The Swedish company BLB Industries developed one of the largest and most productive 3D printers in the world — The BOX additive machine. The device operates on the widely used technology of fused deposition modeling of polymer materials (FFF/FDM), but it sports an important advantage: 3D printing is performed not with filaments but granules, which results in a low cost of products.
With regard to industrial 3D printers, this statement usually remains true, if only because printing functional products in parts leads to a decrease in strength, and adds the necessity of assembly, gluing, and post-processing. It is better to print large-sized parts entirely in one go. When it comes to large-format polymer 3D printing, there are several options to be considered
For example, the Israeli company Massivit offers a monstrous Massivit 1800 photopolymer 3D printer, in which resins have to be poured literally in buckets due to the huge build area reaching 1.2 x 1.5 x 1.8 meters. The machine prints quickly, curing about a kilogram of material per hour. It’s just that a liter of resin costs about 200 dollars, and the finished products are not distinguished by particularly high strength, being completely polymer-made. Basically, such devices are used in the manufacture of advertising and decorative products.
Another option is large-format FDM 3D printers such as the German BigRep ONE. These devices are capable of printing parts with a volume of one cubic meter and, in general, are no different from desktop FDM printers, except for size and weight. You cannot put such a colossus on the table, but the problem is not even in that, but again in the cost of consumables. Even though polymer filaments are cheaper than photopolymer resins, printing large-sized parts is still expensive.
Finally, there are real monsters like Cincinnati Incorporated's BAAM 3D printers. These giants print objects up to 6 x 2.3 x 1.9 meters sized, normally using ABS plastic reinforced with carbon fiber. It is on such systems that cars and unmanned minibuses from Local Motors are printed. There can be no question of any filament here, because in this case, printing would take too long, and the cost of products would be prohibitively high. That is why the developers decided to switch from filament to granulate, extruding molten polymer through a nozzle with a screw extruder. An additional advantage of such a scheme is to reduce the cost, because the granulate is the raw material for the manufacture of filaments.
But, it is true that such equipment is rather costly; besides, you would need a separate workshop. The Swedish company BLB Industries decided to offer a more compact option that uses the same affordable granulate and prints at a sufficiently high speed not only for prototyping but also for serial additive manufacturing. The machine called The Box uses an FGF (Fused Granular Fabrication) screw extruder with a maximum temperature of 400 °C.
The build volume of the base model is 1.5 x 1.1 x 1.5 m, while the performance of the extruder equipped with a liquid cooling system reaches an impressive 6 kg per hour. The size of the standard nozzles varies between 0.4 and 8.0 mm.
A vacuum print bed and heating of the build platform are provided to deal with delamination and detachment. ABS, PLA, polycaprolactone, high-impact polystyrene, polyamide-6 with 40% carbon fiber filler, as well as various polylactide-based composites imitating wood, metals, and so on can be used as consumables.
Additionally, the manufacturer accepts individual orders for customized options. For example, for NorDan AB, the Swedish engineers prepared a device with a dual extruder and a build volume of 2.5 x 1.5 x 1.5 m (pictured above), that is, with a chamber of more than five and a half cubic meters. If desired, the machine can even be extended to the length of a sea container.
