Method of separating a mixture of plastics comprising at least three components using electrostatic techniques
AssigneeKali und Salz Aktiengesellschaft
InventorsIngo Stahl, Axel Hollstein, Ulrich Kleine-Kleffmann, Iring Geisler, Ulrich Neitzel
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Abstract
Plastic mixtures are split up into the individual components by a process combining density separation with electrostatic separation, and includes a special surface treatment which takes place prior to the electrostatic separation.
Claims20
Process for the separation of crushed plastic particles of a plastic mixture of plastics of a chemically different type, which partly have an overlapping density range and partly a different density range selected from the group consisting of polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC), comprising the steps of
- first separating the plastic particles having a different density range according to the principle of density separation;
- and
- second separating the plastic particles with the same density range via a free-fall separator;
- subjecting the plastic mixture to a surface treatment;
- and
- triboelectric charging the plastic mixture.
Process for the separation of plastic particles of a plastic mixture of plastics of a chemically different type, which partly have an overlapping density range and partly a different density range, selected from the group consisting of polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC), comprising
- in a first step, the plastic particles having a different density range are separated from one another according to the principle of density Separation and;
- in a second step, the plastic particles with the same density range are separated,
- wherein the density of a separation liquid is selected in such a way that the density is between the greatest density and the least density of the individual plastics, and
- wherein the separation liquid is selected in such a way that it is either in the basic range having pH about 11 to 12 or in the acid range having pH about 2 to 4.
Process for the separation of plastic particles of a plastic mixture of plastics of a chemically different type, which partly have an overlapping density range and partly a different density range, selected from the group consisting of polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC), comprising
- in a first step, the plastic particles having a different density range are separated from one another according to the principle of density separation;
- in a second step, the plastic particles with the same density range are separated;
- washing the separation liquid out of the plastic mixture by water after the first step of density separation;
- reducing the plastic mixture by a dehydration aggregate to a residual water proportion of under 2% prior to drying;
- drying the plastic mixture after washing;
- and
- adding an organic substance to the plastic mixture.
Dependencies are inferred from the claim text.