Inkjet technology appears in additive manufacturing in two quite different roles, and the phrase powder bed and inkjet head printing names the first of them. In one, the head jets a binder into a bed of powder. In the other, the head jets the build material itself. They share a print head and almost nothing else, which is why the terminology confuses people.
Powder bed and inkjet head printing
This is binder jetting: a recoater spreads a layer of powder, an inkjet head prints binder onto the cross section, and the process repeats. The result is a fragile green part inside the powder bed, which is then depowdered, cured, and in metals and ceramics debound and sintered. The inkjet head is doing exactly what it does in a document printer, but with an adhesive.
Material jetting by inkjet
Here the head jets droplets of the build material itself, usually a photopolymer cured by ultraviolet light as it lands, or a wax that solidifies by cooling. Because several heads can jet different materials in the same layer, this is the route to multi material and full colour parts. It needs a separate support material for overhangs, which binder jetting does not.
Why the distinction matters when buying
A binder jetted metal part shrinks in a furnace and has quite different accuracy and properties from a jetted photopolymer part. A colour part from a material jetting machine is a photopolymer and will degrade in sunlight. Asking which process a supplier means when they say inkjet printing settles what you will actually receive.
Where each is going
Binder jetting is scaling into production metal parts because throughput is high and no supports are needed, with sintering distortion as the limiting problem. Material jetting remains the reference for multi material and colour models and has not become an end use process, because photopolymers do not have the durability that requires.
Questions people ask about powder bed and inkjet head 3d printing
What is powder bed and inkjet head printing?
Binder jetting: an inkjet head prints binder into a bed of powder layer by layer, producing a green part that is later cured and, in metals, sintered.
Is inkjet printing the same as material jetting?
Material jetting uses an inkjet head to deposit the build material itself. Binder jetting uses one to deposit adhesive into powder. The head is shared; the process is not.
Which one gives colour parts?
Material jetting, by jetting pigmented photopolymer. Binder jetting can also produce colour in some sandstone and polymer systems by printing coloured binder.
Which is better for metal?
Binder jetting, which sinters to a dense metal part. Material jetting of metal exists but is at an early stage compared with the established processes.