Analytische Charakterisierung und Modifizierung von Pulverlack-Overspray zum Einsatz als Füllstoff für Polyethylen

Reports from the powder-coating industry indicate that 0.5 to 55 % of the powder-coating resins, depending on the coating system, ends up as overspray or becomes unusable due to degradation. The disposal of these powder coating residues at landfills or by waste incineration is very expensive and pollutes the environment. The goal of this work was the recycling of powder coating residues as fillers for thermoplastic polymers. The biggest challenge was to prevent the metal adhesion of the still chemically active powder coating residues in extrusion or injection molding Machines caused by its thermal curing. The main approach was the chemical deactivation through a reactant. A deactivation was realized with stearic acid in a concentration of two percent by weight. For a first test of material properties, powder-coating residue was mixed with stearic acid and used as recyclate filler in a ratio of 50:50 with LLDPE to be processed to standard test bars. The mechanical values were lower than those of the neat LLDPE. The goal of this work has been achieved. The addition of two percent of stearic acid to powder-coating wastes prevents completely adhesion to metal after cure.