The automatic feeding of 3D printers for the additive manufacturing of metal parts requires a high level of experience with the handling of critical raw materials.
The requirements are diverse:
Uninterrupted supply of one or more 3D printers with metal powder
Storage, provision, conditioning, transport and processing of various powders
Screening of virgin material and processed metal powder
Economic efficiency and careful use of resources due to reuse of unmelted metal powder
Operator protection against respirable and toxic metal powders
Operator, product and explosion protection due to completely inerted handling of the metal powder (introduction, processing, preparation and discharge). Danger from escaping inert gases is excluded by sensors and their reliable evaluation
Reliable handling even of poorly flowing, fine-grained metal powder
Ultrasonic screener with reliable coarse discharge
A glovebox with a refill option during the printing process is available for reactive and harmful metal powders
Central system: One glovebox serves several screening modules
Data evaluation and analysis of the machine and process data possible with additional tools
AZO is the expert for automatic raw material handling
The more complicated the raw material, the more we are in our element
The systems for printer feeding essentially consist of three areas. In the glovebox, the material is supplied, while in the screen module, the preparation and conveying to the printer module takes place. The printer module supplies the printer with new or prepared powder and takes over the removal of the unmelted powder.
The system can be flexibly designed for the various raw material properties, feed options and conveying quantities.
Glovebox
With the system empty and a new printer to be loaded, the containers with metal powder are first fed through the loading door into the glovebox. The glovebox is then flooded with inert gas. With the help of the gloves, the plastic bottles or canisters can be safely emptied into the subsequent storage container.
In the next step, the powder is pneumatically transported to one or more screening modules. These are integrated directly into the 3D printer. The recycling of unused powder takes place either directly during the layer generation (layering) or after a completed print job from the printer room. If the powder is not to remain in the circuit, it can be discharged under a protective gas atmosphere.
Screening module
The powder fed through the glovebox is pneumatically conveyed to the screening module, where it is prepared by an ultrasonic screener. The high-frequency ultrasonic vibration ensures efficient and gentle screening of the powder. The fines fall through the screen into the fines outlet, from where they are conveyed pneumatically to the printing module. The coarse material contained is transported over the screen surface and thus reaches the coarse material outlet, where it is discharged from the process. Thanks to the vibrations, the screen surface cleans itself already during operation, which extends the cleaning intervals and, in the same step, reduces the setup times of the machine.
Printer module
The metal powder, which is pneumatically conveyed to the printer module, separated from the conveying gas in the receiver and can feed up to two machine inlets via a distribution screw. The conveying system is atmospherically separated from the printer room by a flap lock in order to prevent pressure fluctuations in the printer room. Depending on the printer design, the stripped powder is provided in a hopper for the return to the powder supply module.
