Effect of surface treatment on cleaning of a model food soil

The effect of surface modification of 316T stainless steel on removal of a model proteinaceous food soil (baked tomato paste) was studied using fluid dynamic gauging, where the deposit is immersed in liquid and removed by stresses imposed by a well-controlled fluid flow. The surfaces studied were uncoated 316, sol–gel, diamond-like carbon (DLC), and modified DLC (SICON® and SiCAN). The surface energy and topology of the substrates were established before and after a series of 10–12 fouling and cleaning cycles. Surface modification reduced the adhesive interaction between the substrate and soil, to the extent that surface energies of 22–26 mN/m resulted in simple detachment of the deposit from the surface. No significant effect of surface roughness was observed in the range (72 nm < Ra< 700 nm, measured by AFM). The coatings exhibited varying degrees of stability towards repeated fouling and cleaning.