Additive manufacturing (AM) is changing global production, especially in the aerospace and defense industries, where large-format 3D printers produce tooling, fixtures, patterns, and molds. But while AM has been around for more than 30 years, the cost, speed, and size of available technologies have been limiting factors in addressable applications. New solutions in direct pellet-fed 3D printing and hybrid additive and subtractive approaches are making AM affordable and fast enough for implementation throughout aerospace workflow due to the wide variety and low cost of pellet feedstocks, high-throughput, and large-format, industrial 3D-printing systems.
Thermoplastic pellets are a common form of polymers used in molding applications, as well as to make 3D-printing filaments that are spooled for extrusion printing. Using pellets, which are fed directly through an extruder on the 3D printer, the feedstock reduces material costs by up to 10 times vs. traditional filament feedstocks. Beyond time and cost advantages, the diversity of polymers available with direct pellet extrusion is a significant benefit. With pellets, the right material with specific desired properties can be selected or formulated to produce industrial parts.
To enable high-production utilization, cost, part performance, and speed are key. Cutting cost per part can be achieved many ways. In addition to using less raw materials, AM can reduce labor costs by simplifying processes and enabling lights-out manufacturing. Lower capital expenditures further reduce part costs with a selection of reliable and multi-function systems. In terms of performance, pellet extrusion AM is compatible with a diverse material portfolio, including highly filled materials that are loaded with 20-, 30- or even 50 percent carbon-fiber or glass-fiber reinforcement. This allows pellet extrusion parts to be more durable and less prone to warping than typical polymer 3D-printed parts. Increased part performance is also achieved with large build volumes, cutting the need to glue or weld pieces together, which can create joining and integrity issues.
Dual-pellet-extrusion systems and hybrid-pellet and filament-extrusion systems enable printing with two materials on a single print, such as for water-soluble support structures or rigid-to-flexible features. And hybrid manufacturing with additive and CNC machining systems offer a unique solution. While manufacturers may be familiar with machining from a large block of material, this process has its own labor and material cost as well as material waste. In contrast, by quickly printing a near-net shape with pellet extrusion and then milling the part either during or after printing, a smooth, accurate surface finish is achieved without removing the part from the machine. In one shift, a ready-to-use tool or part is achieved, and less chips go to waste.
Pellet extrusion on 3D Systems’ Titan printers is proven in a wide variety of applications within the aerospace and defense industry. For example, Beta Technologies, a manufacturer of eVTOL aircraft, leveraged the large build volume and high-throughput pellet extrusion system on its Titan machine to print full-scale mock-ups of the interior cabin structures and wire-routing options. Using carbon-fiber ABS pellets, an 8-ft-tall [2.44-m] prototype was printed in eight hours using about $100 in raw material, saving the company thousands of dollars compared to outsourced filament-printed parts. Another application is recreating long-discarded sheet metal forming dies for the U.S. Air Force, which was proven using Titan’s integrated printing and machining operations and custom, low-cost pellet material to achieve the required compression strength.
Pellet extrusion and hybrid approaches combine speed, low material cost, and a selection of polymers with large build volumes to democratize AM for A&D, enabling users to apply AM throughout their workflow.
Connect With Us