The powder feeding is one of the most essential parts for the AM sintering process. Manudirect has developed its own powder feeding technology that differs from the conventional feeding system and has been developed in collaboration with MBN as a powder developer and supplier.
The feeding of the fine grain sized powders is challenging because of the adhering forces of the powders enable the particles to stick to the powder storage and the tubing that guides the powders to the nozzle. The required performance of the feeding system reaches beyond the state of the art. The challenge of this system is the constant feeding of very small particles (lower limit is 10-30 μm) which is required for the high resolution sintering process and to be adaptable also for larger powder size (40 to 75 μm).
The feeder is based on the following principle: the powder is stored in a cartridge, in controlled atmosphere, the cartridge is plugged in an automated mechanism remove the cap and push the cartridge vertically to the aerosol chamber.
A rotating brush in the aerosol chamber takes the powder particles out from the cartridge as it is pushed. The cartridge pusher motor works at a speed in the range from 1 to 100μm/s with very high control accuracy to deliver precise amount of powder over time. The powder particles removed by the brush are forced by the gas stream to the connecting tube forming an aerosol.
In addition the feeding principle has to be adapted to the required very low gas (below 1l/min) and powder mass flows which are beyond the state of the art to achieve a precise and reliable flow rate of powder stream.
Thanks to its peculiar design, the powder feeding system will works with of different powder materials and particle sizes that can be switched “on the fly” during the sintering process.
The installation of multiple powder feediers enables the use of different powders, by size or type. The switch valve between powder feeders allows to start the second feeder whilst the first one is connected to the process and thereby keeping a constant powder flows.
The feeding system is directly under control of the machine control software and can be regulated within the deposition strategies.
|Main Technical Data|
|Powder Reservoir Volume||12,6 cm3|
|Powder Feeding Capacity||0,016 to 7,85 mm3/s|
|Maximum Gas Pressure||3 bar|
|Gass Flow Rate||0,4->0.05 to 5,0 L/min|
|Communication Protocol||CANopen DSP402|
|Stand-alone version||Personal PC required (stand alone)|
|Dimension (LxWxH)||160 x 230 x 450 mm|