The washing lines are suitable for treating contaminated materials, which need to be separated from contaminants before moving on to the next processing steps: foil, mixed plastics, rigid plastics, packaging, granules, from municipal waste collection, post-consumer, agriculture, industrial residues, etc. The material for shredding can come in bulk or as bales and can be loaded directly into shredders or grinding mills. Shredders and mills allow the processing of materials with a high degree of contamination. Their special feature is that they can be equipped for the use of water jets, thus also performing pre-washing.

Before the shredding equipment, the line is composed of machines that largely separate good material from contaminants, such as disc, rotary or vibrating sorters, complemented by magnetic separators to remove ferrous contaminants. After the shredding of the material, depending on the degree of contamination, the pre-washing and impurity separation phase follows, the phase carried out by the rotary decanter used as a unit for pre-washing and separating the various impurities or the pre-washing vessel with the main function of separating the material from impurities and plastics from each other, depending on the specific weight.