Binder Jetting

Binder jetting joins powder particles using a liquid binding agent sprayed by an inkjet print head, with no heat during printing.

Working principle

1. A recoater spreads a thin layer of powder on the build platform.
2. The print head moves in X and Y and deposits binder droplets where the part exists.
3. The platform lowers by one layer thickness and fresh powder is spread.
4. After the last layer, the part is left to cure, then removed and the loose powder cleaned off (the powder acts as support).
5. Depending on the material, the green part is sintered, infiltrated with resin or metal, or finished.

Materials

Metals (stainless steel, Inconel), ceramics, sand, gypsum, polymers.

Advantages and limits

Advantages	Limitations
No supports needed	Green parts are fragile
Fast and low cost, large build volume	Shrinkage on sintering
Full colour possible (gypsum)	Lower density and strength than laser melting
No thermal stress during print	Rough surface finish

Applications

Sand casting moulds and cores, metal tooling, architectural models, full-colour prototypes, ceramic parts and medical models.

Exam tip

Draw the powder bed with print head and roller; mention sintering or infiltration.