Anti-fouling surface modified stainless steel for food processing

Fouling on food contact surfaces (e.g. heat exchangers, work tables, conveyors) during food processing has a significant impact on operating efficiency and can promote biofilm development. Processing raw milk on plate heat exchangers results in significant fouling of proteins as well as minerals, and is exacerbated by the wall heating effect. The surface of 316L stainless steel heat exchanger plates was modified to resist fouling during food processing. An electroless nickel plating process was used to co-deposit fluorinated nanoparticles onto 316L stainless steel. The ability to resist fouling was demonstrated on a pilot plant scale plate heat exchanger. The fluorinated nanoparticle modified steel reduced surface energy from 41.4 to 24.7 mN/m, and reduced foulant accumulation by 97%. The anti-fouling coating was demonstrated to improve heat transfer efficiency. Repeatability studies were performed and confirmed that the EN-PTFE surface coating maintained its anti-fouling properties through 10 independent processing runs. Co-deposition of fluorinated particles during electroless nickel plating represents an effective and commercially scalable method to prepare anti-fouling coatings on stainless steel.

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► Surface modified heat exchanger plates reduced foulant accumulation by ∼97%.
► Anti-fouling coating improved heat transfer efficiency.
► Modified stainless steel retained anti-fouling properties for 10 processing runs of 4 h duration each.
► Fluorinated nanoparticle modified stainless steel reduced surface energy from 41.4 to 24.7 mN/m.