Composites Manufacturing - Winter 2022

CompositesManufacturing 10 “We have a proprietary extrusion mechanism and proprietary algorithms that guide the robot through the path,” says David Goodloe, Branch Technology’s program development manager. “The material actually solidifies in free space as extruded, allowing us to print as if the robot was a giant pen tracing a three-dimensional path through the air and leaving behind a reinforced polymer in its wake.” The result is volumetric lattice structures that have strength similar to comparable solid forms but use 20 times less material to build. If additional strength is needed in one area of the structure, the size of the honeycomb cells can be varied to increase the structure density in that location. Branch Technology works with a palette of materials that includes pelletized thermoplastic polymer resins with chopped carbon fiber and various additives. The company currently has 14 robots, 12 for printing and two for milling. “Each one has its own build envelope, so we upload a specific part to a specific robot, and it prints that part within its own designated work cell,” explains Goodloe. Although the robot can print parts 30 feet long, 10 feet wide and 12 feet high, most parts range around 15 x 8 x 8 feet. Goodloe notes the size of the composite parts is usually constrained by logistical choke points such as a doorway or a truck, not by the printing technology. Branch has three products. Branch Matrix™ is the exposed lattice structure of polymer resin and fiber additives. “It’s for architectural and sculptural applications – big, sweeping geometries,” says Goodloe. Nature Clouds, four giant hanging gardens in the center hall of Chicago’s Field Museum of Natural History, were printed by the company. BranchClad™ is a mass-customized, ventilated rainscreen system and building skin that attaches to the structure of a building. Made with a lattice structure and a fire-rated, energyefficient infilling foam, it enables the construction of unique exteriors. For a bank in Chattanooga, Tenn., Branch manufactured BranchClad panels with a wave pattern reminiscent of the waves on the bank’s logo. The company is currently working on cladding for the U.S. Space and Rocket Center in Huntsville, Ala., which will replicate the topology of the moon. In partnership with Sto Corp., a prefabricator of construction components, Branch recently introduced StoPanel® 3DP, which provides builders with a wall assembly fully finished on both the exterior and interior sides. Branch’s technology may be headed for space. The company is working with NASA to develop automated construction technologies for the moon and Mars. “The challenge is to print with in-situ materials to create habitats on these new worlds,” says Goodloe. A Lego® Model for AM The explosion of 3D-printed motor mounts for a drone launched Cole Nielsen, founder and CTO of Orbital Composites, on a quest to rethink additive manufacturing. To start, he spent 18 months studying every manufacturing method used today, with a special emphasis on advanced composites and sequential process compatibilities. Fundamentally, he found that carbon fiber, copper wires and electrically insulating polymers Photo Credit: Branch Technology Branch Technology uses robots to print its 3D lattice structures, which can be used as an architectural design element or infilled with foam to create exterior wall cladding. The pioneers in laser-assisted, thermoplastic production technology www.afpt.de

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