The Department of Energy’s Advanced Manufacturing Office (AMO) has turned to 3D printing to reduce development costs for wind turbines. AMO has started building molds made from six-foot-tall, 3D printed sections in collaboration with Oak Ridge National Laboratory (ORNL), Sandia National Laboratory and TPI Composites.
In order to make the molds, AMO borrowed Cincinnati Incorporated and ORNL’s groundbreaking Big Area Additive Manufacturing (BAAM) 3D printer. According to ORNL, BAAM is 500 to 1,000 times faster than most other industrial 3D printers and also has a build space that is several times larger than those of most competing printers.
As the Department of Energy explains, the wind blade mold is first designed using computer-aided design (CAD). Designers use a CAD file of the final blade shape and use it to produce the mold, which is optimized for 3D printing. Additional features can be added such as assembly holes and heating air ductwork. BAAM then extrudes composite material following the CAD file, printing mold sections up to six feet tall. Once each of the mold sections is complete, a layer of fiberglass laminate is applied to the mold to create a surface compatible with traditional blade-making processes. The fiberglass is then machined in order to make a custom shape.
Each mold segment is then installed on a frame and outfitted with a hot air blower. The air heating technique saves energy and eliminates the labor-intensive step of hand-laying heating wires, which would traditionally be embedded in the mold. The air blowers are also reusable for future molds. Once the frames and air blowers are installed, the blade segments are assembled together and the surface between the segments is patched together to ensure an even, smooth, and vacuum-tight surface.
In addition to cost, AMO says there are also plenty of other benefits to an increased emphasis on 3-D printing in the wind industry.
“[We can] increase our nation’s competitiveness through manufacturing clean energy technologies. Advancements in 3D printing have made it a valuable tool for reducing waste, decreasing lead time, and offering more flexibility in design. 3D printing systems have also grown in size and capabilities as technology has improved,” the AMO team said.