Fig. 2.

Schematic diagram of the compaction process showing the feeding zone and the nip and slip regions. The powder has the maximum density ${\gamma }_{\mathrm{G}}$ at the gap. Past the roller gap, there is a region of elastic recovery where ribbon thickness T increases while reducing the ribbon density to its final value ${\gamma }_{\mathrm{R}}$. The mass flow can be predicted in the feeding zone using either the screw mass flow rate ($\dot{{\mathrm{m}}_{\mathrm{s}}}$) or the gap geometry and the roller speed (${\dot{\mathrm{m}}}_{\mathrm{r}\mathrm{o}\mathrm{l}\mathrm{l}}$). Experimentally, it is the throughput observed after the ribbon relaxation (${\dot{\mathrm{m}}}_{\mathrm{o}\mathrm{b}\mathrm{s}}$).