Innovation in implants
Revealing how the orthopaedic industry is reinventing itself through the use of metal AM processes for production
Metal additive manufacturing (AM) processes such as laser powder bed fusion (PBF) provide real advantages when it comes to the production of orthopaedic implants. PBF can produce both solid and porous geometries in the same process, saving time and materials, while creating complex structures that can simulate the mesh-like porous properties of bone, as well as provide the strength and durability required of a medical implant. Porous textures can be built into implants of any shape or size – from acetabular cups to lumbar cages – allowing medical device manufacturers of orthopaedic implants to offer a full portfolio of superior implants using the PBF process for serial production.
Betatype helps its clients in the orthopaedic implant sector to further reduce costs and deliver on the advantages of metal AM for serial production of orthopaedic implants through its innovative data processing technology, Engine. This is achieved by optimising the high volumes of build data, reducing process times and ultimately maximising machine usage, which results in reduced cost-per-part.
Maximising machine usage
Orthopaedic implants demand complex designs to achieve the optimal porosity size and distribution. This necessary complexity results in the generation of high volumes of data that can often slow down build processors, causing bottlenecks or even halting the AM process altogether. Betatype’s Engine build processor provides supercomputing power to overcome this problem and enable the rapid creation of scan data for laser PBF, paving the way for serial production.
Engine’s virtually limitless scalability for build generation can also produce optimised build data. Betatype recently worked with a company to successfully create serial production build data that produced build files in excess of 50GB. These processing requirements would stop most other build processors in their tracks, but with Engine, the data was generated in a few hours thanks to the platform being able to dynamically scale up to 640 virtual CPUs with 4.88 terabytes of RAM.
Moreover, when applying its specialist algorithms for converting complex geometry, Engine allows implant designers to work in lightweight file formats that are up to 96% lighter than traditional STL files, such as Betatype’s Arch format or nTopology’s LTCX data. For example, a spinal cage model was only 8MB as an LTCX file compared to 235 MB as an STL file. These conversions simplify and shorten the process tremendously, making the manufacturing process more flexible and cost-effective. Lightweight representations combined with Engine’s build data generation enable designers to innovate faster without the headache of dealing with mesh data.
Improving the utilisation of an AM machine’s overall build volume is also key to unlocking the serial production of orthopaedic implants in terms of cost per part. Betatype is able to effectively stack implant parts by designing lattice node matched supports – using the full build envelope of the machine and producing multiple, complex implants in a single build. These engineered supports can subsequently be removed using standard media blasting, saving additional time and expense by eliminating the need for manual post processing.
Reducing build times
Equipment amortisation has a big impact on the cost of parts when it comes to the production of orthopaedic implants with the PBF process. Build time plays a key role in this - the more parts you produce in a build, while reducing the build time, the more cost effective the parts become. Build time can be broken-down into three major components, each of which needs to be addressed to speed up the entire build process.
These include: dosing (applying powder to the machine bed); fusion (applying energy to the powder bed); and motion (movement between fusion)
Betatype has developed a powerful portfolio of technologies that can directly optimise laser firing times and reduce delay times with or without the use of multiple lasers, resulting in the reduction of overall build times by as much as 40%.
In a recent project the firm worked with an orthopaedic manufacturer and using this technology portfolio it was able to decrease implant build time from 25.8 to 15.4 hours. For such applications Betatype technologies optimise the laser scan paths to reduce the total amount of firing and movement time required for complex lattice structures. Moreover, using galvo-driven path optimisation it is possible to reduce delay times from 13 hours to three hours by optimising the delays on an exposure to exposure level, ensuring only the prerequisite delays are applied. This also resulted in a considerable reduction in the travel distances required by the laser(s) from 170km to 100km.
The combination of metal AM, specifically with the PBF process, and Betatype’s portfolio of technologies, enables faster and more cost-effective serial production of orthopaedic implants. By maximising machine usage, optimising data file sizes and reducing build times, the company is working with a range of partners in the orthopaedic implant sector to create safe, robust and more cost effective implants.