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How to Anneal PLN for Stronger 3D Printed Parts

How to Anneal PLN for Stronger 3D Printed Parts

Boost heat resistance and performance with this simple post-processing technique.

If you’re printing parts that need better heat resistance and durability, annealing your PLN or PLA prints is a smart upgrade. This guide walks you through the process to get professional-level results using everyday tools.

For the PLN, the annealing process enables it to reach a heat resistance of up to 175ºC.

What Is Annealing in 3D Printing?

Annealing is a heat treatment that improves the internal structure of polymers by increasing crystallinity.

  • Better heat deflection temperature

  • Stronger, stiffer parts

  • Improved dimensional stability over time

  1. Preheat Oven
    Set to 80–110°C (176–230°F). Lower temps are safer, higher temps provide more crystallization.

  2. Measure Dimensions
    Use calipers to measure the X, Y, and Z axes before annealing.

  3. Place in Oven
    Lay the part flat. Avoid placing supports or overhangs inside, these may deform.

  4. Heat for 30–60 Minutes
    Time depends on part size and wall thickness.

  5. Cool Slowly
    Turn off the oven and leave the door closed until fully cool. Sudden changes in temperature can cause warping or cracks.

  6. Re-measure
    Expect slight shrinkage typically 1–5%. Adjust designs accordingly if needed.

Tips for Best Results

  • Test with a calibration part before annealing a final print

  • Use high infill (50–100%) for better strength

  • Choose annealing-optimized PLA when available

  • Don’t anneal parts with delicate support structures

 

When to Use Annealed PLN?

Annealed PLN is ideal for:

  • Functional parts exposed to heat

  • Prototyping for outdoor or automotive environments

  • Custom tooling with higher mechanical demands

Final Thoughts

Annealing is a simple but powerful method to enhance the performance of your PLN prints, especially when using 3D printing in professional or industrial settings. With just a convection oven or, as a last resort, an air fryer, along with a bit of patience, you can create stronger, more heat-resistant parts without needing to switch to more complex materials. While manufacturing jigs, fixtures, or molds can be beneficial, they are not strictly necessary since PLN already offers high performance.