Strong 3D prints through ANNEALING, but... Part 1: PLA

Everyone, who is into 3D printing has already heard that you can anneal, temper or bake your 3D prints in order to increase strength. There is little data on this topic available, so I tested the influence of annealing on PLA in this video. There will be more videos coming with tests on materials like PETG, ABS or Nylon. I'll be investigating the myth if you can really bake your layers together when you heat treat your 3D prints. Watch and find out more!

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[xyzconceptsYT]

I have done anealing of PLA, I tried a 3D benchy. The layers fused so well, there were no layer lines to the naked eye. The Benchy was now a perfect PLA puddle.

[feliperodrigues]

Hi Sthephan! I was able to get a +300% increase in impact resistance while annealing natural PLA. I tested according to ASTM D4508, for which the sample is smaller. As printed, it broke easily, but after 20min at 95°C they did not even break, using the same pendulum. I will be publishing the results next year at the Brazilian Congress of Manufacturing Engineering (COBEF2023).

[HitsandHeadlines]

Stephan, you are a godsend for the 3d printing community. Thank you for your service

[iandawkins]

I love what you are doing, taking 3D printer to the next level and breaking new ground and dispelling urban myths on 3D printed parts. Thanks and respect.

[MisterMakerNL]

I finally get your you-tube channel name.

[CyanOgilvie]

I've annealed PLA (plain and modified) by dunking the prints into boiling water for 5 minutes, then quenching with cold water (not my original idea, saw it in a youtube vid somewhere). I mainly do it for the improved temperature resistance, but that is almost always with functional, mechanical parts that need to fit with other parts, so warping is not acceptable. I've found the boiling water method produces almost no warping at all, other than the predictable shrinkage in x and y, and growth in z. The shrinkage is predictable enough to compensate for in the slicer. I've printed a fan duct that works fine on the MK2S, a few mm from the heaterblock, printing high temperature materials, so the heat resistance is good with this approach. It's also way quicker and easier than annealing in an oven. My process is to put the part into a mug or similar and pour boiling water over it, tumble the part to get rid of trapped air bubbles, then pour in cold water after 5 minutes. Once the part dries it's ready to use.

[gianfrancolozupone]

I have tried boiling some PLA+ parts (kind of ring shaped) and letting them cool down to 40c in the water. They were thin walled parts, 2mm thick, so 10 minutes boiling was more than enough to change the temperature resistance. As a result the part was still hard at 80c while normal PLA gets rubbery at 50/55. But the same results with deformation and warping. Uneven depending on the axis. I will keep trying with other shapes and failed prints just for fun. I still think that this can be useful in parts that can be printed, annealed and then post proccesed to get the desired dimensions (sanding, drilling, etc. ). Great channel!! I really apreciate your work. Congrats!!

[ZILLIONEVER]

reacting to your question on 2:20: yes, used volcano pla (formfutura, crimps minimal, reasonnably cheap as I live in Belgium, for usa the shipping must be crazy) like you used on that coffee maker like a year ago (?) printed clotheshangers from that and they are holding up after one year of serious (ab)use : one time I noticed visitors put like 3 wet winter jackets (heavy!) on one hook and it didn't fail. Used your 'making parts stronger info' vid and did print them with 5 perimeters instead of high infill. clearly worked, thanx for all the research Stephan!!

[gannacss]

Hi!
I looked a bit into that subject previously to improve my quadcopter strength. I found that if I disabled cooling and tweeked a bit the temperatures the parts were almost not deformed after the heat treatment. Of course, disabling cooling and the temperatures affect the look and it is not suitable for all parts but if you are only looking for strength it is good and you do not need to compensate for any deformation.
Thanks for the work you do. It is quite interesting and helping. :-)

I'd like to see you test the hook that completely melted and see how it fails compared to the normal vertical hook. Great video always enjoy them thanks.

[jonwebb]

As always, this video was incredibly informative and all the testing was very detailed. You really are an asset to the 3D printing community and I've seen no other channel go into detail in the way you do. Great job man

[ElectricalInsanity]

I wonder if using a heated build chamber would make a difference in layer adhesion?

[jonathanramirez]

I just tried annealing Proto-pasta PLA in sand and had great results. I put the parts in a glass baking dish, covered in 70 mesh high purity silica sand and left a probe in the center of the sand/glass plate setup. I used a convection oven. It took about an hour to reach 100C in the middle; I held it for 10 and then turned the oven off and left everything in there to cool. I was pleased with dimensional stability of my parts.

[theKashConnoisseur]

Nylon will appear to be quite stiff and strong fresh from the oven. But take care, as the print adsorbs moisture from the air, the mechanical properties of the nylon change and it becomes more flexible and less stiff. Some people take the initial stiffness to indicate that Nylon can be stiffened from heat treatment, but they fail to acknowledge the temporary nature of it.

Annealing Polymaker's PC-Max blend will be fine, but to anneal real, pure PC prints you need a precision temperature controlled oven. We're talking being able to control temps to a 10c rise over the course of an hour sort of thing. Without such control, you might as well not bother annealing pure PC as it won't be beneficial. Of course, it's better to just print PC in a 120c chamber to begin with so there's not any printed in stresses resulting from the part cooling too fast, but most people don't have setups capable of that.

[andylindsaytunes]

You should have called this episode "Make 'em, Bake 'em, and Break 'em."

[dbaznr]

There are different results changing the infill density. 10%, 50% and 99% behave differently, especially regarding the type of deformation (uniform in X and Y). Z shrinks less, meaning that there is not a big layer fusion. Also, the deformation depends of the infill pattern used.
A ventilated oven usually distributes the temperature more evenly.
I'm not sure of the benefits of the slowdown temperature because in any case the skin remane cooler than the interior, and the process of loosing energy depends mostly from the geometry of the part, creating deformations.
I'm testing the results using the microwave oven...

[TheNorthDevonOrganist]

the expansion in one direction (generally) is caused by the oven heating up all the trapped air bubbles in the material and stretching it.

[nict]

I recently tried drilling small holes on opposite side of my print. With about 20% infill I then used a syringe to push epoxy and silicone glue through two different parts. I used a transparent filament with about 2 or 3 walls. It drastically changed the feel of the parts.

You should try testing some hooks that have epoxy or silicone in them. My only problem is that the epoxy got pretty hot.

[RentableSocks]

please try this with Esun PLA+, in my experience it performs better than standard PLA when annealing.

[anyuferrari]

Thank you very much for this information! I was looking everywhere for a plastic that can stand both about 100ºC and some steam pressure. I´ll try now with PLA, PET and HIPS and annealing them. You helped me a lot!