In the age of large scale FDM 3D printing, there are a number of limitations with typical filament extrusion systems. By incorporating an extrusion system that extrudes directly from plastic resin instead of filament, a number of these limitations can be avoided. 3D printing with plastic pellets has several benefits which include faster print times and lower cost. Titan Robotics recently partnered with Push Plastic to design and build a pellet extruder that fits on Titan’s flag ship large-format 3D printer, the Atlas. (See video below)
By eliminating part of the manufacturing process, the price to print parts can be much more affordable.
Instead of melting down plastic pellets and extruding it into filament, the pellets are melted and extruded directly onto the 3D printer bed. Consider this, 1kg of filament can cost anywhere from $20 to $30, but the same amount of plastic in pellet form costs $2 to $5 and are widely available.
Another advantage is speed. Speed can be a limiting factor when 3D printing large objects. When strength and speed of production are of utmost importance, pellet 3D printing is the best solution. Pellet extrusion can push plastic three times faster than high volume filament extrusion. At Titan Robotics, we’ve achieved flow rates of 5 lbs per hour with a 3mm nozzle and feed rates of 7,000 mm a minute with 1 mm nozzle. With further modifications, we hope to increase the flow rate up to six or seven pounds per hour. Compared to filament extrusion, you’d be lucky to reach a flow rate of 7 lbs over an entire day.
Titan Robotics is also pushing the envelope of pellet 3D printing by using a heated enclosure with the extrusion system.
Most pellet extrusion systems are open air which limits them to materials that do not warp or that are highly filled with carbon fiber. Titans pellet extruder will be able to print with high temp plastics such as unfilled ABS, and Polycarbonate resin. So far, open air test prints with PLA and HIPS resin proved to be extremely successful. Titan is currently working on optimizing printing in an enclosure with ABS and Polycarbonate.
So how did Titan do it? Thanks to Push Plastic, Titan was able to swap out a traditional filament extruder with the pellet extruder directly onto the Atlas.
Because the Atlas is a robustly designed machine, no other auxiliary equipment was needed to adapt the system for pellet extrusion.
This type of affordable pellet extrusion 3D printing is groundbreaking in the 3D printing industry. This 3D printing method is ideal for those looking to combine additive and subtractive manufacturing, where a part is quickly printed using a pellet extruder and then finished with a CNC machine.