Today HP announced the Metal Jet printer, an industrial-scale 3-D printer that builds items not of plastic but of steel.
3-D plastic printing is widely used for custom items such as prosthetics and hearing aids, and by product designers for prototyping. But it's still a relatively small part of overall manufacturing. That's because, compared with more traditional mass-production techniques, 3-D printing is relatively slow and expensive and can be used with a more limited range of materials.
HP is trying to change that. In 2016, it launched its Jet Fusion plastic 3-D printer, designed for mass production rather than one-off printing. Now with the Metal Jet, it wants to get into big manufacturing sectors such as automobiles and medical devices.
For now, many of the products printed by the Metal Jet may be cosmetic—key fobs with custom engravings, for example. It will likely be years before you can buy a car with 3-D-printed metal parts under the hood.
HP is using a different process, known as binder-jet printing, which Weber says is cheaper and more efficient. The Metal Jet printer, which looks a bit like a washing-machine-sized photocopier, spreads layers of metal powder and then sprays it with a binding agent to solidify it in a process not unlike layer-by-layer 3-D printing. These items, essentially made of glued-together metal dust, aren't very sturdy; you can break thin pieces with your bare hands. So the initial pieces are then placed in an furnace—imagine placing cookie sheets in an oven, but instead of cookies you have a tray of car parts—where the extreme heat solidifies the powder. The final results are relatively light, smooth, and can include surprisingly fine details.