Abstract: 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.
Abstract: In the process of spraying in a cubicle having a water-rinsed rear wall the cubicle waste water is separated by ultrafiltration into permeate and lacquer-containing residue. The permeate is recycled. Fresh spraying composition is fed-in. The lacquer preferably is an alkyd resin, an acrylic resin, a polyvinyl acetate resin, a silicone resin, a copolymer thereof, a mixed polymer thereof or a mixture thereof. The spraying composition comprises a component for preventing coalescence, preferably one or several aliphatic amines having an average molecular weight of 75 to 133 or mixtures or derivatives thereof, and a component for retardation of the drying. If the lacquer is capable of being emulgated or dispersed in water, the spraying composition and/or the cubicle waste water preferably comprises a component for stabilizing the emulsion or dispersion. A component for adjusting the throughput in the ultrafiltration is admixed to the cubicle waste water, preferably a derivative of glycol or of a higher alcohol.