A team of engineers from Northwestern University (Illinois, USA) presented HARP (high-area rapid printing) 3D printing technology. This printer has a 2322 sq. Cm liner. and with a maximum height of 4 m, it can print at a speed of almost 50 cm / h, which makes it possible to grow, for example, a full-size human figure in 2-3 hours.
HARP is based on stereolithography technology, in which molten liquid resin is cured by exposure to ultraviolet light. It appeared about four years ago and was full of shortcomings, the main one of which was too much heating. The higher the printing speed, the more intense the radiation, the higher the energy consumption, and the less time it takes for freshly created fragments to cool down. An overheated structure is prone to deformation and destruction.
American researchers have found a solution in the form of the use of "liquid Teflon" - an analogue of a non-stick liquid that flows through a transparent tube in the path of an ultraviolet ray. The liquid removes most of the heat and removes it to the cooling circuit, and the resin hardens under the radiation. This design still consumes a lot of energy, but no longer overheats. And if you figure out how to extract excess heat energy, HARP technology can become much more economical.
Another advantage of HARP, besides speed, is print accuracy. Unlike 3D printers for large parts, it uses high-resolution drawings, so the products have their final shape immediately and do not require additional processing. The developers argue that with HARP it will be possible to print so much and so quickly that it will compete with other types of production of large components for different industries. The technology will enter the market within the next 18 months.