Many households separate their waste at source. For example, people may have a bin for plastics, metals and drink cartons (PMD). These streams are already kept separate from, say, paper and organic material, in the home.
The reason why plastics, metals and drink cartons are put in one container or bag is because it is easy to separate them in a separation line. PMD is usually made up of foils for 40%. For the rest, it is made up of ferrous and non-ferrous materials, and drinks cartons and plastics that keep their shape.
First the bags are opened and the fine material is separated in a sieve. Wind shifters and a ballistic separator ensure that foils are separated from the packaging material that has been separated at source. Iron and non-ferrous metals are separated using a magnet and an eddy current.
Post-separation focuses primarily on quantifying valuable streams. Quantification is followed by qualification, the upgrading of raw materials. That is mainly done in the plastic sorting plant (PSP).
The reprocessed 3D materials from a post-separation plant for residual household waste can serve as input for a plastic sorting plant. The 3D packaging material consists of ferrous, non-ferrous, drink cartons and dimensionally stable plastics. Iron and non-ferrous metals are separated using a magnet and an eddy current.
By installing several near-infrared (NIR) scanners in a row – one after the other – the drinks cartons and plastics are separated into PET, PE, PP and a mixed plastic fraction. Quality controllers ensure that the plastic mono-streams meet the required specifications. The plastic mono-streams are pressed into bales and serve as raw materials for the plastic processing industry.
The plastic sorting plant can be designed and built according to customer specifications, with a processing capacity ranging between 1 t/hour to 15 t/hour.
There are other options for separating waste streams at source. For instance, vegetable, fruit and garden waste can be separated at source. This waste can be recycled in a separation plant to produce green gas and compost.
