Material Jetting: Key Applications, Processes, and Cost Considerations

Material jetting’s limitations are:

1. Plastic components printed by material jetting have some sensitivity to light and will degrade in elevated UV environments.
2. Material jetting materials tend to be among the highest-priced, often exceeding $1000 per kg.
3. The equipment is among the most expensive in the sector to both buy and operate.
4. As the printheads handle viscous and curing fluids, it is necessary for clearing processes to be carried out during and after builds. This increases material consumption and labor costs.
5. The water-soluble build-support materials result in the need for a delicate post-process to wash away supports.
6. Some methods require a UV cure post-processing to cure the resins fully.
7. Build envelopes are generally small (below 300 mm per axis).

How Detailed is Material Jetting?

The nature of the processes used in material jetting applications results in the highest practical resolutions in all three axes. Printed parts can achieve dot resolutions in the printed image (slice) approaching that of paper printers. 

The Material Jetting Process - How it Works

The material jetting process in 3D printing works by jetting the materials. Depending on the material, two processes can be applied—either a bubble-jet process (for volatile materials) or a piezo jetting mechanism (for non-volatile materials). The flow of droplets from the printhead is also variable between technologies. DOD systems eject a single droplet when instructed. The material traverses the limited-port-count printhead in X-Y to the next droplet positions, depositing individual drops of print material. PolyJet, on the other hand, acts in the same drop-on-demand way, except that the printhead is wide and contains many jetting ports that are individually addressed. Droplets land in pre-defined positions on the table and coalesce to form a precise “picture” of the model slice. 

Curing or hardening is dependent upon the nature of the materials. Volatile materials will immediately cool and solidify, once they hit the cooler build surface. UV-cured resins, on the other hand, will cool on the surface and their viscosity will rise to allow them to gel sufficiently to stay in place. A UV lamp will then pass over them, fully or partially curing the catalyzed cross-linking that results in a solid polymer. For some wax printers, a fly cutter passes over the printed and hardened surface, to provide a smooth, flat platform for the next layer to be applied to. In all cases, once a slice is printed, the table will drop by one layer thickness to allow the next vertical layer to be applied.

For more information, see our guide to 3d printers.