During the compounding of plastic pellets, inevitable optical defects arise due to excessive temperatures, pressures, and shear forces in the extruder. These defects, such as burns (black specks) and discolorations, often go unnoticed in subsequent inspections, resulting in the delivery of defective raw materials. Consequently, these impurities can cause production issues or lead to defective products during further thermal processing. The sorting process aims to effectively separate and remove all such impurities.