The cleanability and surface characterization of 0.8-mm thickness bright annealed finish 304 L stainless steel were assessed by standardized methods. Cleanability was previously compared to surface chemical modifications from industrial cleaning procedures commonly used in dairy industries. Strips were cleaned by four different processes including rinsing phases. The reference treatment is a RBS 35(R) surfactant cleaning. The other cleanings were: NaOH cleaning, HNO3 cleaning, and a dairy cleaning in place (including HNO3 and NaOH). The industrial cleaning processes were carried out once to simulate start-up conditions and 10 times to simulate working conditions. No notable differences in surface texture were found between the different cleaned surfaces studied It was assumed that detergent and cleaning conditions used were not aggressive enough to attack stainless steel surfaces. Cleanability differences observed were due to differences in the chemical compositions used. When cleanability results and surface chemical composition results were compared, it was observed that the greater the degree of oxygen and carbon surface concentrations for the same iron surface composition, the lower were the chances of soiling remaining during the test cleaning. In the same way, it was observed that the greater the degree of the iron surface concentration for the same oxygen and carbon surface compositions, the greater was the change of soiling remaining during the test cleaning. As many differences in surface chemical compositions were observed between all studied surfaces, the difference in cleanability observed could be explained by an ageing phenomenon due to chemical surface composition changes induced by cleaning detergent actions.
