Metal additive manufacturing processes are helping engineers to reinvent how parts are designed and produced. In the medical sector, orthopaedic implants are proving to be one of the key applications where metal AM is really having an impact, as the technology enables patient specific structures, as well as complex porous geometries which in turn allow for more lightweight implants.
Betatype, a London-based advanced manufacturing company, recently revealed how its own technologies and services are helping clients in the orthopaedic sector to produce implants that are optimized and offer cost benefits. Specifically, the company highlights its data processing technology, Engine, which has reportedly enabled the serial production of orthopaedic implants thanks to its capacity to optimize high volumes of build data, reduce processing times and maximize machine usage.
Applying a porous internal geometry to an implant is not quite as simple as it may seem, though software platforms can sometimes make it seem so. That is, generating internal structures which demonstrate the optimal porosity size and distribution for a particular implant is a complex process that requires the generation and processing of high volumes of data. This, as well all know, often slows down build processors and the overall manufacturing process.
Engine, Betatype’s build processor, however, boasts the supercomputing power necessary to overcome this challenge, enabling the rapid creation of scan data for powder bed fusion printing and, in the end, making serial production more viable.
Faster processing & lightweight formats
As the company elaborates, its Engine technology is also capable of optimized build data generation and has a “virtually limitless scalability for build generation.” A recent Betatype client was reportedly able to create serial production build data that produced build files over 50 GB in size in just a few hours. This is owed to Engine’s capacity to scale up to 640 virtual CPUs with 4.88 terabytes of RAM, the company says.
Engine also enables users to work with file formats that are up to 96% lighter than traditional STL files. These file formats, including Betatype’s ARCH format or nTopology’s LTCX data, utilize special algorithms to generate complex geometries, thus reducing size significantly—for example, Betatype produced a spinal cage model that was just 8 MB as a LTCX file compared to 235 MB as an STL—as well as simplifying the manufacturing process on the whole.
Breaking down build time
Betatype is also capable of stacking numerous implants together by using special lattice node supports in order to optimize the build space of the 3D printer. “These engineered supports can subsequently e removed using standard media blasting, saving additional time and expense by eliminating the need for manual post processing,” the company writes.
The more parts the printer is capable of turning out in a single build and the consequent build time reduction is an important element in bringing cost-per-part down for PBF production and achieving machine amortisation. Betatype breaks down build time into three main factors: dosing (or applying the powder to the machine bed), fusion (or the application of energy to the powder bed), and motion (or the movement between fusion). By addressing these three components, the company says it is able to achieve build time reductions of up to 40%.
For instance, the company recently partnered with an orthopaedic manufacturer and was able to decrease implant build time from 25.8 hours to just 15.4 hours. The company explains: “For such applications Betatype technologies optimize the laser scan paths to reduce the total amount of firing and movement time required for complex lattice structures. Moreover using galvo-driven path optimization it is possible to reduce delay times from 13 hours to 3 hours by optimizing the delays on an exposure to exposure level, ensuring only the prerequisite delays are applied. This also resulted in a significant reduction in the travel distances required by the laser(s) from 170 km to 100 km.”
Overall, the ability to make the most out of the powder bed fusion hardware—through the utilization of powerful software—results in improved production times and costs for the manufacturing of orthopaedic implants.