Separation by density, using nothing but air.
Overview
The air separator uses a controlled airstream to lift light material — film, label paper, dust — away from heavier flake. Material is fed into the column and the air velocity is set so that the light fraction is carried off while the dense fraction falls through.
Where it fits
Used after washing to polish the output, and also ahead of the crusher to remove film and paper from mixed feed. It is one of the simplest and most reliable ways to raise flake purity.
Adjustment
Air velocity is adjustable, which lets the same unit be tuned for different materials and different target purities as your feed changes.