Can a hobby printer print PEEK or PEI (Ultem)?

PEEK and PEI need the hot end, bed, and chamber written on the filament's own page. Whether a given printer can hold those temperatures is a sentence for that printer's maker. Polycarbonate, nylon, heat resistance, and open printers are the neighboring subjects. Voron parts includes Voron's own refusal of PEEK and PEI.

ThermaX PEEK, two blocks on one page

The ThermaX PEEK page, read 27 October 2026, says to plan on a 360–450 °C (680–842 °F) hot end, a 120–160 °C (248–320 °F) bed, and a fully enclosed, actively heated chamber of 70–150 °C (158–302 °F). It also says most standard desktop printers cannot reliably maintain these conditions. That sentence names a class of machines. It does not name a brand or a model.

The settings chips on the same page list extruder temperature 400–480 °C (752–896 °F), bed temperature 140–180 °C (284–356 °F), a line that reads "Recommended 70-140C if possible" without naming which heater that is, and drying at 120 °C (248 °F) for 4 hours. The 70–140 °C (158–284 °F) line is not merged into the chamber sentence and not merged into the bed sentence.

The benefits list on that page gives a glass-transition temperature of 143 °C (289 °F), a continuous-use temperature of 240–260 °C (464–500 °F), and a melt temperature of 343 °C (649 °F). Glass transition is where the plastic softens. Melt is where it becomes liquid. The catalog row, Open Filament Database verified 13 October 2026, stores a nozzle of 360–420 °C (680–788 °F) and a bed of 120–160 °C (248–320 °F), and stores no chamber. Three nozzle bands are now on the record. They are not averaged.

The same page says PEKK is often easier to dial in than PEEK, and that Ultem (PEI) typically prints more predictably than PEEK. It does not give PEKK or Ultem print temperatures there.

PEI rows, catalog only

Prusament PEI in the catalog lists a nozzle of 400–420 °C (752–788 °F) and a bed of 140–160 °C (284–320 °F), Open Filament Database, verified 13 October 2026. No chamber requirement from a Prusa page was checked for this row, so none is stated. ThermaX PEI lists 340–380 °C (644–716 °F) and a bed of 120–160 °C (248–320 °F) from the same database and date. Those figures are the database cells. They are not the Ultem sentence on the PEEK page.

What Voron says about Voron

Voron's sourcing page, read 27 October 2026, says Voron chambers generally do not exceed 50–60 °C (122–140 °F), that this is insufficient for PEEK and PEI, and that those materials require chamber temperatures of 100–130 °C (212–266 °F). It says Voron printers are not designed for exotic materials and that there are no plans to change that. That is the printer's maker, about that printer. It is not a finding about Bambu, Prusa, Creality, Anycubic, or any other brand.

One comment says PEKK-A-CF gears were printed on a Core One L and that those prints need the HT90. That HT90 line is the comment. It was not copied from a Prusa specification table.

What the community says

a Reddit thread in r/FixMyPrint says they cannot imagine many people on that forum printing in PEEK.

a Reddit thread in r/FixMyPrint says a PEEK benchy would be an expensive one.

a Reddit thread in r/prusa3d says they saw PEKK-A-CF gears printed on a Core One L at Formnext, that PEKK-A is not the same as PEKK, and that you need the HT90 to print those.

Questions