Surface cleaning aluminum foil with ozone gas

Residual oil on rolled aluminum foil prevents good adherence of print or paint. Ozone gas exposure shows promise of effectively reducing the surface hydrocarbons to acceptable levels for industrial coatings (<10% surface carbon). Ozone and thermal treatments performed on laboratory- and industrial-scale samples which were surface analyzed using x-ray photoelectron spectroscopy and further characterized with H2O contact angle measurements. The samples were exposed to oxygen gas including ozone 630 ppm at a flowing rate of 0.5 l/min. Two treatments, heating treatment and ozone treatment with heating, are compared at a heating temperature, 200 °C for 6 h exposure time for laboratory-scale samples and 200 °C for 30 min and for 160 min at higher than 100 °C for industrial-scale samples. The atomic concentration % of carbon (C) proportional to the quantity of oil on the surface was determined to be 9.8% for the laboratory-scale sample and 7.4% for the industrial-scale sample.