How the identification/ detection works?

The overarching part of the packaging is identified by specific light sensors, which identify the material by reflection of a specific light spectrum. Packaging products may still contain or have components of other materials, e.g. caps, labels, etc. If a metal cap is still attached to the jar, the plastic packaging will probably be sorted out because the metal is sorted in front of plastics. Packaging with plastic caps, e.g. PP will probably be sorted into the stream of the packaging, because the size is larger as of the cap. The label is as well important, because the producer have to make sure, that the label-material and print don’t disturb the detection – each label has to be checked.