Polymaker HT-PLA Pro Filament 1.75mm 1kg

PLA that holds its shape when things get warm. HT-PLA Pro prints like ordinary PLA — no enclosure, no hardened nozzle, up to 300 mm/s — and then you anneal the finished part for half an hour and it stops behaving like a PLA in the way that actually matters.

That's what it's for: functional parts that live somewhere hot. Brackets in a car, jigs near a heat source, enclosures for electronics that run warm. Polymaker aim it at engineers and print farms who want real durability without changing how they print.

At a glance

Worth knowing

Annealing is the whole point, and it isn't optional if the part carries a load. Straight off the plate the heat deflection temperature is 53.8°C at 1.8 MPa — ordinary PLA territory. Thirty minutes at 100°C takes that to 68.6°C, and at the lighter 0.45 MPa load it goes from 56.3°C to 107.6°C. Thicker parts need longer.

You'll see a Vicat softening figure of 148°C quoted for this filament. That's measured unloaded, off the build plate — it tells you a part won't slump sitting in a hot car, not that it will hold a bracket at 148°C. Design around the heat deflection numbers above, not that one.

Annealing trades ductility for stiffness: elongation at break drops from about 13% to 4%, while bending strength rises from 60 to 65 MPa. Expect a little dimensional movement as it anneals, so test-fit anything with critical dimensions before you commit a batch.

Storage

Polymaker specify drying at 60°C for 6 hours, and they recommend keeping this one in a dry box while you print, not just in storage — a step their data sheet calls out specifically for HT-PLA Pro.

As filament takes on moisture you'll hear popping or hissing at the nozzle, then see stringing and rough surfaces, and eventually the strand goes brittle enough to snap in the tube. That's almost always moisture, not technique — dry it and it usually comes back.