A method for environmentally friendly paint spray lacquering using water dispersible oven drying varnish

摘要

A method is provided for environmentally benign paint spraying with a dispersion of oven-curable lacquer in water in a paint spraying station having a cubicle with water-rinsed rear wall for collecting and washing out of overspray in cubicle waste water. The entire cubicle waste water is separated by ultrafiltration into permeate and lacquer-containing residue, the permeate being returned to the paint spraying station, the lacquer-containing residue being enriched with lacquer by removing water until its lacquer content is essentially equal to that of dispersion that is freshly fed to the spray painting station. The residue that is enriched with lacquer is admixed to the freshly fed dispersion for reuse in spray painting. A constituent for preventing coalescence of the lacquer is admixed to the dispersion fed to the paint spraying station, wherein a constituent for the inhibition of the drying is admixed to the dispersion that is fed to the paint spraying station, a constituent for adjusting the throughput for ultrafiltration is admixed to the cubicle waste water, and the conductibility of the water returned to the paint spraying station is monitored and kept below the limit.