Category:3D printing (powder-bed)

Powder-bed 3D printers are not normally used by the hobbyist community.

A layer of powder is laid down on the printer bed, and the moving print head then typically either melts it with a laser, or sprays it with water (if the powder is a plaster-of-Paris-like material). The print head then raises (or the bed drops), a new layer of powder is laid down, and the process repeats.

Once the process is finished, the print bed "tank" is filled with a mass of loose powder containing the final printed objects – the objects can be retrieved, and the unused loose powder reused.

Advantages

The advantage of a powder-bed printer is that the loose powder supports the object while it's being created, complete with overhangs, floating or even completely disconnected parts, which is perfect for awkward shapes and models with moving parts such as gearwheels. This means that -- unlike a filament 3D printer or resin 3D printer, a design that meets basic requirements can be almost guaranteed to print perfectly, in any orientation, without the user (or an operator) having to create additional temporary supports. A model can be powder-printed "in mid-air", with unconnected or free-moving parts, and will be fully supported during the print by the remaining loose powder.

Because the models can be packed into the print volume any way up, and directly above and below each other, a commercial powder-bed printer operator will typically try to arrange as many different client models as possible inside the available print volume and print them all at the same time. This reduces the amountof time per model spent waiting for the print to finish, and sieving and re-certifyingthe unused powder for re-use.

Powder-bed printers can typically only use one material, and are usually better suited for commercial or "3D print bureau" use than for home operators, due to the potential for mess, and the need to invest in a "full tank" of print powder before one can start.

Specialist applications

• In theory, one could use nozzles to spray water or dye onto dry plaster powder (or an icing sugar mix) to make large plaster or large edible icing-sugar models.

• A glue and metal powder mix can be used to create delicate intermediate "metal powder" models, that can then be carefully packed in clay and fired in a kiln to burn off the glue and sinter the metal to produce solid metal pieces. This can produce complex metal parts for engineering (although they may need to be deliberately printed oversize to account for shrinkage, and perhaps finished by machining).

• A ceramic powder and glue mix can be used to produce intermediate ceramic models, that can be fired to remove the glue, then dipped in glaze and re-fired to create items of pottery (a lot of the strength of these items will come from the glaze).