How To Anneal Your 3D prints

anneal

 /əˈnēl/
verb
heat (metal or glass) and allow it to cool slowly, in order to remove internal stresses and toughen it.
how to anneal
You may be wondering why would we want to do this to 3D printed plastics or does this actually improve the quality of your prints? The short answer is yes. It will make your 3D prints more durable and more temperature resistant. Basically when you 3D print you are extruding plastic layer by layer and when you anneal it will bond those layers much better resulting in a more solid structure.
 
I have to start by saying not all plastics can be annealed but NatureWorks 3D870 plastics found in the 3D Fuels Pro filament line have a special additive that allows them to be annealed. The parts you are annealing will also have to be printed solid. You also may experience some warping and shrinkage during this process. Some testing will be required. Do this at your own risk.
Don’t try this with other plastics as it might just melt and make a mess!
 

How to anneal general instructions

1. Preheat oven to 80C – 90C (176F – 266F).
2. Place print on a baking sheet at room temp.
3. Wait 30-60 min for anneal to complete
4. Remove print and turn off oven.
 
The shrinkage and warping depends on the geometry of the object. Some have tested with a water bath annealing process using a sous vide cooker. This can provide a more even head distribution through the part.
Some have tried by encasing the part in heated sand. This will help reduce any warping that may occur. The finer the sand the smoother the finish will be.
I have also heard of people grinding salt to a very fine powder and using this to anneal their prints.
 
Let us know which meathod worked best for you!