Engineers at the Fraunhofer Institute for Machine Tools and Forming Technology (Fraunhofer IWU) in Germany have developed a high-speed 3D printing process called Screw Extrusion Additive Manufacturing (SEAM). Standard desktop FDM (fused deposition modeling) 3D printers can output upwards of 60 grams of material per hour, but the SEAM machine can output up to ten kilograms per hour!
That equivocates to 3D printing at a rate of one meter/second, and with its 1.0 mm diameter nozzle, it can create a 30 cm tall object in only 18 minutes (though the other relevant dimensions are unknown). That blazing speed is enabled by a specially-designed screw auger system that quickly and smoothly transitions material granules through plastification. As the system was designed for industrial use, it can handle a wide variety of materials, including polypropylene and polyamide-6 with a 40% content of carbon fibers. The screw extrusion system allows for different materials to be freely mixed so different composites can be created for specific applications.
Because the material flow can’t be interrupted with filament retraction as on an FDM 3D printer, the SEAM design team developed an upstream unit that controls deposition depending on print speeds, from 0 to 100. Using a 1.0 mm nozzle, strands of material can be deposited with widths that range from 1.2 mm to 3.1 mm, enabling superior layer adhesion and the production of thick walls that result in tougher components.
Advanced Motion System
What’s more, the SEAM extruder was built around a hexapod motion system, which is a 6-axis parallel kinematics platform that can be swiveled, angled, and slid with high precision. The dynamic bed allows the 3D printer to produce complex geometries without the use of support materials; it can also print 3D contours over the stepping pattern caused by layering material at an angle, making parts smoother and stronger. Additionally, components can be added to a print in-process and the printer can print around and on top of those components. Used together, those features generate materials cost savings of up to 200%.
Manufacturers and engineers have been waiting for this kind of production capability for some time: fast, large-scale 3D printing of complex geometries with industrial-grade materials. It’s finally here and interested parties can see it in action during the Hannover Messe from April 1 through 5, 2019 at the Fraunhofer Booth C22 in Hall 2.