CLEANABILITY IN RELATION TO SURFACE CHEMICAL-COMPOSITION AND SURFACE FINISHING OF SOME MATERIALS COMMONLY USED IN FOOD-INDUSTRIES

The cleanability and surface characteristics of various materials commonly used in the dairy industry were assessed by standardized methods. When surface topography was reasonably smooth on a microscopical scale, cleanability differences observed were due to differences in chemical composition. For 304 L stainless steel, we compared cleanability of various industrial finishes in relation to topographical aspects. Surfaces with poor cleanability showed many surface defects. These surfaces are likely to retain more soiling because of increased numbers of attachment sites, a larger soiling/surface contact area and topographical areas in which applied cleaning shear forces are reduced. All surface treatments that reduced the number of topographical defects increased the hygienic qualities of surfaces in comparison to ones which increased surface damage. The most commonly used finish of 304 L stainless steel (2B Glazed steel finished) had the worst topographical aspects and was also the least cleanable.