Effect of surface characteristics on cleaning performance for CIP system in food processing

In food processing, insufficient cleaning can result in reduced efficiency, contamination in final product, and energy losses. To optimise widely implemented clean-in-place (CIP) systems, it is critical to understand the influence of the interactions between surfaces, foulant, and chemical agents on the efficiency of the cleaning process. The present work investigates the effect of wall temperature and surface roughness on the surface free energy of stainless steel 316L coupons. Equilibrium contact angles (ECA) of four commonly used liquids, namely ethylene glycol, 1-bromonaphathalene, water, and diiodomethane were measured on the surfaces of interest. Finally, ECAs of liquids were used to quantify surface free energy (SFE) of the solid substrate. Our results show that surface energy is proportional to the roughness and well-prediction of liquids wettability as a function of roughness and temperature. It demonstrates the importance of surface characteristics in determining interfacial energy, and consequently the efficiency of CIP for food engineering.