Refurbishment of a vacuum pump using 3D printing technology
Luk-Plast, a plastics recycling company, commissioned us to print an impeller for a vacuum pump in a process line where waste plastic film is recycled into pellets.
Our job was to design the impeller to effectively replace the existing brass component both on a short- and long-term basis. Moreover, the units operate continuously and are not only exposed to high temperatures but also to aggressive chemicals in a water/gas environment, so the appropriate material for the 3D print had to be carefully selected. As the impeller rotates at 1,400 rpm, the plastic would have to be very durable and capable of withstanding extreme mechanical loads.
‘We decided to use 3D printing technology for a number of reasons. Firstly, it’s very time-saving and cost-effective compared to the normally used production method. Making an identical vacuum pump impeller of brass or stainless steel would be much more expensive and the lead-time much longer. What’s more, two years ago we chose to replace a process line element with one printed by Omni3D and I must say it performed even better than the original part used by the pump manufacturer.’
Łukasz Kubczak, Luk-Plast
3D print of the vacuum pump turbine from Omni3D and original made of brass
The engineers at Omni3D used the original vacuum pump impeller to apply reverse engineering and design and print an identical element using a filament with an admixture of CF-PA-12 carbon fibre. It is an exceptionally durable material characterised by high thermal resistance, and it proved to be perfect for the requirements specified by Luk-Plast.
“Acknowledging the increasing possibilities of 3D printing, customers keep raising the bar for its applications. When two years ago we first heard about the concept of 3D printing we knew that the strongest material, CF-PA-12, would have to be used. The impeller is quite a large part with a diameter of 210 mm, so our Factory 2.0 3D printer had to be set up to print the part in the shortest possible time. The outer layers were made to a high degree of accuracy using the 0.4 mm nozzle, whereas the 100% infill was printed with a 0.8 mm nozzle. This enabled us to largely reduce the printing time and improve the performance characteristics of the part. We were very happy to hear that the element performed well in prolonged use and the customer came back to us asking for an impeller for another pump” Krzysztof Kardach, Omni3D Chief Technologist.
3D print of the Omni3D vacuum pump turbine
Technical specifications of the print:
Print time: 23 h
Item weight: 872 g
Outer walls: 0.2 mm layer, 0.4 mm nozzle
Infill: 100%; 0.4 mm layer; 0.8 mm nozzle