Assessing the process performance of ballistic separators in packaging waste sorting plants using sensor-based...

To effectively utilise secondary raw materials, pre-concentrates of defined quality are required. Packaging waste streams are treated in waste sorting plants, where different sorting operations are applied. Ballistic separators are frequently used to separate 2D and 3D materials during (pre)conditioning and therefore have a major influence on the overall process performance. Despite their widespread use, until now, few studies have examined how parameter settings affect the performance of ballistic separators. To assess and optimise process performance, we conducted a parameter study on packaging waste using an industrial-scale ballistic separator and near-infrared-based process monitoring. At 22.5 wt% 2D input content, we varied 2D material properties, paddle angle (15°, 17.5°, 20°), rotational speeds (s₁-s₅) and paddle types (45 mm, closed). All parameters showed significant effects on the process performance. In the material stream used, which contained a proportion of fine material, the 45 mm paddles demonstrated higher separation performance compared to the closed paddles. A specific rotational speed must be reached to achieve an effective separation efficiency. Beyond this, a further increase does not lead to measurable improvements. Two optimisation strategies were developed to determine process optima and enable the integration of the generated results into operational practice. Therefore, the results contribute to the optimisation and potential automation of ballistic separators and the overall improvement of packaging waste sorting plants.