In 3D printing, it is generally assumed that you can only print with one material at a time. This is because swapping between spools of filament multiple times per layer for dozens or hundreds of layers is a massive pain. While you could occasionally swap to a different color filament, this would likely be just for color banding rather than for a specific part of a layer.
The concept of printing with multiple different materials is even more difficult. Unless their printing temperatures and requirements are similar, they can be hard to combine. Printing a high-temperature material on a low-temperature one would likely cause the low-temperature one to melt again.
What Options Are There?
Despite this, though, there are solutions. In FDM, there is a small selection of tools that can automate the process of switching filaments. They do so by splicing them together into one filament. One example of this is the Mosaic Palette. It uses Bowden tubes to guide filaments and then splices them together in the required colors.
To prevent impurities, you need to clear the melting chamber of the nozzle before you can use it. Depending on the implementation, you can use this clearing process to make internal structures for which color is irrelevant. Alternatively, you can use a purge tower to clear the nozzle.
Dual- or Multi-extruder printers have a much easier time as each filament can be fed into each nozzle. This is primarily used to print dissolvable support structures but can create prints with multiple main materials. The main downside of multi-nozzle printers is that they are more prone to oozing.
Material jetting is another 3D printing technology that can create multi-material prints. In fact, it is easy to do so as there are dozens of nozzles to which the automated material can be easily managed. The fact that material jetting also uses resins rather than filaments also means that different printing temperatures and requirements are not an issue.
Being able to create prints with multiple materials gives a range of advantages. For example, the potential for dissolvable supports or pieces with a range of mechanical properties. Have you made any multi-material prints? What was your experience with it? Let us know down below.