Industrial finishing equipment manufacturer Guyson International has launched the Powder Flush system which aims to flush residual additive manufacturing (AM) powders from medical implant trabecular structures, which aid the interlocking human bone growth into the implant.
Increasingly orthopaedic manufacturers are turning to AM to drive the long term change in the increased complexity of medical implant design and demand for tailor made patient-specific solutions with the change in manufacturing from subtractive to additive techniques.
These 3D printed orthopaedic implants are typically made by SLS, SLM or EBM processes (Selective Laser Sintering, Selective Laser Melting or Electron Beam Melting) from Titanium powders in the size range of 5 to 45 micron for the SLS and SLM processes; and utilising 45 to 90 micron for EBM. After manufacture, the implants then have the bulk of the residue powder removed from the build block with brushes and vacuum’s, sometimes followed with an air-wash or blast process to remove any semi-adhered powder particles, but because of the nature of the porous trabecular structures, small residues of powder are often still trapped inside the component and this must be removed. This is where the Guyson Powder Flush process excels.
The Guyson Powder Flush is based on the company’s Orbit 600 rotary basket spray wash unit, built in full stainless steel 304 construction, fitted with a 100 litre insulated tank and hot spray flushing facilitated through a high flow rate and pressure pump fitted with viton seals. The machine offers directed jets for component flushing followed by compressed air-wash. A PLC/HMI control panel to the left of the machine provides data monitoring and timed pre-heat function. LED interior lighting and a double-glazed viewing window, in the lid, facilitates visual checks on parts in process.
In operation the implants are individually or batch loaded on none contaminating fixtures presenting the work piece to the directed flushing jets in close proximity to the trabecular surface thus ensuring thorough powder removal. Timed electronic door interlocks prevent the door opening during operation and until hot steam has dissipated at the end of the process time. Also being generally installed in a production cell, the machine is equipped with process alarm signals with audible and visual cues via an Andon beacon to show the end of parts process. Completing the system is fluid level sensing and advanced filtration, fitted to the rear of the unit.
Guyson’s managing director, Mark Viner said: “This new Powder Flush unit adds to the already extensive portfolio of Guyson products provided for the 3D Print/Additive Manufacturing market. This includes our Euroblast Ex range of ATEX certified blast cabinets for surface finishing exotic metal AM parts, often used in the aerospace and medical markets. The Guyson PRS (Powder Recovery System), which is an automated post processing system, specifically for EBM additive builds, and uses tried and trusted robotic blasting methodology to reveal components and manage the resultant powder in a highly contained blast system, and our ‘Kerry’ branded range of ultrasonic baths and tanks for 3D printed fused deposition modelling (FDM) support removal. Guyson have become the ‘go to’ company for post processing finishing equipment in the 3D Printing marketplace.”
