Thermoplastic Polyurethane (TPU) coating?

So I recently started 3D printing slot, and I noticed...

TPU seems to have good incompatibility, so why don't we 3D print our own magnets with TPU filament?
It seems really intuitive and the filament would be more or less sterilized going through the extruder at 200°C and it's certainly not cost prohibitive if you have a 3D printer already.


  • did you mean "biocompatibility" instead of "incompatibility" ?
    It's not only about protecting your body from the magnet, but also protecting the magnet from your body. in terms of neodymium magnets they hate water and moisture. even tiny amounts of h2o will lead to long-term failure of the magnet. polyurethanes have a gigantic molecular structure size and will allow water vapor to pass through it at undesirably high rates (like many orders of magnitude more than you want).

    That's one of the reasons why magnets get a metal or parylene coating.

    research permeability of the materials.

    Polyvinylidenechloride might make a good thermoplastic undercoat.
    Kel-F81 if you have access to it.

    Also note that PU comes in about 4 gazillion fucktons of varieties, only very few of them qualify as long term implantation candidates. Most are full of nasty additives, stabelizers and other crap.

    About 3d printing in general, that's an additive step. You basically hot-melt several meters of a thin filament into a volume. You have to 100% (not 99,999%) ensure that every bit of your filamentpart is properly adhering. no gaps, no holes, no cracks, no cold unfused areas, preferably in a microscopically smooth surface. everything else will lead to failure of the coating or invite bacterias to do havoc.

    Coating stuff is difficult, a lot more difficult than most people realize. You'r very welcome to contribute to the research.

  • Yeah. I love thermoplastics. I really do wish it was that simple.
    Take a look at this:

    It'll give you a good idea of how different materials compare. If you do find something that seems promising, do more research and you'll probably be dissapointed. Lol.
    Like Teflon! Did you know it's a thermoplastic NOT thermoset? Sounds promising aye?
    Ha. Totally can't do any kind of extrusion, injection, or 3d printing with it.

Sign In or Register to comment.