Surface modifications – Application potential for the reduction of cleaning costs in the food processing industry

Machine contamination poses serious problems to the food processing industry particularly from an economic and hygienic perspective. Various studies therefore investigated the impact of energy-related and topography-related surface properties on the contamination tendency and the cleanability of material probes. These tests were carried out with stainless steel as reference as well as 46 surface modifications taken from the area of polymer coatings, nanocomposite coatings and physical/chemical vapour depositions (PVD/CVD) on the basis of whey protein and starch contamination. The findings showed that starch deposits on modified surface specimens were reduced by up to 76% (Fluorinated ethylene propylene, FEP) in contrast to stainless steel. Whey protein deposits were reduced by up to 34% (nanocomposite). The remaining starch contamination after one spray cleaning was reduced by up to 50% (FEP) and the whey protein contamination was reduced by up to 88% (FEP). Comparing the roughness and surface energy with the contamination and cleaning behaviour yields no clear correlation. But depending on the kind of contamination there is the tendency that low energetic surfaces show a better cleanability or less deposits. Furthermore, the surface modifications tested showed different abrasion resistance and different levels of resistance to repeated stress with detergents.