Does annealing PLA/PETG make it stronger or more heat resistant?

Annealing raises the published heat-deflection temperature of Polymaker HT-PLA. It is not a documented strength gain, and the ordinary PolyLite PLA and PETG rows in the heat dataset have no annealed condition. The part also moves. Heat, PLA creep, strength, and oven drying are the pages that stay in their own lanes. HT-PLA has the longer schedule note.

What the sheet records

Polymaker HT-PLA lists a nozzle of 210–230 °C (410–446 °F) and a bed of 25–60 °C (77–140 °F). As printed, heat-deflection temperature is 61.4 °C (143 °F) at 0.45 MPa and 58.6 °C (137 °F) at 1.8 MPa. Annealed, it is 107.2 °C (225 °F) and 71.7 °C (161 °F). The dataset lists Vicat at 156.2 °C (313 °F) for both conditions. The HT-PLA answer records a TDS-page annealed Vicat of 155.2 °C (311 °F). The product page expects about 0.3–0.6% dimensional change after 30 minutes at 80–100 °C (176–212 °F), with 100 °C (212 °F) recommended. A conflicting TDS line says 3 minutes at 80–90 °C (176–194 °F).

HT-PLA-GF moves from 75.5 °C (168 °F) to 114.7 °C (238 °F) at 0.45 MPa, and from 59.7 °C (139 °F) to 84 °C (183 °F) at 1.8 MPa. PolyLite PLA stays at 60 °C (140 °F) and 58 °C (136 °F), with no annealed label. PolyLite PETG stays at 78 °C (172 °F) and 75 °C (167 °F), with no annealed label. The order is the annealable PLA, its glass-filled grade, then the two rows the question names that do not show an anneal column. It is not a ranking of strength.

What the community says

a Reddit thread in r/prusa3d says annealing polycarbonate is stress relief because the polymer is amorphous.

a Reddit thread in r/prusa3d says XL prints warp and lose accuracy, and that small parts depend on geometry.

Questions