Siraya Tech Flex TPU 85A Filament — product page Siraya Tech · 2026-08 · vendor
- Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
- add:north TPU Pro Matte 85A product page add:north · 2026-08 · vendor
- Prusament PETG Technical Datasheet v1.1 Prusa Polymers · 2022-02 · tds
- PETG — material basics Polymaker Wiki · 2026-08 · doc
- Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
- TPU — material basics Polymaker Wiki · 2026-08 · doc
- Wet Filament — signs, causes and drying Polymaker Wiki · 2026-08 · doc
- Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
- Composite materials filled with carbon, kevlar or glass Prusa Knowledge Base · 2026-08 · doc
- PET and PETG — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
- NinjaTek technical specs comparison chart (Cheetah, NinjaFlex, Armadillo, Alloy 910, Nylon 645) NinjaTek · 2026-08 · tds
- Extrudr PETG vs PCTG vs XPETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
- Prusament PETG-CF vs PETG V0 vs PETG — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
- BambuLab PETG Basic vs Translucent vs PETG-CF — results spreadsheet My Tech Fun (Igor Gaspar) · 2026-08 · test
- BambuLab TPU 95A HF vs Qidi TPU 95A HF — results spreadsheet My Tech Fun (Igor Gaspar) · 2024-02 · test
- Mechanical Properties of Additively Manufactured Polymeric Materials — PLA and PETG — For Biomechanical Applications Polymers 16(13):1868 · 2024-06 · paper
- Effects of Fiber Orientation on the Coefficient of Thermal Expansion of Fiber-Filled Polymer Systems in Large Format Polymer Extrusion-Based Additive Manufacturing Materials 15(8):2764 · 2022-04 · paper
- 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
- Eastman Spectar copolyester — Chemical resistance (unstressed bars, 1 year at 23 °C) Eastman Chemical Company · 2026-08 · tds
- Improve your 3D prints with chemical smoothing Prusa Research · 2026-08 · doc
- Elastollan — Chemical properties: swelling and chemical resistance BASF · 2026-08 · tds