Remelting 3D printed thermoplastics – The salt method [video]

CNC-kitchen on youtube does some great experiments in unique ways to reinforce 3d prints. His latest video is a slightly more involved version of the salt method where he casts the prints in plaster and then re-melts them. I have been looking at going one step further and using a burn-off filament to make a mold for metal casting.

https://www.youtube.com/watch?v=bG8dlxTX3AI&t

Any system in equilibrium will tend to keep its shape or deform predictably if viscosity is high. I exploit that in a rapid printing method I've developed. It prints directly into a stable volume using various methods such as focused energy or a moving planar array. The potential active printing speed is limited only by the data transfer speed into the volume. A secondary locking step is passive and allows the system to lock (cure or cool etc) in place without further input.

Relating my process to the linked technique, some of the parts could have been made of plastic powder placed precisely in the salt. The baking step could still be performed and the parts would be almost identical.

Imagine 10,000 tiny hourglasses in an array that can switch between depositing plastic or salt. They switch on the fly to leave plastic in the salt matrix. You can see how the speed could go up dramatically.

He mentions grinding the salt - hyper fine salt is available as "popcorn salt" at restaurant supply stores. There may be anti-caking ingredients added it it that may not be desirable however.

This is fantastic. Of course the salt-molten plastic interface and relative densities must be critical. Salt is quite a bit denser...

I wonder if this could accommodate sonication.