Shampoo bottles and cosmetics packaging, sausage and cheese packaging, plastic bags, cling film - they all end up in the recycling bin or are delivered directly to recycling centres. The aim is to recycle as much of this packaging waste as possible and return it to the cycle. If this waste comes from private households, it is referred to as post-consumer recycling (PCR). The recycling of waste from production residues in the manufacture of plastic packaging or products, on the other hand, is known as post-industrial recycling (PIR). A new process from Hosokawa Alpine now ensures that the plastics from this packaging waste can be reused as post-consumer recyclate. The shredding, washing, separating and drying steps produce washed and dried flakes that can be used to manufacture new plastic products.
The waste from the recycling bin is collected and sorted in waste recycling plants. The packaging is already pre-sorted here according to the different types of polymer (LDPE, HDPE, PP, PE, PET ...) and then delivered in bales for recycling. A problem with these source materials is that they still contain a certain amount of foreign materials (e.g. metals, glass, stone) and impurities (product or food residues, printing inks, oils, labels, dirt, etc.). This is a major challenge for the washing systems.
The plastic waste is shredded in a wet or dry grinding process using our Rotoplex granulator. It offers numerous advantages for post-consumer recycling:
- shredding with a clean cross scissor cut, therefore little product loss. You receive flakes without fraying
- minimisation of fines and dust
- very small cutting gap, gap dimension: This enables very precise cutting with less tearing, a clean edge and less product loss overall
- hollow rotor for more cutting space and cooling
- wear-protected designs possible thanks to coating or hardened steel, replaceable sealing plates: This leads to longer service life and requires less maintenance
- robust design
- easy cleaning and maintenance thanks to removable cover
- optionally available with standard chute or tangential chute
We work together with our partner reantec for washing, separating and drying. Plastics must be thoroughly cleaned before they can be reused. This is the only way to remove contamination such as labels, residues of ingredients or sand without leaving any residue so that the plastics can be processed safely and cleanly. A friction cleaner is used for this process step of contaminant separation.
Advantages of friction cleaners:
- high washing and drying performance
- consistent product quality due to continuous self-cleaning in the friction washers
- high-quality end product due to less adhesion of abrasive materials and reduced wear in subsequent processes
- low maintenance requirements
The next step involves shredding the packaging waste with a wet granulator. A specially developed version of the Rotoplex granulator for wet grinding will be available from spring 2024, making the shredding process even more efficient. At the same time, the material will undergo additional cleaning.
After the pre-washed material has been freed from further foreign material in the sink-float tank or in the hydrocyclone by means of density separation, the flakes can be washed again in a friction washer before being sent for final drying. The plastics are now clean and optimally prepared for further processing.