Researchers from USA advanced 3D-printing speed
Engineers of the Massachusetts Institute of Technology (MIT) have improved the desktop 3D printer, that prints 10 times faster than the commercial analogues.
For example, if existing printers need almost an hour to make several Lego-sized bricks, upgraded printer copes with this task in just a few minutes.
The team has developed a new compact printhead, which integrates two components, hastening the printing.
At the first stage, Anastasios John Hart, associate professor of mechanical engineering at MIT, and his colleague Jamison Go identified the main reasons for limiting the speed of typical 3D printers. As it turned out, printing is affected by the speed of movement of the printing mechanism, force applied to push the ink from nozzle and the speed of material heating and melting.
In most 3D printers, plastic is fed through a nozzle using “pinch-wheel”, that is, the two small wheels inside the printhead rotate and push out thermoplastic via the nozzle. The process is relatively slow.
Hart and Go decided to replace this “pinch-wheel” with a screw mechanism. The plastic filament is fed onto the screw, and as the screw turned, it extruded onto the surface at higher forces and speeds.
In addition, the laser, downstreaming the screw, accelerates the heating and melting of the plastic. In conventional 3D printers, the working material is melted due to the heating of the nozzle walls, that also decreases the speed.
The laser and the screw mechanism were packed into compact printhead about the size of a computer mouse and mounted on high-speed gantry mechanism - an H-shaped frame.
However, the inventors faced a complication in their design: one layer of molten plastic does not have time to dry before the next one is fed, due to high output speed. And this, in turn, can lead to the shape of distortion.
Nevertheless, engineers use mathematical calculations trying to optimize the printhead and study new raw materials, for example, high-strength polymers, composite materials.
According to innovators, high-speed 3D printers can be applied in emergency medicine in remote locations. Such a printer can become an expedient tool for drivers when urgent repair is required.
