3D Printing InfoFilament comparison
Magnetic vs TPE SEBS
Compare printing settings, strength, heat resistance, dated prices and sources.
2 selected · all documented properties
| Property | Magnetic filamentSPECIALTY | TPE (SEBS)FLEX |
|---|---|---|
| Market snapshot | ||
| Listing priceUSD/kg; dated snapshots | $64.99/kg median; $64.99–$64.99/kg across 1 dated product listings | $98.25/kg median; $76.50–$120.00/kg across 2 dated product listings |
| Identity & Market | ||
| Base polymer / chemistry | PLA loaded with ferromagnetic iron powder, so printed parts respond to magnets[1] | Styrene-ethylene-butadiene-styrene thermoplastic elastomer — a styrenic rubber, not a polyurethane[2] |
| Densityg/cm³ | About 1.85 (Proto-pasta manufacturer figure) — 1.5× standard PLA[1] | 1.044 printed part density (BASF Ultrafuse TPS 90A, ISO 1183-1) — the lightest elastomer here[2] |
| Typical priceUSD/kg | 1 kg spools cluster near 65[3] | 1 kg-equivalent spools cluster near 77[4] |
| Price range across brandsUSD/kg | 64–70 across formats; 1 kg spool 65, 500 g 70, 2 kg 70[3] | 77 for the Recreus 600 g spool; Proto-pasta only lists a 50 g coil, which prices at 120[4][3] |
| Market availability1–5 | Niche, a handful of specialist brands[3] | Niche, a handful of specialist brands[2][3][4] |
| Spool sizes & diameters | 1.75 and 2.85 mm; 0.1, 0.5, 1 and 2 kg spools[3] | 1.75 and 2.85 mm; 0.05 and 0.6 kg spools[2][4] |
| Typical applications | Sensor targets, magnetic fixtures, and props that need to stick to a magnet or rust deliberately[1] | Soft-touch overmoulds and skin-contact parts where a non-polyurethane elastomer is wanted[2] |
| Printing Parameters | ||
| Nozzle temperature°C | 192 (Proto-pasta)[1] | 260–280 (BASF Ultrafuse TPS 90A) — far hotter than any TPU here[2] |
| Bed temperature°C | 60 (Proto-pasta)[1] | 70–90 (BASF Ultrafuse TPS 90A)[2] |
| Enclosure / chamber requirement1–5 | Open frame is fine[1] | Open frame is fine[2] |
| Bed surface & adhesion aid | Not documented | PEI sheet or painter's tape; Polymaker warns TPU can over-stick and advises a glue stick as a release agent[5][6] |
| Maximum volumetric flow (mm³/s; see test conditions)mm³/s | 1.6–2.4 at Proto-pasta's 20–30 mm/s on a 0.4 mm nozzle at 0.2 mm layer[1] | 0.8–2.4 at the 10–30 mm/s BASF specifies on a 0.4 mm nozzle at 0.2 mm layer — the slowest material in this group[2] |
| Overall printing difficulty1–5 | Intermediate — dry filament and a tuned profile; slow, and brittle in filament form[1] | Advanced — enclosure, hardware upgrades, tuning[2] |
| Extruder requirement | Proto-pasta advises an extrusion width 0.05 mm larger than the nozzle and warns feeding is inconsistent below 0.4 mm and on Bowden machines[1] | Nozzle 0.4 mm or larger; BASF caps print speed at 10–30 mm/s[2] |
| Hardware Wear & Reliability | ||
| Nozzle hardness required1–4 | Brass acceptable; hardened steel for volume work[1] | Brass fine indefinitely[7] |
| Abrasiveness1–5 | Moderately abrasive — metal fill[1] | Non-abrasive[7] |
| Nozzle clog risk1–5 | Moderate — needs dry filament and a clean nozzle; Prusa lists metal-filled composites as a higher clogging risk and recommends a 0.6 mm nozzle minimum[8] | Moderate — needs dry filament and a clean nozzle; BASF caps print speed at 10–30 mm/s and Simplify3D warns that raised feed rates on flexibles most likely end in a jam[5][2] |
| Hotend requirement | Proto-pasta recommends a wear-resistant or larger nozzle for longer service intervals[1] | No special hot-end required, but a direct-drive extruder is (Simplify3D)[5] |
| Moisture Behaviour | ||
| Moisture absorption (hygroscopicity)1–5 | Not documented | Negligible (<0.1 % EMC) — BASF states drying is not necessary, unique among the elastomers here[2] |
| Drying temperature & time | Not documented | None — BASF states Ultrafuse TPS 90A arrives in a printable condition and drying is not necessary[2] |
| Symptoms when wet | Not documented | Bubbling and popping at the nozzle, stringing and a rough surface[9] |
| Effect of moisture on strength | Polymaker rates PLA low-sensitivity and publishes no dry-versus-conditioned figures; absorbed water flashes to steam and shows as bubbling and poor layer adhesion[9] | Not applicable — the SEBS chemistry has no amide or ester linkages to take up water, and BASF specifies no drying at all[2] |
| Storage requirement | Not documented | Sealed with desiccant; often kept in a dryer during the print[9] |
| Mechanical Properties | ||
