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.