Binder Jetting
Process description
The Binder Jetting process is very similar to that of powder bed fusion, except it uses a chemical binder to bond material together instead of melting the material together. In this process, a layer of a powder material is placed onto the whole print bed, a liquid binder is placed on the needed material, and then another layer of powder is layered on top. After the process is complete, the part is left in the powder bed to let the binder fully cure and then cleaned of excess powder.
Strengths & Weaknesses
Strengths
- Low energy: since it requires no melting of materials binder jetting is a very low energy printing technique
- Material flexibility: binder jetting can be printed with any powder material that can be held together with a liquid binder
- Scalable: because the print heads needs to deliver very little binder in relation to the volume of the final part
- No need for supports: very similar to powder bed fusion the excess powder acts as natural supports
Weaknesses
- Material properties: straight out of the printer binder jetting parts tend to be weaker then other am types
- Surface finish: the surface finish is entirely dependent on the powder material used
- Post processing: in order to increase the material properties extensive post processing is sometimes needed such as injecting extra binder, more cure time, or metal sintering.
| Low | High | |
|---|---|---|
| volume X/Y/Z (mm) | 254/381/203 | 800/500/400 |
| resolution (mm) | .5 | .03 |
| layer height (um) | 80 | 100 |
Technologies
There are a number of specific technologies that can vastly change to capabilities of a printer.
- Multi color printing: using a powder of a neutral color allows the binder to both fuse and dye the colors of prints. this makes binder jetting one of the easiest technologies to create multi color printers for.
- Metal sintering: using a temporary binder to hold metal powder together for a further sintering to fuse the powder. this allows binder jetting printers to create metal parts, but this requires heavy post processing and parts must be printed at a larger scale to account for shrinking
- Electron beam melting: this technology uses a stream of electrons instead of a laser heat source. this results in much cleaner parts
References
Rosen, Stucker, and Khorasani, Additive Manufacturing Technologies, chap. 8.
“Binder Jetting - BJ | Make.” Accessed October 6, 2023. https://make.3dexperience.3ds.com/processes/binder-jetting.