The solidified TiO2-PP-bricklets were then transferred to the shredder/granulator, giving a TiO2-PPgranulate. To narrow the grain size distribution, the granulate was fed and recycled through the shredder two additional times. This procedure ensured a rather narrow melting temperature range of the TiO2-PP-grains, increasing the processability of the granulate during filament extrusion in the next step.