| Brittleness1–5 | Brittle — Proto-pasta describes the filament as more brittle than standard PLA and needing extra care in handling[1] | Very ductile — bends far before failing[2] |
| Hardness (scale-specific)Shore A / Shore D / Rockwell | Not documented | 89 Shore A and 29 Shore D (BASF Ultrafuse TPS 90A, ISO 7619-1)[2] |
| Creep resistance / sustained load1–5 | Not documented | Poor — no SEBS creep test; a printed 95A TPU bar crept from 74.5 to 82.7 mm over 5 days at 1.25 kg[10] |
| Fatigue / repeated-flex resistance1–5 | Not documented | Excellent — living hinges viable[6] |
| Elasticity / flexibility1–5 | Rigid[1] | Rubbery / highly elastic[2] |
| Wear resistance & friction | Not documented | Abrasion 111 mm³ (ISO 4649) — the poorest abrasion resistance in this group, well behind TPU[2] |
| Thermal Properties | ||
| Melting point / Vicat°C | Not documented | 242–249 melting (BASF Ultrafuse TPS 90A, ISO 11357-3)[2] |
| Environment & Chemical | ||
| UV resistance1–5 | Not documented | Good — years with some colour shift; Polymaker lists UV exposure among the conditions TPU withstands[6] |
| Outdoor durability | Deliberately rustable — Proto-pasta markets the iron content as oxidising when exposed to moisture[1] | Not documented |
| Chemical resistance | Not documented | Withstands industrial solvents and UV exposure (Polymaker)[6] |
| Water / humidity resistance in service1–5 | Not documented | Excellent — essentially unaffected[2] |
| Food contact | Not documented | Not food safe without specific certification (Polymaker)[6] |
| Biodegradability / compostability | Not documented | Not biodegradable[6] |
| Recyclability | Not documented | Not accepted in household plastic collection[6] |
| Electrical & ESD properties | Ferromagnetic: Proto-pasta states it responds to magnets and behaves similarly to pure iron[1] | Not documented |
| Health & Safety | ||
| Fume toxicity1–5 | Low hazard — minimal VOC and particle emission; none of these materials was in the chamber study[11] | Low hazard — minimal VOC and particle emission; TPU was not among the nine filaments in the chamber study[11] |
| Ventilation / filtration requirement1–5 | Open a window / occasional ventilation[11] | Open a window / occasional ventilation[11] |
| Post-Processing | ||
| Sanding & machining | Polishing and deliberate rusting are the intended finishes[1] | Difficult to sand or smooth; Polymaker limits post-processing to trimming or tumbling[6] |
| Gluing & solvent welding | Not documented | Cyanoacrylate bonds TPU; no common solvent welds it[6] |
| Vapour / chemical smoothing | Not documented | No practical vapour smoothing[6] |
| Support material pairing | Not documented | Polymaker warns TPU supports are often very difficult to remove[6] |
| Solvents & Solubility | ||
| Soluble in | Chloroform dissolves the PLA matrix and leaves the iron powder behind; laboratory reagent, not workshop stock.[12][1] | Toluene dissolves SEBS at room temperature — Kraton quotes solution viscosity at 25 % mass in toluene, 25 °C.[13] |
| Softened or crazed by | Acetone and ethyl acetate plasticise the matrix rather than dissolving it; water attacks the exposed iron.[12][1] | Soaking in hydrocarbon solvents and oils deteriorates it; short exposures are tolerated. Resists water, acids and bases.[13] |
| Solvent welding & smoothing agent | None — PLA has no workshop-safe solvent, and the iron loading blocks the surface flow smoothing needs.[12] | Toluene will weld it, though the joint stays soft; no workshop-safe agent, and vapour smoothing is not practical.[13] |
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
- Magnetic Iron PLA — product page and technical data Proto-pasta · 2026-08 · tds
- Ultrafuse TPS 90A Technical Data Sheet (Version 1.1, SEBS) BASF Forward AM · 2020-12 · tds
- Proto-pasta product catalogue Proto-pasta · 2026-08 · vendor
- Recreus product catalogue Recreus · 2026-08 · vendor
- Flexible (TPE/TPU) — Ultimate 3D Printing Materials Guide Simplify3D · 2026-08 · doc
- TPU — material basics Polymaker Wiki · 2026-08 · doc
- Extrudr Product Catalogue (DURAPRO PA12 data block) Extrudr · 2025-03 · tds
- Composite materials with metal or wood particles Prusa Knowledge Base · 2026-08 · doc
- 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
- 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
- Solubility Study of Ingeo Biopolymer Grades in Common Organic Solvents (NWPD003) NatureWorks · 2019-10 · tds
- KRATON polymers Grade Range — chemical resistance and toluene solution data Kraton Corporation · 2025-07 · tds