Dear A.N. Alobiedy ,

It would be good to understand a bit better what is your polymer, your powder, and also which type of 3d printing are you considering.

Just a couple of comments to illustrate: if the polymer can be melted, then melting it, mixing the powder and extrusion 3d printing might be a good approach. If the polymer can be dissolved, then adding a solvent that afterwards can be evaporated might be useful to achieve a good dispersion of the micropowder. If you are considering material jetting, then the nozzles should be big enough to allow the microparticles to be printed, and so on.

Dear Agustin Forchetti Casarino ,

To provide more context, the polymer type I will use PLA (Polylactic Acid) or PCL, and the powder type is barium titanate BaTiO3. The purpose of mixing these materials is to create a filament or pellets suitable for use in FDM (Fused Deposition Modeling).

I have a few follow-up questions to better understand the process:

Any guidance or recommendations specific to this combination would be greatly appreciated.

Thank you for your assistance.

Dear A.N. Alobiedy ,

Good to know. Let's see. PLA is what is called a thermoplastic polymer (this means that it can be melted when heating and it will the solidify again to its original "form" when cooling). Being that the case, and considering your approach of creating filaments or pellets, the extrusion process would be the best thing to do.

I would use this approach:

1) In a rolling mill, or ball mill, mixing both materials, and grinding them as much as possible, to obtain a powder mix of the particles and the PLA.

2) That mix should go into an extruder (which is mainly composed by an screw, that is spinning), in which everything will mix accordingly. In this stage, normally in the extruder you can approach 200C, causing the melting of the polymer and a good dispersion of the particles within this melted matrix.

3) After that extrusion stage, when cooling, the polymer+particles material can be pelletized (because it will solidify), or you can directly obtain a filament that can go in the FDM printer. To do so, the diameter of nozzle in the extruder is an important detail to take into account.

I found a couple of articles that explain a bit about this, but with other particles, but the approach should work: Article Poly (lactic acid)/titanium dioxide composites: Preparation ...

Article The Development of Biocomposite Filaments for 3D Printing by...

Since you have PLA, the approach of using solvents should be avoided, so for your observation number 1, I would not consider trying it at the moment. Nevertheless, to answer your question, when eliminating solvent you theoretically should obtain a solid again, but you should be careful, because sometimes some solvent molecules might get entrapped into the solid, causing bubbles or defects. If this solvent is trapped, and then you decide to heat the solid to melt it (because you are printing something), that solvent will be released as a vapour, and that might be a problem. Normally when using solvent, the idea is to use as less as possible and with a low boiling point, so it can be easy to eliminate.