Fig. 1

Experimental setup for feeder emptying experiments with (a) LIW feeder system, red lines indicating powder transition levels for A: emptying experiments for paracetamol powder, B: emptying experiments for lactose-base powder, C,D: screw trough with an agitator (1) and concave screws (2). (b) Customized test rig used with sections, E: twin screw feeder, F: NIR probe, G: conveyor belt, and H: catch scale.