The only users who’ve clocked more time with HP’s Multi Jet Fusion additive manufacturing system than service bureau GoProto Inc. (Portland, OR) may be the actual developers of the technology.
Due to a “longstanding partnership” with HP, GoProto has been using the new system for more than a year, said Jeff Dean, who does marketing for the service bureau from its sales office. As a result, GoProto has provided feedback to HP during the system’s development and “learned a few things” in the process, Dean said.
For one, “We figured out that there were issues with the internal dimensions of some parts, but the external dimensions were correct,” said Miguel Diaz, GoProto vice president of manufacturing at its manufacturing facility in San Diego. “So, they did some tweaking on their software and adjusted the way they get the material deposited.”
So far, the bureau has printed parts with HP’s High Reusability PA12 nylon and PA12 with glass beads for the automotive, electronics, medical and military industries, including cell phone cases, circuit boards, electrical plugs and outlets, and parts for drones and coffee makers. “The surface finish is very nice,” Diaz said. “They mimic production parts.”
said powder loading is easier compared with other selective laser sintering machines, where users have to mix buckets of materials by hand. With the HP system, hoses attach to boxes of powder and mixing of new and recycled material is automatic.
One unique feature of Multi Jet Fusion is the ability to modify material properties voxel by voxel to produce different mechanical and physical characteristics in a part or in separate parts printed together in one build, according to HP. The system accomplishes this with transforming agents that can affect surface roughness, tensile strength, electrical and thermal conductivity, opacity in plastics, color and other characteristics.
addition, the agents—printed at 1200 dpi in the X and Y axes—can provide colors viewable only when exposed to ultraviolet light, for security purposes, or can produce a durable, hard surface with a low friction coefficient where contact and wear are expected to occur and different properties elsewhere, according to HP.
Another unique property of parts printed with Multi Jet Fusion is greater strength on the Z axis. This is from a fusing agent that’s printed where powder will be fused together, Diaz said.In addition to the materials mentioned earlier, HP is developing thermoplastics to include PA11, flame-retardant materials and elastomers. Ceramics and other materials are also being investigated and developed.
HP has made Multi Jet Fusion printing an open platform to enable development of new materials. It also is collaborating with the 3MF Consortium to develop a software file format with greater dimensional precision than STL that could fully exploit the capabilities of Multi Jet Fusion’s voxel-by-voxel deposition.
In conjunction with adding six of the new HP printers this year, GoProto’s manufacturing facility expanded to 8000 ft2 (743 m2), with plans to grow to 10,000 ft2 (929 m2) later this year, Dean said. In addition to HP printers, the service bureau uses 3ntr and FormLabs printers, and also provides CNC machining, cast urethane, sheetmetal and injection-molding services to produce prototypes and production parts.