PET-G Thermoforming and Heat Treatment Safety

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I am planning on using PET-G in a project similar to this 3D printed arm brace. https://www.instructables.com/3D-Printed-Thumb-Wrist-Immobilization-Brace/ . The manufacturing process involves submerging the 3D printed part into a pot of boiling water to heat the plastic to its glass transition temperature, then molding it around an object like a person's forearm so that as the part cools it accurately conforms to the arm's dimensions. After that I want to use my oven to heat treat the PET-G to improve its impact resistance. Before doing any of this, I want to ensure this process won't release any harmful vapors or carcinogens during manufacturing. I know PET-G is safe to print without ventilation and is considered food safe. However, is PET-G safe to thermoform and heat treat? Thank you for your help in advance.

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Is PETG safe to thermoform and heat treat?   

 

I don't know, sorry.  Just had some other comments.  It is a higher temp material but still well below boiling and you can definitely mold it and unlike many materials is very similar to PLA in that you can thermoform it just fine.  I'm 80% sure that will work just fine as I've heated PETG and formed it before.  However it's "softening temp" is 20 or 30C hotter than PLA (I forget which) and PLA already just about burns you  when thermoforming against skin - PETG will definitely cause serious burns.  So you'll need to wear some kind of fabric covering the surface to thermoform to and where gloves for the person doing the forming.

 

It seems to me if you can heat it to 230C (or whatever the temp is) to melt it then any gasses created at 90C should be fine!

 

I know nothing about heat treating PETG.  I dont' think that will be necessary since PETG has such a higher melt temp.  You don't have to worry about it melting in a car in direct sunlight on a 40C (105F) day.  Not an issue.  Cars can get to 60C but not the temps necessary to soften PETG (or nGen or CPE).